The study of shortwave(SW) radiation and its interactions with our planet has proven critical for advancing the understanding of the Earth–atmosphere system. Here, the author shares an accessible and high-level persp...The study of shortwave(SW) radiation and its interactions with our planet has proven critical for advancing the understanding of the Earth–atmosphere system. Here, the author shares an accessible and high-level perspective on recent progress, surprises encountered, and promising future research directionsa. A brief context for the study of SW radiation is provided, after which three specific aspects are focused upon that the author considers particularly important. First, the significance of three-dimensional(3D) SW radiative effects is highlighted via impacts on surface downward SW radiation in complex cloud fields. Crucially, it is shown that probability distributions of surface radiation can only be reliably simulated when accounting for 3D effects, which has implications for various applications and next-generation atmospheric modeling. Second, the significance of the often overlooked diurnal cycle in global top-of-atmosphere upward SW radiation is underscored by quantifying the controlling properties and processes. Opportunities for improved future satellite observations of the global diurnal cycle are noted. Third, the wealth of information provided by the spectral dimension of SW radiation is demonstrated through the extraction and attribution of SW spectral signatures. It is argued that further exploration of the spectral dimension, aided by the recently launched and upcoming suite of spectrally resolved SW satellite observations, promises a new era of SW radiation research.展开更多
The infrared channels of the FY-4B advanced geosynchronous radiation imagers(AGRI) play a crucial role in temperature and humidity analyses for mesoscale numerical weather prediction, particularly in enhancing the ini...The infrared channels of the FY-4B advanced geosynchronous radiation imagers(AGRI) play a crucial role in temperature and humidity analyses for mesoscale numerical weather prediction, particularly in enhancing the initial field quality and the forecasting accuracy of the model. This study assimilated FY-4B AGRI data into the CMA-MESO model and analyzed the bias characteristics and correction methods. Analysis of the AGRI data revealed a clear diurnal variation in the bias, which was positively correlated with the solar elevation angle. However, the diurnal variation in the bias lagged behind the solar elevation angle, likely owing to temperature changes and delayed instrument responses resulting from solar radiation. To address this issue, we propose a correction method that utilizes the solar elevation angle after an optimal time shift. Using the time-shifted solar elevation angle as a predictor effectively reduces the diurnal variation in bias and significantly improves the correction effect. This approach provides theoretical support for the assimilation of FY-4B AGRI data into mesoscale numerical weather predictions, thereby enhancing the reliability of the assimilation results.展开更多
The roles of diurnal temperature in providing heat accumulation and chilling requirements for vegetation spring phenology differ.Although previous studies have established a stronger correlation between leaf onset and...The roles of diurnal temperature in providing heat accumulation and chilling requirements for vegetation spring phenology differ.Although previous studies have established a stronger correlation between leaf onset and diurnal temperature than between leaf onset and average temperature,current research on modeling spring phenology based on diurnal temperature indicators remains limited.In this study,we confirmed the start of the growing season(SOS)sensitivity to diurnal temperature and average temperature in boreal forest.The estimation of SOS was carried out by employing K-Nearest Neighbor Regression(KNR-TDN)model,Random Forest Regres-sion(RFR-TDN)model,eXtreme Gradient Boosting(XGB-TDN)model and Light Gradient Boosting Machine model(LightGBM-TDN)driven by diurnal temperature indicators during 1982-2015,and the SOS was projected from 2015 to 2100 based on the Coupled Model Intercomparison Project Phase 6(CMIP6)climate scenario datasets.The sensitivity of boreal forest SOS to daytime temperature is greater than that to average temperature and nighttime temperature.The LightGBM-TDN model perform best across all vegetation types,exhibiting the lowest RMSE and bias compared to the KNR-TDN model,RFR-TDN model and XGB-TDN model.By incorporating diurn-al temperature indicators instead of relying only on average temperature indicators to simulate spring phenology,an improvement in the accuracy of the model is achieved.Furthermore,the preseason accumulated daytime temperature,daytime temperature and snow cover end date emerged as significant drivers of the SOS simulation in the study area.The simulation results based on LightGBM-TDN model exhibit a trend of advancing SOS followed by stabilization under future climate scenarios.This study underscores the potential of diurn-al temperature indicators as a viable alternative to average temperature indicators in driving spring phenology models,offering a prom-ising new method for simulating spring phenology.展开更多
Southerly moisture surges over the central South China Sea(SCS)are characterized by the strengthening of lowlevel southerlies that transport moisture northward from the Pacific or Indian Oceans to South China.These su...Southerly moisture surges over the central South China Sea(SCS)are characterized by the strengthening of lowlevel southerlies that transport moisture northward from the Pacific or Indian Oceans to South China.These surge events typically occur for days in the early-summer season(from April to June)and can lead to heavy rains in South China.This study categorizes surge events into three types of flow patterns and examines their multiscale variations and impacts on rainfall.The first type occurs mainly in April,with the southeasterlies enhanced by a deepening trough in South China and the western Pacific subtropical high established over the SCS.The second type of surge events mostly appears in June,featuring the prevailing southwesterlies of summer monsoon from the Indian Ocean during the active phases of intraseasonal oscillations.Most surge events exhibit semi-diurnal variations with morning and afternoon peaks of northward moisture fluxes.Specifically,the first type features a dominant afternoon peak,while the second type shows a dominant early-morning peak,which is induced by thermal contrast between the Indochina Peninsula and the SCS.In general,the surge events enhance moisture convergence and increase rainfall downstream in South China,but they show some regional differences.The second type strengthens moisture convergence and rainfall in coastal regions with a morning peak.In contrast,the first type enhances inland rainfall with a morning peak,while moisture divergence dominates coastal regions.The third type of surge events denotes transitional conditions between the first two types,in terms of atmospheric circulations,diurnal cycles,and rainfall patterns.These results highlight a diversity of regional moisture surges and related rainfall ranging from diurnal to sub-seasonal scales.展开更多
