Li G.,Xichang Satellite Launch Center |
Chen J.,CAS South China Sea Institute of Oceanology |
Wang X.,CAS South China Sea Institute of Oceanology |
Luo X.,PLA University of Science and Technology |
And 4 more authors.
Climate Dynamics | Year: 2017
As an important oceanic signal, the North Atlantic sea surface temperature (SST) affects not only the climate variability over East China and Northeast China but also can affect climate variability over southwestern China (SWC). Based on station rainfall data and reanalysis datasets, the present study investigates the relationship of North Atlantic SST with SWC rainfall during boreal spring for the period 1979–2016. The results show that there is a significant positive correlation between North Atlantic SST and SWC rainfall during boreal spring. The atmospheric circulation over southern Asia associated with North Atlantic SST is favorable for positive rainfall anomalies. Further analyses show that North Atlantic SST can induce a North Atlantic–western Russia–western Tibetan Plateau–SWC (NRTC) teleconnection wave train from upper level to low level. At low level, two anomalous anticyclones are found over the mid-high latitude of North Atlantic and the western Tibetan Plateau, and two anomalous cyclones are observed over the western Russia and Bay of Bengal (BOB), respectively. The NRTC teleconnection wave train plays a bridging role between the North Atlantic SST and SWC rainfall during boreal spring. Both the observational analysis and two numerical experiments suggest that the North Atlantic SST during boreal spring can induce an anomalous cyclone over BOB by the NRTC teleconnection pattern. The anomalous cyclone over BOB favors moisture transport to SWC, accompanying with significant anomalous ascending motion, and thus results in positive rainfall anomalies in SWC during boreal spring. © 2017 Springer-Verlag Berlin Heidelberg
Zhang J.E.,Meteorological Research Institute of Jiangxi Province |
Xiao H.,Agro meteorological Experiment Station of Jiangxi Province |
Zheng Y.F.,Jiangsu Key Laboratory of Meteorological Disaster |
Wu R.J.,Jiangsu Key Laboratory of Meteorological Disaster |
And 2 more authors.
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2015
The open-top chamber (OTC) is an important device used to study the impact of climate change on ecosystems. These chambers have been widely used in climate change simulation and pollution ecology research. Compared to the conventional closed artificial climate chamber or the newly developed free-air concentration enrichment (FACE) method, the OTC creates a microclimate that is more similar to the atmospheric environment. Moreover, its test gas concentration control is more precise, and its construction and operating costs are lower. Our research results indicated that microclimatic elements inside and outside the OTC are different. Although much research has been carried out on microclimatic elements inside and outside the OTC, and improvements have been made based on these research results, there are only a few reports on the growth and photosynthetic response of plants to these microclimatic differences. This study aimed to evaluate the photosynthetic response of winter wheat (Triticum aestivum L.) grown inside (T1) and outside (T2) an OTC, using the plants of a modern cultivar, ‘YangMai16.’ Gas exchange, photosynthetic pigment content, and chlorophyll fluorescence parameters were evaluated. The test field was located at the Agricultural Meteorological Experiment Station of Nanjing University of Information Science and Technology, China (32º 03′ N, 118º51′ E). The seeds were sown on November 5, 2009, by drilling, with a seeding rate of 220.5 kg/hm2, and plants were harvested on May 31, 2010. The daily mean temperature and relative humidity inside the OTC used in our experiments were 8.9% and 3.3% higher, respectively, than those of the atmospheric environment; however, total radiation was 20.4% lower. The differences in microclimatic elements inside and outside the OTC used in this study were similar to those recorded by other groups.Our results indicated that the net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci), max photo-synthetic rate (Pm), and half-saturation light intensity (Ik) of T1 were significantly higher than those of T2 (P<0.05). Before the filling stage, the apparent quantum yield (AQY) of T1 was significantly higher than that of T2, whereas transpiration rate (Tr) and dark respiratory rate (Rd) were significantly lower (P < 0.05). After the filling stage, the results reversed. The chlorophyll and carotenoid contents of T1 were significantly higher than those of T2 during most of the growth stages P < 0.05). The basic fluorescence yield (Fo) and dark-adapted maximum fluorescence yield (Fm) values of T1 were higher than those of T2, but there was no difference in the maximum photochemical capacity of PSII (photosystem II) (Fv / Fm) between T1 and T2 during most of the growth stages. In the booting and flowering stages, the photochemical