[Objective] The experiment aimed to explore the influence of enhanced ultraviolet radiation-B on maize in arid regions of middle-high elevation for correct assessing the influence of enhanced ultraviolet radiation-B o...[Objective] The experiment aimed to explore the influence of enhanced ultraviolet radiation-B on maize in arid regions of middle-high elevation for correct assessing the influence of enhanced ultraviolet radiation-B on maize and providing scientific reference to make proper countermeasures. [ Method] The location test in field and lift lamp of UV-B were used to observe the changes of maize height, leaf area and number of green leaves under influences of different UV-B radiation. [ Result] In arid regions of middle-high elevation, enhanced ultraviolet radiation-B could dwarf maize plant, decrease leaf area, decline number of green leaves and yield. The reason of decreasing leaf area was that enhanced ultraviolet radiation-B shortened leaf length and leaf width while the reason of declining yield was that yield components were all negatively influ- enced and with the increase of ultraviolet radiation-B, the yield declined dramatically. [ Concluslonl The result of this experiment would be good for maize production in arid regions of middle-high elevation.展开更多
[Objective] This study aimed to conduct correspondence cluster analysis of the trace elements in Chinese wolfberry from Qinghai and Ningxia regions, and to investigate the relationship among the quality of the wolfber...[Objective] This study aimed to conduct correspondence cluster analysis of the trace elements in Chinese wolfberry from Qinghai and Ningxia regions, and to investigate the relationship among the quality of the wolfberry samples, the composition of trace elements and the sample sources. [Method] The determined contents of trace elements and ratios of zinc to copper (Zn/Cu) of wolfberry from 11 different producing areas of Qinghai and Ningxia regions were adopted to construct the raw measurement data matrix, to analyze the distribution characteristics of the trace ele- ments in wolfberry from Qinghai and Ningxia by using the corresponding cluster analysis method. [Result] The quality of wolfberry samples in 7hongning County, Zhongwei City, Pingluo County, Shizuishan City, Heicheng Town of Ningxia Hui Au-tonomous Region and Hehuang Valley, Golmud City of Qinghai Province is mainly related to the contents of Zn and Mn; Zn/Cu greatly affects the quality of Chinese wolfberry in Dulan County of Qinghai Province; Fe has great effect on the quality of Chinese wolfberry in Yinchuan City of Ningxia Hui Autonomous Region; Cu greatly affects the quality of Chinese wolfberry in Nuomuhong Village of Qinghai Province and a wolfberry research institute in Ningxia. [Conclusion] The relationship between the quality of wolfberry from different producing areas and the trace elements was investigated, which provides theoretical and practical basis for the cultivation, har- vesting, processing, and further development and utilization of Chinese wolfberry resources from different producing areas.展开更多
The land-sea thermal contrast is an important driver for monsoon interannual variability and the monsoon onset.The thermal contrast between the Tibetan Plateau and the tropical Indian Ocean at the mid-upper tropospher...The land-sea thermal contrast is an important driver for monsoon interannual variability and the monsoon onset.The thermal contrast between the Tibetan Plateau and the tropical Indian Ocean at the mid-upper troposphere is proposed as a thermal contrast index(TCI)for South Asian monsoon.The authors investigate the TCI associated with South Asian summer monsoon(SASM)intensity and SASM onset.It is observed that the TCI considering the Tibetan Plateau and tropical Indian Ocean demonstrates a stronger and closer correlation with SASM intensity(0.87)than either the Tibetan Plateau(0.42)or tropical Indian Ocean(-0.60)singly.It is implied that the TCI could preferably represent the impact of land-sea thermal condition on SASM activity.Further analysis reveals that the evolution of TCI is related to the SASM onset.The TCI is almost always larger in early onset years than it is in late onset years during the period before SASM onset.In addition,the change of the pentad-by-pentad increment of TCI leads the SASM variation.The correlation coefficient between the TCI increment and SASM index reaches a maximum when the TCI increment leads by 15 pentads.The results of this study show that the TCI plays an important role in SASM activities and is a potential indicator for SASM onset forecasting.展开更多
This study focuses on deep convection anomalies in tropical regions in winter-spring period and their possible influence on the following summer rainfall in Shandong province. On the basis of monthly precipitation wet...This study focuses on deep convection anomalies in tropical regions in winter-spring period and their possible influence on the following summer rainfall in Shandong province. On the basis of monthly precipitation wet and dry summers in Shandong are defined according to a precipitation index. Then monthly OLR data, observed by NOAA satellites, are used to diagnose the features of deep convection for both wet and dry summers. It is found that negative anomalies seem dominant prior to wet summers, while large areas of positive anomalies appear prior to dry summers in tropical oceans. The differences are remarkable especially in the western, middle and eastern tropical Pacific as well as in the tropical Indian Ocean. Correlative analysis confirms the relations between OLR and precipitation. Subtropical High, which plays an essential role in summer rainfall, is also connected with the deep conviction. Altogether eight EOF-CCA forecast models are established on the basis of the above study. The assessment of the models relies on the gauge observing precipitation in 1997 and 1998. The results show that models using spring OLR data appear to be more practicable than those using winter OLR data, and the models established with OLR in western Pacific and the Indian Ocean perform better than the others.展开更多
