Phytocenoses at Environments Contact Sites as Proxies of Climate Dynamics with Time (East Siberia, Russia)

Usage of methods for determination of long-term trends of the dynamics of vegetation formation on the background of climate changes becomes more and more important at modern stage of the assessment of natural systems development. This causes to researchers a series of problems from choice of conceptual base to notions and terms of the processes identified and of state of vegetation of different environments. Solution of such a task results inevitably in necessity to correct the understanding of existing processes occurring in the vegetation cover. It allows establishing a direction of their development in the system of natural factors of any territory. As a result, we have base for determination of age, site and role of current state of phytocenoses in successional systems. It is necessary for this to reveal the peculiarities of phytocenoses composition and formation due to climate dynamics and to determine a period of ecosystems homeostasis, especially for phytocenoses of contact natural conditions. Optimal values of phytocenoses diversity, like one of whole biosystems, depend on the amount of resource in the environment, on stability degree and on evolutional development of cenoses due to ecological, micro-evolutional and evolutional processes.

Some Mathematical and Numerical Issues in Geophysical FluidD ynamics and Climate Dynamics

In this article,we address both recent advances and open questions in some mathematical and computational issues in geophysical fluid dynamics(GFD)and climate dynamics.The main focus is on 1)the primitive equations(PEs)models and their related mathematical and computational issues,2)climate variability,predictability and successive bifurcation,and 3)a new dynamical systems theory and its applications to GFD and climate dynamics.

Application of Auto-regressive Linear Model in Understanding the Effect of Climate on Malaria Vectors Dynamics in the Three Gorges Reservoir

It is important to understand the dynamics of malaria vectors in implementing malaria control strategies. Six villages were selected from different sections in the Three Gorges Reservoir fc,r exploring the relationship between the climatic ｜：actors and its malaria vector density from 1997 to 2007 using the auto-regressive linear model regressi^n method. The result indicated that both temperature and precipitation were better modeled as quadratic rather than linearly related to the density of Anopheles sinensis.

Comparison of a Very-fine-resolution GCM with RCM Dynamical Downscaling in Simulating Climate in China

Regional climate simulation can generally be improved by using an RCM nested within a coarser-resolution GCM.However, whether or not it can also be improved by the direct use of a state-of-the-art GCM with very fine resolution, close to that of an RCM, and, if so, which is the better approach, are open questions. These questions are important for understanding and using these two kinds of simulation approaches, but have not yet been investigated. Accordingly, the present reported work compared simulation results over China from a very-fine-resolution GCM（VFRGCM） and from RCM dynamical downscaling. The results showed that：（1） The VFRGCM reproduces the climatologies and trends of both air temperature and precipitation, as well as inter-monthly variations of air temperature in terms of spatial pattern and amount, closer to observations than the coarse-resolution version of the GCM. This is not the case, however, for the inter-monthly variations of precipitation.（2） The VFRGCM captures the climatology, trend, and inter-monthly variation of air temperature, as well as the trend in precipitation, more reasonably than the RCM dynamical downscaling method.（3） The RCM dynamical downscaling method performs better than the VFRGCM in terms of the climatology and inter-monthly variation of precipitation. Overall,the results suggest that VFRGCMs possess great potential with regard to their application in climate simulation in the future,and the RCM dynamical downscaling method is still dominant in terms of regional precipitation simulation.

Advances in Atmospheric Sciences:A featured journal from Essential Science Indicators

In May 2008, ScienceWatch.com named Advances in Atmospheric Sciences a Rising Star among Geosciences journals. According to Essential Science IndicatorsSM from Thomson Reuters, the journal＇s cur-rent citation record includes 764 papers cited a total of 1,658 times between January 1, 1998 and February 29 2008.

Dynamic Downscaling of Summer Precipitation Prediction over China in 1998 Using WRF and CCSM4

To study the prediction of the anomalous precipitation and general circulation for the summer（June–July–August） of1998, the Community Climate System Model Version 4.0（CCSM4.0） integrations were used to drive version 3.2 of the Weather Research and Forecasting（WRF3.2） regional climate model to produce hindcasts at 60 km resolution. The results showed that the WRF model produced improved summer precipitation simulations. The systematic errors in the east of the Tibetan Plateau were removed, while in North China and Northeast China the systematic errors still existed. The improvements in summer precipitation interannual increment prediction also had regional characteristics. There was a marked improvement over the south of the Yangtze River basin and South China, but no obvious improvement over North China and Northeast China. Further analysis showed that the improvement was present not only for the seasonal mean precipitation, but also on a sub-seasonal timescale. The two occurrences of the Mei-yu rainfall agreed better with the observations in the WRF model,but were not resolved in CCSM. These improvements resulted from both the higher resolution and better topography of the WRF model.

