Atmospheric models are physical equations based on the ideal gas law. Applied to the atmosphere, this law yields equations for water, vapor (gas), ice, air, humidity, dryness, fire, and heat, thus defining the model o...Atmospheric models are physical equations based on the ideal gas law. Applied to the atmosphere, this law yields equations for water, vapor (gas), ice, air, humidity, dryness, fire, and heat, thus defining the model of key atmospheric parameters. The distribution of these parameters across the entire planet Earth is the origin of the formation of the climatic cycle, which is a normal climatic variation. To do this, the Earth is divided into eight (8) parts according to the number of key parameters to be defined in a physical representation of the model. Following this distribution, numerical models calculate the constants for the formation of water, vapor, ice, dryness, thermal energy (fire), heat, air, and humidity. These models vary in complexity depending on the indirect trigonometric direction and simplicity in the sum of neighboring models. Note that the constants obtained from the equations yield 275.156˚K (2.006˚C) for water, 273.1596˚K (0.00963˚C) for vapor, 273.1633˚K (0.0133˚C) for ice, 0.00365 in/s for atmospheric dryness, 1.996 in<sup>2</sup>/s for humidity, 2.993 in<sup>2</sup>/s for air, 1 J for thermal energy of fire, and 0.9963 J for heat. In summary, this study aims to define the main parameters and natural phenomena contributing to the modification of planetary climate. .展开更多
Dear colleagues,We would like to invite you to participate in the special issue of the journal Advances in Polar Science(ISSN 1674-9928)entitled“Past and Present Climatic Change in Antarctica:Geological Proxies and B...Dear colleagues,We would like to invite you to participate in the special issue of the journal Advances in Polar Science(ISSN 1674-9928)entitled“Past and Present Climatic Change in Antarctica:Geological Proxies and Biological Processes”,which is expected to be published in March 2024 as general issue(Vol.35,No.1).We are honored to invite Dra.Carolina Acosta Hospitaleche,Dr.Javier N.Gelfo,Dr.Marcelo Reguero,Dra.Adolfina Savoretti and Dra.展开更多
Like other countries in East Africa, Tanzania has been affected by extreme precipitation incidences both socially and economically. Determining the trend and variability features of extreme precipitation in the countr...Like other countries in East Africa, Tanzania has been affected by extreme precipitation incidences both socially and economically. Determining the trend and variability features of extreme precipitation in the country is crucial. This study used data from 28 meteorological stations for 1981-2020 period to give an annual and seasonal analysis of the patterns of 10 ETCCDI’s extreme precipitation indices over the regions. At annual scale, the results showed that increasing trends had high frequency percentage than the decreasing ones, collecting about 76% in total. The decreasing trend was approximately 24%, and most of the stations with increasing percentage in trend are concentrated in Northern coast, Central, West, North-eastern highlands and Lake Victoria Basin. Most of the stations depicted negative trend are concentrated over Southern region. This highlights that extreme precipitation events have increased over the country for the period 1981-2020. At seasonal scale, during October to December (OND);the patterns of extreme precipitation climatic indices except R99p, showed positive significant increasing trend over Lake Victoria Basin and some Western parts of the country. In general, spatial patterns indicate decrease of precipitation over most parts of the country during OND. The seasonal average time series depicted non-significant positive trend during March to April (MAM) season, except for Consecutive Wet Days (CWD) which showed non-significant decreasing trend. Over the highest mountain in Africa, Kilimanjaro;the study has revealed significant decrease in Annual total-wet Precipitation (PRCPTOT), the number of heavy (very heavy) days of precipitation R10 mm (R20 mm) and Consecutive Wet Days (CWD) during MAM season. While the maximum one-day precipitation amount (RX1 day) was observed to decrease significantly over the Mountain during OND season. The result is very important in risk assessment and preparedness perspective in planning climate change mitigation and adaptations for different sectors like Tourism, Agriculture, Water and Energy.展开更多
In the Sahel region, the population depends largely on rain-fed agriculture. In West Africa in particular, climate models turn out to be unable to capture some basic features of present-day climate variability. This s...In the Sahel region, the population depends largely on rain-fed agriculture. In West Africa in particular, climate models turn out to be unable to capture some basic features of present-day climate variability. This study proposes a contribution to the analysis of the evolution of agro-climatic risks in the context of climate variability. Some statistical tests are used on the main variables of the rainy season to determine the trends and the variabilities described by the data series. Thus, the paper provides a statistical modeling of the different agro-climatic risks while the seasonal variability of agro-climatic parameters was analyzed as well as their inter annual variability. The study identifies the probability distributions of agroclimatic risks and the characterization of the rainy season was clarified.展开更多