In this paper, Geostationary Meteorological Satellite (GMS) infrared black-body temperature (Tbb) data from June to August 1998 are used to automatically track the activity of Mesoscale Convective System (MCS) over th...In this paper, Geostationary Meteorological Satellite (GMS) infrared black-body temperature (Tbb) data from June to August 1998 are used to automatically track the activity of Mesoscale Convective System (MCS) over the Tibetan Plateau in China. Consequently, the features of MCS, such as area, intensity, life cycle, activity region and shape, are obtained. High Resolution Limited Area Analysis and Forecasting System (HLAFS) values provided by China National Meteorological Center are used to study the relationships between the MCS trajectories and their environmental physical field values, based on the distribution and trajectories of MCSs over the Tibetan Plateau. Favorable environmental physical field charts of influencing MCS movement out of the Tibetan Plateau in different UTC (Universal Time Coordinate) are developed by using spatial data mining techniques at levels of 400hPa and 500hPa, respectively.展开更多
By using 40-year NCEP reanalysis daily data (1958-1997), we have analyzed the climatic characteristics of summer monsoon onset in the South China Sea (105E ~ 120E, 5N ~ 20N, to be simplified as SCS in the text followe...By using 40-year NCEP reanalysis daily data (1958-1997), we have analyzed the climatic characteristics of summer monsoon onset in the South China Sea (105E ~ 120E, 5N ~ 20N, to be simplified as SCS in the text followed) pentad by pentad (5 days). According to our new definition, in the monsoon area of the SCS two of the following conditions should be satisfied: 1) At 850hPa, the southwest winds should be greater than 2m/s. 2) At 850 hPa, seq should be greater than 335K. The new definition means that the summer monsoon is the southwest winds with high temperature and high moisture. The onset of the SCS summer monsoon is defined to start when one half of the SCS area (105E ~ 120E,5N ~ 20N) is controlled by the summer monsoon. The analyzed results revealed the following: 1) The summer monsoon in the SCS starts to build up abruptly in the 4th pentad in May. 2) The summer monsoon onset in the SCS is resulted from the development and intensification of southwesterly monsoon in the Bay of Bengal. 3) The onset of the summer monsoon and establishment of the summer monsoon rainfall season in the SCS occur simultaneously. 4) During the summer monsoon onset in the SCS, troughs deepen and widen quickly in the lower troposphere of the India; the subtropical high in the Western Pacific moves eastward off the SCS in the middle troposphere; the easterly advances northward over the SCS in the upper troposphere.展开更多
The pentad average minimum outgoing longwave radiation (OLR) data over the northern South China Sea (SCS) are selected as indexes to analyze the intensity of the convection connected with the SCS monsoon onset. Statis...The pentad average minimum outgoing longwave radiation (OLR) data over the northern South China Sea (SCS) are selected as indexes to analyze the intensity of the convection connected with the SCS monsoon onset. Statistic analysis demonstrates that the index can account for the intensity of the SCS monsoon about, at least, 75%. A significant negative correlation (confident level over 90%) between Shandong’s summer rainfall and the index is found only in the period of 24-26 pentads and limited to the area above the deeper water basin of the SCS (10°-20°N, 110°-117.5°E). Thus the minimum OLR over the deeper water basin during 24-26 pentads can be used as a valuable predictor for the long lead forecast of the precipitation. The 500 hPa geopotential height data in the Northern Hemisphere for the period from 1951 to 2000 are used in order to characterize the physical mechanisms involved. The composite anomalies of the 500 hPa level allow for the identification and detection of the teleconnection of the East Asia North America (EAP) pattern that is responsible to some extent for the interannual variability of the precipitation of Shandong Province. Besides, the interannual differences of the intraseasonal variations (ISV) of OLR and their northward transmission probably make a contribution to the position of the subtropical high which is vital for the summer rainfall in the province.展开更多
Since the South China Sea (SCS) summer monsoon (SCSSM) is pronouncedly featured by abruptly intensified southwesterly and obviously increased precipitation over the SCS,the lower-tropospheric winds and/or convection i...Since the South China Sea (SCS) summer monsoon (SCSSM) is pronouncedly featured by abruptly intensified southwesterly and obviously increased precipitation over the SCS,the lower-tropospheric winds and/or convection intensities are widely used to determine the SCSSM onset.The methods can be used successfully in most of the years but not in 2006.Due to the intrusion of Typhoon Chanchu(0601)that year,the usual method of determining SCSSM onset date by utilizing the SCS regional indices is less capable of pinpointing the real onset date.In order to solve the problem,larger-scale situations have to be taken into account.Zonal and meridional circulations would be better to determine the break-out date of SCSSM in 2006.The result indicates that its onset date is May 16.Moreover,similar onset dates for other years can be obtained using various methods,implying that large-scale zonal and meridional circulations can be used as an alternative method for determining the SCSSM onset date.展开更多
The important effects of local land-sea thermodynamic contrast between the South China Sea (SCS) and Indochina Peninsula on SCS summer monsoon onset are preliminarily studied by using two sets of SSTA tests and two id...The important effects of local land-sea thermodynamic contrast between the South China Sea (SCS) and Indochina Peninsula on SCS summer monsoon onset are preliminarily studied by using two sets of SSTA tests and two ideal tests in s-p regional climate model. The result shows that warm SST in the SCS in winter and spring is favorable for the formation of monsoon circulation throughout all levels of the atmosphere over the sea, which hastens the onset of SCS summer monsoon. The effects of cold SST are generally the opposite. The local land-sea contrast in the SCS is one of the possible reasons for SCS summer monsoon onset. Superposed upon large-scale land-sea thermodynamic differences, it facilitates the formation of out-breaking onset characteristics of SCS summer monsoon in the SCS area.展开更多
