A modified three-dimensional turbulence parameterization scheme,implemented by replacing the conventional eddydiffusivity formulation with the H-gradient model,has shown good performance in representing the subgrid-sc...A modified three-dimensional turbulence parameterization scheme,implemented by replacing the conventional eddydiffusivity formulation with the H-gradient model,has shown good performance in representing the subgrid-scale(SGS)turbulent fluxes associated with convective clouds in idealized tropical cyclone(TC)simulations.To evaluate the capability of the modified scheme in simulating real TCs,two sets of simulations of TC Soudelor(2015),one with the modified scheme and the other with the original scheme,are conducted.Comparisons with observations and coarse-grained results from large eddy simulation benchmarks demonstrate that the modified scheme improves the forecasting of the intensity and structure,as well as the SGS turbulent fluxes of Soudelor.Using the modified turbulence scheme,a TC with stronger intensity,smaller size,a shallower but stronger inflow layer,and a more intense but less inclined convective updraft is simulated.The rapid intensification process and secondary eyewall features can also be captured better by the modified scheme.By analyzing the mechanism by which turbulent transport impacts the intensity and structure of TCs,it is shown that accurately representing the turbulent transport associated with convective clouds above the planetary boundary layer helps to initiate the TC spin-up process.展开更多
GENERAL Asian Pacific Journal of Tropical Biomedicine is sponsored by Hainan Medical University Journal Publisher,and aims to set up an acdemic communicating platform for scientists all over the world on tropical biom...GENERAL Asian Pacific Journal of Tropical Biomedicine is sponsored by Hainan Medical University Journal Publisher,and aims to set up an acdemic communicating platform for scientists all over the world on tropical biomedicine and related sciences.The Journal invites concise reports of original research in all areas of tropical biomedicine and related fields,both experimental and clinical,including modern,traditional and epidemiological studies,from any part of the world.Review articles based primarily on authors'own research on internationally important topics will be accepted.Short communications and letters to the editor are also welcome.Authors are requested to submit a covering letter indicating that their manuscript represents original unpublished material that has not been and will not be published elsewhere(if accepted).This restriction does not apply to results published as abstracts of communications,letters to the editor or as preliminary reports.By submitting a manuscript the authors warrant that they have obtained permission to use any copyrighted or previously published materials.展开更多
Asian Pacific Journal of Tropical Biomedicine is sponsored by Hainan Medical University Journal Publisher,and aims to set up an acdemic communicating platform for scientists all over the world on tropical biomedicine ...Asian Pacific Journal of Tropical Biomedicine is sponsored by Hainan Medical University Journal Publisher,and aims to set up an acdemic communicating platform for scientists all over the world on tropical biomedicine and related sciences.The Journal invites concise reports of original research in all areas of tropical biomedicine and related fields,both experimental and clinical,including modern,traditional and epidemiological studies,from any part of the world.Review articles based primarily on authors'own research on internationally important topics will be accepted.Short communications and letters to the editor are also welcome.Authors are requested to submit a covering letter indicating that their manuscript represents original unpublished material that has not been and will not be published elsewhere(if accepted).This restriction does not apply to results published as abstracts of communications,letters to the editor or as preliminary reports.By submitting a manuscript the authors warrant that they have obtained permission to use any copyrighted or previously published materials.展开更多
GENERAL Asian Pacific Journal of Tropical Biomedicine is sponsored by Hainan Medical University Journal Publisher,and aims to set up an acdemic communicating platform for scientists all over the world on tropical biom...GENERAL Asian Pacific Journal of Tropical Biomedicine is sponsored by Hainan Medical University Journal Publisher,and aims to set up an acdemic communicating platform for scientists all over the world on tropical biomedicine and related sciences.The Journal invites concise reports of original research in all areas of tropical biomedicine and related fields,both experimental and clinical,including modern,traditional and epidemiological studies,from any part of the world.Review articles based primarily on authors'own research on internationally important topics will be accepted.Short communications and letters to the editor are also welcome.Authors are requested to submit a covering letter indicating that their manuscript represents original unpublished material that has not been and will not be published elsewhere(if accepted).This restriction does not apply to results published as abstracts of communications,letters to the editor or as preliminary reports.By submitting a manuscript the authors warrant that they have obtained permission to use any copyrighted or previously published materials.展开更多
In this study,numerical experiments with different initial radius of maximum wind(RMW)are performed to study the effects of tropical cyclone(TC)size combined with land-sea contrast on TC motion and low-level wind stru...In this study,numerical experiments with different initial radius of maximum wind(RMW)are performed to study the effects of tropical cyclone(TC)size combined with land-sea contrast on TC motion and low-level wind structure before landfall.By idealized numerical simulations,we found that larger TC arrived coastline earlier than smaller TC,when they started moving from the same position.This is because that the larger TCs not only accelerate earlier but also have greater movement speed than smaller TCs when they approach the coastline.The mechanism responsible for this is that the edge of large TCs reach coastline earlier,thus their movement speed accelerated earlier than small TCs,due to the asymmetries in diabatic heating and radial flow generated by the land-sea contrast.Moreover,when TCs in three experiments all affected by the land-sea contrast,the stronger asymmetries generated in larger TC,thus resulting in faster movement in larger TC.The stronger inflow in western quadrant and weaker inflow(even outflow)in eastern quadrant of larger TC deduced apparently difference in vertical motion and diabatic heating between western and eastern quadrant of TC before landfall.An analysis of potential vorticity tendency proved that the diabatic heating terms were important and considered in determining the TC landward drift because asymmetries in vertical motion and relative vorticity developed due to asymmetric flow.展开更多
Recent studies identify large uncertainties in the projections of tropical cyclone(TC)activity due to discrepancies in tropical Pacific sea surface temperature(SST)warming patterns.While observational datasets consist...Recent studies identify large uncertainties in the projections of tropical cyclone(TC)activity due to discrepancies in tropical Pacific sea surface temperature(SST)warming patterns.While observational datasets consistently reveal a La Niña-like warming pattern[0.15℃-0.25℃(10 yr)^(−1) relative cooling in the eastern equatorial Pacific],over 80%of CMIP6 models project an erroneous El Niño-like trend.These discrepancies arise from biases in cloud feedbacks,Walker circulation strength,and oceanic upwelling processes.This review examines the key mechanisms shaping observed versus modeled warming patterns,evaluates the complex link between tropical SST patterns and TC activity,and explores the feasibility of storm-resolving models for improving TC projections.We propose that pattern-conditioned TC projections using convection-permitting models,alongside physics-informed interpretations,offer a path forward in reducing uncertainties in future climate predictions.展开更多
