A study was conducted in Northern Province of Rwanda, from the College of Agriculture and Veterinary Medicine, Busogo Campus located in Musanze district to evaluate the effect of feed type on rabbit growth in rabbit i...A study was conducted in Northern Province of Rwanda, from the College of Agriculture and Veterinary Medicine, Busogo Campus located in Musanze district to evaluate the effect of feed type on rabbit growth in rabbit intensification systems in Rwanda. The Complete Randomized Design (CRD) was used and data were collected on rabbit growth weekly for a period of 12 weeks. The experiment was composed of three treatments replicated ten times. The treatments included three types of feeds namely;cabbage combined with Mucuna pruriens added to local forage (I), cabbages combined with Leucaena leucocephala added to local forage (II) and a control composed of other varieties of locally available forage, such as Bidens pilosa, Crassocephalum vitellium and Galinsoga parviflora (III) which was considered as the control (Farmers practice). The feeds were given to ten rabbits separated in individual cages, and each rabbit was considered a replicate. Water was given ad libitum. One month old rabbits (weaners) were used and data were collected after one week of adaptation for 12 weeks. The results showed that the mean of weight gain after 12 weeks was 783.3 g, 760.7 g and 705.7 g for feed type I, II and III respectively. The difference between means of feed types after 12 weeks was not significant (p > 0.5), which implied that rabbit growth did not depend on the feed type. The mean weight gain after 8 weeks was 707.5 g, 661.4 g and 577.1 g for feed type I, II and III respectively. At 8 weeks, the difference between means of feed types was significant (p Mucuna pruriens combined with cabbage and local forage were growing faster than rabbits from other treatments at 8 weeks. The researchers recommended that farmers should be facilitated with feeding materials by the concerned institutions. Training of rabbit farmers and further researches on locally available feeding materials were also given as recommendations at the end of this study.展开更多
Existing studies have mostly focused on sustainable intensification(SI)in agricultural systems,while neglecting the integrated analysis of SI for the land space utilization system(LSUS).This has resulted in a lack of ...Existing studies have mostly focused on sustainable intensification(SI)in agricultural systems,while neglecting the integrated analysis of SI for the land space utilization system(LSUS).This has resulted in a lack of systematic solutions in balancing sustainable resource utilization and environmental protection.This study reviewed SI's conceptual framework and evaluation,identified the gaps,and proposed an analytical framework of SI with clear logic and modeling processes for LSUS.Key findings include:(1)Resource competition and ecosystem pressures have highlighted the need to extend traditional agriculture-focused SI to LSUS and establish a clear quantitative evaluation framework for SI;(2)SI for LSUS refers to a system state in which a specific sub-system produces its dominant functions with resource savings,reduced environmental impact,efficient function output,and stable/enhanced function provision,while sub-systems evolve in a coordinated and orderly manner;(3)The assessment framework of SI for LSUS clarifies modeling processes,suggested indicators,methods and scale hierarchy system to help policymakers identify SI priorities across scales,informing strategies to balance agricultural,socioeconomic,and ecosystem goals.This study overcomes the limitations of traditional SI,providing crucial insights for tracking SI performance and identifying barriers in LSUS to enlighten the sustainable land use and management practices.展开更多
The liquid-only transfer dividing wall column(LDWC)offers a promising path for industrializing dividing wall columns by simplifying vapor split control.However,their energy efficiency is insufficient due to the additi...The liquid-only transfer dividing wall column(LDWC)offers a promising path for industrializing dividing wall columns by simplifying vapor split control.However,their energy efficiency is insufficient due to the addition of heat at the bottom and its removal at the top.Therefore,developing an effective strategy to enhance the energy efficiency of the entire LDWC system is crucial.This work investigates the intensification of LDWC based on the column grand composite curve(CGCC)and thermodynamic analysis,proposing a novel intensification strategy to improve energy efficiency effectively.An optimization model with four blocks is developed to minimize the total annual cost(TAC)of the intensified LDWC.Energy,exergy,economic,and environmental analyses are used to evaluate its performance.Ternary mixtures with different easy separation indexes(ESI)are selected as illustrative examples.For mixtures with ESI≤1,the optimal configuration involves partial feed preheating,compressors and intermediate reboilers on both side sections,along with optimized operating pressure.This setup leads to significant reductions in total energy consumption,TAC,and gas emissions by 43.80%,28.08%,and 42.85%for ESI=1,and by 46.17%,29.06%,and 45.35%for ESI<1,respectively,when compared to conventional distillation sequences(CDS).For mixtures with ESI>1,the best performance is achieved by implementing partial feed preheating and modifications only to the right section.This results in reductions of 21.64%in energy consumption,16.26%in TAC,and 21.51%in gas emissions when compared to CDS.In all cases,the optimal configurations show the lowest lost work and minimum work,indicating an improved thermodynamic performance.展开更多
Using observational and reanalysis datasets,this study explores the mechanisms by which the interactions among multi-timescale flows impacted the onset of rapid intensification(RI)of Typhoon Hato(2017).Hato(2017)forme...Using observational and reanalysis datasets,this study explores the mechanisms by which the interactions among multi-timescale flows impacted the onset of rapid intensification(RI)of Typhoon Hato(2017).Hato(2017)formed within a northwest–southeast-oriented synoptic-scale(with periods<10 days)wave train,concurring with a developing intraseasonal(10–90 days)oscillation and an elongated low-frequency(>90 days)monsoon trough in the western North Pacific.Impacted by continuously increasing vertical wind shear,the TC long maintained a highly asymmetric convective structure.Prior to RI onset,the synoptic-scale circulation and the inner-core asymmetric convection of Hato(2017)greatly strengthened,which are the key factors believed to trigger RI.A multi-timescale eddy kinetic energy budget indicates that the wind convergence associated with the intraseasonal circulation and monsoon trough led to barotropic energy conversion that largely enhanced the synoptic-scale cyclonic circulation.Besides,the pronounced increases in midlevel relative humidity(RH)and surface latent heat flux(LHF)were observed upshear before RI onset,which were primarily driven by the strong intraseasonal and synoptic-scale RH anomalies and the strengthened low-level wind speed,respectively.The increased LHF and midlevel RH,together with the enhanced downshear confluence between synoptic-scale and Intraseasonal Oscillation(ISO)/low-frequency winds,could have helped the intensification of asymmetric convection that supports RI onset.Overall,this study suggests that the interactions across multiple timescales may create favorable dynamic and thermodynamic conditions that promoted RI onset,offering new insights into RI processes for highly asymmetric tropical cyclones like Hato(2017).展开更多
Intensification in rice crop production is generally understood as requiring increased use of material inputs: water, inorganic fertilizers, and agrochemicals. However, this is not the only kind of intensification ava...Intensification in rice crop production is generally understood as requiring increased use of material inputs: water, inorganic fertilizers, and agrochemicals. However, this is not the only kind of intensification available. More productive crop phenotypes, with traits such as more resistance to biotic and abiotic stresses and shorter crop cycles, are possible through modifications in the management of rice plants, soil, water, and nutrients, reducing rather than increasing material inputs. Greater factor productivity can be achieved through the application of new knowledge and more skill, and(initially) more labor, as seen from the System of Rice Intensification(SRI), whose practices are used in various combinations by as many as 10 million farmers on about 4 million hectares in over 50 countries. The highest yields achieved with these management methods have come from hybrids and improved rice varieties, confirming the importance of making genetic improvements. However,unimproved varieties are also responsive to these changes, which induce better growth and functioning of rice root systems and more abundance, diversity, and activity of beneficial soil organisms. Some of these organisms as symbiotic endophytes can affect and enhance the expression of rice plants' genetic potential as well as their phenotypic resilience to multiple stresses, including those of