This study aims to analyze the synoptic patterns conducive to extreme rainfall(ER)over the South China Coast(SCC)and the low-level thermodynamic structure over the sea.Using observational and reanalysis data,a cluster...This study aims to analyze the synoptic patterns conducive to extreme rainfall(ER)over the South China Coast(SCC)and the low-level thermodynamic structure over the sea.Using observational and reanalysis data,a clustering analysis of the 700 hPa synoptic conditions is conducted during the pre-summer rainy seasons of South China from 1988 to 2017.The conditions are classified into three patterns:Type-L(Low-pressure type),Type-I(Intermediate type),and Type-H(High-pressure type).The circulation characteristics and diurnal variations associated with ER in each pattern are examined.Type-L is characterized by a low-level southwest airflow from the South China Sea(SCS),which strengthens coastal convergence,providing abundant moisture and favorable thermodynamic conditions.Therefore,Type-L is associated with more ER events than the other patterns.In Type-I,the SCC lies between a shallow trough and a ridge,influenced by southerly airflow.Type-H is dominated by a high-pressure system over the eastern SCS,where moisture conditions are weaker than in the first two patterns,leading to fewer ER events.During ER events,a significant warm belt below 850 hPa forms on the lee side of the Indochina Peninsula due to descending motion.In all synoptic patterns,a profound low-level warm advection occurs from the southwest.However,moisture transfer paths notably differ.In Type-L,low-level moisture primarily originates from the western SCS,driven by strong southwesterly winds in the boundary layer.In contrast,moisture in Type-I and Type-H is sourced from the central and eastern SCS,respectively.The diurnal variation of low-level winds is a key factor in controlling the diurnal cycles of moisture transport and rainfall.The enhancement of ER at night is related to the land-sea thermal contrast over the SCC,coupled with an increase in moisture and meridional winds.Among the three patterns,Type-I is primarily driven by local thermal convection,which plays an important role in ER.展开更多
Active atmospheric convection on the monsoon coast is crucial for the Earth’s climate system.In particular,the upscale convective growth(UCG)from ordinary isolated convection to organized convective system is a key p...Active atmospheric convection on the monsoon coast is crucial for the Earth’s climate system.In particular,the upscale convective growth(UCG)from ordinary isolated convection to organized convective system is a key process causing severe weather,but its activities on the monsoon coast are less understood because of the lack of fine-resolution datasets.For the first time,we present the climatology of UCG on a typical monsoon coast using kilometer-mesh radar data from southern China.The UCG undergoes pronounced subseasonal and diurnal variations in the early-summer rainy season.The subseasonal UCG increase is attributed to the onshore flows shifting from easterlies in April to monsoon southwesterlies in June.UCG becomes vigorous following summer monsoon onset,with hotspots near windward coastal mountains.Daytime UCG first peaks near noontime along coastal land,where onshore flows are destabilized by boundary-layer heating and mountains.Afternoon inland peaks and off-coast minimums are recognized due to land–sea thermal contrast and sea-breeze circulation.Nighttime UCG is revived at the coast by nocturnally enhanced southerlies,followed by offshore activity as the convergence of land-breeze northerlies shifts seaward.The UCG thus responds strongly to changing atmospheric conditions,land heating/cooling,and thermally driven local circulations.Our results may help clarify the predictability of monsoon coastal convection.展开更多
The Sichuan Basin(SCB),China has a high incidence of extremely persistent heavy rainfall(EPHR)events.The EPHR events from 2009 to 2019 in the SCB were mainly concentrated over the northern and northwestern windward sl...The Sichuan Basin(SCB),China has a high incidence of extremely persistent heavy rainfall(EPHR)events.The EPHR events from 2009 to 2019 in the SCB were mainly concentrated over the northern and northwestern windward slopes and the central basin.They occurred from June to September,but especially in July,and peaked at 0300 LST.ERA5 reanalysis data and objective classification were used to investigate the synoptic patterns and their effects.There were three synoptic patterns during EPHR events,all accompanied by a Southwest Vortex.The location and intensity of the Southwest Vortex,thermal forcing of the Tibetan Plateau(TP),and low-level winds can greatly affect the intensity and spatial distribution of EPHR.When the Southwest Vortex was located in the western SCB and there were southerly low-level jets(LLJs),convergence and upslope wind would lead to EPHR over the northwestern or northern windward slopes.If there was no LLJ and the whole SCB was under the center of the Southwest Vortex,nocturnal EPHR was controlled by the internal circulation of the Southwest Vortex and the updraft generated by the thermal forcing of the TP,and the rainfall was weaker.The southeastern entrance of the SCB was a key area where the low-level wind dominated the nocturnal peak of EPHR.The nocturnal strengthened southeasterly wind in the key area is attributable to inertial oscillation,and the topographic friction plays an essential role in transporting momentum and moisture into the basin by generating easterly and northeasterly ageostrophic winds.展开更多
Due to its impact on cereal yields,vegetation growth,animal wellbeing,and human health,considerable attention has been paid to diurnal temperature range,focusing on the temporal dimension of surface air temperature.Ho...Due to its impact on cereal yields,vegetation growth,animal wellbeing,and human health,considerable attention has been paid to diurnal temperature range,focusing on the temporal dimension of surface air temperature.However,the characteristics of spatial temperature range and its response to climate change remain unclear,despite its importance to various natural and societal activities.Here,we proposed a daily spatial temperature range(DSTR,difference between spatial maximum and minimum temperature,STmax and STmin)indicator to measure the maximum spatial temperature range within a given region over a day.We analyzed the spatiotemporal pattern of DSTR and its trend under climate change at four scales(global,hemispheric,national,and provincial),with the following main results:(1)DSTR was scale dependent,provincial pattern of which were mainly related to sensible and latent heat fluxes.(2)The key regions affecting DSTR and temporal distribution at different scales were mapped out.(3)Under climate change,DSTR significantly decreased globally,hemispherically,and in several Chinese provinces due to the greater warming of STmin than STmax.The influence of latent heat flux and solar shortwave radiation was larger at global/hemispheric scales,while the albedo was a more critical driver at provincial scale.For the first time,we proposed the DSTR indicator and emphasized the importance of exploring spatial temperature heterogeneity.This spatial information is important to optimize relevant societal activities,and the response of DSTR to climate change has further led to the consideration of the relationship between DSTR and extreme events,biodiversity,etc.展开更多
Cloud diurnal variation is crucial for regulating cloud radiative effects and atmospheric dynamics.However,it is often overlooked in the evaluation and development of climate models.Thus,this study aims to investigate...Cloud diurnal variation is crucial for regulating cloud radiative effects and atmospheric dynamics.However,it is often overlooked in the evaluation and development of climate models.Thus,this study aims to investigate the daily mean(CFR)and diurnal variation(CDV)of cloud fraction across high-,middle-,low-level,and total clouds in the FGOALS-f3-L general circulation model.The bias of total CDV is decomposed into the model biases in CFRs and CDVs of clouds at all three levels.Results indicate that the model generally underestimates low-level cloud fraction during the daytime and high-/middle-level cloud fraction at nighttime.The simulation biases of low clouds,especially their CDV biases,dominate the bias of total CDV.Compensation effects exist among the bias decompositions,where the negative contributions of underestimated daytime low-level cloud fraction are partially offset by the opposing contributions from biases in high-/middle-level clouds.Meanwhile,the bias contributions have notable land–ocean differences and region-dependent characteristics,consistent with the model biases in these variables.Additionally,the study estimates the influences of CFR and CDV biases on the bias of shortwave cloud radiative effects.It reveals that the impacts of CDV biases can reach half of those from CFR biases,highlighting the importance of accurate CDV representation in climate models.展开更多