Tropical cyclones(TCs)have profound impacts on socioeconomic conditions and pose substantial risks to lives and property.However,it is still unclear whether the multitimescale changes in TC activity over the past 2000...Tropical cyclones(TCs)have profound impacts on socioeconomic conditions and pose substantial risks to lives and property.However,it is still unclear whether the multitimescale changes in TC activity over the past 2000 years in the Northwestern Pacific(NWP)were regulated by Asian dust forcing.Here,we assessed the impact of Asian dust on TC activity using observational data and reconstructed records from the northern and southern NWP.Our correlation analysis of instrumental data from 1954 to 2017 reveals no significant relationship between observed TC activity and Asian dust forcing.Furthermore,we found a meridional dipole pattern of TC variation across the NWP in observations and reconstructions.These finding challenges current explanations that are based on the synchronous changes in TC activity and Asian dust forcing.Alternatively,we propose that the Western Pacific Subtropical High(WPSH)plays a crucial role in driving these meridional dipole patterns in TC variations,as supported by observations and reconstructions.The southwestward extension of an enhanced WPSH intensifies easterly flow,steering TCs westward along its southern edge.This leads to more TC activity in the southern NWP but less in the north,and vice versa when the WPSH is weakened.With the expected strengthening of the WPSH due to global warming,it is vital to consider its impact on NWP TC activity for effective risk-mitigation strategies.展开更多
The present study employs statistical analysis to investigate the relationship between the geopotential height anomalies induced by tropical cyclones(TCs)and the meridional movement of the western Pacific subtropical ...The present study employs statistical analysis to investigate the relationship between the geopotential height anomalies induced by tropical cyclones(TCs)and the meridional movement of the western Pacific subtropical high(WPSH),as well as the mechanisms through which TCs can induce such geopotential height anomalies.Results show that TCs can cause the WPSH to move northward,and the meridional motion of the WPSH ridgeline is related with the geopotential height anomalies,which is better indicated by the relative geopotential height anomalies.In the process of TCs causing the WPSH to move northward,the TCs cause abnormal horizonal warm(cold)advection and abnormal ascending(descending)motion in the region south(north)of 40°N.Since the influence of the abnormal vertical motion is weaker,the abnormal temperature tendency eventually shows a more consistent phase distribution with the abnormal horizonal temperature advection,which is favorable for the temperature to abnormally increase near 40°N.Such an abnormal increase in temperature causes the geopotential height to abnormally increase under the static equilibrium constraint,which further changes the location of the centroid of the WPSH geopotential height,and hence the location of the WPSH ridgeline changes as well.展开更多
Based on morphology and phylogenetic analyses,a new species,Efibula candidissima,is described from Bawangling,National Park of Hainan Tropical Rainforest.The basidiomata are resupinate,waxy,snow white when fresh,white...Based on morphology and phylogenetic analyses,a new species,Efibula candidissima,is described from Bawangling,National Park of Hainan Tropical Rainforest.The basidiomata are resupinate,waxy,snow white when fresh,white to cream and soft corky to fragile when dry,with distinct snow white rhizomorph at margin.Hymenophore surface are smooth,and the clamp connections are absent.Ellipsoid to oblong-ellipsoid basidiospores measure 4.8–5.8×3.3–4μm.This species is distributed in tropical forest in southern China.展开更多
This paper investigates the impact of the model top and damping layer on the numerical simulation of tropical cyclones(TCs)and reveals the significant role of stratospheric gravity waves(SGWs).TCs can generate SGWs,wh...This paper investigates the impact of the model top and damping layer on the numerical simulation of tropical cyclones(TCs)and reveals the significant role of stratospheric gravity waves(SGWs).TCs can generate SGWs,which propagate upward and outward into the stratosphere.These SGWs can reach the damping layer,which is a consequence of the numerical scheme employed,where they can affect the tangential circulation through the dragging and forcing processes.In models with a higher top boundary,this tangential circulation develops far from the TC and has minimal direct impact on TC intensity.By comparison,in models with a lower top(e.g.,20 km),the damping layer is located just above the top of the TC.The SGW dragging in the damping layer and the consequent tangential force can thus induce ascent outside the eyewall,promote latent heat release,tilt the eyewall,and enlarge the inner-core radius.This process will reduce inner-core vorticity advection within the boundary layer,and eventually inhibits the intensification of the TC.This suggests that when the thickness of the damping layer is 5 km,the TC numerical model top height should be at least higher than 20 km to generate more accurate simulations.展开更多
Tropical cyclones(TCs)are one of the most serious types of natural disasters,and accurate TC activity predictions are key to disaster prevention and mitigation.Recently,TC track predictions have made significant progr...Tropical cyclones(TCs)are one of the most serious types of natural disasters,and accurate TC activity predictions are key to disaster prevention and mitigation.Recently,TC track predictions have made significant progress,but the ability to predict their intensity is obviously lagging behind.At present,research on TC intensity prediction takes atmospheric reanalysis data as the research object and mines the relationship between TC-related environmental factors and intensity through deep learning.However,reanalysis data are non-real-time in nature,which does not meet the requirements for operational forecasting applications.Therefore,a TC intensity prediction model named TC-Rolling is proposed,which can simultaneously extract the degree of symmetry for strong TC convective cloud and convection intensity,and fuse the deviation-angle variance with satellite images to construct the correlation between TC convection structure and intensity.For TCs'complex dynamic processes,a convolutional neural network(CNN)is used to learn their temporal and spatial features.For real-time intensity estimation,multi-task learning acts as an implicit time-series enhancement.The model is designed with a rolling strategy that aims to moderate the long-term dependent decay problem and improve accuracy for short-term intensity predictions.Since multiple tasks are correlated,the loss function of 12 h and 24 h are corrected.After testing on a sample of TCs in the Northwest Pacific,with a 4.48 kt root-mean-square error(RMSE)of 6 h intensity prediction,5.78 kt for 12 h,and 13.94 kt for 24 h,TC records from official agencies are used to assess the validity of TC-Rolling.展开更多
Spaceborne microwave instruments possess the capability of day-and-night and all-weather measurements that can penetrate clouds and fog,and directly measure tropical cyclone(TC)ocean surface winds.In this study,we est...Spaceborne microwave instruments possess the capability of day-and-night and all-weather measurements that can penetrate clouds and fog,and directly measure tropical cyclone(TC)ocean surface winds.In this study,we establish an effective methodology to estimate TC dynamic characteristic parameters(DCP),including the storm center location,intensity,radius of maximum wind(RMW)and wind structure,purely from TC ocean winds measured by multi-platform spaceborne microwave instruments.Combining measurements from active and passive sensors can provide long time series data for monitoring changes in storm DCP.Here,the evolution of the DCP for TC Freddy(2023),from its genesis to its landfall,is evaluated using data from synthetic aperture radars(SARs),as well as radiometer(RAD)and scatterometer(SCA)observations.Comparing the results to the best-track datasets for the longitudes and latitudes of the storm centers,we show that the root-mean-square errors(RMSEs)are 0.22°and 0.31°,respectively,both with a correlation of 0.99.For the detected intensity,the RMSEs are 6.8 m s^(−1) for SARs and 7.3 m s^(−1) for RADs.However,TC intensities measured by C-band SCAs are significantly underestimated,especially for wind speeds less than 50 m s^(−1).In terms of RMW and wind radii,the SARs,RADs and SCAs demonstrate good accuracy and applicability.Our investigation emphasizes the crucial role played by spaceborne microwave instruments in the study of TCs.This is helpful in monitoring,and in the future,will help improve the forecasting of TC intensities and their characteristic structures.展开更多