climate change. SRI experience and data suggest that decades of plant breeding have been selecting for the best crop genetic endowments under suboptimal growing conditions, with crowding of plants that impedes their photosynthesis and growth, flooding of rice paddies that causes roots to degenerate and forgoes benefits derived from aerobic soil organisms, and overuse of agrochemicals that adversely affect these organisms as well as soil and human health. This review paper reports evidence from research in India and Indonesia that changes in crop and water management can improve the expression of rice plants' genetic potential, thereby creating more productive and robustphenotypes from given rice genotypes. Data indicate that increased plant density does not necessarily enhance crop yield potential, as classical breeding methods suggest. Developing cultivars that can achieve their higher productivity under a wide range of plant densities—breeding for density-neutral cultivars using alternative selection strategies—will enable more effective exploitation of available crop growth resources. Density-neutral cultivars that achieve high productivity under ample environmental growth resources can also achieve optimal productivity under limited resources, where lower densities can avert crop failure due to overcrowding. This will become more important to the extent that climatic and other factors become more adverse to crop production. Focusing more on which management practices can evoke the most productive and robust phenotypes from given genotypes is important for rice breeding and improvement programs since it is phenotypes that feed our human populations.展开更多
The demand of water for irrigation purposes in Tanzania outstrips the amount of water available for irrigation and other demands. On the other hand, the demand for more food to feed the growing population is increasin...The demand of water for irrigation purposes in Tanzania outstrips the amount of water available for irrigation and other demands. On the other hand, the demand for more food to feed the growing population is increasing, calling for the need to have technologies and farming practices that ensure more food production while minimizing water uses. Rice is among cereal crops grown in Tanzania, and it can assist in meeting the food demand for the nation. Majority of rice producers in Tanzania and Sub-Saharan Africa(SSA) are subsistence farmers and they practice continuous flooding, a technique that requires much water. In addition to using large amounts of water, the conventional practices of growing paddy using local varieties transplanting process are implemented when seedlings are more than 21 days old, and 3-4 seedlings are transplanted in one hole. This practice results in low yields, and low water productivity and water use efficiency. The system of rice intensification (SRI) on the other hand, is a promising new practice of growing paddy rice that has proven to be very effective in saving water and increasing rice yields in many parts of the world. SRI practice is spreading fast and it has been adopted in many countries. The SRI practice has been introduced in Tanzania during the last 3 years as such it is not widely practiced. This paper reviews SRI practice at global, regional and country (Tanzania) level, and evaluates the challenges, opportunities and implications for its adoption in Tanzania. Knowledge gaps at each level have been identified and discussed as well as suggestions for researchable areas.展开更多
This research aimed to know the influence of liquid organic fertilizer and planting space to the growth and yield of rice in System of Rice Intensification （SRI） methods. The research was conducted in Palur, Sukohar...This research aimed to know the influence of liquid organic fertilizer and planting space to the growth and yield of rice in System of Rice Intensification （SRI） methods. The research was conducted in Palur, Sukoharjo, laid on 98 m above sea level from December 2008 to April 2009. Experimental design used was Randomized Completely Block Design with two factors of treatment. The first factor was liquid organic fertilizer; consist of control, cebreng leaf, rumen of goat, banana tree hump, and maja fruit. The second factor was planting space; consisting of 25 cm × 25 cm, 30 cm ×30 cm and 35 cm× 35 cm. There were 15 combinations of treatment and each repeated three times. Data analyzed with F test at 5% and DMRT at 5%. Research result showed that liquid organic fertilizer of maja fruit serves the best on variable of stalk length. Planting space of 35 cm × 35 cm serves the best on variable of plant height, number of total sapling, number of productive sapling, weight of dry plant, weight of rice per clump, and weight of 1,000 rice grains. There is no interaction between liquid organic fertilizer and planting space on all variables.展开更多
One of the greatest challenges in the agroecosystem is to improve cropland intensification while preserving agroecosystem services.While many studies have investigated the effect of cropland intensification on agroeco...One of the greatest challenges in the agroecosystem is to improve cropland intensification while preserving agroecosystem services.While many studies have investigated the effect of cropland intensification on agroecosystem service,the interactive coupling and coordination among these factors remain largely unexplored.In view of this,this study performed a case study of the Loess Plateau in Shaanxi Province,China and constructed comprehensive evaluation models to quantify the cropland intensification and agroecosystem service in this area.Balance analysis and the coupling coordination degree model were used to evaluate the interactive relationship between cropland intensification and agroecosystem service,and statistical analysis and spatial autocorrelation were used to analyze the spatial characteristics and potential mechanism of the coupling coordination.Results show that both the cropland intensification and agroecosystem service in the study area were relatively low yet gradually increased from 2000 to 2020.Agroecosystem service lag was identified as the dominant unbalanced development type.Improving the supply capacity of agroecosystem services plays a key role in the balanced development of cropland in the Loess Plateau.The coupling coordination degree between cropland intensification and agroecosystem service ranges from basic coordination to serious incoordination.Therefore,cropland intensification practices in the area should be optimized to enhance this coordination degree.An upward trend was also observed in the coupling coordination degree from2000 to 2020.The withdrawal of marginal cropland in the Grain for Green program is one of the most important reasons for this trend,especially for the northern region.Around 83.6%of the high-high clusters are concentrated in the southern region of the Loess Plateau,whereas 70.5%of the low-low clusters are distributed in the northern region.These clustering characteristics are mainly attributed to the environmental suitability of these areas for agriculture and their degree of economic development.展开更多
Upland crop-rice cropping systems(UCR)facilitate sustainable agricultural intensification.Accurate UCR cultivation mapping is needed to ensure food security,sustainable water management,and rural revitalization.Howeve...Upland crop-rice cropping systems(UCR)facilitate sustainable agricultural intensification.Accurate UCR cultivation mapping is needed to ensure food security,sustainable water management,and rural revitalization.However,datasets describing cropping systems are limited in spatial coverage and crop types.Mapping UCR is more challenging than crop identification and most existing approaches rely heavily on accurate phenology calendars and representative training samples,which limits its applications over large regions.We describe a novel algorithm(RRSS)for automatic mapping of upland crop-rice cropping systems using Sentinel-1 Synthetic Aperture Radar(SAR)and Sentinel-2 Multispectral Instrument(MSI)data.One indicator,the VV backscatter range,was proposed to discriminate UCR and another two indicators were designed by coupling greenness and pigment indices to further discriminate tobacco or oilseed UCR.The RRSS algorithm was applied to South China characterized by complex smallholder rice cropping systems and diverse topographic conditions.This study developed 10-m UCR maps of a major rice bowl in South China,the Xiang-Gan-Min(XGM)region.The performance of the RRSS algorithm was validated based on 5197 ground-truth reference sites,with an overall accuracy of 91.92%.There were7348 km^(2) areas of UCR,roughly one-half of them located in plains.The UCR was represented mainly by oilseed-UCR and tobacco-UCR,which contributed respectively 69%and 15%of UCR area.UCR patterns accounted for only one-tenth of rice production,which can be tripled by intensification from single rice cropping.Application to complex and fragmented subtropical regions suggested the spatiotemporal robustness of the RRSS algorithm,which could be further applied to generate 10-m UCR datasets for application at national or global scales.展开更多