The influence of summer monsoon on tropical cyclone (TC) genesis over the Bay of Bengal (BoB) is explored using an empirical genesis potential (GP) index. The annual cycle of cyclogenesis frequency over the BoB shows ...The influence of summer monsoon on tropical cyclone (TC) genesis over the Bay of Bengal (BoB) is explored using an empirical genesis potential (GP) index. The annual cycle of cyclogenesis frequency over the BoB shows an asymmetric bimodal pattern with the maximum genesis number appearing in late October and the second largest in early May. The two peaks correspond to the withdrawal and onset of the BoB summer monsoon, respectively. The semimonthly GP index calculated without TC days over the BoB is consistent with TC genesis frequency, indicating that the index captures the monsoon-induced changes in the environment that are responsible for the seasonal variation of TC genesis frequency. Of the four environmental variables (i.e., low-level vorticity, mid-level relative humidity, potential intensity, and vertical wind shear) that enter into the GP index, the potential intensity makes the largest contribution to the bimodal distribution, followed by vertical wind shear due to small wind speed during the summer monsoon onset and withdrawal. The difference in TC genesis frequency between autumn and late spring is mainly owing to the relative humid-ity difference because a divergence (convergence) of horizontal moisture flux associated with cold dry northerlies (warm wet wester-lies) dominates the BoB in late spring (autumn).展开更多
Mesoscale convective system (MCS) cloud clusters,defined using an objective recognition analysis based on hourly geostationary infrared satellite data over East Asia during the warm seasons of 1996-2008 (except 2004),...Mesoscale convective system (MCS) cloud clusters,defined using an objective recognition analysis based on hourly geostationary infrared satellite data over East Asia during the warm seasons of 1996-2008 (except 2004),were investigated in this study.The geographical pattern of MCS distribution over East Asia shows several high-frequency centers at low latitudes,including the Indo-China peninsula,the Bay of Bengal,the Andaman Sea,the Brahmaputra river delta,the south China coastal region,and the Philippine Islands.There are several middle-frequency centers in the middle latitudes,e.g.,the central-east of the Tibet Plateau,the Plateau of west Sichuan,Mount Wuyi,and the Sayan Mountains in Russia;whereas in Lake Baikal,the Tarim Basin,the Taklimakan Desert,the Sea of Japan,and the Sea of Okhotsk,rare MCS distributions are observed.MCSs are most intensely active in summer,with the highest monthly frequency in July,which is partly associated with the breaking out and prevailing of the summer monsoon in East Asia.An obvious diurnal cycle feature is also found in MCS activities,which shows that MCSs are triggered in the afternoon,mature in the evening,and dissipate at night.MCS patterns over East Asia can be characterized as small,short-lived,or elongated,which move slowly and usually lead to heavy rains or floods.展开更多
Using the monthly mean reanalysis data of height, wind and vertical velocity of NCEP/NCAR from 1958 to 2003, the characteristics of 500hPa height anomalies in the Northern Hemisphere, convergence and divergence on the...Using the monthly mean reanalysis data of height, wind and vertical velocity of NCEP/NCAR from 1958 to 2003, the characteristics of 500hPa height anomalies in the Northern Hemisphere, convergence and divergence on the levels of 200hPa and 925hPa and vertical stream over the Shandong province were studied and compared with that over North China. The study shows that the teleconnection pattern called East Asia-Pacific pattern (EAP) plays important roles in the summer rainfall of Shandong. Weaker Okhotsk sea high, stronger upward stream over tropical areas and Shandong and northward location of subtropical high and stronger Indian low, are likely to lead to more rain in Shandong province in summer, but there are some flood (drought) years in which these characteristics such as the location and intensity of subtropical high change with the least extent. The difference between Shandong and North China in 500hPa height is that there is a teleconnection pattern called Europe / Asia pattern in North China, while there is a negative East Asia Pattern in Shandong during drought years. There is a teleconnection relation between Shandong summer rainfall and convective activities happening in tropical areas in spring and summer accomplished by the Rossby waves. During the flood years in Shandong, the convective activities happening in tropical India Ocean and tropical west Pacific and Walker circulation are much stronger than that during the drought years, but the convective activities happening in tropical east Pacific are weaker than those during the drought years.展开更多
To assess the effects of hypoxia, macrobenthic communities along an estuarine gradient of the Changjiang estuary and adjacent continental shelf were analyzed. This revealed spatial variations in the communities and re...To assess the effects of hypoxia, macrobenthic communities along an estuarine gradient of the Changjiang estuary and adjacent continental shelf were analyzed. This revealed spatial variations in the communities and relationships with environmental variables during periods of reduced dissolved oxygen (DO) concentration in summer. Statistical analyses revealed significant differences in macrobenthic community composition among the three zones: estuarine zone (EZ), mildly hypoxic zone (MHZ) in the continental shelf, and norrnoxic zone (NZ) in the continental shelf(Global R=0.206, P=0.002). Pairwise tests showed that the macrobenthic community composition of the EZ was significantly different from the MHZ (pairwise test R=0.305, P=0.001) and the NZ (pairwise test R=0.259, P=-0.001). There was no significant difference in macrobenthic communities between the MHZ and the NZ (pairwise test R=0.062, P=-0.114). The taxa included small and typically opportunistic polychaetes, which made the greatest contribution to the dissimilarity between the zones. The effects of mild hypoxia on the macrobenthic communities are a result not only of reduced DO concentration but also of differences in environmental variables such as temperature, salinity, and nutrient concentrations caused by stratification.展开更多
Based on the temperature of the black body (TBB),station observed and NCEP reanalysis data,the impacts of the eastward propagation of convective cloud systems over the Tibetan Plateau on the southwest vortex (SWV) for...Based on the temperature of the black body (TBB),station observed and NCEP reanalysis data,the impacts of the eastward propagation of convective cloud systems over the Tibetan Plateau on the southwest vortex (SWV) formation that occurred at 1800 UTC on 29 June 2003 are analyzed by using the Zwack-Okossi (Z-O) equation to diagnose the thermal and dynamic processes.It is found that,in summer,severe convective activities often occur over the Tibetan Plateau due to the abundant supply of moisture.The convective cloud near the east edge of the plateau could move eastward with a shortwave trough in the westerly.The divergent center that is induced by latent heat release,which is associated with severe convective activities,moves out with the convective cloud and contributes to the low level decompression which is favorable for the formation of plateau edge cyclogenesis (PEC).The Z-O equation indicates that,in this case,the latent heat release and convergence are the two most important factors for SWV formation,which amounts to about 42% and 15% of the term TOTAL,respectively.It is implied that the thermal process effect was more important than the dynamic process during SWV formation.展开更多