WHU-Grace01s:A new temporal gravity field model recovered from GRACE KBRR data alone

A new temporal gravity field model called WHU-Grace01s solely recovered from Gravity Recovery and Climate Experiment （GRACE） K-Band Range Rate （KBRR） data based on dynamic integral approach is presented in this paper. After meticulously preprocessing of the GRACE KBRR data, the root mean square of its post residuals is about 0.2 micrometers per second, and seventy-two monthly temporal solutions truncated to degree and order 60 are computed for the period from January 2003 to December 2008. After applying the combi- nation filter in WHU-Grace01s, the global temporal signals show obvious periodical change rules in the large-scale fiver basins. In terms of the degree variance, our solution is smaller at high degrees, and shows a good consistency at the rest of degrees with the Release 05 models from Center for Space Research （CSR）, GeoForschungsZentrum Potsdam （GFZ） and Jet Pro- pulsion Laboratory 0PL）. Compared with other published models in terms of equivalent water height distribution, our solution is consistent with those published by CSR, GFZ, JPL, Delft institute of Earth Observation and Space system （DEOS）, Tongji University （Tongji）, Institute of Theoretical Geodesy （ITG）, Astronomical Institute in University of Bern （AIUB） and Groupe de Recherche de Geodesie Spatiale （GRGS}, which indicates that the accuracy of WHU-Grace01s has a good consistency with the previously published GRACE solutions.

Palynoflora and climatic dynamics of the Laizhou Bay of Bohai Sea,North China Plain,since the late middle Pleistocene

The coastal plain of Laizhou Bay in Bohai Sea is a transitional area of land-sea interaction.Sediments in this area can bear significant information of sea-level fluctuation,climate change,as well as regional geological setting.Here,in this study,new sporopollen data from three boreholes(GK138,GK111 and GK95)in the coastal plain of Laizhou Bay,Bohai Sea were investigated,and the pollen spectrum since the late middle Pleistocene was established as six sporopollen assemblage zones(Ⅰ-Ⅵ),i.e.,Pinus-Quercus-Artemisia,Gramineae-Artemisia-Chenopodiaceae,Picea-Pinus-QuercusArtemisia,Picea-Pinus-Betula-Gramineae-Artemisia,Picea-Pinus-Cupressaceae-Chenopodiaceae and Pinus-Quercus-Gramineae-Artemisia-Chenopodiaceae.Combining with existing sedimentary successions and detailed radiocarbon dating results of the sediments from the three boreholes,paleovegetation and climatic evolution since the late middle Pleistocene were reconstructed.The findings revealed that climatic changes in this area since the late middle Pleistocene were characterized by alternating cold-arid and warmhumid conditions,which were well correlated with marine isotopic stages(MIS).The present study offers specific insight into the climatic dynamics in the North China Plain since the late middle Pleistocene and provides evidence of a clear link among the palynoflora in the area,the glacial-interglacial period climatedriven sea-level changes,and the marineδ^(18)O records.

Critical climate issues toward carbon neutrality targets

In 2020,China announced the"emission peak,carbon neutrality"policy,that is,China aims to have CO2 emissions peak before 2030 and achieve carbon neutrality before 2060.The scenario of carbon neutrality will be significantly distinguished from the scenario we experienced since the industrial revolution.However,instrumental data are unavailable in the future carbon-neutral scenario.Earth system models and climate dynamics theory are needed to comprehend and project the climate change.In this paper,we illustrate our perspective of the issues related to"emission peak,carbon neutrality",including climate dynamics,climate-carbon feedback,interaction between China and global climate and carbon emissions and solutions,etc.We highlight that climate change has profoundly affected human production and life.The frequent occurrence of extreme weather disasters in recent years,together with the impact of epidemics,make the future"carbon peak&carbon-neutral"scenario more complex.There is whopping uncertainty but also a massive challenge to the scientific community.Thus,carbon neutrality is closely related to domestic production and lives,and there is little time left for planning.We believe that we will make a breakthrough in climate dynamics in the context of carbon neutrality with our joint efforts,which will serve our country’s carbon emission policy at different stages.

IMPACT OF UPLIFT OF TIBETAN PLATEAU AND CHANGE OF LAND-OCEAN DISTRIBUTION ON CLIMATE OVER ASIA

Using an improved CCM1/NCAR climate dynamic model and a combination distribution of land-ocean-vegetation during 40-50 MaBP,a series of numerical experiments representing different stages of the Tibetan Plateau uplifting and different land-ocean distributions are designed to discuss the influence of the Plateau uplifting and land-ocean distribution variation on Asian climate change.It is shown that Tibetan Plateau uplifting can firstly increase the precipitation in China during the period from initial uplift to half height of modern Tibetan Plateau and then decrease the rainfall during the time from the half height to the present plateau.At the same time. the uplifting can reduce surface air temperature over China.Besides.the effects of the uplift and land-ocean distribution change on the variation of winter and summer Asian monsoon circulation are also discussed.