BACKGROUND To investigate whether seasonal differences in ambient temperature affect the incidence of early postoperative cognitive dysfunction(POCD)among elderly patients undergoing laparoscopic surgery in tropical r...BACKGROUND To investigate whether seasonal differences in ambient temperature affect the incidence of early postoperative cognitive dysfunction(POCD)among elderly patients undergoing laparoscopic surgery in tropical regions.Additionally,it explored the perioperative risk factors associated with early POCD following abdominal laparoscopic surgery.AIM To investigate the influence of seasonal differences in ambient temperature on POCD of elderly patients METHODS A total of 125 patients aged≥65 years from Hainan Province,China,who underwent laparoscopic surgery under general anesthesia with tracheal intubation,were enrolled. All patients completed the Mini-Mental State Examination one day before surgery and onpostoperative days 1, 3, and 7. A decline of ≥ 2 points from baseline was considered indicative of cognitivedysfunction. Serum levels of S100 calcium binding protein B and neuron-specific enolase were measured usingenzyme-linked immunosorbent assay at three time points: Preoperatively, immediately after extubation, and 24hours postoperatively. Perioperative clinical data were collected to identify potential risk factors for POCD.Propensity score matching (PSM) was performed (1:1, caliper = 0.03), resulting in 41 matched patient pairs betweenwinter and summer groups.RESULTSAfter PSM, baseline characteristics including age, gender, body mass index, education level, comorbidities, andsurgical variables were well balanced between groups. There were no significant differences in the incidence ofPOCD on postoperative days 1, 3, and 7 between patients undergoing laparoscopic surgery in winter vs summer.However, multivariable logistic regression revealed that surgical duration (day 1, P value = 0.049), advanced ageand elevated creatinine (day 3, P value = 0.044, P value = 0.008), and hypoalbuminemia (day 3, P value = 0.042;day7, P value = 0.015) were independently associated with early POCD.CONCLUSIONAmbient temperature differences between winter and summer in tropical regions did not significantly affect theincidence of early POCD in elderly patients undergoing laparoscopic surgery. Nonetheless, age, longer surgicalduration, elevated creatinine, and hypoalbuminemia emerged as key risk factors. These findings underscore theimportance of perioperative optimization to reduce the risk of POCD in elderly patients, regardless of seasonaltemperature variations.展开更多
GENERAL Asian Pacific Journal of Tropical Biomedicine is sponsored by Hainan Medical University Journal Publisher,and aims to set up an acdemic communicating platform for scientists all over the world on tropical biom...GENERAL Asian Pacific Journal of Tropical Biomedicine is sponsored by Hainan Medical University Journal Publisher,and aims to set up an acdemic communicating platform for scientists all over the world on tropical biomedicine and related sciences.The Journal invites concise reports of original research in all areas of tropical biomedicine and related fields,both experimental and clinical,including modern,traditional and epidemiological studies,from any part of the world.Review articles based primarily on authors'own research on internationally important topics will be accepted.Short communications and letters to the editor are also welcome.Authors are requested to submit a covering letter indicating that their manuscript represents original unpublished material that has not been and will not be published elsewhere(if accepted).展开更多
The dynamic processes responsible for the movement of tropical cyclone Khanun(2017)were studied by analyzing data from the mesoscale WRF model simulation.The simulated motion was induced by the ventilation flow of bot...The dynamic processes responsible for the movement of tropical cyclone Khanun(2017)were studied by analyzing data from the mesoscale WRF model simulation.The simulated motion was induced by the ventilation flow of both the environmentaland asymmetric rotational wind averaged over an area within a radius of 200 km from Khanun's center.The results revealed that during Khanun's intensification period,environmental wind barely changed,whereas the speed and direction of asymmetric rotational wind exhibited significant changes as Khanun's southwestward movement switched to a northwestward movement.The streamfunction analysis revealed that the change in the direction of movement was consistent with the ventilation flow of asymmetric rotational wind across Khanun's center associated with the asymmetric circulation rotation.The cyclonic circulation center rotated counterclockwise,moving from the northeast to the north before and during the rapid intensification period,and exhibited wandering behavior during this period.The rotational rate of asymmetric circulation was quantitatively estimated using the formulation based on the budget of asymmetric rotational kinetic energy.This calculation revealed that the rapid counterclockwise rotation resulted from the conversion of environmental to asymmetric rotational kinetic energy and was related to the horizontal advection of environmental tangential flow.The rotation of the asymmetric circulation displayed a wandering behavior when the dissipation term became significant.The dissipation term plus the conversion from symmetric to asymmetric rotational kinetic energy associated with the advection of symmetric tangential wind by the environmental radial wind led to a slow clockwise rotation of the asymmetric cyclonic center to the north.展开更多
Tropical cyclone activity has undergone significant changes under the impact of global warming since the 20th century.However,the characteristic and trend changes of landfalling tropical cyclones over China still need...Tropical cyclone activity has undergone significant changes under the impact of global warming since the 20th century.However,the characteristic and trend changes of landfalling tropical cyclones over China still need to be further clarified.The study conducted an analysis of the spatiotemporal characteristics and trends of landfalling tropical cyclones over China from 1949 to 2022 using the dataset of the best tracks of tropical cyclones from the China Meteorological Administration.Additionally,we explored the influences of ENSO and the Pacific Decadal Oscillation(PDO)on landfalling tropical cyclone activities.The results indicate that:(1)The annual average number of landfalling tropical cyclones over China is approximately 8.85,showing a significant decreasing trend,and the decreasing range becomes larger with lower latitude overall.However,both the proportion of landfalling tropical cyclones to the total number and the percentage of higher intensity tropical cyclones increase.(2)The landfall locations of tropical cyclones in China are mainly concentrated between 18°N and 26°N,accounting for approximately 88.2%of the total,and the landfall frequency shows a sharp decline in the regions north of 30°N.The central landfall location of tropical cyclones has shifted significantly northwestward,moving closer to China.Compared to 1949–1969,the central genesis location from 2010 to 2022 shifted 4.5°westward and 2.0°northward.(3)There is a correlation between ENSO and the genesis frequency variation of tropical cyclones in the Northwest Pacific and landfalling over China.El Ni?o promotes the genesis of strong tropical cyclones and leads to a more southeastern bias in the genesis location of landfalling tropical cyclones,while La Ni?a has an opposite effect.The PDO also affects the tropical cyclones to a certain extent.During the PDO warm phase,the genesis position of tropical cyclones is westward and the number is smaller than that in the cold phase.This study further clarifies the changing trends and characteristics of landfalling tropical cyclones over China since 1949.It also highlights the impacts of ENSO and the PDO on tropical cyclone activities.The findings can serve as a scientific basis for conducting simulations and assessments of tropical cyclones and for disaster prevention and mitigation efforts.展开更多