The distribution characteristics of cloud-top and tropopause height in the tropics and subtropics in boreal summer are analyzed based on CALIPSO data for the period 2008-2012.The maximum values of cloud-top vertical c...The distribution characteristics of cloud-top and tropopause height in the tropics and subtropics in boreal summer are analyzed based on CALIPSO data for the period 2008-2012.The maximum values of cloud-top vertical cumulative frequency above the tropopause (CTAT) are concentrated in three tropical regions:the Asian summer monsoon region,Central America,and western Africa.The contributions to the area-weighted CTAT frequency in the three regions from the Northern Hemisphere are 49.0%,13.5%,and 12.4%,respectively.Moreover,the contribution of troposphere-to-stratosphere transport (TST) in the Asian monsoon region to global TST can be far greater than 50%,according to analysis of the continuous equation,velocity potential,and divergent wind from ERA-Interim data.Furthermore,the Asian summer monsoon circulation system controls the distribution of the cloud top.On the south side of the Tibetan Plateau,the maximum frequency of the cloud top,more than 10% per 500 m vertically,is most likely to appear in the core of the high-level easterlyjet near the tropopause height (16.5 km).Over the Tibetan Plateau,the maximum frequency of the cloud top,greater than 3% per 500 m vertically,is suppressed below 11 km,far away from the thermodynamic tropopause height but close to the dynamic tropopause height of 2 PVU (potential vorticity units).展开更多
This study designed a simple index for measuring irregular tropospheric biennial oscillation(TBO) activities, which was used to determine that the TBO in the East Asian Summer Monsoon(EASM), the most important summer ...This study designed a simple index for measuring irregular tropospheric biennial oscillation(TBO) activities, which was used to determine that the TBO in the East Asian Summer Monsoon(EASM), the most important summer precipitation system for China, has strengthened rather than weakened since the late 1970s. The lead/lag correlations between the EASM and tropical Indian-Pacific sea surface temperature(SST) suggest a relationship between interbasin SST and EASM coupling processes and that this alternative correlation pattern is likely related to TBO. Significant correlation occurred only in recent decades, which implies a reinforcement of TBO in the EASM. From records of representative points in the Indian-Pacific, the interdecadal intrinsic SST modes of the areas can be obtained with ensemble empirical mode decomposition owing to its good temporal locality. Statistical results show Indian-Pacific SST interdecadal trends that include out-of-phase and in-phase warming before and after the late 1970s, respectively, which may be responsible for the TBO interdecadal augmentation present since the late 1970s.展开更多
OBJECTIVE: To study the protective effects of Dongchongxiacao(Cordyceps)(DCXC) on contrast-induced nephropathy(CIN) in patients with type 2 diabetes and renal insufficiency undergoing coronary angiography.METHODS: A t...OBJECTIVE: To study the protective effects of Dongchongxiacao(Cordyceps)(DCXC) on contrast-induced nephropathy(CIN) in patients with type 2 diabetes and renal insufficiency undergoing coronary angiography.METHODS: A total of 120 patients with type 2 diabetes whose estimated glomerular filtration rate(e GFR) was ≤ 60 m L/minee grou·1.73 m2,were divided randomly into thrps,basic treatment group(n = 41),standard DCXC therapy group(n = 39,2-g corbrin capsules,3 times/d,3 days before and after angiography),and intensive DCXC therapy group(n = 40,3-g corbrin capsules,3 times/d,3 days before and after angiography). Serum creatinine(Scr)and e GFR were assessed at the time of admission to hospital,and on days 1,2 and 3 after angiography. Urine neutrophil-gelatinase-associated-lipocalin(NGAL),kidney injury molecule-1(KIM-1) and interleukin-18(IL-18) were measured before angiography and at day 1 after angiography for all patients. The primary end point was the prevalence of CIN. The secondary end point was a 25% or greater reduction in e GFR.RESULTS: CIN occurred in 11 of 120 patients(9.17 %). The prevalence of CIN was lower in the DCXC treatment groups than in the basic treatment group(P < 0.05),with a more significant decrease in the prevalence of CIN in the intensive DCXC therapy group(P < 0.01). Compared with the basic treatment group,a lower proportion of patients in the DCXC treatment groups had an e GFR decrease of 25% or greater(P < 0.05); patients with an e GFR decrease of 25% or greater accounted for an even lower proportion in the intensive DCXC therapy group(P < 0.01). Within 1 day of the procedure,urine levels of KIM-1,NGAL and IL-18 in patients in the intensive DCXC therapy group were lower than those in the basic treatment group and standard therapy group(P < 0.05).CONCLUSION: DCXC treatment may protect against CIN in patients with type 2 diabetes and renal insufficiency undergoing coronary angiography,with intensive DCXC therapy being more effective.展开更多
基金Supported by Natural Science Foundation of Ningxia Autonomous Re-gion(A1012)~~
文摘[Objective] The experiment aimed to explore the influence of enhanced ultraviolet radiation-B on maize in arid regions of middle-high elevation for correct assessing the influence of enhanced ultraviolet radiation-B on maize and providing scientific reference to make proper countermeasures. [ Method] The location test in field and lift lamp of UV-B were used to observe the changes of maize height, leaf area and number of green leaves under influences of different UV-B radiation. [ Result] In arid regions of middle-high elevation, enhanced ultraviolet radiation-B could dwarf maize plant, decrease leaf area, decline number of green leaves and yield. The reason of decreasing leaf area was that enhanced ultraviolet radiation-B shortened leaf length and leaf width while the reason of declining yield was that yield components were all negatively influ- enced and with the increase of ultraviolet radiation-B, the yield declined dramatically. [ Concluslonl The result of this experiment would be good for maize production in arid regions of middle-high elevation.