Irrigated rice cultivation has long been associated with large amounts of water. Currently convectional rice production is faced with major challenges of water shortage as a result of increasing population sharing the...Irrigated rice cultivation has long been associated with large amounts of water. Currently convectional rice production is faced with major challenges of water shortage as a result of increasing population sharing the same water resources, as well as global environmental changes. The System of Rice Intensification (SRI), as opposed to conventional rice production, involves alternate wetting and drying (AWD) of rice fields. The objective of this study was to determine the optimum drying days period of paddy fields that has a positive effect on rice yields and the corresponding water saving. The experimental design used was randomized complete block design (RCBD). Four treatments and the conventional rice irrigation method were used. The treatments were the dry days allowed after draining the paddy under SRI before flooding again. These were set as 0, 4, 8, 12 and 16 day-intervals. Yield parameters were monitored during the growth period of the crop where a number of tillers, panicles, panicle length and panicle filling were monitored. Amount of water utilized for crop growth for each treatment was measured. Average yield and corresponding water saving were determined for each treatment. The results obtained show that the 8 days drying period gave the highest yield of 7.13 tons/ha compared with the conventional method of growing rice which gave a yield of 4.87 tons/ha. This was an increase of 46.4% above the conventional method of growing rice. Water saving associated with this drying regime was 32.4%. This was taken as evidence that SRI improved yields with reduction in water use.展开更多
The system of rice intensification(SRI) is a production system that involves the adoption of certain changes in management practices for rice cultivation that create a better growing environment for the crop.This syst...The system of rice intensification(SRI) is a production system that involves the adoption of certain changes in management practices for rice cultivation that create a better growing environment for the crop.This system was compared with conventional practices and assessed under organic and inorganic management.SRI practices showed significant response in root number,number of effective tillers per hill,days to flowering and harvest index.In addition,SRI was found effective in minimizing pest and disease incidence,shortening the crop cycle,and improving plant stand.Grain yield was not different from conventional method.Except for harvest index and plant lodging percentage,there were no significant effects from management treatments.Synergistic responses were noted when SRI practices were combined with organic management for plant height,number of effective tillers per hill,days to flowering and to maturity.The improved panicle characteristics,lower plant lodging percentage and higher harvest index that ultimately led to comparable grain yields.Net returns increased approximately 1.5 times for SRI-organic management regardless of the added labor requirements for weed control.However,comparatively higher grain yield from conventional-inorganic methods underscore the need for further investigations in defining what constitutes an optimum set of practices for an SRI-organic system specifically addressing grain yield and weed management.展开更多
A programme effort for SRI impact assessment has been undertaken in 20 project villages in the Narayanpet block. The villages have been pooled under four clusters, for which quantitative and qualitative analyses have ...A programme effort for SRI impact assessment has been undertaken in 20 project villages in the Narayanpet block. The villages have been pooled under four clusters, for which quantitative and qualitative analyses have been carried out on water usage, input cost, plant growth, farmer group collectivization, gross and net returns of SRI, and conventional paddy cultivation. The result shows that significant water saving was achieved for SRI, i.e., 8586 m<sup>3</sup>∙ha<sup>−1</sup> under tubewell irrigation over conventional. This approximation has served as an auxiliary to the number of pumping hours and number of irrigation days that have been reduced for SRI. Less utilisation of water and distance maintained in SRI has benefited in reducing the biotic and abiotic stress caused by snails and nutrient deprivation, respectively. The total yield for a sampled number of SRI farmers has been found to have a 22% increase for the total expenditure difference of Rs. 6153, i.e., 13% less than conventional paddy farmers, which highly impacts the SRI farmers’ net income, i.e., 69% more than the conventional returns. The SRI method has a lower labour deployment of 8 people/ha than the conventional method, which requires 16 people/ha with a constant price of Rs 250/person. Input cost saving in these two categories has ranked top and has fetched maximum production efficiency among the others. The seed cost at a fixed price of 32 Rs/kg was significantly (87%) reduced for SRI as 8 kg per ha was required rather than the conventional that required 62 kg/ha. Social benefits were listed based on the qualitative analysis and were transformed using the theory of planned behaviour.展开更多
With inevitable growth of demand for human and industrial needs,water available for agriculture will become scarcer in the future.India is a highly water-stressed country.Hence,India needs to invest in improving its w...With inevitable growth of demand for human and industrial needs,water available for agriculture will become scarcer in the future.India is a highly water-stressed country.Hence,India needs to invest in improving its water productivity,and any capacity to produce more rice with less water.System of Rice Intensification(SRI)has attracted much attention in increasing rice yield per unit area.For this study,fifteen farmers were selected those were practicing SRI technology by themselves during the Boro-cultivation season(January-April).The study was continued for three consecutive years 2012 to 14 on the same fields.In addition to the SRI plots,a similar size of non-SRI plot was maintained in conventional cultivation for comparison purpose.On an average,the non-SR I ight increased by 12%,number of tillers per square meter by 85%,number of reproductive tillers per hill by 286%,weight of panicle per hill by 139%,number of seeds per panicle by 41%and test weight by 26% due to SRI practice over the non-SRI practice.Average increment in straw and grain yield due to SRI over the non-SRI is 70%and 59%respectively.The physico-chemical and biological properties of soil improved due to SRI practice.展开更多
In order to solve the problems of high coupling and poor scalability of the traditional monomer early warning release system architecture,multi-level deployment in a complex network environment will lead to high inves...In order to solve the problems of high coupling and poor scalability of the traditional monomer early warning release system architecture,multi-level deployment in a complex network environment will lead to high investment in software and hardware and cannot achieve intensive multi-level deployment.This paper realizes the goal of system scalability by introducing micro service architecture and technology stack and realizes the goal of resource intensification by introducing the idea of a data forwarding agent.The designed architecture scheme has been practically applied in the“Jiangxi emergency early warning information release system software platform(phase I)project”(hereinafter referred to as“provincial emergency”),which meets the needs of flexible deployment of multi-level applications across meteorological wide area network(WAN),business private network of other commissions,offices,and bureaus,government extranet,Internet and other complex networks,and fully verifies the scientificity and rationality of the scheme.It has achieved the goal of intensive and scalable construction of provincial emergencies under the complex network environment,greatly improved the early warning capacity and communication capacity of emergencies and comprehensive disasters,provided a reliable guarantee for disaster prevention and reduction,and provided a reference for the construction of current and future early warning release system and capacity improvement project.展开更多
The mixing process plays a pivotal role in the design,optimization,and scale-up of chemical reactors.For most chemical reactions,achieving uniform and rapid contact between reactants at the molecular level is crucial....The mixing process plays a pivotal role in the design,optimization,and scale-up of chemical reactors.For most chemical reactions,achieving uniform and rapid contact between reactants at the molecular level is crucial.Mixing intensification encompasses innovative methods and tools that address the limitations of inadequate mixing within reactors,enabling efficient reaction scaling and boosting the productivity of industrial processes.This review provides a concise introduction to the fundamentals of multiphase mixing,followed by case studies highlighting the application of mixing intensification in the production of energy-storage materials,advanced optical materials,and nanopesticides.These examples illustrate the significance of theoretical analysis in informing and advancing engineering practices within the chemical industry.We also explore the challenges and opportunities in this field,offering insights based on our current understanding.展开更多