The study determined the carbon stocks and litter nutrient concentration in tropical forests along the ecological gradient in Kenya.This could help understand the potential of mitigating climate change using tropical ...The study determined the carbon stocks and litter nutrient concentration in tropical forests along the ecological gradient in Kenya.This could help understand the potential of mitigating climate change using tropical forest ecosystems in different ecological zones,which are being affected by climate change to a level that they are becoming carbon sources instead of sinks.Stratified sampling technique was used to categorize tropical forests into rain,moist deciduous and dry zone forests depending on the average annual rainfall received.Simple random sampling technique was used to select three tropical forests in each category.Modified consistent sampling technique was used to develop 10 main 20 m×100 m plots in each forest,with 202 m×50 m sub-plots in each plot.Systematic random sampling technique was used in selecting 10 sub-plots from each main plot for inventory study.Non-destructive approach based on allometric equations using trees’diameter at breast height(DBH),total height and species’wood specific gravity were used in estimating tree carbon stock in each forest.Soil organic carbon(SOC)and litter nutrient concentration(total phosphorus and nitrogen)were determined in each forest based on standard laboratory procedures.The results indicated that,whilst trees in rain forests recorded a significantly higher(p<0.001)DBH(20.36 cm)and total tree height(12.1 m),trees in dry zone forests recorded a significantly higher(p<0.001)specific gravity(0.67 kg m^(−3)).Dry zone tropical forests stored a significantly lower amount of total tree carbon of 73 Mg ha^(−1),compared to tropical rain forests(439.5 Mg ha^(−1))and moist deciduous tropical forests(449 Mg ha^(−1)).The SOC content was significantly higher in tropical rainforests(3.9%),compared to soils from moist deciduous(2.9%)and dry zone forests(1.8%).While litter from tropical rain forests recorded a significantly higher amount of total nitrogen(3.4%),litter from dry zone forests recorded a significantly higher concentration of total phosphorus(0.27%).In conclusion,ecological gradient that is dictated by the prevailing temperatures and precipitation affects the tropical forests carbon stock potential and litter nutrient concentration.This implies that,the changing climate is having a serious implication on the ecosystem services such as carbon stock and nutrients cycling in tropical forests.展开更多
In this study, a variety of high-resolution satellite data were used to analyze the similarities and differences in horizontal and vertical cloud microphysical characteristics of 11 tropical cyclones(TCs) in three dif...In this study, a variety of high-resolution satellite data were used to analyze the similarities and differences in horizontal and vertical cloud microphysical characteristics of 11 tropical cyclones(TCs) in three different ocean basins.The results show that for the 11 TCs in different ocean basins, no matter in what season the TCs were generated when they reached or approached Category 4, their melting layers were all distributed in the vertical direction at the height of about 5 km. The high value of ice water contents in the vertical direction of 11 TCs all reach or approach about 2000 g cm^(–3).The total attenuated scattering coefficient at 532 nm, TAB-532, can successfully characterize the distribution of areas with high ice water content when the vertical distribution was concentrated near 0.1 km^(–1)sr^(–1), possibly because the diameter distribution of the corresponding range of aerosol particles had a more favorable effect on the formation of ice nuclei,indicating that aerosols had a significant impact on the ice-phase processes and characteristics. Moreover, by analyzing the horizontal cloud water content, the distribution analysis of cloud water path(CWP) and ice water path(IWP) shows that when the sea surface temperature was at a relatively high value, and the vertical wind shear was relatively small, the CWP and the IWP can reach a relatively high value, which also proves the importance of environmental field factors on the influence of TC cloud microphysical characteristics.展开更多
Volume models for the long-term management of Okomu National Park in Nigeria are not available. The main challenge in assessing forest resources is the lack of accurate, species-specific baseline data and updated info...Volume models for the long-term management of Okomu National Park in Nigeria are not available. The main challenge in assessing forest resources is the lack of accurate, species-specific baseline data and updated information on volume models, growth rates, and disturbances. This complicates the development of effective management plans. This study addresses this by modelling tree volume using temporary sample plots laid out using a systematic line transect method Data was collected from 16 40 m × 50 m plots using a Spiegel relascope. DBH, top, middle, and base diameters, and overall height were measured for trees ≤ 10 cm DBH. Newton’s formula calculated volume of each tree, and per hectare estimates generated. The results showed an average of 132 trees per hectare. Population densities of individual species ranged from 1–11/ha, indicating a low density. Strombosia pustulata was the most abundant species. For coefficients that form the basis for species grouping, species-specific volume equations were developed and grouped into three clusters. Regression equations were fitted and selected based on specific statistical metrics. The volume models showed that generalized (V_(i)=b_(0)+b_(1)(D_(i)^(2)H_(i))+ε_(i)) functions, based on the statistical metrics, performed more effectively. The generalized functions exhibited superior performance, evidenced by the uniform residual plot distribution for DBH^(2)H, implying consistent experimental error and adherence to regression assumptions. A t-test at 95% confidence showed that the discrepancy between predicted and actual values was insignificant. This study indicates that the prediction models provide effective management tools for climate mitigation and determining carbon sequestration by a tropical forest.展开更多
The karst forest in southwestern China is characterized by thin soil layers,numerous fissures and holes,resulting in low soil water availability and poor water retention,making it challenging for plant growth and surv...The karst forest in southwestern China is characterized by thin soil layers,numerous fissures and holes,resulting in low soil water availability and poor water retention,making it challenging for plant growth and survival.While the relationship between plant functional traits and tree growth performance has been extensively studied,the links between tree seasonal growth and drought-tolerant traits in tree species with different leaf habit remains poorly understood.This study evaluated the associations between four-year averaged rainy season stem diameter growth rate and 17 branch and leaf traits across evergreen and deciduous species in a tropical karst forest in southwest China.The cross-species variations in tree growth rates were related to plant hydraulic traits(e.g.,vessel lumen diameter,xylem vessel density,stomatal density,and stomatal size)and leaf anatomical traits(e.g.,total leaf thickness,lower/upper epidermis thickness,and spongy thickness).The growth of evergreen trees exhibited lower hydraulic efficiency but greater drought tolerance than deciduous tree,which enabled them to maintain higher persistence under low soil water availability and consequently a relatively longer growing season.In contrast,deciduous species showed no correlation between their functional traits and growth rate.The distinct water use strategies of evergreen and deciduous trees may offer a potential explanation for their co-existence in the tropical karst forests.展开更多
基金supported by the National Key Research and Development Program of China(Grant No.2021YFC3000803)the National Natural Science Foundation of China(Grant Nos.42375149,41975133 and 42205070)the Shanghai Pujiang Program(Grant No.22PJ1415900)。
文摘A modified three-dimensional turbulence parameterization scheme,implemented by replacing the conventional eddydiffusivity formulation with the H-gradient model,has shown good performance in representing the subgrid-scale(SGS)turbulent fluxes associated with convective clouds in idealized tropical cyclone(TC)simulations.To evaluate the capability of the modified scheme in simulating real TCs,two sets of simulations of TC Soudelor(2015),one with the modified scheme and the other with the original scheme,are conducted.Comparisons with observations and coarse-grained results from large eddy simulation benchmarks demonstrate that the modified scheme improves the forecasting of the intensity and structure,as well as the SGS turbulent fluxes of Soudelor.Using the modified turbulence scheme,a TC with stronger intensity,smaller size,a shallower but stronger inflow layer,and a more intense but less inclined convective updraft is simulated.The rapid intensification process and secondary eyewall features can also be captured better by the modified scheme.By analyzing the mechanism by which turbulent transport impacts the intensity and structure of TCs,it is shown that accurately representing the turbulent transport associated with convective clouds above the planetary boundary layer helps to initiate the TC spin-up process.