Tsutsusi is one of the eight subgenera of the Rhododendron genus.Four Tsutsusi species,R.indicum,R.simisii,R.oldhamii,and R.schlippenbachii,have high ornamental and medicinal values,resulting in an increasing market d...Tsutsusi is one of the eight subgenera of the Rhododendron genus.Four Tsutsusi species,R.indicum,R.simisii,R.oldhamii,and R.schlippenbachii,have high ornamental and medicinal values,resulting in an increasing market demand.These species thrive in cool and humid environments and are widely distributed in Europe and Asia.Whether global climate warming will affect the distribution of these valuable resources remains unclear.Thus,this study analyzed the climatic suitability of these species for the first time on the basis of 1552 geographical distribution points and 19 bioclimatic factors using the maximum entropy model.The results show that a suitable distribution area for all four species would decrease under climate warming.The main bioclimatic factors affecting their distribution are the mean temperature of the coldest quarter for R.indicum,the mean diurnal range for R.simisii,and precipitation of the warmest quarter for R.oldhamii and R.schlippenbachii.In addition,the contribution of the temperature-related bioclimatic factors to the distribution of R.indicum and R.simisii is higher than that of the associated precipitation-related climatic factors;in contrast,the contribution of precipitation-related bioclimatic factors to the distribution of R.oldhamii and R.schlippenbachii is higher than that of the temperature-related climatic factors.These results provide references for the introduction,conservation,sustainable development,and utilization of these four species in the future,and may also provide information with regards to other Rhododendron species.展开更多
Glacier shrinkage is a globally occurring phenomena.High-resolution change detection based on frequent mapping and monitoring of high-altitude glaciers is necessary to precisely evaluate future water availability and ...Glacier shrinkage is a globally occurring phenomena.High-resolution change detection based on frequent mapping and monitoring of high-altitude glaciers is necessary to precisely evaluate future water availability and to understand glacier evolution under different climatic scenarios in the Hindukush-Karakoram-Himalayan(HKH)region.This also holds true for the Bhaga basin of the western Himalaya.This study investigates glacier and glacier lake changes in the Bhaga basin,over the last five decades based on satellite imagery including Corona KH4(1971),Landsat 7 Enhanced Thematic Mapper Plus(ETM+;2000),Linear Imaging Self-Scanning Sensor(LISS Ⅳ;2013),and Sentinel 2(2020).Regional temperature and precipitation trends were evaluated from gridded climatic datasets(1900–2020).In the Bhaga basin 306 glaciers(>0.2 km^(2))were mapped with a total area of 360.3±4.0 km^(2),of which 55.7±0.6 km^(2)was covered with debris in 2013.The total glacier covered area decreased by∼8.2±1.5%(0.16±0.03%yr-1)during the entire observation period 1971–2020,with noticeable heterogeneity between tributary watersheds.In the past two decades(2000–2020),the deglaciation rate has increased significantly(0.25%yr-1)compared to the previous decades(1971–2000;0.12%yr-1).Glacier lake area increased by 0.6±0.1 km^(2)(0.012 km^(2)yr-1)between 1971 and 2020.The NCEP/NCAR climatic data reveals an increase of 0.63℃in temperature and a decrease of 6.39 mm in precipitation for the period 1948–2018.In comparison,APHRODITE data shows an increasing trend in temperature of 1.14℃between 1961 and 2015 and decreasing trend in precipitation of 31 mm between 1951 and 2007.Both NCEP/NCAR and APHRODITE data reveal significant temperature increase and precipitation decrease since the 1990s,which have probably augmented ice loss in the Bhaga basin during the early 21st century.展开更多
Using meteorological data from 8 national basic meteorological observation stations in Qingyang City of Longdong region from 1972 to 2021,the causes and change characteristics of high-temperature weather were analyzed...Using meteorological data from 8 national basic meteorological observation stations in Qingyang City of Longdong region from 1972 to 2021,the causes and change characteristics of high-temperature weather were analyzed,and targeted countermeasures and suggestions were proposed for residents' production,life,and energy security supply affected by high-temperature weather.The results showed that①affected by global warming,the annual average temperature,annual average maximum temperature,annual extreme maximum temperature,days of daily maximum temperature≥30℃,and days of daily maximum temperature≥35℃in Longdong region were all showing an upward trend;②due to the different terrain and soil properties of the underlying surface,the increase in high temperature weather varied in different regions.Due to the influence of desert and hilly terrain,the frequency and days of high temperature occurrence were relatively high in the central and northern parts of Qingyang City.Due to the climate regulation of the Ziwuling Mountains,the days of high temperature in the central and southern parts was significantly less than that in the central and northern parts;③if the warm high pressure ridge on the Qinghai-Tibet Plateau developed strongly in summer,the temperature of the closed warm center reached 0-4℃on the 500 hPa of high-altitude weather map.If the warm air mass developed eastward,it often led to sustained high temperature weather in Longdong region;④when the El Nino phenomenon occurred,the subtropical high in the western Pacific developed strongly in summer,with a center located northward,which was stable,with little movement.It was dry,sunny,hot,and rainless in Longdong region,and the high temperature weather was more significant than that in normal years.展开更多