The rapid intensification(RI)magnitude of tropical cyclones(TCs)over the western North Pacific(WNP)exhibits significant interannual variability and is influenced by multiple factors across various scales.These factors...The rapid intensification(RI)magnitude of tropical cyclones(TCs)over the western North Pacific(WNP)exhibits significant interannual variability and is influenced by multiple factors across various scales.These factors primarily include:interannual factors—sea surface temperature(SST)in key regions of the WNP,eastern Indian Ocean SST,El Niño-Southern Oscillation(ENSO),South Pacific Subtropical Dipole(SPSD),and western Pacific teleconnection;decadal factors—Atlantic Multidecadal Oscillation(AMO)and Pacific Decadal Oscillation(PDO);and longer-term factor—global warming.This study systematically analyzes these factors and their potential impacts,quantitatively assessing their relative importance.A statistical prediction model for the WNP TC-RI magnitude is developed based on ridge regression methods.The results indicate that the influence of these factors on the RI magnitude is closely related to the large-scale thermodynamic and dynamic conditions.Among them,the SPSD plays the most critical role in the interannual variability of the RI magnitude,followed by global warming and the AMO.Further analysis reveals that the statistical prediction model based on multiple factors demonstrates good predictive skill for the interannual variability of the TC RI magnitude.展开更多
Typhoon Hinnamnor(2022)was the only tropical cyclone(TC)during 1982-2023 that maintained strong or higher intensity north of 25°N while undergoing two rapid intensification(RI)events under marine heatwave(MHW)con...Typhoon Hinnamnor(2022)was the only tropical cyclone(TC)during 1982-2023 that maintained strong or higher intensity north of 25°N while undergoing two rapid intensification(RI)events under marine heatwave(MHW)conditions.These RI events differed significantly in both duration and intensification rates.This study investigated the role of MHWs in modulating these events,with a focus on variations in ocean stratification and atmospheric circulation.The results revealed that the first RI lasted 18 h,during which typhoon Hinnamnor intensified from a strong tropical storm to a super typhoon,which was driven primarily by oceanic thermal conditions.The anomalous MHW deepened the warm subsurface waters,leading to sustained accumulation of upper ocean heat content(UOHC),which fueled the RI.The cyclone’s rapid movement and moderate intensity helped preserve the abnormally thick barrier layer(BL),which maintained the UOHC via a subsurface“heat pump”effect,thus supporting continued intensification.In contrast,the second RI lasted only 6 h and involved a one-category intensification from a strong typhoon to a super typhoon,influenced by both oceanic and atmospheric factors.The prolonged and intensified MHW maintained a high UOHC,while strong upper-level divergence,increased mid-level moisture and low-level convergence enhanced deep convection,triggering the RI.However,a shallow mixed layer confined warm anomalies to the surface,whereas the cyclone’s slower movement,stronger winds,and thinner BL induced cold water upwelling.This“cold suction”effect depleted the UOHC,prematurely terminating the RI.These findings highlight the complex interplay between oceanic and atmospheric factors in shaping TC intensification under MHW conditions,emphasizing the critical role of upper ocean stratification in improving TC intensity forecasts.展开更多
While steady improvements have been achieved for the track forecasts of typhoons,there has been a lack of improvement for intensity forecasts.One challenge for intensity forecasts is to capture the rapid intensificati...While steady improvements have been achieved for the track forecasts of typhoons,there has been a lack of improvement for intensity forecasts.One challenge for intensity forecasts is to capture the rapid intensification(RI),whose nonlinear characteristics impose great difficulties for numerical models.The ensemble sensitivity analysis(ESA)method is used here to analyze the initial conditions that contribute to typhoon intensity forecasts,especially with RI.Six RI processes from five typhoons(Chaba,Haima,Meranti,Sarika,and Songda)in 2016,are applied with ESA,which also gives a composite initial condition that favors subsequent RI.Results from individual cases have generally similar patterns of ESA,but with different magnitudes,when various cumulus parameterization schemes are applied.To draw the initial conditions with statistical significance,sample-mean azimuthal components of ESA are obtained.Results of the composite sensitivity show that typhoons that experience RI in 24 h favor enhanced primary circulation from low to high levels,intensified secondary circulation with increased radial inflow at lower levels and increased radial outflow at upper levels,a prominent warm core at around 300 hPa,and increased humidity at low levels.As the forecast lead time increases,the patterns of ESA are retained,while the sensitivity magnitudes decay.Given the general and quantitative composite sensitivity along with associated uncertainties for different cumulus parameterization schemes,appropriate sampling of the composite sensitivity in numerical models could be beneficial to capturing the RI and improving the forecasting of typhoon intensity.展开更多
The synoptic process of a super Arctic cyclone in August 2016(AC16)is investigated based on the Weather Research and Forecasting(WRF)model,and the key factors affecting the rapid intensification(RI)of AC16 and their r...The synoptic process of a super Arctic cyclone in August 2016(AC16)is investigated based on the Weather Research and Forecasting(WRF)model,and the key factors affecting the rapid intensification(RI)of AC16 and their relative contributions are analyzed by diagnosing a new surface pressure tendency equation(SPTE).The major physical mechanisms behind the two RI stages of AC16 are revealed.The trajectory,intensity changes,and structural characteristics of AC16 are well simulated by the WRF model.A diagnosis based on the SPTE promisingly reproduces the two RI stages of AC16.The leading factor that influenced the intensity of AC16 was identified to be the air-column potential temperature tendency,while the pressure change at the upper boundary had less of an impact.Further analysis reveals that the horizontal potential temperature advection was the decisive factor in a warming of the air column.Specifically,the upper-level warm advection generated by the strong wind field of the upper-level jet played a dominant role in warming the air column,which caused the initial RI of AC16.The AC16 movement into a strong potential temperature gradient generated by tropopause polar vortices increased the upper-level warm advection,which warmed the air column and thereby induced the second RI of AC16.However,the net effect of vertical potential temperature advection and latent heating,as well as radiation processes,caused a cooling of the air column and thereby negatively contributed to the RI of AC16.展开更多
文摘A study was conducted in Northern Province of Rwanda, from the College of Agriculture and Veterinary Medicine, Busogo Campus located in Musanze district to evaluate the effect of feed type on rabbit growth in rabbit intensification systems in Rwanda. The Complete Randomized Design (CRD) was used and data were collected on rabbit growth weekly for a period of 12 weeks. The experiment was composed of three treatments replicated ten times. The treatments included three types of feeds namely;cabbage combined with Mucuna pruriens added to local forage (I), cabbages combined with Leucaena leucocephala added to local forage (II) and a control composed of other varieties of locally available forage, such as Bidens pilosa, Crassocephalum vitellium and Galinsoga parviflora (III) which was considered as the control (Farmers practice). The feeds were given to ten rabbits separated in individual cages, and each rabbit was considered a replicate. Water was given ad libitum. One month old rabbits (weaners) were used and data were collected after one week of adaptation for 12 weeks. The results showed that the mean of weight gain after 12 weeks was 783.3 g, 760.7 g and 705.7 g for feed type I, II and III respectively. The difference between means of feed types after 12 weeks was not significant (p > 0.5), which implied that rabbit growth did not depend on the feed type. The mean weight gain after 8 weeks was 707.5 g, 661.4 g and 577.1 g for feed type I, II and III respectively. At 8 weeks, the difference between means of feed types was significant (p Mucuna pruriens combined with cabbage and local forage were growing faster than rabbits from other treatments at 8 weeks. The researchers recommended that farmers should be facilitated with feeding materials by the concerned institutions. Training of rabbit farmers and further researches on locally available feeding materials were also given as recommendations at the end of this study.