文摘GENERAL Asian Pacific Journal of Tropical Biomedicine is sponsored by Hainan Medical University Journal Publisher,and aims to set up an acdemic communicating platform for scientists all over the world on tropical biomedicine and related sciences.The Journal invites concise reports of original research in all areas of tropical biomedicine and related fields,both experimental and clinical,including modern,traditional and epidemiological studies,from any part of the world.Review articles based primarily on authors'own research on internationally important topics will be accepted.Short communications and letters to the editor are also welcome.Authors are requested to submit a covering letter indicating that their manuscript represents original unpublished material that has not been and will not be published elsewhere(if accepted).This restriction does not apply to results published as abstracts of communications,letters to the editor or as preliminary reports.By submitting a manuscript the authors warrant that they have obtained permission to use any copyrighted or previously published materials.
文摘Asian Pacific Journal of Tropical Biomedicine is sponsored by Hainan Medical University Journal Publisher,and aims to set up an acdemic communicating platform for scientists all over the world on tropical biomedicine and related sciences.The Journal invites concise reports of original research in all areas of tropical biomedicine and related fields,both experimental and clinical,including modern,traditional and epidemiological studies,from any part of the world.Review articles based primarily on authors'own research on internationally important topics will be accepted.Short communications and letters to the editor are also welcome.Authors are requested to submit a covering letter indicating that their manuscript represents original unpublished material that has not been and will not be published elsewhere(if accepted).This restriction does not apply to results published as abstracts of communications,letters to the editor or as preliminary reports.By submitting a manuscript the authors warrant that they have obtained permission to use any copyrighted or previously published materials.
文摘GENERAL Asian Pacific Journal of Tropical Biomedicine is sponsored by Hainan Medical University Journal Publisher,and aims to set up an acdemic communicating platform for scientists all over the world on tropical biomedicine and related sciences.The Journal invites concise reports of original research in all areas of tropical biomedicine and related fields,both experimental and clinical,including modern,traditional and epidemiological studies,from any part of the world.Review articles based primarily on authors'own research on internationally important topics will be accepted.Short communications and letters to the editor are also welcome.Authors are requested to submit a covering letter indicating that their manuscript represents original unpublished material that has not been and will not be published elsewhere(if accepted).This restriction does not apply to results published as abstracts of communications,letters to the editor or as preliminary reports.By submitting a manuscript the authors warrant that they have obtained permission to use any copyrighted or previously published materials.
基金The National Natural Science Foundation of China under contract Nos 42175011,42192554,and 42305007.
文摘In this study,numerical experiments with different initial radius of maximum wind(RMW)are performed to study the effects of tropical cyclone(TC)size combined with land-sea contrast on TC motion and low-level wind structure before landfall.By idealized numerical simulations,we found that larger TC arrived coastline earlier than smaller TC,when they started moving from the same position.This is because that the larger TCs not only accelerate earlier but also have greater movement speed than smaller TCs when they approach the coastline.The mechanism responsible for this is that the edge of large TCs reach coastline earlier,thus their movement speed accelerated earlier than small TCs,due to the asymmetries in diabatic heating and radial flow generated by the land-sea contrast.Moreover,when TCs in three experiments all affected by the land-sea contrast,the stronger asymmetries generated in larger TC,thus resulting in faster movement in larger TC.The stronger inflow in western quadrant and weaker inflow(even outflow)in eastern quadrant of larger TC deduced apparently difference in vertical motion and diabatic heating between western and eastern quadrant of TC before landfall.An analysis of potential vorticity tendency proved that the diabatic heating terms were important and considered in determining the TC landward drift because asymmetries in vertical motion and relative vorticity developed due to asymmetric flow.
基金supported partly by the AORI visiting professorship programsupported in part by a Moonshot R&D grant(Grant No.JPMJMS2282-02)from the Japan Science and Technology Agency+1 种基金the JSPS Core-to-Core Program,“International Core-to-Core Project on Global Storm Resolving Analysis”(Grant No.JPJSCCA20220001)JSPS KAKENHI(Grant Nos.20B202,20H05728,and 24K00703)。
文摘Recent studies identify large uncertainties in the projections of tropical cyclone(TC)activity due to discrepancies in tropical Pacific sea surface temperature(SST)warming patterns.While observational datasets consistently reveal a La Niña-like warming pattern[0.15℃-0.25℃(10 yr)^(−1) relative cooling in the eastern equatorial Pacific],over 80%of CMIP6 models project an erroneous El Niño-like trend.These discrepancies arise from biases in cloud feedbacks,Walker circulation strength,and oceanic upwelling processes.This review examines the key mechanisms shaping observed versus modeled warming patterns,evaluates the complex link between tropical SST patterns and TC activity,and explores the feasibility of storm-resolving models for improving TC projections.We propose that pattern-conditioned TC projections using convection-permitting models,alongside physics-informed interpretations,offer a path forward in reducing uncertainties in future climate predictions.