文摘[Objective] This study aimed to conduct correspondence cluster analysis of the trace elements in Chinese wolfberry from Qinghai and Ningxia regions, and to investigate the relationship among the quality of the wolfberry samples, the composition of trace elements and the sample sources. [Method] The determined contents of trace elements and ratios of zinc to copper (Zn/Cu) of wolfberry from 11 different producing areas of Qinghai and Ningxia regions were adopted to construct the raw measurement data matrix, to analyze the distribution characteristics of the trace ele- ments in wolfberry from Qinghai and Ningxia by using the corresponding cluster analysis method. [Result] The quality of wolfberry samples in 7hongning County, Zhongwei City, Pingluo County, Shizuishan City, Heicheng Town of Ningxia Hui Au-tonomous Region and Hehuang Valley, Golmud City of Qinghai Province is mainly related to the contents of Zn and Mn; Zn/Cu greatly affects the quality of Chinese wolfberry in Dulan County of Qinghai Province; Fe has great effect on the quality of Chinese wolfberry in Yinchuan City of Ningxia Hui Autonomous Region; Cu greatly affects the quality of Chinese wolfberry in Nuomuhong Village of Qinghai Province and a wolfberry research institute in Ningxia. [Conclusion] The relationship between the quality of wolfberry from different producing areas and the trace elements was investigated, which provides theoretical and practical basis for the cultivation, har- vesting, processing, and further development and utilization of Chinese wolfberry resources from different producing areas.
基金supported jointly by the Strategic Priority Research Program of the Chinese Academy of Sciences[Grant number XDA20060501]the National Natural Science Foundation of China[Grant numbers U1902209 and 91637208]。
文摘The land-sea thermal contrast is an important driver for monsoon interannual variability and the monsoon onset.The thermal contrast between the Tibetan Plateau and the tropical Indian Ocean at the mid-upper troposphere is proposed as a thermal contrast index(TCI)for South Asian monsoon.The authors investigate the TCI associated with South Asian summer monsoon(SASM)intensity and SASM onset.It is observed that the TCI considering the Tibetan Plateau and tropical Indian Ocean demonstrates a stronger and closer correlation with SASM intensity(0.87)than either the Tibetan Plateau(0.42)or tropical Indian Ocean(-0.60)singly.It is implied that the TCI could preferably represent the impact of land-sea thermal condition on SASM activity.Further analysis reveals that the evolution of TCI is related to the SASM onset.The TCI is almost always larger in early onset years than it is in late onset years during the period before SASM onset.In addition,the change of the pentad-by-pentad increment of TCI leads the SASM variation.The correlation coefficient between the TCI increment and SASM index reaches a maximum when the TCI increment leads by 15 pentads.The results of this study show that the TCI plays an important role in SASM activities and is a potential indicator for SASM onset forecasting.
基金Physical Causes of Short-term Drought and Floods Climate in Shandong Province and the Prediction a sub-subject in the item of Studies on Short-term Climate Prediction System in China (96-908-05-06-10)
文摘This study focuses on deep convection anomalies in tropical regions in winter-spring period and their possible influence on the following summer rainfall in Shandong province. On the basis of monthly precipitation wet and dry summers in Shandong are defined according to a precipitation index. Then monthly OLR data, observed by NOAA satellites, are used to diagnose the features of deep convection for both wet and dry summers. It is found that negative anomalies seem dominant prior to wet summers, while large areas of positive anomalies appear prior to dry summers in tropical oceans. The differences are remarkable especially in the western, middle and eastern tropical Pacific as well as in the tropical Indian Ocean. Correlative analysis confirms the relations between OLR and precipitation. Subtropical High, which plays an essential role in summer rainfall, is also connected with the deep conviction. Altogether eight EOF-CCA forecast models are established on the basis of the above study. The assessment of the models relies on the gauge observing precipitation in 1997 and 1998. The results show that models using spring OLR data appear to be more practicable than those using winter OLR data, and the models established with OLR in western Pacific and the Indian Ocean perform better than the others.