The monument thermal effect(MTE)displacements could result in periodical signals with several mil-limeters magnitudes in the vertical and horizontal GPS position time series.However,the interaction ofvarious origins o...The monument thermal effect(MTE)displacements could result in periodical signals with several mil-limeters magnitudes in the vertical and horizontal GPS position time series.However,the interaction ofvarious origins of periodic signals in GPS observations makes it difficult to isolate the millimeter-levelMTE displacement from other signals and noises.In this study,to assess the diurnal and semidiurnalsignals induced by MTE,we processed 12 very short GPS baselines(VSGB)with length<150 m.Themonument pairs for each baseline differ in their heights,horizontal structure,or base foundations.Meanwhile,two zero-baselines were also processed as the control group.Results showed that the sea-sonal signals observed in VSGB time series in the horizontal and vertical directions,were mainly inducedby seasonal MTE.Time-varying diurnal and semidiurnal signals with amplitude up to 4 mm wereobserved in the vertical direction for baselines with monument height difference(MHD)larger than10 m.Horizontal diurnal signal with an amplitude of about 2 mm was also detected for baselines withnon-axisymmetric monument structure.The orientation of the detected horizontal displacement wascoherent with the direction of daily temperature variation(DTV)driven by direct solar radiation,whichindicates that the diurnal and semidiurnal signals are likely induced by MTE.The observed high-frequency MTE displacements,if not well modeled and removed,may propagate into spurious long-term signals and bias the velocity estimation in the daily GPS time series.展开更多
The diurnal cycle of sea surface skin temperature(SST_(skin))plays a critical role in the air-sea system by modulating oceanic and atmospheric processes on longer timescales.The European Centre for Medium-Range Weathe...The diurnal cycle of sea surface skin temperature(SST_(skin))plays a critical role in the air-sea system by modulating oceanic and atmospheric processes on longer timescales.The European Centre for Medium-Range Weather Forecasts(ECMWF)forecasting system has taken the diurnal cycle of SST_(skin)into account by incorporating parameterization schemes for warm-layer and cool-skin effects,and provides hourly SST_(skin)outputs in ECMWF Reanalysis v5(ERA5 reanalysis).This study evaluates the SST_(skin)diurnal amplitude(i.e.,the diurnal temperature range)and phase(i.e.,the timing of the daytime maximum)in ERA5 using observations from the Global Tropical Moored Buoy Array(GTMBA).Compared to GTMBA,the SST_(skin)diurnal amplitude in ERA5 is significantly underestimated,with a mean bias of−0.12 K and a percentage error of 36%.The amplitude error declines with increasing surface wind speed but grows with increasing surface shortwave radiation.The timing of the daytime SST_(skin)maximum in ERA5 is substantially advanced,with an average lead of 1.69 h,and the lead time increases with increasing wind speed/shortwave radiation.These results suggest that the warm-layer parameterization scheme incorporated in the ECMWF system likely underestimates the daytime warming from air-sea heat exchange and/or overestimates the cooling effect of oceanic turbulent mixing,providing insights for future improvements of this scheme.展开更多
Based on the chemical composition data of a regional long-lasting haze event that occurred in the Yangtze River Delta(YRD)region from 17 December 2023 to 8 January 2024,the evolutionary characteristics of the chemical...Based on the chemical composition data of a regional long-lasting haze event that occurred in the Yangtze River Delta(YRD)region from 17 December 2023 to 8 January 2024,the evolutionary characteristics of the chemical components and sources of fine particulate matter(PM2.5)under different pollution levels were comparatively analyzed using PMF(Positive Matrix Factorization)and backward trajectory analysis.SNA(NO_(3)^(-),NH_(4)^(+),SO_(4)^(2-))was found to be the primary chemical component of PM2.5,making up 63.6%(clean days)to 69.7%(heavy pollution)of it.The NO_(3)^(-)concentration was 3.14(clean days)to 6.01(heavy pollution)times higher than that of SO_(4)^(2-).NO_(3)^(-),POC,Fe,Mn,Al concentrations increased,while SOC,EC,crustal elements(Ca,Si)and other water-soluble ions(WSIs)concentrations decreased as the pollution level increased.The contribution of secondary inorganics and biomass-burning emissions and industrial and ship emissions increased significantly as the pollution level increased,which accounted for 40.3%and 36.7%,respectively,in the heavy pollution stage.The contribution of traffic sources decreases gradually with increasing pollution levels,accounting for only 59.1%of the light pollution stage in the heavy pollution stage.PM_(2.5) and its main chemical components showed similar potential source distribution,located in the northwest(Fuyang,Huainan,Nanjing),south(Taizhou,Lishui,Jiande)and north(Taizhou,Yancheng).However,distinct transport routes were observed under the different air quality levels.During the heavy pollution period,the polluted air masses primarily came from the harbor regions,whereas during the light pollution period they were transported from the southeast(Taizhou)and the North China Plain.展开更多
The volatile compounds from ash-leaf maple (Acer negundo L.) were examined by adsorption-thermodesorption and GC-MS. Thirty-two compounds, including alcohols, ketones, aldehydes, esters, terpenoids, carboxylic acids, ...The volatile compounds from ash-leaf maple (Acer negundo L.) were examined by adsorption-thermodesorption and GC-MS. Thirty-two compounds, including alcohols, ketones, aldehydes, esters, terpenoids, carboxylic acids, etc. were identified. The analysis revealed that the diurnal rhythm of release of volatile compounds from maple differed in July and in August. In July, the releasing of most volatile compounds reached the peak at 14 o'clock, when in August, the emission of volatile compounds reached the peak at 10 o'clock. Besides diurnal rhythm, there also existed other differences in the releasing of volatiles and their relative contents in July and in August. A possible explanation for this phenomenon is the maturation of leaves, since the sampling conditions were the same both in July and August. At the same time, the response of Anoplophora glabrpennis Motschulsky to volatiles was examined with field bioassay with traps. cis-3-hexen-1-ol was found to be more effective to attract A. glabrpennis than other volatiles released by ash-leaf maple tree in field trapping test. A mixture of 1-butanol, 1-pentanol and 2-pentanol was tested to be the most attractive to A. glabripennis among all tested volatiles. More field trapping tests should be conducted.展开更多
[ Objective] Study on the photosynthesis and influencing factors in super high-yield combination C Liangyou H255. [ Method] The photosynthetic characteristies were measured at a hot and muggy day under natural conditi...[ Objective] Study on the photosynthesis and influencing factors in super high-yield combination C Liangyou H255. [ Method] The photosynthetic characteristies were measured at a hot and muggy day under natural conditions. [ Result] A respective single peak at 11：30 was observed in diurnal variation curves of net photosynthetic rate （Pn） and transpiration rate（Tr）. Correlation analysis shows that Pn presents an extremely significant correlation with photon flux densities （PFD） of photosynthetically active radiation, in comparison assumes a significant correlation either with stomatal conductance （Gs） or with ambient CO2 concentration （Ca）. [ Conclusion] Gs followed by PFD presented most influence on Pn of super high-yield combination C Liangyou H255.展开更多