基金National Natural Science Foundation of China,No.42201269,No.42401316Natural Science Foundation of Jiangsu Province,No.BK20241666+3 种基金Humanity and Social Science Youth Foundation of Ministry of Education of China,No.22YJC630087Social Science Foundation of Jiangsu Province,No.24EYB004Open Fund of Key Laboratory of Coastal Zone Exploitation and Protection,Ministry of Natural Resources,No.2023CZEPK07Fundamental Research Funds for the Central Universities,No.2024QN11056。
文摘Existing studies have mostly focused on sustainable intensification(SI)in agricultural systems,while neglecting the integrated analysis of SI for the land space utilization system(LSUS).This has resulted in a lack of systematic solutions in balancing sustainable resource utilization and environmental protection.This study reviewed SI's conceptual framework and evaluation,identified the gaps,and proposed an analytical framework of SI with clear logic and modeling processes for LSUS.Key findings include:(1)Resource competition and ecosystem pressures have highlighted the need to extend traditional agriculture-focused SI to LSUS and establish a clear quantitative evaluation framework for SI;(2)SI for LSUS refers to a system state in which a specific sub-system produces its dominant functions with resource savings,reduced environmental impact,efficient function output,and stable/enhanced function provision,while sub-systems evolve in a coordinated and orderly manner;(3)The assessment framework of SI for LSUS clarifies modeling processes,suggested indicators,methods and scale hierarchy system to help policymakers identify SI priorities across scales,informing strategies to balance agricultural,socioeconomic,and ecosystem goals.This study overcomes the limitations of traditional SI,providing crucial insights for tracking SI performance and identifying barriers in LSUS to enlighten the sustainable land use and management practices.
基金support provided by the National Natural Science Foundation of China(U24B6016)the Higher Education Institution Academic Discipline Innovation and Talent Introduction Plan(“111 Plan”)(No.B23025)are gratefully acknowledged.
文摘The liquid-only transfer dividing wall column(LDWC)offers a promising path for industrializing dividing wall columns by simplifying vapor split control.However,their energy efficiency is insufficient due to the addition of heat at the bottom and its removal at the top.Therefore,developing an effective strategy to enhance the energy efficiency of the entire LDWC system is crucial.This work investigates the intensification of LDWC based on the column grand composite curve(CGCC)and thermodynamic analysis,proposing a novel intensification strategy to improve energy efficiency effectively.An optimization model with four blocks is developed to minimize the total annual cost(TAC)of the intensified LDWC.Energy,exergy,economic,and environmental analyses are used to evaluate its performance.Ternary mixtures with different easy separation indexes(ESI)are selected as illustrative examples.For mixtures with ESI≤1,the optimal configuration involves partial feed preheating,compressors and intermediate reboilers on both side sections,along with optimized operating pressure.This setup leads to significant reductions in total energy consumption,TAC,and gas emissions by 43.80%,28.08%,and 42.85%for ESI=1,and by 46.17%,29.06%,and 45.35%for ESI<1,respectively,when compared to conventional distillation sequences(CDS).For mixtures with ESI>1,the best performance is achieved by implementing partial feed preheating and modifications only to the right section.This results in reductions of 21.64%in energy consumption,16.26%in TAC,and 21.51%in gas emissions when compared to CDS.In all cases,the optimal configurations show the lowest lost work and minimum work,indicating an improved thermodynamic performance.
基金supported by the National Key Research and Development Program of China(Grant No.2023YFF0807000)supported by the National Natural Science Foundation of China(Grant Nos.42305004,42175073 and 42175013)supported partly by the China Postdoctoral Science Foundation(Grant No.2023M743283).
文摘Using observational and reanalysis datasets,this study explores the mechanisms by which the interactions among multi-timescale flows impacted the onset of rapid intensification(RI)of Typhoon Hato(2017).Hato(2017)formed within a northwest–southeast-oriented synoptic-scale(with periods<10 days)wave train,concurring with a developing intraseasonal(10–90 days)oscillation and an elongated low-frequency(>90 days)monsoon trough in the western North Pacific.Impacted by continuously increasing vertical wind shear,the TC long maintained a highly asymmetric convective structure.Prior to RI onset,the synoptic-scale circulation and the inner-core asymmetric convection of Hato(2017)greatly strengthened,which are the key factors believed to trigger RI.A multi-timescale eddy kinetic energy budget indicates that the wind convergence associated with the intraseasonal circulation and monsoon trough led to barotropic energy conversion that largely enhanced the synoptic-scale cyclonic circulation.Besides,the pronounced increases in midlevel relative humidity(RH)and surface latent heat flux(LHF)were observed upshear before RI onset,which were primarily driven by the strong intraseasonal and synoptic-scale RH anomalies and the strengthened low-level wind speed,respectively.The increased LHF and midlevel RH,together with the enhanced downshear confluence between synoptic-scale and Intraseasonal Oscillation(ISO)/low-frequency winds,could have helped the intensification of asymmetric convection that supports RI onset.Overall,this study suggests that the interactions across multiple timescales may create favorable dynamic and thermodynamic conditions that promoted RI onset,offering new insights into RI processes for highly asymmetric tropical cyclones like Hato(2017).
