Spatio-temporal Variation Characteristics of Extreme Climate Events and Their Teleconnections to Large-scale Ocean-atmospheric Circulation Patterns in Huaihe River Basin,China During 1959–2019

Huaihe River Basin(HRB) is located in China’s north-south climatic transition zone,which is very sensitive to global climate change.Based on the daily maximum temperature,minimum temperature,and precipitation data of 40 meteorological stations and nine monthly large-scale ocean-atmospheric circulation indices data during 1959–2019,we present an assessment of the spatial and temporal variations of extreme temperature and precipitation events in the HRB using nine extreme climate indices,and analyze the teleconnection relationship between extreme climate indices and large-scale ocean-atmospheric circulation indices.The results show that warm extreme indices show a significant(P < 0.05) increasing trend,while cold extreme indices(except for cold spell duration) and diurnal temperature range(DTR) show a significant decreasing trend.Furthermore,all extreme temperature indices show significant mutations during 1959-2019.Spatially,a stronger warming trend occurs in eastern HRB than western HRB,while maximum 5-d precipitation(Rx5day) and rainstorm days(R25) show an increasing trend in the southern,central,and northwestern regions of HRB.Arctic oscillation(AO),Atlantic multidecadal oscillation(AMO),and East Atlantic/Western Russia(EA/WR) have a stronger correlation with extreme climate indices compared to other circulation indices.AO and AMO(EA/WR) exhibit a significant(P < 0.05) negative(positive)correlation with frost days and diurnal temperature range.Extreme warm events are strongly correlated with the variability of AMO and EA/WR in most parts of HRB,while extreme cold events are closely related to the variability of AO and AMO in eastern HRB.In contrast,AMO,AO,and EA/WR show limited impacts on extreme precipitation events in most parts of HRB.

Spatiotemporal variation of ecological environment quality and extreme climate drivers on the Qinghai-Tibetan Plateau

Protecting the ecological security of the Qinghai-Tibet Plateau(QTP)is of great importance for global ecology and climate.Over the past few decades,climate extremes have posed a significant challenge to the ecological environment of the QTP.However,there are few studies that explored the effects of climate extremes on ecological environment quality of the QTP,and few researchers have made quantitative analysis.Hereby,this paper proposed the Ecological Environmental Quality Index(EEQI)for analyzing the spatial and temporal variation of ecological environment quality on the QTP from 2000 to 2020,and explored the effects of climate extremes on EEQI based on Geographically and Temporally Weighted Regression(GTWR)model.The results showed that the ecological environment quality in QTP was poor in the west,but good in the east.Between 2000 and 2020,the area of EEQI variation was large(34.61%of the total area),but the intensity of EEQI variation was relatively low and occurred mainly by a slightly increasing level(EEQI change range of 0.05-0.1).The overall ecological environment quality of the QTP exhibited spatial and temporal fluctuations,which may be attributed to climate extremes.Significant spatial heterogeneity was observed in the effects of the climate extremes on ecological environment quality.Specifically,the effects of daily temperature range(DTR),number of frost days(FD0),maximum 5-day precipitation(RX5day),and moderate precipitation days(R10)on ecological environment quality were positive in most regions.Furthermore,there were significant temporal differences in the effects of consecutive dry days(CDD),consecutive wet days(CWD),R10,and FD0 on ecological environment quality.These differences may be attributed to variances in ecological environment quality,climate extremes,and vegetation types across different regions.In conclusion,the impact of climate extremes on ecological environment quality exhibits complex patterns.These findings will assist managers in identifying changes in the ecological environment quality of the QTP and addressing the effects of climate extremes.