To understand influence of litters on the emission/absorption of CO2, N2O and CH4 in broadleaved/Korean pine forest in Changbai Mountain, fluxes of soil CO2, N2O and CH4 were measured by closed static chamber techniqu...To understand influence of litters on the emission/absorption of CO2, N2O and CH4 in broadleaved/Korean pine forest in Changbai Mountain, fluxes of soil CO2, N2O and CH4 were measured by closed static chamber technique, from Sept 3, 2002 to Oct 30, 2003 in two types of soil ecosystems, of which one was covered with litters on the surface soil, and the other had no litters. The results showed that litters had significant influences on CO2, N2O and CH4 fluxes (p<0.05). Their diurnal change patterns of plot with litters and litter-free plot were similar, and they all showed emission/absorption peak at 18:00. The diurnal change fluxes of CO2 and N2O of plot with litters were significantly higher than those of the litter-free plot, while the diurnal flux of CH4 of plot with litters was lower than that of litter-free plot. The fluxes of CO2, N2O, and CH4 showed the similar seasonal patternsfor both plots. The fluxes of CO2, CH4 showed their peak fluxes in June, but the fluxes of N2O showed its peak emissions in August. The annual fluxes of CO2 and N2O of plot with litters were significantly higher than those of the litter-free plot, while the annual flux of CH4 of plot with litters was lower than that of litter-free plot. Keywords Flux - CO2, N2O and CH4 - Seasonal variation - Diurnal variation CLC number S718.5 Document code A Foundation item: The study was supported by innovation research project of Institute of Appiied Ecology, Chinese Academy of Sciences (SCXZD0101-02) and National Natural Science Foundation of China (30271068)Bigraphy: XIAO Dong-mei (1979-), female, master of Institute of Applied Ecology. Chinese Academy of Sciences, Shenyang 110016. P. R. China.Responsible editor: Song Funan展开更多
The cellular localization of Rubisco and Rubisco activase (RCA) in rice (Oryza sativa subsp. indica cv. Zhenong 952) leaf was investigated with immunogold-labeled electron microscope techniques on the basis of determi...The cellular localization of Rubisco and Rubisco activase (RCA) in rice (Oryza sativa subsp. indica cv. Zhenong 952) leaf was investigated with immunogold-labeled electron microscope techniques on the basis of determining the diurnal changes of photosynthetic rate (Pn), Rubisco and RCA activities, and quantifying two enzyme contents in the leaf with immuno-diffusion method in order to understand why RCA activity decreased in the midday when its contents was high. The results showed that Rubisco mainly was located in chloroplast, and RCA were found both in chloroplast and mitochondria. The lowering of Rubisco in chloroplast as well as Rubisco activity at noon could be one of good reasons to explain the photosynthetic midday depression in leaf. The density of RCA in chloroplast reached the maximum at 14:00 and a valley at 11:00. The result much coincided with the activity of RCA in leaf. In mitochondria, the density of RCA changed abruptly in one day with the highest at 13:00 and it can well elucidate why the activities of Rubisco declined at noon when its amount was increasing. Therefore the cellular localization and/or distribution of Rubisco and RCA during a day is more important for Pn, Rubisco and RCA activities.展开更多
In July 2006, the diurnal activity rhythms of 13 heads of captive Qinling golden takin were observed in Shaanxi Provincial Centre for the Breeding and Conservation of Rare Wildlife （SPCBCRW） at daylight （from 9：00...In July 2006, the diurnal activity rhythms of 13 heads of captive Qinling golden takin were observed in Shaanxi Provincial Centre for the Breeding and Conservation of Rare Wildlife （SPCBCRW） at daylight （from 9：00 am to 4：00 pm in July）. The behavioral ethnogram was identified through observation at the sampling site, with the behaviors of golden takin recorded at 5 min interval using instantaneous scannable sampling method. The results indicated that the resting of golden takin took an important part in the daylight activities. Meanwhile, drinking and urinating and defecating were 1.92 and 0.54 and 0.92 times per head per day. Ambient temperature had a strong effect on the diurnal activity rhythms of golden takin. The diurnal activity rhymes were affected by ages of the animals effectively, which was expressed through differentiation of the time budgets. Moreover, different individuals in the same population showed some non-synchronously activity rhythms.展开更多
The cDNA encoding the luciferase from lantern mRNA of one diurnal firefly Pyrocoelia pygidialis Pic, 1926 has been cloned, sequenced and functionally expressed. The cDNA sequence of P pygidialis luciferase is 1647 bas...The cDNA encoding the luciferase from lantern mRNA of one diurnal firefly Pyrocoelia pygidialis Pic, 1926 has been cloned, sequenced and functionally expressed. The cDNA sequence of P pygidialis luciferase is 1647 base pairs in length, coding a protein of 548 amino acid residues. Sequence analysis of the deduced amino acid sequence showed that this luciferase had 97.8% resemblance to luciferases from the fireflies Lampyris noctiluca, Lampyris turkestanicus and Nyctophila cf. caucasica. Phylogenetic analysis using deduced amino acid sequence showed that P pygidialis located at the base of Lampyris＋Nyctophila clade with robust support （BP=97%）; but did not show a monophyletic relationship with its congeneric species P pectoralis, P tufa and P miyako, all three are strong luminous and nocturnal species. The expression worked in recombinant Escherichia coli. Expression product had a 70kDa band and emitted yellow-green luminescence in the presence of luciferin. Five loops in the P pygidialis luciferase, L1 （NI98-G208）, L2 （T240-G247）, L3 （G317-K322）, L4 （L343-I350） and L5 （G522-D532）, were found from the structure modeling analysis in the cleft, where it was considered the active site for the substrate compound entering and binding. Different amino acid residues between the luciferases of P. pygidialis and the three other known strong luminous species can not explain the situation of weak or strong luminescence. Future study of these loops, residues or crystal structure analysis may be helpful in understanding the real differences between the luciferases between diurnal and nocturnal species.展开更多
基金the NOAA Atmospheric Science for Renewable Energy (ASRE) programthe Earth Venture Continuity 1 (EVC-1) Libera project under NASA Contract 80LARC20D0006the NOAA cooperative agreement with CIRES,NA22OAR4320151。
文摘The study of shortwave(SW) radiation and its interactions with our planet has proven critical for advancing the understanding of the Earth–atmosphere system. Here, the author shares an accessible and high-level perspective on recent progress, surprises encountered, and promising future research directionsa. A brief context for the study of SW radiation is provided, after which three specific aspects are focused upon that the author considers particularly important. First, the significance of three-dimensional(3D) SW radiative effects is highlighted via impacts on surface downward SW radiation in complex cloud fields. Crucially, it is shown that probability distributions of surface radiation can only be reliably simulated when accounting for 3D effects, which has implications for various applications and next-generation atmospheric modeling. Second, the significance of the often overlooked diurnal cycle in global top-of-atmosphere upward SW radiation is underscored by quantifying the controlling properties and processes. Opportunities for improved future satellite observations of the global diurnal cycle are noted. Third, the wealth of information provided by the spectral dimension of SW radiation is demonstrated through the extraction and attribution of SW spectral signatures. It is argued that further exploration of the spectral dimension, aided by the recently launched and upcoming suite of spectrally resolved SW satellite observations, promises a new era of SW radiation research.