基金National Natural Science Foundation of China,No.42225105,No.42201176National Natural Science Foundation of China Basic Science Center for Tibetan Plateau Earth System Project(NSFC BSCTPES Project),No.41988101。
文摘Tropical cyclones(TCs)have profound impacts on socioeconomic conditions and pose substantial risks to lives and property.However,it is still unclear whether the multitimescale changes in TC activity over the past 2000 years in the Northwestern Pacific(NWP)were regulated by Asian dust forcing.Here,we assessed the impact of Asian dust on TC activity using observational data and reconstructed records from the northern and southern NWP.Our correlation analysis of instrumental data from 1954 to 2017 reveals no significant relationship between observed TC activity and Asian dust forcing.Furthermore,we found a meridional dipole pattern of TC variation across the NWP in observations and reconstructions.These finding challenges current explanations that are based on the synchronous changes in TC activity and Asian dust forcing.Alternatively,we propose that the Western Pacific Subtropical High(WPSH)plays a crucial role in driving these meridional dipole patterns in TC variations,as supported by observations and reconstructions.The southwestward extension of an enhanced WPSH intensifies easterly flow,steering TCs westward along its southern edge.This leads to more TC activity in the southern NWP but less in the north,and vice versa when the WPSH is weakened.With the expected strengthening of the WPSH due to global warming,it is vital to consider its impact on NWP TC activity for effective risk-mitigation strategies.
基金sponsored by the National Natural Science Foundation of China[grant number 42305011]。
文摘The present study employs statistical analysis to investigate the relationship between the geopotential height anomalies induced by tropical cyclones(TCs)and the meridional movement of the western Pacific subtropical high(WPSH),as well as the mechanisms through which TCs can induce such geopotential height anomalies.Results show that TCs can cause the WPSH to move northward,and the meridional motion of the WPSH ridgeline is related with the geopotential height anomalies,which is better indicated by the relative geopotential height anomalies.In the process of TCs causing the WPSH to move northward,the TCs cause abnormal horizonal warm(cold)advection and abnormal ascending(descending)motion in the region south(north)of 40°N.Since the influence of the abnormal vertical motion is weaker,the abnormal temperature tendency eventually shows a more consistent phase distribution with the abnormal horizonal temperature advection,which is favorable for the temperature to abnormally increase near 40°N.Such an abnormal increase in temperature causes the geopotential height to abnormally increase under the static equilibrium constraint,which further changes the location of the centroid of the WPSH geopotential height,and hence the location of the WPSH ridgeline changes as well.
基金supported by the Hainan Institute of National Park(KY-24ZK02)the Key Research and Development Program Project of Hainan Province,China(ZDYF2023RDYL01)+1 种基金the Postdoctoral Fellowship Program(Grade C)of China Postdoctoral Science Foundation(GZC20230254)the National Natural Science Foundation of China(32270011).
文摘Based on morphology and phylogenetic analyses,a new species,Efibula candidissima,is described from Bawangling,National Park of Hainan Tropical Rainforest.The basidiomata are resupinate,waxy,snow white when fresh,white to cream and soft corky to fragile when dry,with distinct snow white rhizomorph at margin.Hymenophore surface are smooth,and the clamp connections are absent.Ellipsoid to oblong-ellipsoid basidiospores measure 4.8–5.8×3.3–4μm.This species is distributed in tropical forest in southern China.
基金supported by the National Natural Science Foundation of China(Grant Nos.42475016,42192555 and 42305085)the China Postdoctoral Science Foundation(Grant No.2023M741615)the 2023 Graduate Research Innovation Project of Hunan Province(Grant No.CX20230011)。
文摘This paper investigates the impact of the model top and damping layer on the numerical simulation of tropical cyclones(TCs)and reveals the significant role of stratospheric gravity waves(SGWs).TCs can generate SGWs,which propagate upward and outward into the stratosphere.These SGWs can reach the damping layer,which is a consequence of the numerical scheme employed,where they can affect the tangential circulation through the dragging and forcing processes.In models with a higher top boundary,this tangential circulation develops far from the TC and has minimal direct impact on TC intensity.By comparison,in models with a lower top(e.g.,20 km),the damping layer is located just above the top of the TC.The SGW dragging in the damping layer and the consequent tangential force can thus induce ascent outside the eyewall,promote latent heat release,tilt the eyewall,and enlarge the inner-core radius.This process will reduce inner-core vorticity advection within the boundary layer,and eventually inhibits the intensification of the TC.This suggests that when the thickness of the damping layer is 5 km,the TC numerical model top height should be at least higher than 20 km to generate more accurate simulations.
基金jointly supported by the National Natural Science Foundation of China(Grant Nos.42075138 and 42375147)the Program on Key Basic Research Project of Jiangsu(Grant No.BE2023829)。
文摘Tropical cyclones(TCs)are one of the most serious types of natural disasters,and accurate TC activity predictions are key to disaster prevention and mitigation.Recently,TC track predictions have made significant progress,but the ability to predict their intensity is obviously lagging behind.At present,research on TC intensity prediction takes atmospheric reanalysis data as the research object and mines the relationship between TC-related environmental factors and intensity through deep learning.However,reanalysis data are non-real-time in nature,which does not meet the requirements for operational forecasting applications.Therefore,a TC intensity prediction model named TC-Rolling is proposed,which can simultaneously extract the degree of symmetry for strong TC convective cloud and convection intensity,and fuse the deviation-angle variance with satellite images to construct the correlation between TC convection structure and intensity.For TCs'complex dynamic processes,a convolutional neural network(CNN)is used to learn their temporal and spatial features.For real-time intensity estimation,multi-task learning acts as an implicit time-series enhancement.The model is designed with a rolling strategy that aims to moderate the long-term dependent decay problem and improve accuracy for short-term intensity predictions.Since multiple tasks are correlated,the loss function of 12 h and 24 h are corrected.After testing on a sample of TCs in the Northwest Pacific,with a 4.48 kt root-mean-square error(RMSE)of 6 h intensity prediction,5.78 kt for 12 h,and 13.94 kt for 24 h,TC records from official agencies are used to assess the validity of TC-Rolling.
基金supported by the Zhejiang Provincial Natural Science Foundation of China (Grant Nos. LZJMZ25D050008 and LQ21D060001)the National Natural Science Foundation of China (Grant No. 42305153)+4 种基金the East China Meteorological Science and Technology Collaborative Innovation Foundation Cooperation Project (Grant No. QYHZ202307)the Zhejiang Meteorological Science and Technology Plan Project (Grant Nos. 2021YB07, 2022ZD06 and 2023YB06)the Youth Innovation Team Fund of the China Meteorological Administration (Grant No.CMA2023QN12)support of the Canadian program “Transforming Climate Action” led by Dalhousie University in Canadathe Canadian Space Agency (CSA) projects “Ocean surface features related to aggregation of North Atlantic Right Whales (NARWs)” and “Fine resolution classification of sea ice from the RADARSAT Constellation Mission (RCM)”
文摘Spaceborne microwave instruments possess the capability of day-and-night and all-weather measurements that can penetrate clouds and fog,and directly measure tropical cyclone(TC)ocean surface winds.In this study,we establish an effective methodology to estimate TC dynamic characteristic parameters(DCP),including the storm center location,intensity,radius of maximum wind(RMW)and wind structure,purely from TC ocean winds measured by multi-platform spaceborne microwave instruments.Combining measurements from active and passive sensors can provide long time series data for monitoring changes in storm DCP.Here,the evolution of the DCP for TC Freddy(2023),from its genesis to its landfall,is evaluated using data from synthetic aperture radars(SARs),as well as radiometer(RAD)and scatterometer(SCA)observations.Comparing the results to the best-track datasets for the longitudes and latitudes of the storm centers,we show that the root-mean-square errors(RMSEs)are 0.22°and 0.31°,respectively,both with a correlation of 0.99.For the detected intensity,the RMSEs are 6.8 m s^(−1) for SARs and 7.3 m s^(−1) for RADs.However,TC intensities measured by C-band SCAs are significantly underestimated,especially for wind speeds less than 50 m s^(−1).In terms of RMW and wind radii,the SARs,RADs and SCAs demonstrate good accuracy and applicability.Our investigation emphasizes the crucial role played by spaceborne microwave instruments in the study of TCs.This is helpful in monitoring,and in the future,will help improve the forecasting of TC intensities and their characteristic structures.