quenching coefficient (qP) of T1 was significantly lower than that of T2 (P<0.05). There was no difference in the quantum yield of photochemical energy conversion in PSII [Y(II)]of T1 and T2 during most of the growth stages. The non-photochemical quenching coefficient (NPQ) and quantum yield of regulated non-photochemical energy loss in PSII [Y(NPQ) ] of T1 were significantly higher than those of T2 after the filling stage (P <0.05), whereas the quantum yield of non-regulated non-photochemical energy loss in PSII [Y(NO) ] was lower. Our results indicate that the gas exchange capability, light response capability, and photosynthetic pigment content of winter wheat grown inside the OTC were higher than those of wheat grown outside. There were no differences in the maximum photochemical capacity and quantum yield of photochemical energy conversion in the PSII of winter wheat grown inside and outside the OTC. In contrast, the fraction of energy dissipated as heat via the regulated photo-protective NPQ mechanism was higher, while the fraction that was passively dissipated in the form of heat and fluorescence was lower, for winter wheat grown inside the OTC. Photo-protection of the photosynthetic apparatus from excess energy in PSII was also better in the winter wheat grown inside the OTC. Our results are expected to help improve OTCs, including the evaluation of data from controversial ecology projects and the application of research knowledge obtained from OTCs to field conditions. © 2015, Ecological Society of China. All rights reserved.
Yan H.,Yunnan Climate Center |
Yang H.,CAS Institute of Atmospheric Physics |
Yuan Y.,National Climate Center |
Li C.,CAS Institute of Atmospheric Physics |
Li C.,PLA University of Science and Technology
Advances in Atmospheric Sciences | Year: 2011
Using National Centers for Environmental Prediction/National Centre for Atmospheric Research (NCEP/NCAR) reanalysis data and monthly Hadley Center sea surface temperature (SST) data, and selecting a representative East Asian winter monsoon (EAWM) index, this study investigated the relationship between EAWM and East Asian summer monsoon (EASM) using statistical analyses and numerical simulations. Some possible mechanisms regarding this relationship were also explored. Results indicate a close relationship between EAWM and EASM: a strong EAWM led to a strong EASM in the following summer, and a weak EAWM led to a weak EASM in the following summer. Anomalous EAWM has persistent impacts on the variation of SST in the tropical Indian Ocean and the South China Sea, and on the equatorial atmospheric thermal anomalies at both lower and upper levels. Through these impacts, the EAWM influences the land-sea thermal contrast in summer and the low-level atmospheric divergence and convergence over the Indo-Pacific region. It further affects the meridional monsoon circulation and other features of the EASM. Numerical simulations support the results of diagnostic analysis. The study provides useful information for predicting the EASM by analyzing the variations of preceding EAWM and tropical SST. © 2011 Chinese National Committee for International Association of Meteorology and Atmospheric Sciences, Institute of Atmospheric Physics, Science Press and Springer-Verlag Berlin Heidelberg.
Li Y.,Nanjing University of Information Science and Technology |
Li Y.,Chinese Academy of Meteorological Sciences |
Ren F.,Chinese Academy of Meteorological Sciences |
Ren F.,Jiangsu Collaborative Innovation Center for Climate Change |
And 3 more authors.
Journal of Meteorological Research | Year: 2014
An objective identification technique for regional extreme events (OITREE) and the daily compositedrought index (CI) at 101 stations in Southwest China (including Sichuan, Yunnan, Guizhou, and Chongqing) are used to detect regional meteorological drought events between 1960 and 2010. Values of the parameters of the OITREE method are determined. A total of 87 drought events are identified, including 9 extreme events. The 2009-2010 drought is the most serious in Southwest China during the past 50 years. The regional meteorological drought events during 1960-2010 generally last for 10-80 days, with the longest being 231 days. Droughts are more common from November to next April, and less common in the remaining months. Droughts occur more often and with greater intensity in Yunnan and southern Sichuan than in other parts of Southwest China. Strong (extreme and severe) regional meteorological drought events can be divided into five types. The southern type has occurred most frequently, and Yunnan is the area most frequently stricken by extreme and severe drought events. The regional meteorological drought events in Southwest China have increased in both frequency and intensity over the study period, and the main reason appears to be a significant decrease in precipitation over this region, but a simultaneous increase in temperature also contributes. © 2014 The Chinese Meteorological Society and Springer-Verlag Berlin Heidelberg.