The aim of this study is to establish the prevailing conditions of changing climatic trends and change point dates in four selected meteorological stations of Uyo, Benin, Port Harcourt, and Warri in the Niger Delta re...The aim of this study is to establish the prevailing conditions of changing climatic trends and change point dates in four selected meteorological stations of Uyo, Benin, Port Harcourt, and Warri in the Niger Delta region of Nigeria. Using daily or 24-hourly annual maximum series (AMS) data with the Indian Meteorological Department (IMD) and the modified Chowdury Indian Meteorological Department (MCIMD) models were adopted to downscale the time series data. Mann-Kendall (MK) trend and Sen’s Slope Estimator (SSE) test showed a statistically significant trend for Uyo and Benin, while Port Harcourt and Warri showed mild trends. The Sen’s Slope magnitude and variation rate were 21.6, 10.8, 6.00 and 4.4 mm/decade, respectively. The trend change-point analysis showed the initial rainfall change-point dates as 2002, 2005, 1988, and 2000 for Uyo, Benin, Port Harcourt, and Warri, respectively. These prove positive changing climatic conditions for rainfall in the study area. Erosion and flood control facilities analysis and design in the Niger Delta will require the application of Non-stationary IDF modelling.展开更多
In the global climatic change, China's climatic change will be more compliCated and itS compact on the agroclimatic resources and agricultural production will also be more obvious. Therefore, it is absolutely nec...In the global climatic change, China's climatic change will be more compliCated and itS compact on the agroclimatic resources and agricultural production will also be more obvious. Therefore, it is absolutely necessary to take the agroclimatic resources as a comprehensive climatic information syStem for evaluating the impact of climatic change on agriculture and exploring the corresPOndent ways to deal with it. This article studies the compact of climatic change on China's thermal resources and make a correlation analySis of the climatic COndition and the agroclimatic thermal resources in order to establish a regression equation and made simulant computation with Monte Cario Method. In addition, it analyses the change of the thermal resources possibly resulted from climatic change, evaluates its impact on agricultural, and finally sets up the corresPOndent countermeasures.展开更多
The steep North to South (N-S) gradient and complex topography markssignificant variations in the spatial and temporal patterns of climatic variationsurrounding within a few distances in the Nepal Himalayas. Hence,to ...The steep North to South (N-S) gradient and complex topography markssignificant variations in the spatial and temporal patterns of climatic variationsurrounding within a few distances in the Nepal Himalayas. Hence,to validate climatic linkages between the stations under two distinct topographicconditions, the study examines the observational climatic data from106m a.s.l. and 1801m a.s.l., as a representative station from a plain andhilly area. Different statistical tools including Pearson correlation analysisand a best-fit regression model were applied to analyze climate data. Theanalysis of 13129 daily average temperature records and 13147 daily totalprecipitation records showed that the variation in their sum and average ofdaily, five days, ten days, and monthly values between the stations in thedifferent elevations marked significantly.Despite these variations, temperaturerecords are measured to be consistent in different altitudes and stronglycorrelated. The precipitation data showed a comparatively weaker correlation.The coefficients (0.85-1.6) with R2>0.50 in the regression models forthe lower elevation and higher elevation station in the mid-mountain regionexcept for the monsoon season. It indicated a similar fluctuation of temperaturebetween these two stations in the respective area. The strong degreeof association and the change of climatic parameters in different rangeand elevations indicate the possibilities of using climatic data from Terai torepresent the Mid-mountain region of central Nepal.展开更多
The preliminary analysis of climatic variation in China during the last 39 years has been made in this paper. The results show that although the global climate is getting warmer, some parts of China are cooling. The w...The preliminary analysis of climatic variation in China during the last 39 years has been made in this paper. The results show that although the global climate is getting warmer, some parts of China are cooling. The warming only occurs in Northeast, North and the west part of Northwest China while the areas between about 35°N and Nanling Mountain, east of the Tibetan Plateau in China are getting cooler. The cooling centers are located in Sichuan, the south part of Shaanxi and the north part of Yunnan respectively. According to the theory of greenhouse effect, there are much precipitation at low and high latitudes and less precipitation in middle latitude. However, the precipitation in the most parts of China has been decreased, especially in North and Northwest China.展开更多
Using radiation data from the Automatic Weather Stations (AWSs) for thermal balance observations, which were set up at Lhasa, Nagqu, Xigaze and Nyingchi by the Sino-Japanese Asian Monsoon Mechanism Co-operative Projec...Using radiation data from the Automatic Weather Stations (AWSs) for thermal balance observations, which were set up at Lhasa, Nagqu, Xigaze and Nyingchi by the Sino-Japanese Asian Monsoon Mechanism Co-operative Project in 1993-1996, and 1985-1989 Earth Radiation Balance Experiment (ERBE) measurements of Langley Research Center / NASA of US, and 1961-1996 monthly mean data from 148 surface stations over the Qinghai-Xizang Plateau (QXP) and its neighborhood, study is performed on empirical calculation methods of surface albedo, surface total radiation, planetary a lbedo and outgoing longwave radiation with the climatic features of radiation balance at the surface and the atmospheric top examined. Evidences suggest that the empirical formulae for surface albedo, planetary albedo, surface total radiation and outgoing longwave radiation from the atmospheric top are capable of describing their seasonal and interannual variations over the QXP. The surface albedo is marked by noticeable seasonal variation and yearly mean of 0.22 with the maximum of 0.29 in January and minimum of 0. 