基金Under the auspices of the National Natural Science Foundation of China (No. 40371080), Key Project of ChineseMinistry of Education (No. 104083), Foundation of Wuhan University State Key Laboratory of Information Engineering in Survey-ing, Mapping and Remote Sensing (No. WKL(03) 0103), the Scientific Research Foundation for the Returned Overseas ChineseScholars, Ministry of Education
文摘In this paper, Geostationary Meteorological Satellite (GMS) infrared black-body temperature (Tbb) data from June to August 1998 are used to automatically track the activity of Mesoscale Convective System (MCS) over the Tibetan Plateau in China. Consequently, the features of MCS, such as area, intensity, life cycle, activity region and shape, are obtained. High Resolution Limited Area Analysis and Forecasting System (HLAFS) values provided by China National Meteorological Center are used to study the relationships between the MCS trajectories and their environmental physical field values, based on the distribution and trajectories of MCSs over the Tibetan Plateau. Favorable environmental physical field charts of influencing MCS movement out of the Tibetan Plateau in different UTC (Universal Time Coordinate) are developed by using spatial data mining techniques at levels of 400hPa and 500hPa, respectively.
基金National Scaling Project A The Scientific Experiment on South China Sea Monsoon
文摘By using 40-year NCEP reanalysis daily data (1958-1997), we have analyzed the climatic characteristics of summer monsoon onset in the South China Sea (105E ~ 120E, 5N ~ 20N, to be simplified as SCS in the text followed) pentad by pentad (5 days). According to our new definition, in the monsoon area of the SCS two of the following conditions should be satisfied: 1) At 850hPa, the southwest winds should be greater than 2m/s. 2) At 850 hPa, seq should be greater than 335K. The new definition means that the summer monsoon is the southwest winds with high temperature and high moisture. The onset of the SCS summer monsoon is defined to start when one half of the SCS area (105E ~ 120E,5N ~ 20N) is controlled by the summer monsoon. The analyzed results revealed the following: 1) The summer monsoon in the SCS starts to build up abruptly in the 4th pentad in May. 2) The summer monsoon onset in the SCS is resulted from the development and intensification of southwesterly monsoon in the Bay of Bengal. 3) The onset of the summer monsoon and establishment of the summer monsoon rainfall season in the SCS occur simultaneously. 4) During the summer monsoon onset in the SCS, troughs deepen and widen quickly in the lower troposphere of the India; the subtropical high in the Western Pacific moves eastward off the SCS in the middle troposphere; the easterly advances northward over the SCS in the upper troposphere.
基金sponsored by the program‘The comprehensive research on the Nansha islands and the adjacent sea’ratified by the Ministry of Science and Technology of China(No.2001DIA50041)
文摘The pentad average minimum outgoing longwave radiation (OLR) data over the northern South China Sea (SCS) are selected as indexes to analyze the intensity of the convection connected with the SCS monsoon onset. Statistic analysis demonstrates that the index can account for the intensity of the SCS monsoon about, at least, 75%. A significant negative correlation (confident level over 90%) between Shandong’s summer rainfall and the index is found only in the period of 24-26 pentads and limited to the area above the deeper water basin of the SCS (10°-20°N, 110°-117.5°E). Thus the minimum OLR over the deeper water basin during 24-26 pentads can be used as a valuable predictor for the long lead forecast of the precipitation. The 500 hPa geopotential height data in the Northern Hemisphere for the period from 1951 to 2000 are used in order to characterize the physical mechanisms involved. The composite anomalies of the 500 hPa level allow for the identification and detection of the teleconnection of the East Asia North America (EAP) pattern that is responsible to some extent for the interannual variability of the precipitation of Shandong Province. Besides, the interannual differences of the intraseasonal variations (ISV) of OLR and their northward transmission probably make a contribution to the position of the subtropical high which is vital for the summer rainfall in the province.
基金Major State Basic Research Development Program of China(973 Program)(2010CB950304)
文摘Since the South China Sea (SCS) summer monsoon (SCSSM) is pronouncedly featured by abruptly intensified southwesterly and obviously increased precipitation over the SCS,the lower-tropospheric winds and/or convection intensities are widely used to determine the SCSSM onset.The methods can be used successfully in most of the years but not in 2006.Due to the intrusion of Typhoon Chanchu(0601)that year,the usual method of determining SCSSM onset date by utilizing the SCS regional indices is less capable of pinpointing the real onset date.In order to solve the problem,larger-scale situations have to be taken into account.Zonal and meridional circulations would be better to determine the break-out date of SCSSM in 2006.The result indicates that its onset date is May 16.Moreover,similar onset dates for other years can be obtained using various methods,implying that large-scale zonal and meridional circulations can be used as an alternative method for determining the SCSSM onset date.
基金National Natural Science Foundation of China (40175021 40233037)
文摘The important effects of local land-sea thermodynamic contrast between the South China Sea (SCS) and Indochina Peninsula on SCS summer monsoon onset are preliminarily studied by using two sets of SSTA tests and two ideal tests in s-p regional climate model. The result shows that warm SST in the SCS in winter and spring is favorable for the formation of monsoon circulation throughout all levels of the atmosphere over the sea, which hastens the onset of SCS summer monsoon. The effects of cold SST are generally the opposite. The local land-sea contrast in the SCS is one of the possible reasons for SCS summer monsoon onset. Superposed upon large-scale land-sea thermodynamic differences, it facilitates the formation of out-breaking onset characteristics of SCS summer monsoon in the SCS area.