Zhao Z.,Yunnan Climate Center |
Wang P.Y.,Kunming Agromcteorological Station |
Zheng Y.F.,Kunming Agromcteorological Station |
Wu R.J.,Kunming Agromcteorological Station |
Zhang J.E.,Kunming Agromcteorological Station
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2015
Dry matter accumulation, photosynthetic pigments content and chlorophyll a fluorescence parameters (via IMAGIN-PAM, H. Walz, Effeltrich, Germany) in the pericarp were studied in developing wheat grains in response to varying ozone concentration: charcoal filtered air (CF, O3ranging over 4—28 nL/ L), ambient air (NF, O3ranging over 7—78 nL/ L), 100 nL/ L O3(CF100, O3ranging over 96—108 nL/ L) and 150 nL/ L O3(CF150, O3ranging over 145— 160nL/ L) and beside, a closed Open Top Chamber(5H, O3ranging over 15—68 nL/ L) was set up for comparison. It was observed that CF100 and CF150 treatment significantly reduced the length of winter wheat grain along with its maximum width, maximum thickness, volume, number of grain per ear, grain filling duration and the average filling rate before the end of peak compared with NF. Their 1000-grain weight of CF100 and CF150 was constantly lower than NF (and CF), finally, there was 10.7% and 17.8% decline, respectively. From 8thto 16thday after anthesis, CF100 and CF150 were significantly higher than other three groups, yet after 16 days, they declined rapidly to the extent that they lag the other groups significantly after 18th day. Under enhanced O3, grain yield decrease resulted mainly from the declining of volume, grain filling duration and number of grain per ear. In conclusion, high concentration of O3delayed the grain development process at the earlier period of grain filling but advances senescence at the later period which sharply shorted the grain filling duration. The potential electron transport rate, equivalent to the parameter ETRmax, was suppressed at the beginning of grain filling stage but promoted in middle stage. And then it fell rapidly due to the grain aging in advance. In addition, under high concentration of O3, the green layer of pericarp played a more important role in dry matter accumulation and nutrient synthesis. © (2015), Ecological Society of China. All rights reserved.
PubMed | Yunnan Climate Center, Yunnan University, Southwest University and Plant Protection and Quarantine Station of Yunnan Province
Type: | Journal: Journal of insect science (Online) | Year: 2015
Sogatella furcifera (Horvth) is the most threatening migratory rice pest in Yunnan, China. S. furcifera overwinters in low-altitude basins and valleys in southern Yunnan and migrates northward in spring and summer of the following year, causing serious damage during migration. The overwintering distribution, areas, and spatial pattern of S. furcifera are relevant to the migration and outbreak of this pest. Based on a 4-yr field survey (2010-2013), this study projected areas suitable for S. furcifera to overwinter using a species distribution model, and analyzed the key influencing climatic factors using principal component analysis (PCA) and ecological niche factor analysis (ENFA). Our field survey showed that the northern latitudinal- and upper elevation limits of overwintering S. furcifera was 25.4 N and 1,608m in western Yunnan and 24.2 N and 1,563m in eastern Yunnan. The species distribution model produced a fragmented distribution pattern, with most of which in western Yunnan and only a few in eastern Yunnan. The PCA and ENFA analyses showed that the mean temperature of the driest quarter and the precipitation of the coldest quarter significantly influenced the distribution of S. furcifera in winter. The results suggested that the complex topography, spatial differences in winter temperatures, and host availability altogether determined the distribution of overwintering S. furcifera. Compared with previous surveys, the northern latitudinal- and upper elevation limits of overwintering S. furcifera were higher, while the population became rarer in some suitable areas due to change of farmland utilization in winter and possibly climate change.