基金National Key Research and Development Program of China (2022YFC3004004)National Natural Science Foundation of China (42075155,12241104)National Natural Science Foundation of China Joint Fund (U2342213)。
文摘The infrared channels of the FY-4B advanced geosynchronous radiation imagers(AGRI) play a crucial role in temperature and humidity analyses for mesoscale numerical weather prediction, particularly in enhancing the initial field quality and the forecasting accuracy of the model. This study assimilated FY-4B AGRI data into the CMA-MESO model and analyzed the bias characteristics and correction methods. Analysis of the AGRI data revealed a clear diurnal variation in the bias, which was positively correlated with the solar elevation angle. However, the diurnal variation in the bias lagged behind the solar elevation angle, likely owing to temperature changes and delayed instrument responses resulting from solar radiation. To address this issue, we propose a correction method that utilizes the solar elevation angle after an optimal time shift. Using the time-shifted solar elevation angle as a predictor effectively reduces the diurnal variation in bias and significantly improves the correction effect. This approach provides theoretical support for the assimilation of FY-4B AGRI data into mesoscale numerical weather predictions, thereby enhancing the reliability of the assimilation results.
基金Under the auspices of National Natural Science Foundation of China(No.42201374,42071359)。
文摘The roles of diurnal temperature in providing heat accumulation and chilling requirements for vegetation spring phenology differ.Although previous studies have established a stronger correlation between leaf onset and diurnal temperature than between leaf onset and average temperature,current research on modeling spring phenology based on diurnal temperature indicators remains limited.In this study,we confirmed the start of the growing season(SOS)sensitivity to diurnal temperature and average temperature in boreal forest.The estimation of SOS was carried out by employing K-Nearest Neighbor Regression(KNR-TDN)model,Random Forest Regres-sion(RFR-TDN)model,eXtreme Gradient Boosting(XGB-TDN)model and Light Gradient Boosting Machine model(LightGBM-TDN)driven by diurnal temperature indicators during 1982-2015,and the SOS was projected from 2015 to 2100 based on the Coupled Model Intercomparison Project Phase 6(CMIP6)climate scenario datasets.The sensitivity of boreal forest SOS to daytime temperature is greater than that to average temperature and nighttime temperature.The LightGBM-TDN model perform best across all vegetation types,exhibiting the lowest RMSE and bias compared to the KNR-TDN model,RFR-TDN model and XGB-TDN model.By incorporating diurn-al temperature indicators instead of relying only on average temperature indicators to simulate spring phenology,an improvement in the accuracy of the model is achieved.Furthermore,the preseason accumulated daytime temperature,daytime temperature and snow cover end date emerged as significant drivers of the SOS simulation in the study area.The simulation results based on LightGBM-TDN model exhibit a trend of advancing SOS followed by stabilization under future climate scenarios.This study underscores the potential of diurn-al temperature indicators as a viable alternative to average temperature indicators in driving spring phenology models,offering a prom-ising new method for simulating spring phenology.
基金Guangdong Major Project of Basic and Applied Basic Research(2020B0301030004)National Natural Science Foundation of China(42475003)Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(SML2023SP209)。
文摘Southerly moisture surges over the central South China Sea(SCS)are characterized by the strengthening of lowlevel southerlies that transport moisture northward from the Pacific or Indian Oceans to South China.These surge events typically occur for days in the early-summer season(from April to June)and can lead to heavy rains in South China.This study categorizes surge events into three types of flow patterns and examines their multiscale variations and impacts on rainfall.The first type occurs mainly in April,with the southeasterlies enhanced by a deepening trough in South China and the western Pacific subtropical high established over the SCS.The second type of surge events mostly appears in June,featuring the prevailing southwesterlies of summer monsoon from the Indian Ocean during the active phases of intraseasonal oscillations.Most surge events exhibit semi-diurnal variations with morning and afternoon peaks of northward moisture fluxes.Specifically,the first type features a dominant afternoon peak,while the second type shows a dominant early-morning peak,which is induced by thermal contrast between the Indochina Peninsula and the SCS.In general,the surge events enhance moisture convergence and increase rainfall downstream in South China,but they show some regional differences.The second type strengthens moisture convergence and rainfall in coastal regions with a morning peak.In contrast,the first type enhances inland rainfall with a morning peak,while moisture divergence dominates coastal regions.The third type of surge events denotes transitional conditions between the first two types,in terms of atmospheric circulations,diurnal cycles,and rainfall patterns.These results highlight a diversity of regional moisture surges and related rainfall ranging from diurnal to sub-seasonal scales.