Analyses of Extreme Climate Events over China Based on CMIP5 Historical and Future Simulations

Based on observations and 12 simulations from Coupled Model Intercomparison Project Phase 5 （CMIP5） models, cli- matic extremes and their changes over China in the past and under the future scenarios of three Representative Concentration Pathways （RCPs） are analyzed. In observations, frost days （FD） and low-temperature threshold days （TN10P） show a de- creasing trend, and summer days （SU）, high-temperature threshold days （TX90P）, heavy precipitation days （R20）, and the contribution of heavy precipitation days （P95T） show an increasing trend. Most models are able to simulate the main char- acteristics of most extreme indices. In particular, the mean FD and TX90P are reproduced the best, and the basic trends of FD, TN10P, SU and TX90P are represented. For the FD and SU indexes, most models show good ability in capturing the spatial differences between the mean state of the periods 1986--2005 and 1961-80; however, for other indices, the simulation abilities for spatial disparity are less satisfactory and need to be improved. Under the high emissions scenario of RCP8.5, the century-scale linear changes of the multi-model ensemble （MME） for FD, SU, TN10P, TX90P, R20 and P95T are -46.9, 46.0, -27.1, 175.4, and 2.9 days, and 9.9%, respectively; and the spatial change scope for each index is consistent with the emissions intensity. Due to the complexities of physical process pararneterizations and the limitation of forcing data, great uncertainty still exists with respect to the simulation of climatic extremes.

Simulation of Extreme Climate Events over China with Different Regional Climate Models

During phase II of the Regional Climate Model Inter-comparison Project （RMIP） for Asia, the Asian climate was estimated from July 1988 to December 1998 using six climate models. In this paper, the abilities of six climate models to simulate several important ex- treme climate events in China during the last years of the last century were analyzed. The modeled results for the intensity of the precipitation anomaly over the Yang- tze-Huaihe Valley during the summers of 1991 and 1998 were weaker than the observed values. The positive pre- cipitation anomaly responsible for a catastrophic flood in 1991 was well reproduced in almost all simulation results, but the intensity and range of the precipitation anomaly in 1998 were weaker in the modeled results. The spatial dis- tribution of extreme climate events in 1997, when severe drought affected North China and flood impacted South China, was reproduced by most of the regional models because the anomaly of the large-scale background field was well-simulated, despite poor simulation of high temperature areas in the north during the summer by all models.

Changes in Climatic Factors and Extreme Climate Events in Northeast China during 1961-2010

This study focuses on examining the characteristics of climate factors and extreme climate events in Northeast China during 1961- 2010 by using daily data from 104 stations, including surface air temperature, precipitation, wind speed, sunshine duration, and snow depth. Results show that annual mean temperature increased at a significant rate of 0.35℃ per decade, most notably in the Lesser Khingan Mountains and in winter. Annual rainfall had no obvious linear trend, while rainy days had a significant decreasing trend. So, the rain intensity increased. High-temperature days had a weak increasing trend, and low-temperature days and cold wave showed significant decreasing trends with rates of 3.9 d per decade and -0.64 times per decade, respectively. Frequency and spatial scope of low-temperature hazard reduced significantly. Warm days and warm nights significantly increased at 1.0 and 2.4 d per decade, while cold days and cold nights decreased significantly at -1.8 and -4.1 d per decade, respectively. The nighttime warming rate was much higher than that for daytime, indicating that nighttime warming had a greater contribution to the overall warming trend than daytime warming. The annual mean wind speed, gale days, and sunshine duration had significant decreasing trends at rates of-0.21 m s-1 per decade, -4.0 d per decade and -43.3 h per decade, respectively. The snow cover onset dates postponed at a rate of 1.2 d per decade, and the snow cover end date advanced at 1.5 d per decade, which leads to shorter snow cover duration by -2.7 d per decade. Meanwhile, the maximum snow depth decreased at -0.52 cm per decade. In addition, the snow cover duration shows a higher correlation with precipitation than with temperature, which suggests that precipitation plays a more important role in maintaining snow cover duration than temperature.