Changes of citrus climate risk in subtropics of China

Based on the citrus temperature, precipitation, sunlight and climate risk degree, the article divides subtropics of China into three types： the low risk region, the moderate risk region and the high risk region. The citrus temperature risk increases with increasing latitude （except for the western mountainous area of subtropics of China）. The citrus precipitation risk in the central part of subtropics of China is higher than that in the northern and western parts. The distributions of citrus sunlight risk are not consistent to those of the citrus precipitation risk. The citrus climate risk is mainly influenced by temperature. There is latitudinal zonal law for the distribution of the climate risk, that is, the climate risk increases with increasing latitude At the same time the climate risk in mountainous area is high and that in eastern plain area is low. There are differences in the temporal and spatial changes of the citrus climate. In recent 46 years, the citrus climate risk presents a gradual increasing trend in subtropics of China, especially it has been increasing fast since the 1980s. Because of the global warming, the low risk region in the eastern and southern parts has a gradual decreasing trend, however, the high risk region in the northern and western parts has an increasing trend and the high risk region has been extending eastward and southward. The article analyses the distribution of the citrus climate risk degree of reduction rates of 〉10%, 〉20% and 〉30% in subtropics of China, and studies their changes in different time periods. Results show that the risk is increasing from southeast to northwest.

Impact of Climate Change on Maize Potential Productivity and the Potential Productivity Gap in Southwest China

The impact of climate change on maize potential productivity and the potential productivity gap in Southwest China（SWC） are investigated in this paper.We analyze the impact of climate change on the photosynthetic,light-temperature,and climatic potential productivity of maize and their gaps in SWC,by using a crop growth dynamics statistical method.During the maize growing season from 1961 to 2010,minimum temperature increased by 0.20℃ per decade（p 〈 0.01） across SWC.The largest increases in average and minimum temperatures were observed mostly in areas of Yunnan Province.Growing season average sunshine hours decreased by 0.2 h day^（-1） per decade（p 〈 0.01） and total precipitation showed an insignificant decreasing trend across SWC.Photosynthetic potential productivity decreased by 298 kg ha^（-1）per decade（p 〈 0.05）.Both light-temperature and climatic potential productivity decreased（p 〈 0.05） in the northeast of SWC,whereas they increased（p 〈 0.05） in the southwest of SWC.The gap between lighttemperature and climatic potential productivity varied from 12 to 2729 kg ha^（-1）,with the high value areas centered in northern and southwestern SWC.Climatic productivity of these areas reached only 10%-24%of the light-temperature potential productivity,suggesting that there is great potential to increase the maize potential yield by improving water management in these areas.In particular,the gap has become larger in the most recent 10 years.Sensitivity analysis shows that the climatic potential productivity of maize is most sensitive to changes in temperature in SWC.The findings of this study are helpful for quantification of irrigation water requirements so as to achieve maximum yield potentials in SWC.

THE NUMERICAL SIMULATION OF TWO-DIMENSIONAL DYNAMICAL CLIMATE MODEL WITH MOUNTAIN FORCING

In order to investigate the effects of trace gases on climate variation in the atmosphere, we have devel- oped a primitive equation two-dimensional dynamical climate model with five levels. A series of simula- tion results and discussions are shown in this paper, indicating that the model is useful and can correctly reproduced the main feature of the general atmospheric circulation and its seasonal changes. In addition, we have discussed the role of the Qinghai-Xizang Plateau on the formation process of summer monsoon in South Asia and found that the thermal effect of the Qjnghai-Xizang Plateau may not be the main factor controlling the onset and the variation of the summer monsoon in South Asia.

Regional climate dynamical downscaling over the Tibetan Plateau——From quarter-degree to kilometer-scale

The Tibetan Plateau(TP)possesses the largest cryosphere in the world outside of the Arctic and Antarctic,and is the source of nine major rivers in Asia.The surface environment of the TP has undergone significant changes against the background of global warming.It is projected that the continuation of climate change in the future will result in most of the glaciers and frozen soil disappearing by the end of this century,and freshwater resources will be greatly reduced,on which 22%of the world’s population depends.These environmental changes are of great concern to global society given the influences of the TP on the climate at the global scale.However,great uncertainties exist in global climate simulations over the TP,which affects our ability to properly understand the associated water security crisis.Based on atmospheric dynamics and physical processes,dynamical downscaling can characterize surface conditions more accurately than global simulations,and better simulate and predict regional or local weather and climate situations.With advances in supercomputing,the grid spacing of dynamical downscaling simulations has been continuously increasing,marching the technique into the kilometer-scale era.In this paper,the origin and development of dynamical downscaling in the TP region from the quarter-degree to kilometer scale is firstly introduced,including an assessment of the advantages and disadvantages of dynamical downscaling at the kilometer scale over the TP.Then,the main land surface factors affecting the performance of dynamical downscaling over the TP are described,as well as a brief introduction to a land surface model with specific plateau characteristics.Specifically,it has emerged that perfecting the land surface model and improving the performance of land-atmosphere interaction are the most effective ways to advance the performance of dynamic downscaling in this region.Finally,the challenges and some recommended future research directions are discussed and proposed.