基金the National Natural Science Foundation of China(No.42205014)the State Key Laboratory of Severe Weather Meteorological Science and Technology(No.2025QZA10)。
文摘This study aims to analyze the synoptic patterns conducive to extreme rainfall(ER)over the South China Coast(SCC)and the low-level thermodynamic structure over the sea.Using observational and reanalysis data,a clustering analysis of the 700 hPa synoptic conditions is conducted during the pre-summer rainy seasons of South China from 1988 to 2017.The conditions are classified into three patterns:Type-L(Low-pressure type),Type-I(Intermediate type),and Type-H(High-pressure type).The circulation characteristics and diurnal variations associated with ER in each pattern are examined.Type-L is characterized by a low-level southwest airflow from the South China Sea(SCS),which strengthens coastal convergence,providing abundant moisture and favorable thermodynamic conditions.Therefore,Type-L is associated with more ER events than the other patterns.In Type-I,the SCC lies between a shallow trough and a ridge,influenced by southerly airflow.Type-H is dominated by a high-pressure system over the eastern SCS,where moisture conditions are weaker than in the first two patterns,leading to fewer ER events.During ER events,a significant warm belt below 850 hPa forms on the lee side of the Indochina Peninsula due to descending motion.In all synoptic patterns,a profound low-level warm advection occurs from the southwest.However,moisture transfer paths notably differ.In Type-L,low-level moisture primarily originates from the western SCS,driven by strong southwesterly winds in the boundary layer.In contrast,moisture in Type-I and Type-H is sourced from the central and eastern SCS,respectively.The diurnal variation of low-level winds is a key factor in controlling the diurnal cycles of moisture transport and rainfall.The enhancement of ER at night is related to the land-sea thermal contrast over the SCC,coupled with an increase in moisture and meridional winds.Among the three patterns,Type-I is primarily driven by local thermal convection,which plays an important role in ER.
基金the Guangdong Major Project of Basic and Applied Basic Research(Grant No.2020B0301030004)the National Natural Science Foundation of China(Grant Nos.42275002 and 42275006)+1 种基金the National Institute of Natural Hazards,Ministry of Emergency Management of China(Grant Nos.ZDJ2024-01 and ZDJ2024-25)the Science and Technology Planning Project of Guangdong Province(Grant No.2023B1212060019).
文摘Active atmospheric convection on the monsoon coast is crucial for the Earth’s climate system.In particular,the upscale convective growth(UCG)from ordinary isolated convection to organized convective system is a key process causing severe weather,but its activities on the monsoon coast are less understood because of the lack of fine-resolution datasets.For the first time,we present the climatology of UCG on a typical monsoon coast using kilometer-mesh radar data from southern China.The UCG undergoes pronounced subseasonal and diurnal variations in the early-summer rainy season.The subseasonal UCG increase is attributed to the onshore flows shifting from easterlies in April to monsoon southwesterlies in June.UCG becomes vigorous following summer monsoon onset,with hotspots near windward coastal mountains.Daytime UCG first peaks near noontime along coastal land,where onshore flows are destabilized by boundary-layer heating and mountains.Afternoon inland peaks and off-coast minimums are recognized due to land–sea thermal contrast and sea-breeze circulation.Nighttime UCG is revived at the coast by nocturnally enhanced southerlies,followed by offshore activity as the convergence of land-breeze northerlies shifts seaward.The UCG thus responds strongly to changing atmospheric conditions,land heating/cooling,and thermally driven local circulations.Our results may help clarify the predictability of monsoon coastal convection.
基金supported by the National Natural Science Foundation of China(Grant Nos.42330610 and 42075010)。
文摘The Sichuan Basin(SCB),China has a high incidence of extremely persistent heavy rainfall(EPHR)events.The EPHR events from 2009 to 2019 in the SCB were mainly concentrated over the northern and northwestern windward slopes and the central basin.They occurred from June to September,but especially in July,and peaked at 0300 LST.ERA5 reanalysis data and objective classification were used to investigate the synoptic patterns and their effects.There were three synoptic patterns during EPHR events,all accompanied by a Southwest Vortex.The location and intensity of the Southwest Vortex,thermal forcing of the Tibetan Plateau(TP),and low-level winds can greatly affect the intensity and spatial distribution of EPHR.When the Southwest Vortex was located in the western SCB and there were southerly low-level jets(LLJs),convergence and upslope wind would lead to EPHR over the northwestern or northern windward slopes.If there was no LLJ and the whole SCB was under the center of the Southwest Vortex,nocturnal EPHR was controlled by the internal circulation of the Southwest Vortex and the updraft generated by the thermal forcing of the TP,and the rainfall was weaker.The southeastern entrance of the SCB was a key area where the low-level wind dominated the nocturnal peak of EPHR.The nocturnal strengthened southeasterly wind in the key area is attributable to inertial oscillation,and the topographic friction plays an essential role in transporting momentum and moisture into the basin by generating easterly and northeasterly ageostrophic winds.
基金the financial support from the National Key Research and Development Program of China(Grant No.2023YFB3907402)the Strategic Priority Research Program of the Chinese Academy of Sciences(Category B,Geographic Intelligence,Grant No.XDB0740300)the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(Grant No.GZC20241691).
文摘Due to its impact on cereal yields,vegetation growth,animal wellbeing,and human health,considerable attention has been paid to diurnal temperature range,focusing on the temporal dimension of surface air temperature.However,the characteristics of spatial temperature range and its response to climate change remain unclear,despite its importance to various natural and societal activities.Here,we proposed a daily spatial temperature range(DSTR,difference between spatial maximum and minimum temperature,STmax and STmin)indicator to measure the maximum spatial temperature range within a given region over a day.We analyzed the spatiotemporal pattern of DSTR and its trend under climate change at four scales(global,hemispheric,national,and provincial),with the following main results:(1)DSTR was scale dependent,provincial pattern of which were mainly related to sensible and latent heat fluxes.(2)The key regions affecting DSTR and temporal distribution at different scales were mapped out.(3)Under climate change,DSTR significantly decreased globally,hemispherically,and in several Chinese provinces due to the greater warming of STmin than STmax.The influence of latent heat flux and solar shortwave radiation was larger at global/hemispheric scales,while the albedo was a more critical driver at provincial scale.For the first time,we proposed the DSTR indicator and emphasized the importance of exploring spatial temperature heterogeneity.This spatial information is important to optimize relevant societal activities,and the response of DSTR to climate change has further led to the consideration of the relationship between DSTR and extreme events,biodiversity,etc.
基金supported by the National Natural Science Foundation of China[grant number 42275074].