17 in July and August; In winter the albedo has great horizontal difference, bigger in the mountains than in the river valleys, and small in summer, The planetary albedo shows a smaller range of its annual variation with the yearly mean of 0.37. the maximum (minimum) occurring in February and March (autumn). In winter its high-value regions are mainly at Gar (Shiquanhe) in the western QXP and from the southwestern Qinghai to the northeastern Tibet and the low-value area at the northern slope of the central Himalayas; in summer, however, the albedo distribution displays clearly a progressive decrease from southeast to northwest, As for the surface total radiation, its values and annual varying range are smaller in tile east than in the southwest, its high-value center is at the southern slope of the Himalayas in winter and makes a conspicuous westward migration in spring, remaining there for a long time, and it begins to retreat eastward in autumn. Monthly mean values of the surface net radiation are all positive and larger in summer than in winter. The net radiation is significantly intensified under the combined effect of surface total radiation and surface albedo from spring to early summer, resulting in the strongest sector in the mid plateau with its center staying nearly motionless from March to September, and is reduced in autumn dominantly by surface effective radiation. The earth-atmosphere system loses heat outward from October to next February and gains in other months. On an average, the plateau gains heat of 15 W m-2 on an annual basis.展开更多
A two-phase trend model is presented to investigate the turning-point signals of evolution trend in long-term series of a climatic element. Based on nonlinear fitting, the revised model brings out more evident improve...A two-phase trend model is presented to investigate the turning-point signals of evolution trend in long-term series of a climatic element. Based on nonlinear fitting, the revised model brings out more evident improvement of the linear model proposed by Solow et al. (1987). Both theoretical deduction and case calculation show that our version can search the turning point and period accurately and objectively. In particular it is fit for computer exploring the turning points in long-range records from stations covering a large area, thus avoiding subjective judgement by a usual drawing method.展开更多
Tourism Climatic Indices(TCIs)are widely used in the global North to quantify the climatic suitability of a destination for tourism.Only one such study has been conducted in southern Africa to date.It is in a chronic ...Tourism Climatic Indices(TCIs)are widely used in the global North to quantify the climatic suitability of a destination for tourism.Only one such study has been conducted in southern Africa to date.It is in a chronic shortage of research on tourism and climate change in the southern hemisphere.This study presents the application of the TCI in Lesotho,calculated for the eastern Lesotho Highlands.The region has an emerging tourism sector,which primarily comprises outdoor activities.These include hiking,horse-riding,music festivals,mountain biking,cultural visits,sightseeing,and at the Afriski lodge,skiing and snowboarding.These activities are reliant on climatic conditions that are conducive to the activity taking place,prolonged periods outdoors,and tourist satisfaction of the activity.Climate is a major determinant of both the length of season for these activities and the timing of peak tourist arrivals.Rising temperatures and changes in relative humidity and precipitation pose real threats to hiking,sightseeing and snow tourism at Afriski.The reliance of tourism in the region on specific climatic conditions for successful tourism prompted the use of the TCI.TCI results classify the eastern Lesotho Highlands as having‘good'climatic conditions with an overall TCI score of 64 for the period 2012-2017.Monthly TCI scores for the eastern Lesotho reveal a bimodal-shoulder,meaning the peak climatic conditions are in the regional summer months(December to February).This conflicts with the peak tourist seasons of summer and winter,which align with South African school holidays,and the timing of the most profitable tourism activity(skiing)which occurs during the winter months of June,July and August.Lesotho is landlocked by South Africa.TCI analysis for South Africa reveals more suitable climatic conditions for tourism than Lesotho,with significantly higher scores of 80-89.展开更多
The spatial and temporal variations of daily maximum temperature(Tmax), daily minimum temperature(Tmin), daily maximum precipitation(Pmax) and daily maximum wind speed(WSmax) were examined in China using Mann-Kendall ...The spatial and temporal variations of daily maximum temperature(Tmax), daily minimum temperature(Tmin), daily maximum precipitation(Pmax) and daily maximum wind speed(WSmax) were examined in China using Mann-Kendall test and linear regression method. The results indicated that for China as a whole, Tmax, Tmin and Pmax had significant increasing trends at rates of 0.15℃ per decade, 0.45℃ per decade and 0.58 mm per decade,respectively, while WSmax had decreased significantly at 1.18 m·s^(-1) per decade during 1959—2014. In all regions of China, Tmin increased and WSmax decreased significantly. Spatially, Tmax increased significantly at most of the stations in South China(SC), northwestern North China(NC), northeastern Northeast China(NEC), eastern Northwest China(NWC) and eastern Southwest China(SWC), and the increasing trends were significant in NC, SC, NWC and SWC on the regional average. Tmin increased significantly at most of the stations in China, with notable increase in NEC, northern and southeastern NC and northwestern and eastern NWC. Pmax showed no significant trend at most of the stations in China, and on the regional average it decreased significantly in NC but increased in SC, NWC and the mid-lower Yangtze River valley(YR). WSmax decreased significantly at the vast majority of stations in China, with remarkable decrease in northern NC, northern and central YR, central and southern SC and in parts of central NEC and western NWC. With global climate change and rapidly economic development, China has become more vulnerable to climatic extremes and meteorological disasters, so more strategies of mitigation and/or adaptation of climatic extremes,such as environmentally-friendly and low-cost energy production systems and the enhancement of engineering defense measures are necessary for government and social publics.展开更多