Change in Extreme Climate Events over China Based on CMIP5

The changes in a selection of extreme climate indices(maximum of daily maximum temperature(TXx),minimum of daily minimum temperature(TNn),annual total precipitation when the daily precipitation exceeds the 95th percentile of wet-day precipitation(very wet days,R95p),and the maximum number of consecutive days with less than 1 mm of precipitation(consecutive dry days,CDD))were projected using multi-model results from phase 5 of the Coupled Model Intercomparison Project in the early,middle,and latter parts of the 21st century under different Representative Concentration Pathway(RCP)emissions scenarios.The results suggest that TXx and TNn will increase in the future and,moreover,the increases of TNn under all RCPs are larger than those of TXx.R95p is projected to increase and CDD to decrease significantly.The changes in TXx,TNn,R95p,and CDD in eight sub-regions of China are different in the three periods of the 21st century,and the ranges of change for the four indices under the higher emissions scenario are projected to be larger than those under the lower emissions scenario.The multi-model simulations show remarkable consistency in their projection of the extreme temperature indices,but poor consistency with respect to the extreme precipitation indices.More substantial inconsistency is found in those regions where high and low temperatures are likely to happen for TXx and TNn,respectively.For extreme precipitation events(R95p),greater uncertainty appears in most of the southern regions,while for drought events(CDD)it appears in the basins of Xinjiang.The uncertainty in the future changes of the extreme climate indices increases with the increasing severity of the emissions scenario.

Changes in Climate Factors and Extreme Climate Events in South China during 1961-2010

Daily climate data at 110 stations during 1961-2010 were selected to examine the changing characteristics of climate factors and extreme climate events in South China. The annual mean surface air temperature has increased significantly by 0.16℃ per decade, most notably in the Pearl River Delta and in winter. The increase rate of the annual extreme minimum temperature (0.48℃ per decade) is over twice that of the annual extreme maximum temperature (0.20℃ per decade), and the increase of the mean temperature is mainly the result of the increase of the extreme minimum temperature. The increase rate of high-temperature days (1.1 d per decade) is close to the decrease rate of low-temperature days (-1.3 d per decade). The rainfall has not shown any significant trend, but the number of rainy days has decreased and the rain intensity has increased. The regional mean sunshine duration has a significant decreasing trend of -40.9 h per decade, and the number of hazy days has a significant increasing trend of 6.3 d per decade. The decrease of sunshine duration is mainly caused by the increase of total cloud, not by the increase of hazy days in South China. Both the regional mean pan evaporation and mean wind speed have significant decreasing trends of -65.9 mm per decade and -0.11 m s-1 per decade, respectively. The decrease of both sunshine duration and mean wind speed plays an important role in the decrease of pan evaporation. The number of landing tropical cyclones has an insignificant decreasing trend of -0.6 per decade, but their intensities show a weak increasing trend. The formation location of tropical cyclones landing in South China has converged towards 10-19°N, and the landing position has shown a northward trend. The date of the first landfall tropical cyclone postpones 1.8 d per decade, and the date of the last landfall advances 3.6 d per decade, resulting in reduction of the typhoon season by 5.4 d per decade.

Extreme climate events over northern China during the last 50 years

Climate extremes for agriculture-pasture transitional zone, northern China, are analyzed on the basis of daily mean temperature and precipitation observations for 31 stations in the period 1956-2001. Analysis season for precipitation is May-September, i.e., the rainy season. For temperature is the hottest three months, i.e., June through August. Heavy rain events, defined as those with daily precipitation equal to or larger than 50 mm, show no significant secular trend. A jump-like change, however, is found occurring in about 1980. For the period 1980-1993, the frequency of heavy rain events is significantly lower than the previous periods. Simultaneously, the occurring time of heavy rains expanded, commencing about one month early and ending one month later. Long dry spells are defined as those with longer than 10 days without rainfall. The frequency of long dry spells displays a significant (at the 99% confidence level) trend at the value of +8.3% /10a. That may be one of the major causes of the frequent droughts emerging over northern China during the last decades. Extremely hot and low temperature events are defined as the uppermost 10% daily temperatures and the lowest 10% daily temperatures, respectively. There is a weak and non-significant upward trend in frequency of extremely high temperatures from the 1950s to the mid-1990s. But the number of hot events increases as much as twice since 1997. That coincides well with the sudden rise in mean summer temperature for the same period. Contrary to that, the frequency of low temperature events have been decreasing steadily since the 1950s, with a significant linear trend of-15%/10a.