文摘Cloud diurnal variation is crucial for regulating cloud radiative effects and atmospheric dynamics.However,it is often overlooked in the evaluation and development of climate models.Thus,this study aims to investigate the daily mean(CFR)and diurnal variation(CDV)of cloud fraction across high-,middle-,low-level,and total clouds in the FGOALS-f3-L general circulation model.The bias of total CDV is decomposed into the model biases in CFRs and CDVs of clouds at all three levels.Results indicate that the model generally underestimates low-level cloud fraction during the daytime and high-/middle-level cloud fraction at nighttime.The simulation biases of low clouds,especially their CDV biases,dominate the bias of total CDV.Compensation effects exist among the bias decompositions,where the negative contributions of underestimated daytime low-level cloud fraction are partially offset by the opposing contributions from biases in high-/middle-level clouds.Meanwhile,the bias contributions have notable land–ocean differences and region-dependent characteristics,consistent with the model biases in these variables.Additionally,the study estimates the influences of CFR and CDV biases on the bias of shortwave cloud radiative effects.It reveals that the impacts of CDV biases can reach half of those from CFR biases,highlighting the importance of accurate CDV representation in climate models.
基金funded by the Independent Innovation Project of Changjiang Institute of Survey,Planning,Design and Research Corporation (CX2020Z32)supported by the National Natural Science Foundation of China (Grant Numbers42204006 and 42104028)the Open Fund of Hubei Luojia Laboratory (Grant Numbers 230100020 and 230100019)
文摘The monument thermal effect(MTE)displacements could result in periodical signals with several mil-limeters magnitudes in the vertical and horizontal GPS position time series.However,the interaction ofvarious origins of periodic signals in GPS observations makes it difficult to isolate the millimeter-levelMTE displacement from other signals and noises.In this study,to assess the diurnal and semidiurnalsignals induced by MTE,we processed 12 very short GPS baselines(VSGB)with length<150 m.Themonument pairs for each baseline differ in their heights,horizontal structure,or base foundations.Meanwhile,two zero-baselines were also processed as the control group.Results showed that the sea-sonal signals observed in VSGB time series in the horizontal and vertical directions,were mainly inducedby seasonal MTE.Time-varying diurnal and semidiurnal signals with amplitude up to 4 mm wereobserved in the vertical direction for baselines with monument height difference(MHD)larger than10 m.Horizontal diurnal signal with an amplitude of about 2 mm was also detected for baselines withnon-axisymmetric monument structure.The orientation of the detected horizontal displacement wascoherent with the direction of daily temperature variation(DTV)driven by direct solar radiation,whichindicates that the diurnal and semidiurnal signals are likely induced by MTE.The observed high-frequency MTE displacements,if not well modeled and removed,may propagate into spurious long-term signals and bias the velocity estimation in the daily GPS time series.
基金The National Key Research and Development Program of China under contract No.2024YFF0808900the China National Funds for Distinguished Young Scientists under contract No.42425601+1 种基金the National Natural Science Foundation of China under contract No.42376002the Hainan Province Science and Technology Special Fund under contract No.SOLZSKY2025006.
文摘The diurnal cycle of sea surface skin temperature(SST_(skin))plays a critical role in the air-sea system by modulating oceanic and atmospheric processes on longer timescales.The European Centre for Medium-Range Weather Forecasts(ECMWF)forecasting system has taken the diurnal cycle of SST_(skin)into account by incorporating parameterization schemes for warm-layer and cool-skin effects,and provides hourly SST_(skin)outputs in ECMWF Reanalysis v5(ERA5 reanalysis).This study evaluates the SST_(skin)diurnal amplitude(i.e.,the diurnal temperature range)and phase(i.e.,the timing of the daytime maximum)in ERA5 using observations from the Global Tropical Moored Buoy Array(GTMBA).Compared to GTMBA,the SST_(skin)diurnal amplitude in ERA5 is significantly underestimated,with a mean bias of−0.12 K and a percentage error of 36%.The amplitude error declines with increasing surface wind speed but grows with increasing surface shortwave radiation.The timing of the daytime SST_(skin)maximum in ERA5 is substantially advanced,with an average lead of 1.69 h,and the lead time increases with increasing wind speed/shortwave radiation.These results suggest that the warm-layer parameterization scheme incorporated in the ECMWF system likely underestimates the daytime warming from air-sea heat exchange and/or overestimates the cooling effect of oceanic turbulent mixing,providing insights for future improvements of this scheme.
基金supported by the National Key Research and Development Program of China(No.2022YFC3701204)the Natural Science Foundation of Jiangsu Province(No.BK20231300).
文摘Based on the chemical composition data of a regional long-lasting haze event that occurred in the Yangtze River Delta(YRD)region from 17 December 2023 to 8 January 2024,the evolutionary characteristics of the chemical components and sources of fine particulate matter(PM2.5)under different pollution levels were comparatively analyzed using PMF(Positive Matrix Factorization)and backward trajectory analysis.SNA(NO_(3)^(-),NH_(4)^(+),SO_(4)^(2-))was found to be the primary chemical component of PM2.5,making up 63.6%(clean days)to 69.7%(heavy pollution)of it.The NO_(3)^(-)concentration was 3.14(clean days)to 6.01(heavy pollution)times higher than that of SO_(4)^(2-).NO_(3)^(-),POC,Fe,Mn,Al concentrations increased,while SOC,EC,crustal elements(Ca,Si)and other water-soluble ions(WSIs)concentrations decreased as the pollution level increased.The contribution of secondary inorganics and biomass-burning emissions and industrial and ship emissions increased significantly as the pollution level increased,which accounted for 40.3%and 36.7%,respectively,in the heavy pollution stage.The contribution of traffic sources decreases gradually with increasing pollution levels,accounting for only 59.1%of the light pollution stage in the heavy pollution stage.PM_(2.5) and its main chemical components showed similar potential source distribution,located in the northwest(Fuyang,Huainan,Nanjing),south(Taizhou,Lishui,Jiande)and north(Taizhou,Yancheng).However,distinct transport routes were observed under the different air quality levels.During the heavy pollution period,the polluted air masses primarily came from the harbor regions,whereas during the light pollution period they were transported from the southeast(Taizhou)and the North China Plain.
文摘The volatile compounds from ash-leaf maple (Acer negundo L.) were examined by adsorption-thermodesorption and GC-MS. Thirty-two compounds, including alcohols, ketones, aldehydes, esters, terpenoids, carboxylic acids, etc. were identified. The analysis revealed that the diurnal rhythm of release of volatile compounds from maple differed in July and in August. In July, the releasing of most volatile compounds reached the peak at 14 o'clock, when in August, the emission of volatile compounds reached the peak at 10 o'clock. Besides diurnal rhythm, there also existed other differences in the releasing of volatiles and their relative contents in July and in August. A possible explanation for this phenomenon is the maturation of leaves, since the sampling conditions were the same both in July and August. At the same time, the response of Anoplophora glabrpennis Motschulsky to volatiles was examined with field bioassay with traps. cis-3-hexen-1-ol was found to be more effective to attract A. glabrpennis than other volatiles released by ash-leaf maple tree in field trapping test. A mixture of 1-butanol, 1-pentanol and 2-pentanol was tested to be the most attractive to A. glabripennis among all tested volatiles. More field trapping tests should be conducted.