文摘BACKGROUND To investigate whether seasonal differences in ambient temperature affect the incidence of early postoperative cognitive dysfunction(POCD)among elderly patients undergoing laparoscopic surgery in tropical regions.Additionally,it explored the perioperative risk factors associated with early POCD following abdominal laparoscopic surgery.AIM To investigate the influence of seasonal differences in ambient temperature on POCD of elderly patients METHODS A total of 125 patients aged≥65 years from Hainan Province,China,who underwent laparoscopic surgery under general anesthesia with tracheal intubation,were enrolled. All patients completed the Mini-Mental State Examination one day before surgery and onpostoperative days 1, 3, and 7. A decline of ≥ 2 points from baseline was considered indicative of cognitivedysfunction. Serum levels of S100 calcium binding protein B and neuron-specific enolase were measured usingenzyme-linked immunosorbent assay at three time points: Preoperatively, immediately after extubation, and 24hours postoperatively. Perioperative clinical data were collected to identify potential risk factors for POCD.Propensity score matching (PSM) was performed (1:1, caliper = 0.03), resulting in 41 matched patient pairs betweenwinter and summer groups.RESULTSAfter PSM, baseline characteristics including age, gender, body mass index, education level, comorbidities, andsurgical variables were well balanced between groups. There were no significant differences in the incidence ofPOCD on postoperative days 1, 3, and 7 between patients undergoing laparoscopic surgery in winter vs summer.However, multivariable logistic regression revealed that surgical duration (day 1, P value = 0.049), advanced ageand elevated creatinine (day 3, P value = 0.044, P value = 0.008), and hypoalbuminemia (day 3, P value = 0.042;day7, P value = 0.015) were independently associated with early POCD.CONCLUSIONAmbient temperature differences between winter and summer in tropical regions did not significantly affect theincidence of early POCD in elderly patients undergoing laparoscopic surgery. Nonetheless, age, longer surgicalduration, elevated creatinine, and hypoalbuminemia emerged as key risk factors. These findings underscore theimportance of perioperative optimization to reduce the risk of POCD in elderly patients, regardless of seasonaltemperature variations.
文摘GENERAL Asian Pacific Journal of Tropical Biomedicine is sponsored by Hainan Medical University Journal Publisher,and aims to set up an acdemic communicating platform for scientists all over the world on tropical biomedicine and related sciences.The Journal invites concise reports of original research in all areas of tropical biomedicine and related fields,both experimental and clinical,including modern,traditional and epidemiological studies,from any part of the world.Review articles based primarily on authors'own research on internationally important topics will be accepted.Short communications and letters to the editor are also welcome.Authors are requested to submit a covering letter indicating that their manuscript represents original unpublished material that has not been and will not be published elsewhere(if accepted).
基金supported by the National Natural Science Foundation of China(Grant No.41930967)。
文摘The dynamic processes responsible for the movement of tropical cyclone Khanun(2017)were studied by analyzing data from the mesoscale WRF model simulation.The simulated motion was induced by the ventilation flow of both the environmentaland asymmetric rotational wind averaged over an area within a radius of 200 km from Khanun's center.The results revealed that during Khanun's intensification period,environmental wind barely changed,whereas the speed and direction of asymmetric rotational wind exhibited significant changes as Khanun's southwestward movement switched to a northwestward movement.The streamfunction analysis revealed that the change in the direction of movement was consistent with the ventilation flow of asymmetric rotational wind across Khanun's center associated with the asymmetric circulation rotation.The cyclonic circulation center rotated counterclockwise,moving from the northeast to the north before and during the rapid intensification period,and exhibited wandering behavior during this period.The rotational rate of asymmetric circulation was quantitatively estimated using the formulation based on the budget of asymmetric rotational kinetic energy.This calculation revealed that the rapid counterclockwise rotation resulted from the conversion of environmental to asymmetric rotational kinetic energy and was related to the horizontal advection of environmental tangential flow.The rotation of the asymmetric circulation displayed a wandering behavior when the dissipation term became significant.The dissipation term plus the conversion from symmetric to asymmetric rotational kinetic energy associated with the advection of symmetric tangential wind by the environmental radial wind led to a slow clockwise rotation of the asymmetric cyclonic center to the north.
基金Young Taishan Scholars Program of Shandong Province,No.tsqn202103065National Natural Science Foundation of China,No.42371084。
文摘Tropical cyclone activity has undergone significant changes under the impact of global warming since the 20th century.However,the characteristic and trend changes of landfalling tropical cyclones over China still need to be further clarified.The study conducted an analysis of the spatiotemporal characteristics and trends of landfalling tropical cyclones over China from 1949 to 2022 using the dataset of the best tracks of tropical cyclones from the China Meteorological Administration.Additionally,we explored the influences of ENSO and the Pacific Decadal Oscillation(PDO)on landfalling tropical cyclone activities.The results indicate that:(1)The annual average number of landfalling tropical cyclones over China is approximately 8.85,showing a significant decreasing trend,and the decreasing range becomes larger with lower latitude overall.However,both the proportion of landfalling tropical cyclones to the total number and the percentage of higher intensity tropical cyclones increase.(2)The landfall locations of tropical cyclones in China are mainly concentrated between 18°N and 26°N,accounting for approximately 88.2%of the total,and the landfall frequency shows a sharp decline in the regions north of 30°N.The central landfall location of tropical cyclones has shifted significantly northwestward,moving closer to China.Compared to 1949–1969,the central genesis location from 2010 to 2022 shifted 4.5°westward and 2.0°northward.(3)There is a correlation between ENSO and the genesis frequency variation of tropical cyclones in the Northwest Pacific and landfalling over China.El Ni?o promotes the genesis of strong tropical cyclones and leads to a more southeastern bias in the genesis location of landfalling tropical cyclones,while La Ni?a has an opposite effect.The PDO also affects the tropical cyclones to a certain extent.During the PDO warm phase,the genesis position of tropical cyclones is westward and the number is smaller than that in the cold phase.This study further clarifies the changing trends and characteristics of landfalling tropical cyclones over China since 1949.It also highlights the impacts of ENSO and the PDO on tropical cyclone activities.The findings can serve as a scientific basis for conducting simulations and assessments of tropical cyclones and for disaster prevention and mitigation efforts.