The intensity, landing time, track trend and intensity variation of tropical cyclones (TCs) afterlandfall are analyzed using the TCs data (of best track from the China Meteorological Administration)between 1949 and 20...The intensity, landing time, track trend and intensity variation of tropical cyclones (TCs) afterlandfall are analyzed using the TCs data (of best track from the China Meteorological Administration)between 1949 and 2006 for the western North Pacific and South China Sea. The trend differences of trackand intensity between the TCs that directly land in East China and those making the second landfall in EastChina after landing in Taiwan Island are categorically discussed. The results show that the first kind oflanding TCs are more likely to go northward or turn while the second kind of TCs have a larger tendency tokeep going northwest. The intensity of the first kind of TCs is more persistent than the second one. There isa higher percentage for the intensity to be weakened significantly if the TCs keep going west to northwest orsouthwest after landing.展开更多
The authors investigated lacustrine chemical sediments on terrace-I of Dong Co---a salt lake in the interiorof the northern Tibetan Plateau and firstly discovered borax and a complete sedimentary section with five pur...The authors investigated lacustrine chemical sediments on terrace-I of Dong Co---a salt lake in the interiorof the northern Tibetan Plateau and firstly discovered borax and a complete sedimentary section with five pure mirabilitebeds. According to the sedimentary characteristics of rhythmic layering, palaeotemperatures for the formation of the cold-phase mineral-mirabilite-at the profiles and 14C dating, the authors applied the theory and method of comparativesalinology in the study of the history of the palaeoclimate and palaeoenvironment of Dong Co in the early and middleHolocene and drew the conclusion that the salt lake had experienced the following climatic evolution: the warm and moiststage (>8470 a BP and possibly to 10500 a BP)→cold and dry stage (8470-8170 a BP)→warm and moist stage (8170-7590a BP)→stage of repeated climatic oscillations (7590-7400 a BP, alternation of three dry oscillations and three moist os-cillations in a generally cold climatic background)→cold and dry stage (7400-6940 a BP)→warm and moist stage (6940-6620 a BP)→cold and dry stage (6620-6410 a B P)→ warm and moist stage (after 6410 a BP).展开更多
According to the marine records from the Bay of Bengal, northeastern Indian Ocean, and the continental records from the South China, the authors make a detailed discussion in this paper about the correlation between t...According to the marine records from the Bay of Bengal, northeastern Indian Ocean, and the continental records from the South China, the authors make a detailed discussion in this paper about the correlation between them and their implication of rapid climatic change. The marine records show its good response to the high latitudes both for cold events and for warm ones while the continental records mainly mirror those cold Heinrich events corresponding to the North Atlantic but bear strongly a local color in reflecting warm events. The authors assume that the heat transmission style may cause the unbalanced coupling relationship.展开更多
文摘Atmospheric models are physical equations based on the ideal gas law. Applied to the atmosphere, this law yields equations for water, vapor (gas), ice, air, humidity, dryness, fire, and heat, thus defining the model of key atmospheric parameters. The distribution of these parameters across the entire planet Earth is the origin of the formation of the climatic cycle, which is a normal climatic variation. To do this, the Earth is divided into eight (8) parts according to the number of key parameters to be defined in a physical representation of the model. Following this distribution, numerical models calculate the constants for the formation of water, vapor, ice, dryness, thermal energy (fire), heat, air, and humidity. These models vary in complexity depending on the indirect trigonometric direction and simplicity in the sum of neighboring models. Note that the constants obtained from the equations yield 275.156˚K (2.006˚C) for water, 273.1596˚K (0.00963˚C) for vapor, 273.1633˚K (0.0133˚C) for ice, 0.00365 in/s for atmospheric dryness, 1.996 in<sup>2</sup>/s for humidity, 2.993 in<sup>2</sup>/s for air, 1 J for thermal energy of fire, and 0.9963 J for heat. In summary, this study aims to define the main parameters and natural phenomena contributing to the modification of planetary climate. .
文摘Dear colleagues,We would like to invite you to participate in the special issue of the journal Advances in Polar Science(ISSN 1674-9928)entitled“Past and Present Climatic Change in Antarctica:Geological Proxies and Biological Processes”,which is expected to be published in March 2024 as general issue(Vol.35,No.1).We are honored to invite Dra.Carolina Acosta Hospitaleche,Dr.Javier N.Gelfo,Dr.Marcelo Reguero,Dra.Adolfina Savoretti and Dra.