文摘[ Objective] Study on the photosynthesis and influencing factors in super high-yield combination C Liangyou H255. [ Method] The photosynthetic characteristies were measured at a hot and muggy day under natural conditions. [ Result] A respective single peak at 11：30 was observed in diurnal variation curves of net photosynthetic rate （Pn） and transpiration rate（Tr）. Correlation analysis shows that Pn presents an extremely significant correlation with photon flux densities （PFD） of photosynthetically active radiation, in comparison assumes a significant correlation either with stomatal conductance （Gs） or with ambient CO2 concentration （Ca）. [ Conclusion] Gs followed by PFD presented most influence on Pn of super high-yield combination C Liangyou H255.
基金The study was supported by innovation research project of Institute of Applied Ecology Chinese Academy of Sciences (SCXZD0101-02) and National Natural Science Foundation of China (302
文摘To understand influence of litters on the emission/absorption of CO2, N2O and CH4 in broadleaved/Korean pine forest in Changbai Mountain, fluxes of soil CO2, N2O and CH4 were measured by closed static chamber technique, from Sept 3, 2002 to Oct 30, 2003 in two types of soil ecosystems, of which one was covered with litters on the surface soil, and the other had no litters. The results showed that litters had significant influences on CO2, N2O and CH4 fluxes (p<0.05). Their diurnal change patterns of plot with litters and litter-free plot were similar, and they all showed emission/absorption peak at 18:00. The diurnal change fluxes of CO2 and N2O of plot with litters were significantly higher than those of the litter-free plot, while the diurnal flux of CH4 of plot with litters was lower than that of litter-free plot. The fluxes of CO2, N2O, and CH4 showed the similar seasonal patternsfor both plots. The fluxes of CO2, CH4 showed their peak fluxes in June, but the fluxes of N2O showed its peak emissions in August. The annual fluxes of CO2 and N2O of plot with litters were significantly higher than those of the litter-free plot, while the annual flux of CH4 of plot with litters was lower than that of litter-free plot. Keywords Flux - CO2, N2O and CH4 - Seasonal variation - Diurnal variation CLC number S718.5 Document code A Foundation item: The study was supported by innovation research project of Institute of Appiied Ecology, Chinese Academy of Sciences (SCXZD0101-02) and National Natural Science Foundation of China (30271068)Bigraphy: XIAO Dong-mei (1979-), female, master of Institute of Applied Ecology. Chinese Academy of Sciences, Shenyang 110016. P. R. China.Responsible editor: Song Funan
文摘The cellular localization of Rubisco and Rubisco activase (RCA) in rice (Oryza sativa subsp. indica cv. Zhenong 952) leaf was investigated with immunogold-labeled electron microscope techniques on the basis of determining the diurnal changes of photosynthetic rate (Pn), Rubisco and RCA activities, and quantifying two enzyme contents in the leaf with immuno-diffusion method in order to understand why RCA activity decreased in the midday when its contents was high. The results showed that Rubisco mainly was located in chloroplast, and RCA were found both in chloroplast and mitochondria. The lowering of Rubisco in chloroplast as well as Rubisco activity at noon could be one of good reasons to explain the photosynthetic midday depression in leaf. The density of RCA in chloroplast reached the maximum at 14:00 and a valley at 11:00. The result much coincided with the activity of RCA in leaf. In mitochondria, the density of RCA changed abruptly in one day with the highest at 13:00 and it can well elucidate why the activities of Rubisco declined at noon when its amount was increasing. Therefore the cellular localization and/or distribution of Rubisco and RCA during a day is more important for Pn, Rubisco and RCA activities.
基金The project was sponsored by the Scientific Re-search Foundation for the Returned Overseas Chinese Scholars, State Education Ministry (1999-363).
文摘In July 2006, the diurnal activity rhythms of 13 heads of captive Qinling golden takin were observed in Shaanxi Provincial Centre for the Breeding and Conservation of Rare Wildlife （SPCBCRW） at daylight （from 9：00 am to 4：00 pm in July）. The behavioral ethnogram was identified through observation at the sampling site, with the behaviors of golden takin recorded at 5 min interval using instantaneous scannable sampling method. The results indicated that the resting of golden takin took an important part in the daylight activities. Meanwhile, drinking and urinating and defecating were 1.92 and 0.54 and 0.92 times per head per day. Ambient temperature had a strong effect on the diurnal activity rhythms of golden takin. The diurnal activity rhymes were affected by ages of the animals effectively, which was expressed through differentiation of the time budgets. Moreover, different individuals in the same population showed some non-synchronously activity rhythms.
基金the Natural Foundation of Sciences of Yunnan Province (2006C0046Q)Partly by the Chinese Academy of Sciences (O706551141)
文摘The cDNA encoding the luciferase from lantern mRNA of one diurnal firefly Pyrocoelia pygidialis Pic, 1926 has been cloned, sequenced and functionally expressed. The cDNA sequence of P pygidialis luciferase is 1647 base pairs in length, coding a protein of 548 amino acid residues. Sequence analysis of the deduced amino acid sequence showed that this luciferase had 97.8% resemblance to luciferases from the fireflies Lampyris noctiluca, Lampyris turkestanicus and Nyctophila cf. caucasica. Phylogenetic analysis using deduced amino acid sequence showed that P pygidialis located at the base of Lampyris＋Nyctophila clade with robust support （BP=97%）; but did not show a monophyletic relationship with its congeneric species P pectoralis, P tufa and P miyako, all three are strong luminous and nocturnal species. The expression worked in recombinant Escherichia coli. Expression product had a 70kDa band and emitted yellow-green luminescence in the presence of luciferin. Five loops in the P pygidialis luciferase, L1 （NI98-G208）, L2 （T240-G247）, L3 （G317-K322）, L4 （L343-I350） and L5 （G522-D532）, were found from the structure modeling analysis in the cleft, where it was considered the active site for the substrate compound entering and binding. Different amino acid residues between the luciferases of P. pygidialis and the three other known strong luminous species can not explain the situation of weak or strong luminescence. Future study of these loops, residues or crystal structure analysis may be helpful in understanding the real differences between the luciferases between diurnal and nocturnal species.