Spatial and Temporal Variations of Extreme Climate Events in Xinjiang, China during 1961-2010

Daily maximum/minimum temperature and precipitation data from 35 weather stations in Xinjiang during 1961-2010 were examined using kriging spatial analysis, linear tendency estimation, and correlation analysis. Temporal trends and spatial distribution patterns of extreme temperature and precipitation in this area were then analyzed using 12 extreme temperature and 7 extreme precipitation indices. The following results were obtained. 1) Over the past 50 years, extreme cold indices, excepting the monthly maximum temperature minimum value and monthly extreme minimum temperature, showed slight decreasing trends. These indices include the maximum number of consecutive frost days, icy days, cold-nighttime days, and cold-daytime days. 2) Extreme warm events generally showed significant increasing trends (P < 0.01), including the indices of summertime days, warm-nighttime days, warm-daytime days, monthly extreme maximum temperature, and monthly minimum temperature maximum value. 3) The spatial distributions of threshold values of extreme warm and cold events showed notable regional differences. A reducing trend of extreme cold events and an increase in extreme warm events has occurred mainly in northern Xinjiang. 4) For the past 50 years, six extreme precipitation indices, aside from consecutive dry days, showed significant increasing trends in Xinjiang (P < 0.05) and notable differences in spatial distribution. The increase in extreme precipitation events was more rapid at northern than at southern sites. Extreme precipitation intensity was greater in mountainous areas, and precipitation frequency increased in the plain region. 5) Factor analysis revealed good correlations among extreme temperature indices, excepting extreme temperature days.

Choice of Beef Herd Adaptation Strategy on Canadian Prairie Mixed Farms Under Extreme Climate Events

Economic impact of climate extremes on beef operation is expected to be significant due to its direct impact on feed production. Impact of such events on farm management and longer term farm financial situation is relatively unstudied in the Canadian Prairie. This study compared three alternative beef herd management strategies in dealing with climate extreme events under reference climate scenario of 1971-2000 and the future scenario of 2041-2070. The study used farm simulation model that integrated the model of cattle herd simulation, pasture model, crop simulation model combined with models of economic decisions. Purchasing feed and maintaining herd size is preferred option in dealing with drought Changes in management such as early weaning combined with limit feeding strategies reduce the feed demand and also reduce the financial burden during the years of extreme event, but it has severe negative consequences on amount of slaughter cattle sold. Cull herd strategy not only reduces feed demand but also increases income from sell of herd during the year/s of extreme event, but it severely impacts the farm＇s long term output supply potential. However, expansion of existing agriculture risk management policy to cover climate risk in beef production is necessary to support farmers in the year/s to extreme events.

2023: Weather and Climate Extremes Hitting the Globe with Emerging Features

Globally,2023 was the warmest observed year on record since at least 1850 and,according to proxy evidence,possibly of the past 100000 years.As in recent years,the record warmth has again been accompanied with yet more extreme weather and climate events throughout the world.Here,we provide an overview of those of 2023,with details and key background causes to help build upon our understanding of the roles of internal climate variability and anthropogenic climate change.We also highlight emerging features associated with some of these extreme events.Hot extremes are occurring earlier in the year,and increasingly simultaneously in differing parts of the world(e.g.,the concurrent hot extremes in the Northern Hemisphere in July 2023).Intense cyclones are exacerbating precipitation extremes(e.g.,the North China flooding in July and the Libya flooding in September).Droughts in some regions(e.g.,California and the Horn of Africa)have transitioned into flood conditions.Climate extremes also show increasing interactions with ecosystems via wildfires(e.g.,those in Hawaii in August and in Canada from spring to autumn 2023)and sandstorms(e.g.,those in Mongolia in April 2023).Finally,we also consider the challenges to research that these emerging characteristics present for the strategy and practice of adaptation.

Impact of extreme climate and train traffic loads on the performance of high-speed railway geotechnical infrastructures

High-speed railways are very important in global transportation.However,the railway subgrade is significantly affected by the environment due to its exposure to the atmosphere.At present,global warming is the primary trend in world climate change and seriously damages railway infrastructure.Owing to the coupling effect of extreme environmental and train loads,various subgrade problems tend to arise,such as settlement,ballast fouling,and mud pumping,thus inducing frequent railway accidents and reducing travel safety.Insights into the problems triggered by extreme climate and train loads are critical to the design and long-term operation of high-speed railway subgrades.This study therefore presents a detailed survey of recent advances in typical subgrade problems through analyzing the problem formation mechanisms and influences.Traditional and emerging detection/monitoring technologies in respect of subgrade problems are discussed in detail,as well as pre-accident and post-accident maintenance methods.Finally,according to the existing challenges in long-term subgrade shakedown assessment,an outlook on open opportunities is provided for future research.