文摘Like other countries in East Africa, Tanzania has been affected by extreme precipitation incidences both socially and economically. Determining the trend and variability features of extreme precipitation in the country is crucial. This study used data from 28 meteorological stations for 1981-2020 period to give an annual and seasonal analysis of the patterns of 10 ETCCDI’s extreme precipitation indices over the regions. At annual scale, the results showed that increasing trends had high frequency percentage than the decreasing ones, collecting about 76% in total. The decreasing trend was approximately 24%, and most of the stations with increasing percentage in trend are concentrated in Northern coast, Central, West, North-eastern highlands and Lake Victoria Basin. Most of the stations depicted negative trend are concentrated over Southern region. This highlights that extreme precipitation events have increased over the country for the period 1981-2020. At seasonal scale, during October to December (OND);the patterns of extreme precipitation climatic indices except R99p, showed positive significant increasing trend over Lake Victoria Basin and some Western parts of the country. In general, spatial patterns indicate decrease of precipitation over most parts of the country during OND. The seasonal average time series depicted non-significant positive trend during March to April (MAM) season, except for Consecutive Wet Days (CWD) which showed non-significant decreasing trend. Over the highest mountain in Africa, Kilimanjaro;the study has revealed significant decrease in Annual total-wet Precipitation (PRCPTOT), the number of heavy (very heavy) days of precipitation R10 mm (R20 mm) and Consecutive Wet Days (CWD) during MAM season. While the maximum one-day precipitation amount (RX1 day) was observed to decrease significantly over the Mountain during OND season. The result is very important in risk assessment and preparedness perspective in planning climate change mitigation and adaptations for different sectors like Tourism, Agriculture, Water and Energy.
文摘In the Sahel region, the population depends largely on rain-fed agriculture. In West Africa in particular, climate models turn out to be unable to capture some basic features of present-day climate variability. This study proposes a contribution to the analysis of the evolution of agro-climatic risks in the context of climate variability. Some statistical tests are used on the main variables of the rainy season to determine the trends and the variabilities described by the data series. Thus, the paper provides a statistical modeling of the different agro-climatic risks while the seasonal variability of agro-climatic parameters was analyzed as well as their inter annual variability. The study identifies the probability distributions of agroclimatic risks and the characterization of the rainy season was clarified.
基金supported by the National Natural Science Foundation of China(32260415)Guizhou Provincial Science and Technology Project(Qianke Combination Foundation-ZK[2023]Key 010)。
文摘Tsutsusi is one of the eight subgenera of the Rhododendron genus.Four Tsutsusi species,R.indicum,R.simisii,R.oldhamii,and R.schlippenbachii,have high ornamental and medicinal values,resulting in an increasing market demand.These species thrive in cool and humid environments and are widely distributed in Europe and Asia.Whether global climate warming will affect the distribution of these valuable resources remains unclear.Thus,this study analyzed the climatic suitability of these species for the first time on the basis of 1552 geographical distribution points and 19 bioclimatic factors using the maximum entropy model.The results show that a suitable distribution area for all four species would decrease under climate warming.The main bioclimatic factors affecting their distribution are the mean temperature of the coldest quarter for R.indicum,the mean diurnal range for R.simisii,and precipitation of the warmest quarter for R.oldhamii and R.schlippenbachii.In addition,the contribution of the temperature-related bioclimatic factors to the distribution of R.indicum and R.simisii is higher than that of the associated precipitation-related climatic factors;in contrast,the contribution of precipitation-related bioclimatic factors to the distribution of R.oldhamii and R.schlippenbachii is higher than that of the temperature-related climatic factors.These results provide references for the introduction,conservation,sustainable development,and utilization of these four species in the future,and may also provide information with regards to other Rhododendron species.
基金the University Grant Commission, New Delhi (3090/ (NET–DEC.2014) for financial support during field visitsthe Department of Science and Technology, Govt of India, for sponsoring the project “Himalayan Cryosphere: Science and Society”
文摘Glacier shrinkage is a globally occurring phenomena.High-resolution change detection based on frequent mapping and monitoring of high-altitude glaciers is necessary to precisely evaluate future water availability and to understand glacier evolution under different climatic scenarios in the Hindukush-Karakoram-Himalayan(HKH)region.This also holds true for the Bhaga basin of the western Himalaya.This study investigates glacier and glacier lake changes in the Bhaga basin,over the last five decades based on satellite imagery including Corona KH4(1971),Landsat 7 Enhanced Thematic Mapper Plus(ETM+;2000),Linear Imaging Self-Scanning Sensor(LISS Ⅳ;2013),and Sentinel 2(2020).Regional temperature and precipitation trends were evaluated from gridded climatic datasets(1900–2020).In the Bhaga basin 306 glaciers(>0.2 km^(2))were mapped with a total area of 360.3±4.0 km^(2),of which 55.7±0.6 km^(2)was covered with debris in 2013.The total glacier covered area decreased by∼8.2±1.5%(0.16±0.03%yr-1)during the entire observation period 1971–2020,with noticeable heterogeneity between tributary watersheds.In the past two decades(2000–2020),the deglaciation rate has increased significantly(0.25%yr-1)compared to the previous decades(1971–2000;0.12%yr-1).Glacier lake area increased by 0.6±0.1 km^(2)(0.012 km^(2)yr-1)between 1971 and 2020.The NCEP/NCAR climatic data reveals an increase of 0.63℃in temperature and a decrease of 6.39 mm in precipitation for the period 1948–2018.In comparison,APHRODITE data shows an increasing trend in temperature of 1.14℃between 1961 and 2015 and decreasing trend in precipitation of 31 mm between 1951 and 2007.Both NCEP/NCAR and APHRODITE data reveal significant temperature increase and precipitation decrease since the 1990s,which have probably augmented ice loss in the Bhaga basin during the early 21st century.