文摘Intensification in rice crop production is generally understood as requiring increased use of material inputs: water, inorganic fertilizers, and agrochemicals. However, this is not the only kind of intensification available. More productive crop phenotypes, with traits such as more resistance to biotic and abiotic stresses and shorter crop cycles, are possible through modifications in the management of rice plants, soil, water, and nutrients, reducing rather than increasing material inputs. Greater factor productivity can be achieved through the application of new knowledge and more skill, and(initially) more labor, as seen from the System of Rice Intensification(SRI), whose practices are used in various combinations by as many as 10 million farmers on about 4 million hectares in over 50 countries. The highest yields achieved with these management methods have come from hybrids and improved rice varieties, confirming the importance of making genetic improvements. However,unimproved varieties are also responsive to these changes, which induce better growth and functioning of rice root systems and more abundance, diversity, and activity of beneficial soil organisms. Some of these organisms as symbiotic endophytes can affect and enhance the expression of rice plants' genetic potential as well as their phenotypic resilience to multiple stresses, including those of climate change. SRI experience and data suggest that decades of plant breeding have been selecting for the best crop genetic endowments under suboptimal growing conditions, with crowding of plants that impedes their photosynthesis and growth, flooding of rice paddies that causes roots to degenerate and forgoes benefits derived from aerobic soil organisms, and overuse of agrochemicals that adversely affect these organisms as well as soil and human health. This review paper reports evidence from research in India and Indonesia that changes in crop and water management can improve the expression of rice plants' genetic potential, thereby creating more productive and robustphenotypes from given rice genotypes. Data indicate that increased plant density does not necessarily enhance crop yield potential, as classical breeding methods suggest. Developing cultivars that can achieve their higher productivity under a wide range of plant densities—breeding for density-neutral cultivars using alternative selection strategies—will enable more effective exploitation of available crop growth resources. Density-neutral cultivars that achieve high productivity under ample environmental growth resources can also achieve optimal productivity under limited resources, where lower densities can avert crop failure due to overcrowding. This will become more important to the extent that climatic and other factors become more adverse to crop production. Focusing more on which management practices can evoke the most productive and robust phenotypes from given genotypes is important for rice breeding and improvement programs since it is phenotypes that feed our human populations.
文摘The demand of water for irrigation purposes in Tanzania outstrips the amount of water available for irrigation and other demands. On the other hand, the demand for more food to feed the growing population is increasing, calling for the need to have technologies and farming practices that ensure more food production while minimizing water uses. Rice is among cereal crops grown in Tanzania, and it can assist in meeting the food demand for the nation. Majority of rice producers in Tanzania and Sub-Saharan Africa(SSA) are subsistence farmers and they practice continuous flooding, a technique that requires much water. In addition to using large amounts of water, the conventional practices of growing paddy using local varieties transplanting process are implemented when seedlings are more than 21 days old, and 3-4 seedlings are transplanted in one hole. This practice results in low yields, and low water productivity and water use efficiency. The system of rice intensification (SRI) on the other hand, is a promising new practice of growing paddy rice that has proven to be very effective in saving water and increasing rice yields in many parts of the world. SRI practice is spreading fast and it has been adopted in many countries. The SRI practice has been introduced in Tanzania during the last 3 years as such it is not widely practiced. This paper reviews SRI practice at global, regional and country (Tanzania) level, and evaluates the challenges, opportunities and implications for its adoption in Tanzania. Knowledge gaps at each level have been identified and discussed as well as suggestions for researchable areas.
文摘This research aimed to know the influence of liquid organic fertilizer and planting space to the growth and yield of rice in System of Rice Intensification （SRI） methods. The research was conducted in Palur, Sukoharjo, laid on 98 m above sea level from December 2008 to April 2009. Experimental design used was Randomized Completely Block Design with two factors of treatment. The first factor was liquid organic fertilizer; consist of control, cebreng leaf, rumen of goat, banana tree hump, and maja fruit. The second factor was planting space; consisting of 25 cm × 25 cm, 30 cm ×30 cm and 35 cm× 35 cm. There were 15 combinations of treatment and each repeated three times. Data analyzed with F test at 5% and DMRT at 5%. Research result showed that liquid organic fertilizer of maja fruit serves the best on variable of stalk length. Planting space of 35 cm × 35 cm serves the best on variable of plant height, number of total sapling, number of productive sapling, weight of dry plant, weight of rice per clump, and weight of 1,000 rice grains. There is no interaction between liquid organic fertilizer and planting space on all variables.
基金Under the auspices of the National Natural Science Foundation of China(No.41901262)Natural Science Basic Research Program of Shaanxi(No.2024JC-YBQN-0300)Fundamental Research Funds for the Central Universities(No.GK202103125,GK202207005)。
文摘One of the greatest challenges in the agroecosystem is to improve cropland intensification while preserving agroecosystem services.While many studies have investigated the effect of cropland intensification on agroecosystem service,the interactive coupling and coordination among these factors remain largely unexplored.In view of this,this study performed a case study of the Loess Plateau in Shaanxi Province,China and constructed comprehensive evaluation models to quantify the cropland intensification and agroecosystem service in this area.Balance analysis and the coupling coordination degree model were used to evaluate the interactive relationship between cropland intensification and agroecosystem service,and statistical analysis and spatial autocorrelation were used to analyze the spatial characteristics and potential mechanism of the coupling coordination.Results show that both the cropland intensification and agroecosystem service in the study area were relatively low yet gradually increased from 2000 to 2020.Agroecosystem service lag was identified as the dominant unbalanced development type.Improving the supply capacity of agroecosystem services plays a key role in the balanced development of cropland in the Loess Plateau.The coupling coordination degree between cropland intensification and agroecosystem service ranges from basic coordination to serious incoordination.Therefore,cropland intensification practices in the area should be optimized to enhance this coordination degree.An upward trend was also observed in the coupling coordination degree from2000 to 2020.The withdrawal of marginal cropland in the Grain for Green program is one of the most important reasons for this trend,especially for the northern region.Around 83.6%of the high-high clusters are concentrated in the southern region of the Loess Plateau,whereas 70.5%of the low-low clusters are distributed in the northern region.These clustering characteristics are mainly attributed to the environmental suitability of these areas for agriculture and their degree of economic development.