Extreme drought with seasonal timing consistently promotes CH_(4) uptake through inconsistent pathways in a temperate grassland, China

Methane(CH_(4))is a potent greenhouse gas that has a substantial impact on global warming due to its substantial influence on the greenhouse effect.Increasing extreme precipitation events,such as drought,attributable to global warming that caused by greenhouse gases,exert a profound impact on the intricate biological processes associated with CH_(4) uptake.Notably,the timing of extreme drought occurrence emerges as a pivotal factor influencing CH_(4) uptake,even when the degree of drought remains constant.However,it is still unclear how the growing season regulates the response of CH_(4) uptake to extreme drought.In an effort to bridge this knowledge gap,we conducted a field manipulative experiment to evaluate the impact of extreme drought on CH_(4) uptake during early,middle,and late growing stages in a temperate steppe of Inner Mongolia Autonomous Region,China.The result showed that all extreme drought consistently exerted positive effects on CH_(4) uptake regardless of seasonal timing.However,the magnitude of this effect varied depending on the timing of season,as evidenced by a stronger effect in early growing stage than in middle and late growing stages.Besides,the pathways of CH_(4) uptake were different from seasonal timing.Extreme drought affected soil physical-chemical properties and aboveground biomass(AGB),consequently leading to changes in CH_(4) uptake.The structural equation model showed that drought both in the early and middle growing stages enhanced CH_(4) uptake due to reduced soil water content(SWC),leading to a decrease in NO_(3)–-N and an increase in pmoA abundance.However,drought in late growing stage primarily enhanced CH_(4) uptake only by decreasing SWC.Our results suggested that seasonal timing significantly contributed to regulate the impacts of extreme drought pathways and magnitudes on CH_(4) uptake.The findings can provide substantial implications for understanding how extreme droughts affect CH_(4) uptake and improve the prediction of potential ecological consequence under future climate change.

Long-term changes in radial growth of seven tree species in the mixed broadleaf-Korean pine forest in Northeast China:Are deciduous trees favored by climate change?

The role of the temperate mixed broadleaf-Korean pine forest(BKF)in global biogeochemical cycles will depend on how the tree species community responds to climate;however,species-specific responses and vulner-abilities of common trees in BKF to extreme climates are poorly understood.Here we used dendrochronological meth-ods to assess radial growth of seven main tree species(Pinus koraiensis,Picea jezoensis,Abies nephrolepis,Fraxinus mandshurica,Phellodendron amurense,Quercus mongolica,and Ulmus davidiana)in an old-growth BKF in response to climate changes in the Xiaoxing’an Mountains and to improve predictions of changes in the tree species compo-sition.Temperature in most months and winter precipita-tion significantly negatively affected growth of P.jezoensis and A.nephrolepis,but positively impacted growth of P.koraiensis and the broadleaf species,especially F.mandshu-rica and U.davidiana.Precipitation and relative humidity in June significantly positively impacted the growth of most tree species.The positive effect of the temperature during the previous non-growing season(PNG)on growth of F.mandshurica and Q.mongolica strengthened significantly with rapid warming around 1981,while the impact of PNG temperature on the growth of P.jezoensis and A.nephrolepis changed from significantly negative to weakly negative or positive at this time.The negative response of radial growth of P.jezoensis and A.nephrolepis to precipitation during the growing season gradually weakened,and the negative response to PNG precipitation was enhanced.Among the studied species,P.koraiensis was the most resistant to drought,and U.davidiana recovered the best after extreme drought.Ulmus davidiana,P.jezoensis and A.nephrolepis were more resistant to extreme cold than the other species.Climate warming generally exacerbated the opposite growth patterns of conifer(decline)and broadleaf(increase)spe-cies.Deciduous broadleaf tree species in the old-growth BKF probably will gradually become dominant as warming continues.Species-specific growth-climate relationships should be considered in future models of biogeochemical cycles and in forestry management practices.