文摘Using meteorological data from 8 national basic meteorological observation stations in Qingyang City of Longdong region from 1972 to 2021,the causes and change characteristics of high-temperature weather were analyzed,and targeted countermeasures and suggestions were proposed for residents' production,life,and energy security supply affected by high-temperature weather.The results showed that①affected by global warming,the annual average temperature,annual average maximum temperature,annual extreme maximum temperature,days of daily maximum temperature≥30℃,and days of daily maximum temperature≥35℃in Longdong region were all showing an upward trend;②due to the different terrain and soil properties of the underlying surface,the increase in high temperature weather varied in different regions.Due to the influence of desert and hilly terrain,the frequency and days of high temperature occurrence were relatively high in the central and northern parts of Qingyang City.Due to the climate regulation of the Ziwuling Mountains,the days of high temperature in the central and southern parts was significantly less than that in the central and northern parts;③if the warm high pressure ridge on the Qinghai-Tibet Plateau developed strongly in summer,the temperature of the closed warm center reached 0-4℃on the 500 hPa of high-altitude weather map.If the warm air mass developed eastward,it often led to sustained high temperature weather in Longdong region;④when the El Nino phenomenon occurred,the subtropical high in the western Pacific developed strongly in summer,with a center located northward,which was stable,with little movement.It was dry,sunny,hot,and rainless in Longdong region,and the high temperature weather was more significant than that in normal years.
文摘The aim of this study is to establish the prevailing conditions of changing climatic trends and change point dates in four selected meteorological stations of Uyo, Benin, Port Harcourt, and Warri in the Niger Delta region of Nigeria. Using daily or 24-hourly annual maximum series (AMS) data with the Indian Meteorological Department (IMD) and the modified Chowdury Indian Meteorological Department (MCIMD) models were adopted to downscale the time series data. Mann-Kendall (MK) trend and Sen’s Slope Estimator (SSE) test showed a statistically significant trend for Uyo and Benin, while Port Harcourt and Warri showed mild trends. The Sen’s Slope magnitude and variation rate were 21.6, 10.8, 6.00 and 4.4 mm/decade, respectively. The trend change-point analysis showed the initial rainfall change-point dates as 2002, 2005, 1988, and 2000 for Uyo, Benin, Port Harcourt, and Warri, respectively. These prove positive changing climatic conditions for rainfall in the study area. Erosion and flood control facilities analysis and design in the Niger Delta will require the application of Non-stationary IDF modelling.
文摘In the global climatic change, China's climatic change will be more compliCated and itS compact on the agroclimatic resources and agricultural production will also be more obvious. Therefore, it is absolutely necessary to take the agroclimatic resources as a comprehensive climatic information syStem for evaluating the impact of climatic change on agriculture and exploring the corresPOndent ways to deal with it. This article studies the compact of climatic change on China's thermal resources and make a correlation analySis of the climatic COndition and the agroclimatic thermal resources in order to establish a regression equation and made simulant computation with Monte Cario Method. In addition, it analyses the change of the thermal resources possibly resulted from climatic change, evaluates its impact on agricultural, and finally sets up the corresPOndent countermeasures.
文摘The steep North to South (N-S) gradient and complex topography markssignificant variations in the spatial and temporal patterns of climatic variationsurrounding within a few distances in the Nepal Himalayas. Hence,to validate climatic linkages between the stations under two distinct topographicconditions, the study examines the observational climatic data from106m a.s.l. and 1801m a.s.l., as a representative station from a plain andhilly area. Different statistical tools including Pearson correlation analysisand a best-fit regression model were applied to analyze climate data. Theanalysis of 13129 daily average temperature records and 13147 daily totalprecipitation records showed that the variation in their sum and average ofdaily, five days, ten days, and monthly values between the stations in thedifferent elevations marked significantly.Despite these variations, temperaturerecords are measured to be consistent in different altitudes and stronglycorrelated. The precipitation data showed a comparatively weaker correlation.The coefficients (0.85-1.6) with R2>0.50 in the regression models forthe lower elevation and higher elevation station in the mid-mountain regionexcept for the monsoon season. It indicated a similar fluctuation of temperaturebetween these two stations in the respective area. The strong degreeof association and the change of climatic parameters in different rangeand elevations indicate the possibilities of using climatic data from Terai torepresent the Mid-mountain region of central Nepal.