基金funded by the Kenya National Research Fund(NRF-Kenya,2018).
文摘The study determined the carbon stocks and litter nutrient concentration in tropical forests along the ecological gradient in Kenya.This could help understand the potential of mitigating climate change using tropical forest ecosystems in different ecological zones,which are being affected by climate change to a level that they are becoming carbon sources instead of sinks.Stratified sampling technique was used to categorize tropical forests into rain,moist deciduous and dry zone forests depending on the average annual rainfall received.Simple random sampling technique was used to select three tropical forests in each category.Modified consistent sampling technique was used to develop 10 main 20 m×100 m plots in each forest,with 202 m×50 m sub-plots in each plot.Systematic random sampling technique was used in selecting 10 sub-plots from each main plot for inventory study.Non-destructive approach based on allometric equations using trees’diameter at breast height(DBH),total height and species’wood specific gravity were used in estimating tree carbon stock in each forest.Soil organic carbon(SOC)and litter nutrient concentration(total phosphorus and nitrogen)were determined in each forest based on standard laboratory procedures.The results indicated that,whilst trees in rain forests recorded a significantly higher(p<0.001)DBH(20.36 cm)and total tree height(12.1 m),trees in dry zone forests recorded a significantly higher(p<0.001)specific gravity(0.67 kg m^(−3)).Dry zone tropical forests stored a significantly lower amount of total tree carbon of 73 Mg ha^(−1),compared to tropical rain forests(439.5 Mg ha^(−1))and moist deciduous tropical forests(449 Mg ha^(−1)).The SOC content was significantly higher in tropical rainforests(3.9%),compared to soils from moist deciduous(2.9%)and dry zone forests(1.8%).While litter from tropical rain forests recorded a significantly higher amount of total nitrogen(3.4%),litter from dry zone forests recorded a significantly higher concentration of total phosphorus(0.27%).In conclusion,ecological gradient that is dictated by the prevailing temperatures and precipitation affects the tropical forests carbon stock potential and litter nutrient concentration.This implies that,the changing climate is having a serious implication on the ecosystem services such as carbon stock and nutrients cycling in tropical forests.
基金National Natural Science Foundation of China(42192554, 42175008)Shanghai Typhoon Research Foundation(TFJJ202201)+1 种基金S&T Development Fund of CAMS (2022KJ012)Basic Research Fund of CAMS (2022Y006)。
文摘In this study, a variety of high-resolution satellite data were used to analyze the similarities and differences in horizontal and vertical cloud microphysical characteristics of 11 tropical cyclones(TCs) in three different ocean basins.The results show that for the 11 TCs in different ocean basins, no matter in what season the TCs were generated when they reached or approached Category 4, their melting layers were all distributed in the vertical direction at the height of about 5 km. The high value of ice water contents in the vertical direction of 11 TCs all reach or approach about 2000 g cm^(–3).The total attenuated scattering coefficient at 532 nm, TAB-532, can successfully characterize the distribution of areas with high ice water content when the vertical distribution was concentrated near 0.1 km^(–1)sr^(–1), possibly because the diameter distribution of the corresponding range of aerosol particles had a more favorable effect on the formation of ice nuclei,indicating that aerosols had a significant impact on the ice-phase processes and characteristics. Moreover, by analyzing the horizontal cloud water content, the distribution analysis of cloud water path(CWP) and ice water path(IWP) shows that when the sea surface temperature was at a relatively high value, and the vertical wind shear was relatively small, the CWP and the IWP can reach a relatively high value, which also proves the importance of environmental field factors on the influence of TC cloud microphysical characteristics.
文摘Volume models for the long-term management of Okomu National Park in Nigeria are not available. The main challenge in assessing forest resources is the lack of accurate, species-specific baseline data and updated information on volume models, growth rates, and disturbances. This complicates the development of effective management plans. This study addresses this by modelling tree volume using temporary sample plots laid out using a systematic line transect method Data was collected from 16 40 m × 50 m plots using a Spiegel relascope. DBH, top, middle, and base diameters, and overall height were measured for trees ≤ 10 cm DBH. Newton’s formula calculated volume of each tree, and per hectare estimates generated. The results showed an average of 132 trees per hectare. Population densities of individual species ranged from 1–11/ha, indicating a low density. Strombosia pustulata was the most abundant species. For coefficients that form the basis for species grouping, species-specific volume equations were developed and grouped into three clusters. Regression equations were fitted and selected based on specific statistical metrics. The volume models showed that generalized (V_(i)=b_(0)+b_(1)(D_(i)^(2)H_(i))+ε_(i)) functions, based on the statistical metrics, performed more effectively. The generalized functions exhibited superior performance, evidenced by the uniform residual plot distribution for DBH^(2)H, implying consistent experimental error and adherence to regression assumptions. A t-test at 95% confidence showed that the discrepancy between predicted and actual values was insignificant. This study indicates that the prediction models provide effective management tools for climate mitigation and determining carbon sequestration by a tropical forest.
基金financially funded by the National Natural Science Foundation of China(3186113307,31770533,31870591)the West Light Talent Program of the Chinese Academy of Sciences(xbzg-zdsys-202218).
文摘The karst forest in southwestern China is characterized by thin soil layers,numerous fissures and holes,resulting in low soil water availability and poor water retention,making it challenging for plant growth and survival.While the relationship between plant functional traits and tree growth performance has been extensively studied,the links between tree seasonal growth and drought-tolerant traits in tree species with different leaf habit remains poorly understood.This study evaluated the associations between four-year averaged rainy season stem diameter growth rate and 17 branch and leaf traits across evergreen and deciduous species in a tropical karst forest in southwest China.The cross-species variations in tree growth rates were related to plant hydraulic traits(e.g.,vessel lumen diameter,xylem vessel density,stomatal density,and stomatal size)and leaf anatomical traits(e.g.,total leaf thickness,lower/upper epidermis thickness,and spongy thickness).The growth of evergreen trees exhibited lower hydraulic efficiency but greater drought tolerance than deciduous tree,which enabled them to maintain higher persistence under low soil water availability and consequently a relatively longer growing season.In contrast,deciduous species showed no correlation between their functional traits and growth rate.The distinct water use strategies of evergreen and deciduous trees may offer a potential explanation for their co-existence in the tropical karst forests.