A systematic review of climate change impacts,adaptation strategies,and policy development in West Africa

Climate change studies are diverse with no single study giving a comprehensive review of climate change impacts,adaptation strategies,and policy development in West Africa.The unavailability of an all-inclusive study to serve as a guide for practitioners affects the effectiveness of climate change adaptation strategies proposed and adopted in the West African sub-region.The purpose of this study was to review the impacts of climate change risks on the crop,fishery,and livestock sectors,as well as the climate change adaptation strategies and climate-related policies aimed at helping to build resilient agricultural production systems in West Africa.The review process followed a series of rigorous stages until the final selection of 56 articles published from 2009 to 2023.Generally,the results highlighted the adverse effects of climate change risks on food security.We found a continuous decline in food crop production.Additionally,the livestock sector experienced morbidity and mortality,as well as reduction in meat and milk production.The fishery sector recorded loss of fingerlings,reduction in fish stocks,and destruction of mariculture and aquaculture.In West Africa,climate-smart agriculture technologies,physical protection of fishing,and inclusion of gender perspectives in programs appear to be the major adaptation strategies.The study therefore recommends the inclusion of ecosystem and biodiversity restoration,weather insurance,replacement of unsafe vessels,and strengthening gender equality in all climate change mitigation programs,as these will help to secure enough food for present and future generations.

Assessment of the Spatio-Temporal Trends of Annual Extreme Temperature Indices over Tanzania during the Period of 1982-2022

Extreme weather and climatic phenomena, such as heatwaves, cold waves, floods and droughts, are expected to become more common and have a significant impact on ecosystems, biodiversity, and society. Devastating disasters are mostly caused by record-breaking extreme events, which are becoming more frequent throughout the world, including Tanzania. A clear global signal of an increase in warm days and nights and a decrease in cold days and nights has been observed. The present study assessed the trends of annual extreme temperature indices during the period of 1982 to 2022 from 29 meteorological stations in which the daily minimum and maximum data were obtained from NASA/POWER. The Mann-Kendall and Sen slope estimator were employed for trend analysis calculation over the study area. The analyzed data have indicated for the most parts, the country has an increase in warm days and nights, extreme warm days and nights and a decrease in cold days and nights, extreme cold days and nights. It has been disclosed that the number of warm nights and days is on the rise, with the number of warm nights trending significantly faster than the number of warm days. The percentile-based extreme temperature indices exhibited more noticeable changes than the absolute extreme temperature indices. Specifically, 66% and 97% of stations demonstrated positive increasing trends in warm days (TX90p) and nights (TN90p), respectively. Conversely, the cold indices demonstrated 41% and 97% negative decreasing trends in TX10p and TN10p, respectively. The results are seemingly consistent with the observed temperature extreme trends in various parts of the world as indicated in IPCC reports.

Spatio-temporal Characteristics of the Extreme Climate Events and Their Potential Effects on Crop Yield in Ethiopia

Extreme climate events exhibit an increasing spatio-temporal trend globally, and the increasing intensity and frequency may have severe impacts on the human society and natural ecosystems. This study analyzed the extreme temperature and precipitation variability from 1956 to 2016, and evaluated their potential effects on crop yield in Ethiopia. Relative extreme temperature indices exhibited a decreasing trend with low-temperature events, but a significantly upward trend with extreme high temperature events. The frequency of annual warm nights increased to a greater degree than that of cold days. The total annual wet-day precipitation decreased significantly at a rate of-46 mm/decade. Further, the succession of dry days gradually increased by 5.6 day/decade, while an opposite trend of wet days was found with a decline of 1.4 day/decade. The correlation between annual precipitation and crop production was 0.422, indicating that extreme precipitation indices may have higher explanatory power than extreme temperature indices in the crop yield variations. Moreover, the extreme climate changes have induced significant adverse impacts on crops yield particularly in Ethiopia where no proper adaptation measures have been implemented.