Huang Z.,Yunnan Climate Center
Advances in Climate Change Research | Year: 2011
Factor analysis was used to investigate the changes of dry-wet climate in the dry season in Yunnan during 1961-2007 based on observed data from 15 stations. Three common factors were extracted from the 9 climatic factors. The results showed that the dry-wet climate has evidently changed since the early 1960s. The general trends in the changes of dry-wet climate were described as slight decrease in humidity and gradual enhancement in drought intensity. The climate during 1960s-1980s was under weak-medium drought. But since early 1990s, dry conditions have markedly strengthened and continued due to uneven temporal distribution of rainfall and climate warming.
Wong M.,Yunnan University |
Duan C.-Q.,Yunnan University |
Long Y.-C.,Nature Conservancy China Program |
Luo Y.,Nature Conservancy China Program |
Xie G.-Q.,Yunnan Climate Center
Physical Geography | Year: 2010
The changing recruitment rate of subalpine tree populations could indicate the effects of climate change on a mountain ecosystem. The population of the dominant tree species of the Baima Snow Mountains in northwestern Yunnan, Abies georgei Orr, was investigated with a vegetation survey and tree-ring analysis. Structural and age characteristics were used to indicate the process and rates of geographical change, and the altitudinal range and size of forest were predicted using GIS with various climate change scenarios. The greatest increase of recruitment has occurred near the upper treeline on north-facing slopes, and the regeneration rate has been reduced at and below its once-optimal altitudinal range. The species limit has advanced upslope at an average rate of 11 m per decade, while the lowest limit of regeneration has retreated upslope at an average rate of 31 m per decade. In the 21st century, the altitudinal range of A. georgei forest may decrease by 13.6-25.9% and the forest size may contract by 16.4-38.6%. We demonstrate that the study of both upper and lower species limits of migrating subalpine species is crucial for predicting forest change, and suggest the involvement of spatial (geometry) as well as temporal (climate) factors in the shifting of alpine treeline.
Hu X.-Q.,Yunnan Climate Center |
Xu M.-Y.,Yunnan Climate Center |
He Y.-Q.,Yunnan Climate Center |
Zhang M.-D.,Yunnan Climate Center |
And 2 more authors.
Chinese Journal of Applied Ecology | Year: 2016
The climatic suitability distribution of flue-cured tobacco planting in Yunnan will be profoundly affected by climate change. According to three key factors influencing climatic suitability of flue-cured tobacco planting in Yunnan, namely, average temperature in July, sunshine duration from July to August, precipitation from April to September, the variations of climatic suitability distribution of fluecured tobacco planting in Yunnan respectively in 1986-2005, 2021-2040 and 2041-2060 under RCP4.5 and RCP8.5 climate scenarios were investigated by using the climatic simulation data in 1981-2060 and the meteorological observation data during 1986-2005. The results showed that climatic suitability region would expand northward and eastward and plantable area of flue-cured tobacco would gradually increase. The increment of plantable area was more in 2041-2060 than in 2021-2040, and under RCP8.5 scenario than under RCP4.5 scenario. The optimum climatic area and sub-suitable climatic area were expanded considerably, while the suitable climatic area was not much changed. In the future, the north-central Yunnan such as Kunming, Qujing, Dali, Chuxiong, Lijiang would have a big increase in both the optimum climatic area and the cultivable area, meanwhile, the southern Yunnan including Wenshan, Honghe, Puer and Xishuangbanna would have a big decrease in both the optimum climatic area and the cultivable area. © 2016, Science Press. All right reserved.
PubMed | Yunnan Climate Center
Type: Journal Article | Journal: Ying yong sheng tai xue bao = The journal of applied ecology | Year: 2013
Based on the 2010-2011 experimental data of planting flue-cured tobacco in its representative production counties of Yunnan Province, Southwest China, the models of the tobacco plant physiological development period and growing degree days were established, and validated by the observation data from local agro-meteorological stations. The two models had good performance at pre-transplanting stage, and the errors of the estimated dates were smaller. After transplanting stage, the errors of the estimated dates were larger, because of the disturbances from farming activities such as transplanting and topping. The simulated values based on the tobacco plant physiological development period had a higher coincidence with the observed values, especially at the pretransplanting stage, with the errors of the estimated dates being smaller than two days. As affected by the photoperiod effect, the model of tobacco plant physiological development period fitted better in high latitude regions than in low latitude regions.