基金supported by the National Natural Science Foundation of China(42171325,41771468)the National Key Research and Development Program of China(2022YFD2001101)+1 种基金the Science Bureau of Fujian Province(2023Y0042)the Finance Department and the Digital Economy Alliance of Fujian Province。
文摘Upland crop-rice cropping systems(UCR)facilitate sustainable agricultural intensification.Accurate UCR cultivation mapping is needed to ensure food security,sustainable water management,and rural revitalization.However,datasets describing cropping systems are limited in spatial coverage and crop types.Mapping UCR is more challenging than crop identification and most existing approaches rely heavily on accurate phenology calendars and representative training samples,which limits its applications over large regions.We describe a novel algorithm(RRSS)for automatic mapping of upland crop-rice cropping systems using Sentinel-1 Synthetic Aperture Radar(SAR)and Sentinel-2 Multispectral Instrument(MSI)data.One indicator,the VV backscatter range,was proposed to discriminate UCR and another two indicators were designed by coupling greenness and pigment indices to further discriminate tobacco or oilseed UCR.The RRSS algorithm was applied to South China characterized by complex smallholder rice cropping systems and diverse topographic conditions.This study developed 10-m UCR maps of a major rice bowl in South China,the Xiang-Gan-Min(XGM)region.The performance of the RRSS algorithm was validated based on 5197 ground-truth reference sites,with an overall accuracy of 91.92%.There were7348 km^(2) areas of UCR,roughly one-half of them located in plains.The UCR was represented mainly by oilseed-UCR and tobacco-UCR,which contributed respectively 69%and 15%of UCR area.UCR patterns accounted for only one-tenth of rice production,which can be tripled by intensification from single rice cropping.Application to complex and fragmented subtropical regions suggested the spatiotemporal robustness of the RRSS algorithm,which could be further applied to generate 10-m UCR datasets for application at national or global scales.
文摘Irrigated rice cultivation has long been associated with large amounts of water. Currently convectional rice production is faced with major challenges of water shortage as a result of increasing population sharing the same water resources, as well as global environmental changes. The System of Rice Intensification (SRI), as opposed to conventional rice production, involves alternate wetting and drying (AWD) of rice fields. The objective of this study was to determine the optimum drying days period of paddy fields that has a positive effect on rice yields and the corresponding water saving. The experimental design used was randomized complete block design (RCBD). Four treatments and the conventional rice irrigation method were used. The treatments were the dry days allowed after draining the paddy under SRI before flooding again. These were set as 0, 4, 8, 12 and 16 day-intervals. Yield parameters were monitored during the growth period of the crop where a number of tillers, panicles, panicle length and panicle filling were monitored. Amount of water utilized for crop growth for each treatment was measured. Average yield and corresponding water saving were determined for each treatment. The results obtained show that the 8 days drying period gave the highest yield of 7.13 tons/ha compared with the conventional method of growing rice which gave a yield of 4.87 tons/ha. This was an increase of 46.4% above the conventional method of growing rice. Water saving associated with this drying regime was 32.4%. This was taken as evidence that SRI improved yields with reduction in water use.
文摘The system of rice intensification(SRI) is a production system that involves the adoption of certain changes in management practices for rice cultivation that create a better growing environment for the crop.This system was compared with conventional practices and assessed under organic and inorganic management.SRI practices showed significant response in root number,number of effective tillers per hill,days to flowering and harvest index.In addition,SRI was found effective in minimizing pest and disease incidence,shortening the crop cycle,and improving plant stand.Grain yield was not different from conventional method.Except for harvest index and plant lodging percentage,there were no significant effects from management treatments.Synergistic responses were noted when SRI practices were combined with organic management for plant height,number of effective tillers per hill,days to flowering and to maturity.The improved panicle characteristics,lower plant lodging percentage and higher harvest index that ultimately led to comparable grain yields.Net returns increased approximately 1.5 times for SRI-organic management regardless of the added labor requirements for weed control.However,comparatively higher grain yield from conventional-inorganic methods underscore the need for further investigations in defining what constitutes an optimum set of practices for an SRI-organic system specifically addressing grain yield and weed management.
文摘A programme effort for SRI impact assessment has been undertaken in 20 project villages in the Narayanpet block. The villages have been pooled under four clusters, for which quantitative and qualitative analyses have been carried out on water usage, input cost, plant growth, farmer group collectivization, gross and net returns of SRI, and conventional paddy cultivation. The result shows that significant water saving was achieved for SRI, i.e., 8586 m<sup>3</sup>∙ha<sup>−1</sup> under tubewell irrigation over conventional. This approximation has served as an auxiliary to the number of pumping hours and number of irrigation days that have been reduced for SRI. Less utilisation of water and distance maintained in SRI has benefited in reducing the biotic and abiotic stress caused by snails and nutrient deprivation, respectively. The total yield for a sampled number of SRI farmers has been found to have a 22% increase for the total expenditure difference of Rs. 6153, i.e., 13% less than conventional paddy farmers, which highly impacts the SRI farmers’ net income, i.e., 69% more than the conventional returns. The SRI method has a lower labour deployment of 8 people/ha than the conventional method, which requires 16 people/ha with a constant price of Rs 250/person. Input cost saving in these two categories has ranked top and has fetched maximum production efficiency among the others. The seed cost at a fixed price of 32 Rs/kg was significantly (87%) reduced for SRI as 8 kg per ha was required rather than the conventional that required 62 kg/ha. Social benefits were listed based on the qualitative analysis and were transformed using the theory of planned behaviour.
文摘With inevitable growth of demand for human and industrial needs,water available for agriculture will become scarcer in the future.India is a highly water-stressed country.Hence,India needs to invest in improving its water productivity,and any capacity to produce more rice with less water.System of Rice Intensification(SRI)has attracted much attention in increasing rice yield per unit area.For this study,fifteen farmers were selected those were practicing SRI technology by themselves during the Boro-cultivation season(January-April).The study was continued for three consecutive years 2012 to 14 on the same fields.In addition to the SRI plots,a similar size of non-SRI plot was maintained in conventional cultivation for comparison purpose.On an average,the non-SR I ight increased by 12%,number of tillers per square meter by 85%,number of reproductive tillers per hill by 286%,weight of panicle per hill by 139%,number of seeds per panicle by 41%and test weight by 26% due to SRI practice over the non-SRI practice.Average increment in straw and grain yield due to SRI over the non-SRI is 70%and 59%respectively.The physico-chemical and biological properties of soil improved due to SRI practice.
文摘In order to solve the problems of high coupling and poor scalability of the traditional monomer early warning release system architecture,multi-level deployment in a complex network environment will lead to high investment in software and hardware and cannot achieve intensive multi-level deployment.This paper realizes the goal of system scalability by introducing micro service architecture and technology stack and realizes the goal of resource intensification by introducing the idea of a data forwarding agent.The designed architecture scheme has been practically applied in the“Jiangxi emergency early warning information release system software platform(phase I)project”(hereinafter referred to as“provincial emergency”),which meets the needs of flexible deployment of multi-level applications across meteorological wide area network(WAN),business private network of other commissions,offices,and bureaus,government extranet,Internet and other complex networks,and fully verifies the scientificity and rationality of the scheme.It has achieved the goal of intensive and scalable construction of provincial emergencies under the complex network environment,greatly improved the early warning capacity and communication capacity of emergencies and comprehensive disasters,provided a reliable guarantee for disaster prevention and reduction,and provided a reference for the construction of current and future early warning release system and capacity improvement project.