基金supported by the National Basic Research Program of China(973Program:2012CB955604)National Natural Science Foundation of China(No.40975038,40830106)the CMA Program(GYHY200906008)
文摘The influence of summer monsoon on tropical cyclone (TC) genesis over the Bay of Bengal (BoB) is explored using an empirical genesis potential (GP) index. The annual cycle of cyclogenesis frequency over the BoB shows an asymmetric bimodal pattern with the maximum genesis number appearing in late October and the second largest in early May. The two peaks correspond to the withdrawal and onset of the BoB summer monsoon, respectively. The semimonthly GP index calculated without TC days over the BoB is consistent with TC genesis frequency, indicating that the index captures the monsoon-induced changes in the environment that are responsible for the seasonal variation of TC genesis frequency. Of the four environmental variables (i.e., low-level vorticity, mid-level relative humidity, potential intensity, and vertical wind shear) that enter into the GP index, the potential intensity makes the largest contribution to the bimodal distribution, followed by vertical wind shear due to small wind speed during the summer monsoon onset and withdrawal. The difference in TC genesis frequency between autumn and late spring is mainly owing to the relative humid-ity difference because a divergence (convergence) of horizontal moisture flux associated with cold dry northerlies (warm wet wester-lies) dominates the BoB in late spring (autumn).
基金supported by the National Basic Research Program of China(973Program,Grant No.2011CB309704)the Ministry of Finance of China and the China Meteorological Administration for the Special Project of Meteorological Sector(Grant No.GYHY(QX)201006014)the National Natural Science Foundation of China(Grant No.40875022)
文摘Mesoscale convective system (MCS) cloud clusters,defined using an objective recognition analysis based on hourly geostationary infrared satellite data over East Asia during the warm seasons of 1996-2008 (except 2004),were investigated in this study.The geographical pattern of MCS distribution over East Asia shows several high-frequency centers at low latitudes,including the Indo-China peninsula,the Bay of Bengal,the Andaman Sea,the Brahmaputra river delta,the south China coastal region,and the Philippine Islands.There are several middle-frequency centers in the middle latitudes,e.g.,the central-east of the Tibet Plateau,the Plateau of west Sichuan,Mount Wuyi,and the Sayan Mountains in Russia;whereas in Lake Baikal,the Tarim Basin,the Taklimakan Desert,the Sea of Japan,and the Sea of Okhotsk,rare MCS distributions are observed.MCSs are most intensely active in summer,with the highest monthly frequency in July,which is partly associated with the breaking out and prevailing of the summer monsoon in East Asia.An obvious diurnal cycle feature is also found in MCS activities,which shows that MCSs are triggered in the afternoon,mature in the evening,and dissipate at night.MCS patterns over East Asia can be characterized as small,short-lived,or elongated,which move slowly and usually lead to heavy rains or floods.
基金Dedicated Research Fund for Public Interest from the Ministry of Science and Technology (2001DIB20104) "Relationship Between Subtropical Monsoon Circulation and Summer Precipitation in Shandong", a key science project for 2002 in the Shandong province.
文摘Using the monthly mean reanalysis data of height, wind and vertical velocity of NCEP/NCAR from 1958 to 2003, the characteristics of 500hPa height anomalies in the Northern Hemisphere, convergence and divergence on the levels of 200hPa and 925hPa and vertical stream over the Shandong province were studied and compared with that over North China. The study shows that the teleconnection pattern called East Asia-Pacific pattern (EAP) plays important roles in the summer rainfall of Shandong. Weaker Okhotsk sea high, stronger upward stream over tropical areas and Shandong and northward location of subtropical high and stronger Indian low, are likely to lead to more rain in Shandong province in summer, but there are some flood (drought) years in which these characteristics such as the location and intensity of subtropical high change with the least extent. The difference between Shandong and North China in 500hPa height is that there is a teleconnection pattern called Europe / Asia pattern in North China, while there is a negative East Asia Pattern in Shandong during drought years. There is a teleconnection relation between Shandong summer rainfall and convective activities happening in tropical areas in spring and summer accomplished by the Rossby waves. During the flood years in Shandong, the convective activities happening in tropical India Ocean and tropical west Pacific and Walker circulation are much stronger than that during the drought years, but the convective activities happening in tropical east Pacific are weaker than those during the drought years.
基金Supported by the National Basic Research Program of China(973 Program)(No.2010CB428903)the National Marine Public Welfare Research Project of China(Nos.201505004-3,201305043)+1 种基金the Scientific Research Fund of the Second Institute of Oceanography,SOA(No.JG1312)the National Special Fund of Chinese Offshore Investigation and Assessment(No.908-01-ST04)
文摘To assess the effects of hypoxia, macrobenthic communities along an estuarine gradient of the Changjiang estuary and adjacent continental shelf were analyzed. This revealed spatial variations in the communities and relationships with environmental variables during periods of reduced dissolved oxygen (DO) concentration in summer. Statistical analyses revealed significant differences in macrobenthic community composition among the three zones: estuarine zone (EZ), mildly hypoxic zone (MHZ) in the continental shelf, and norrnoxic zone (NZ) in the continental shelf(Global R=0.206, P=0.002). Pairwise tests showed that the macrobenthic community composition of the EZ was significantly different from the MHZ (pairwise test R=0.305, P=0.001) and the NZ (pairwise test R=0.259, P=-0.001). There was no significant difference in macrobenthic communities between the MHZ and the NZ (pairwise test R=0.062, P=-0.114). The taxa included small and typically opportunistic polychaetes, which made the greatest contribution to the dissimilarity between the zones. The effects of mild hypoxia on the macrobenthic communities are a result not only of reduced DO concentration but also of differences in environmental variables such as temperature, salinity, and nutrient concentrations caused by stratification.