Spatial Distribution and Temporal Trend Characteristics of Agro-Climatic Resources and Extreme Climate Events during the Soybean Growing Season in Northeast China from 1981 to 2017

Soybean is an important oil crop.Agro-climatic resources and extreme climate events during the growing season directly affect the crop growth and grain yield.In this study,we used historical climate data and phenology observation data to investigate the spatial distributions and temporal trends of agro-climatic resources and extreme climate events during the growing season for soybean in Northeast China(NEC).The results showed that during the soybean growing season,the thermal time increased while both the effective precipitation and photosynthetically active radiation(PAR)decreased.Within the growing season,the thermal time increased by 44.0°C day decade–1 during the vegetative stage but decreased by 16.5°C day decade–1 during the reproductive stage;the effective precipitation increased by 1.8 mm decade–1 during the vegetative stage but decreased by 7.3 mm decade–1 during the reproductive stage;PAR decreased by 6.5 and 11.9 MJ m–2 decade–1 during the vegetative and reproductive stages.The frequency of extreme cold days showed a decreasing trend during the four study phases of sowing to emergence,sowing–flowering,15 days before flowering–flowering,and pod to physiological maturity.During the soybean growing season,the frequency of extreme heat days and the maximum number of consecutive dry days(CDD)increased,and the maximum number of consecutive wet days(CWD)and heavy precipitation days decreased.The results of this study could be used in selecting optimal management in soybean production in order to take advantage of beneficial climatic elements.

The Role of Local Knowledge in the Risk Management of Extreme Climates in Local Communities:A Case Study in a Nomadic NIAHS Site

In the context of climate change,research on extreme climates and disaster risk management has become a crucial component of climate change adaptation.Local communities,which have been facing extreme climates for a long time in their production and daily life,have developed some locally applicable traditional knowledge that has played an important role in their adaptation to extreme climate and disaster risk management.Therefore,this research aims to link Local knowledge(LK)to community extreme climate disaster risk management in order to construct a conceptual model.It then takes the extreme climate adaptation strategy of traditional nomads in a temperate grassland of China as an example to analyze the role of LK in extreme climate adaptation using the proposed theoretical framework.The main research objectives of this study are:(1)To construct a conceptual model to illustrate the relations among extreme climate events,risk management,LK,and farmers’adaptation strategies;(2)To apply the theoretical framework to a field case to reveal context-specific extreme climate adaptation mechanisms with LK as a critical component;(3)To test the framework and provide suggestions for the extreme climates adaptation,and the conservation of LK related to climate change adaptation.The results show that from the perspective of disaster risk management,local communities could manage extreme climates as a disaster risk through adaptation strategies formed from LK,because as a knowledge system,LK contains relevant knowledge covering the whole process of disaster risk management.

An assessment method of annual climatic status in China using extreme climate indices:2021 as an example

A proper assessment of annual climatic status(ACS)is conducive to rationally formulating disaster prevention and mitigation measures.The former definition of ACS lacks either information on extreme climate or an intuitive grade feature service to the public.The ACS defined in the National Standard of the People's Republic of China(GBACS)only considers the accumulated climate effects of each weighted 10-d temperature/precipitation anomaly in a year.Under global warming,the losses caused by extreme climate events often have a significant impact on the grades of ACS,but this impact cannot be reasonably reflected by GBACS.This study proposed the assessment of ACS using extreme climate indices(extreme climate-based ACS(ECACS))and compared it with GBACS.The results indicated that GBACS and ECACS can be used to evaluate the ACS from different angles.The ECACS is an important supplement to the GBACS,especially considering the years with frequently occurring extreme climate events.The sum of GBACS and ECACS is a reasonable and comprehensive way to evaluate the ACS.The empirical orthogonal function(EOF)analysis indicated a uniform mode(EOF1)and a dipole mode(EOF2)in GBACS and ECACS in China.The interannual variation characteristics of ECACS in northern and southern China(EOF2 pattern)are consistent with real climate features,which is conducive to providing better and more detailed regional information in the ACS forecast service.The results have essential instructive and application value for ACS assessment and government decision making.