基金supported by the National Natural Science Foundation of China(22288102,22035007,and 22122815)。
文摘The mixing process plays a pivotal role in the design,optimization,and scale-up of chemical reactors.For most chemical reactions,achieving uniform and rapid contact between reactants at the molecular level is crucial.Mixing intensification encompasses innovative methods and tools that address the limitations of inadequate mixing within reactors,enabling efficient reaction scaling and boosting the productivity of industrial processes.This review provides a concise introduction to the fundamentals of multiphase mixing,followed by case studies highlighting the application of mixing intensification in the production of energy-storage materials,advanced optical materials,and nanopesticides.These examples illustrate the significance of theoretical analysis in informing and advancing engineering practices within the chemical industry.We also explore the challenges and opportunities in this field,offering insights based on our current understanding.
基金Guangdong Major Project of Basic and Applied Basic Research(2020B0301030004)National Natural Science Foundation of China(41875114)Science and Technology Commission of Shanghai Municipality,China(23DZ1204703)。
文摘The rapid intensification(RI)magnitude of tropical cyclones(TCs)over the western North Pacific(WNP)exhibits significant interannual variability and is influenced by multiple factors across various scales.These factors primarily include:interannual factors—sea surface temperature(SST)in key regions of the WNP,eastern Indian Ocean SST,El Niño-Southern Oscillation(ENSO),South Pacific Subtropical Dipole(SPSD),and western Pacific teleconnection;decadal factors—Atlantic Multidecadal Oscillation(AMO)and Pacific Decadal Oscillation(PDO);and longer-term factor—global warming.This study systematically analyzes these factors and their potential impacts,quantitatively assessing their relative importance.A statistical prediction model for the WNP TC-RI magnitude is developed based on ridge regression methods.The results indicate that the influence of these factors on the RI magnitude is closely related to the large-scale thermodynamic and dynamic conditions.Among them,the SPSD plays the most critical role in the interannual variability of the RI magnitude,followed by global warming and the AMO.Further analysis reveals that the statistical prediction model based on multiple factors demonstrates good predictive skill for the interannual variability of the TC RI magnitude.
基金The National Natural Science Foundation of China under contract Nos 42275024,42405063,42575023,W2441014,and 42176001the Guangdong Basic and Applied Basic Research Foundation under contract Nos 2023B1515020009 and 2024B1515040024+1 种基金the Special Fund of the South China Sea Institute of Oceanology,Chinese Academy of Sciences,under contract Nos SCSIO2023QY01 and SCSIO2023HC07the Science and Technology Planning Project of Guangzhou under contract No.2024A04J6275.
文摘Typhoon Hinnamnor(2022)was the only tropical cyclone(TC)during 1982-2023 that maintained strong or higher intensity north of 25°N while undergoing two rapid intensification(RI)events under marine heatwave(MHW)conditions.These RI events differed significantly in both duration and intensification rates.This study investigated the role of MHWs in modulating these events,with a focus on variations in ocean stratification and atmospheric circulation.The results revealed that the first RI lasted 18 h,during which typhoon Hinnamnor intensified from a strong tropical storm to a super typhoon,which was driven primarily by oceanic thermal conditions.The anomalous MHW deepened the warm subsurface waters,leading to sustained accumulation of upper ocean heat content(UOHC),which fueled the RI.The cyclone’s rapid movement and moderate intensity helped preserve the abnormally thick barrier layer(BL),which maintained the UOHC via a subsurface“heat pump”effect,thus supporting continued intensification.In contrast,the second RI lasted only 6 h and involved a one-category intensification from a strong typhoon to a super typhoon,influenced by both oceanic and atmospheric factors.The prolonged and intensified MHW maintained a high UOHC,while strong upper-level divergence,increased mid-level moisture and low-level convergence enhanced deep convection,triggering the RI.However,a shallow mixed layer confined warm anomalies to the surface,whereas the cyclone’s slower movement,stronger winds,and thinner BL induced cold water upwelling.This“cold suction”effect depleted the UOHC,prematurely terminating the RI.These findings highlight the complex interplay between oceanic and atmospheric factors in shaping TC intensification under MHW conditions,emphasizing the critical role of upper ocean stratification in improving TC intensity forecasts.
基金supported by the National Natural Science Foundation of China[grant numbers 42192553 and 41922036]the Fundamental Research Funds for the Central Universities–Cemac“GeoX”Interdisciplinary Program[grant number 020714380207]。
文摘While steady improvements have been achieved for the track forecasts of typhoons,there has been a lack of improvement for intensity forecasts.One challenge for intensity forecasts is to capture the rapid intensification(RI),whose nonlinear characteristics impose great difficulties for numerical models.The ensemble sensitivity analysis(ESA)method is used here to analyze the initial conditions that contribute to typhoon intensity forecasts,especially with RI.Six RI processes from five typhoons(Chaba,Haima,Meranti,Sarika,and Songda)in 2016,are applied with ESA,which also gives a composite initial condition that favors subsequent RI.Results from individual cases have generally similar patterns of ESA,but with different magnitudes,when various cumulus parameterization schemes are applied.To draw the initial conditions with statistical significance,sample-mean azimuthal components of ESA are obtained.Results of the composite sensitivity show that typhoons that experience RI in 24 h favor enhanced primary circulation from low to high levels,intensified secondary circulation with increased radial inflow at lower levels and increased radial outflow at upper levels,a prominent warm core at around 300 hPa,and increased humidity at low levels.As the forecast lead time increases,the patterns of ESA are retained,while the sensitivity magnitudes decay.Given the general and quantitative composite sensitivity along with associated uncertainties for different cumulus parameterization schemes,appropriate sampling of the composite sensitivity in numerical models could be beneficial to capturing the RI and improving the forecasting of typhoon intensity.
基金sponsored by the funding of the National Natural Science Foundation of China(Grant Nos.42075011,42192552,42005025,and 42075035).
文摘The synoptic process of a super Arctic cyclone in August 2016(AC16)is investigated based on the Weather Research and Forecasting(WRF)model,and the key factors affecting the rapid intensification(RI)of AC16 and their relative contributions are analyzed by diagnosing a new surface pressure tendency equation(SPTE).The major physical mechanisms behind the two RI stages of AC16 are revealed.The trajectory,intensity changes,and structural characteristics of AC16 are well simulated by the WRF model.A diagnosis based on the SPTE promisingly reproduces the two RI stages of AC16.The leading factor that influenced the intensity of AC16 was identified to be the air-column potential temperature tendency,while the pressure change at the upper boundary had less of an impact.Further analysis reveals that the horizontal potential temperature advection was the decisive factor in a warming of the air column.Specifically,the upper-level warm advection generated by the strong wind field of the upper-level jet played a dominant role in warming the air column,which caused the initial RI of AC16.The AC16 movement into a strong potential temperature gradient generated by tropopause polar vortices increased the upper-level warm advection,which warmed the air column and thereby induced the second RI of AC16.However,the net effect of vertical potential temperature advection and latent heating,as well as radiation processes,caused a cooling of the air column and thereby negatively contributed to the RI of AC16.