基金supported by the National Natural Science Foundation of China (Grant Nos. 40875021 and 40930951)the project of the State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences (Grant No. 2009LASW-A03)
文摘Based on the temperature of the black body (TBB),station observed and NCEP reanalysis data,the impacts of the eastward propagation of convective cloud systems over the Tibetan Plateau on the southwest vortex (SWV) formation that occurred at 1800 UTC on 29 June 2003 are analyzed by using the Zwack-Okossi (Z-O) equation to diagnose the thermal and dynamic processes.It is found that,in summer,severe convective activities often occur over the Tibetan Plateau due to the abundant supply of moisture.The convective cloud near the east edge of the plateau could move eastward with a shortwave trough in the westerly.The divergent center that is induced by latent heat release,which is associated with severe convective activities,moves out with the convective cloud and contributes to the low level decompression which is favorable for the formation of plateau edge cyclogenesis (PEC).The Z-O equation indicates that,in this case,the latent heat release and convergence are the two most important factors for SWV formation,which amounts to about 42% and 15% of the term TOTAL,respectively.It is implied that the thermal process effect was more important than the dynamic process during SWV formation.
基金supported by National Key Research and Development Program of China[grant number 2017YFC1501802]the National Natural Science Foundation of China[grant number 41375047],[grant number 91537213],and[grant number 41675039]
文摘The distribution characteristics of cloud-top and tropopause height in the tropics and subtropics in boreal summer are analyzed based on CALIPSO data for the period 2008-2012.The maximum values of cloud-top vertical cumulative frequency above the tropopause (CTAT) are concentrated in three tropical regions:the Asian summer monsoon region,Central America,and western Africa.The contributions to the area-weighted CTAT frequency in the three regions from the Northern Hemisphere are 49.0%,13.5%,and 12.4%,respectively.Moreover,the contribution of troposphere-to-stratosphere transport (TST) in the Asian monsoon region to global TST can be far greater than 50%,according to analysis of the continuous equation,velocity potential,and divergent wind from ERA-Interim data.Furthermore,the Asian summer monsoon circulation system controls the distribution of the cloud top.On the south side of the Tibetan Plateau,the maximum frequency of the cloud top,more than 10% per 500 m vertically,is most likely to appear in the core of the high-level easterlyjet near the tropopause height (16.5 km).Over the Tibetan Plateau,the maximum frequency of the cloud top,greater than 3% per 500 m vertically,is suppressed below 11 km,far away from the thermodynamic tropopause height but close to the dynamic tropopause height of 2 PVU (potential vorticity units).
文摘This study designed a simple index for measuring irregular tropospheric biennial oscillation(TBO) activities, which was used to determine that the TBO in the East Asian Summer Monsoon(EASM), the most important summer precipitation system for China, has strengthened rather than weakened since the late 1970s. The lead/lag correlations between the EASM and tropical Indian-Pacific sea surface temperature(SST) suggest a relationship between interbasin SST and EASM coupling processes and that this alternative correlation pattern is likely related to TBO. Significant correlation occurred only in recent decades, which implies a reinforcement of TBO in the EASM. From records of representative points in the Indian-Pacific, the interdecadal intrinsic SST modes of the areas can be obtained with ensemble empirical mode decomposition owing to its good temporal locality. Statistical results show Indian-Pacific SST interdecadal trends that include out-of-phase and in-phase warming before and after the late 1970s, respectively, which may be responsible for the TBO interdecadal augmentation present since the late 1970s.
文摘OBJECTIVE: To study the protective effects of Dongchongxiacao(Cordyceps)(DCXC) on contrast-induced nephropathy(CIN) in patients with type 2 diabetes and renal insufficiency undergoing coronary angiography.METHODS: A total of 120 patients with type 2 diabetes whose estimated glomerular filtration rate(e GFR) was ≤ 60 m L/minee grou·1.73 m2,were divided randomly into thrps,basic treatment group(n = 41),standard DCXC therapy group(n = 39,2-g corbrin capsules,3 times/d,3 days before and after angiography),and intensive DCXC therapy group(n = 40,3-g corbrin capsules,3 times/d,3 days before and after angiography). Serum creatinine(Scr)and e GFR were assessed at the time of admission to hospital,and on days 1,2 and 3 after angiography. Urine neutrophil-gelatinase-associated-lipocalin(NGAL),kidney injury molecule-1(KIM-1) and interleukin-18(IL-18) were measured before angiography and at day 1 after angiography for all patients. The primary end point was the prevalence of CIN. The secondary end point was a 25% or greater reduction in e GFR.RESULTS: CIN occurred in 11 of 120 patients(9.17 %). The prevalence of CIN was lower in the DCXC treatment groups than in the basic treatment group(P < 0.05),with a more significant decrease in the prevalence of CIN in the intensive DCXC therapy group(P < 0.01). Compared with the basic treatment group,a lower proportion of patients in the DCXC treatment groups had an e GFR decrease of 25% or greater(P < 0.05); patients with an e GFR decrease of 25% or greater accounted for an even lower proportion in the intensive DCXC therapy group(P < 0.01). Within 1 day of the procedure,urine levels of KIM-1,NGAL and IL-18 in patients in the intensive DCXC therapy group were lower than those in the basic treatment group and standard therapy group(P < 0.05).CONCLUSION: DCXC treatment may protect against CIN in patients with type 2 diabetes and renal insufficiency undergoing coronary angiography,with intensive DCXC therapy being more effective.