基金This work is supported by National Environment and Protect Agency under Program 891205
文摘The preliminary analysis of climatic variation in China during the last 39 years has been made in this paper. The results show that although the global climate is getting warmer, some parts of China are cooling. The warming only occurs in Northeast, North and the west part of Northwest China while the areas between about 35°N and Nanling Mountain, east of the Tibetan Plateau in China are getting cooler. The cooling centers are located in Sichuan, the south part of Shaanxi and the north part of Yunnan respectively. According to the theory of greenhouse effect, there are much precipitation at low and high latitudes and less precipitation in middle latitude. However, the precipitation in the most parts of China has been decreased, especially in North and Northwest China.
文摘Using radiation data from the Automatic Weather Stations (AWSs) for thermal balance observations, which were set up at Lhasa, Nagqu, Xigaze and Nyingchi by the Sino-Japanese Asian Monsoon Mechanism Co-operative Project in 1993-1996, and 1985-1989 Earth Radiation Balance Experiment (ERBE) measurements of Langley Research Center / NASA of US, and 1961-1996 monthly mean data from 148 surface stations over the Qinghai-Xizang Plateau (QXP) and its neighborhood, study is performed on empirical calculation methods of surface albedo, surface total radiation, planetary a lbedo and outgoing longwave radiation with the climatic features of radiation balance at the surface and the atmospheric top examined. Evidences suggest that the empirical formulae for surface albedo, planetary albedo, surface total radiation and outgoing longwave radiation from the atmospheric top are capable of describing their seasonal and interannual variations over the QXP. The surface albedo is marked by noticeable seasonal variation and yearly mean of 0.22 with the maximum of 0.29 in January and minimum of 0. 17 in July and August; In winter the albedo has great horizontal difference, bigger in the mountains than in the river valleys, and small in summer, The planetary albedo shows a smaller range of its annual variation with the yearly mean of 0.37. the maximum (minimum) occurring in February and March (autumn). In winter its high-value regions are mainly at Gar (Shiquanhe) in the western QXP and from the southwestern Qinghai to the northeastern Tibet and the low-value area at the northern slope of the central Himalayas; in summer, however, the albedo distribution displays clearly a progressive decrease from southeast to northwest, As for the surface total radiation, its values and annual varying range are smaller in tile east than in the southwest, its high-value center is at the southern slope of the Himalayas in winter and makes a conspicuous westward migration in spring, remaining there for a long time, and it begins to retreat eastward in autumn. Monthly mean values of the surface net radiation are all positive and larger in summer than in winter. The net radiation is significantly intensified under the combined effect of surface total radiation and surface albedo from spring to early summer, resulting in the strongest sector in the mid plateau with its center staying nearly motionless from March to September, and is reduced in autumn dominantly by surface effective radiation. The earth-atmosphere system loses heat outward from October to next February and gains in other months. On an average, the plateau gains heat of 15 W m-2 on an annual basis.
基金This wirk is supported jointly National Natural Science Foundation of China and China Meteoroloical Administration 8th-Five-year Major Project Foundation.
文摘A two-phase trend model is presented to investigate the turning-point signals of evolution trend in long-term series of a climatic element. Based on nonlinear fitting, the revised model brings out more evident improvement of the linear model proposed by Solow et al. (1987). Both theoretical deduction and case calculation show that our version can search the turning point and period accurately and objectively. In particular it is fit for computer exploring the turning points in long-range records from stations covering a large area, thus avoiding subjective judgement by a usual drawing method.
基金funded by the DST-NRF Centre of Excellence for Palaeoscience
文摘Tourism Climatic Indices(TCIs)are widely used in the global North to quantify the climatic suitability of a destination for tourism.Only one such study has been conducted in southern Africa to date.It is in a chronic shortage of research on tourism and climate change in the southern hemisphere.This study presents the application of the TCI in Lesotho,calculated for the eastern Lesotho Highlands.The region has an emerging tourism sector,which primarily comprises outdoor activities.These include hiking,horse-riding,music festivals,mountain biking,cultural visits,sightseeing,and at the Afriski lodge,skiing and snowboarding.These activities are reliant on climatic conditions that are conducive to the activity taking place,prolonged periods outdoors,and tourist satisfaction of the activity.Climate is a major determinant of both the length of season for these activities and the timing of peak tourist arrivals.Rising temperatures and changes in relative humidity and precipitation pose real threats to hiking,sightseeing and snow tourism at Afriski.The reliance of tourism in the region on specific climatic conditions for successful tourism prompted the use of the TCI.TCI results classify the eastern Lesotho Highlands as having‘good'climatic conditions with an overall TCI score of 64 for the period 2012-2017.Monthly TCI scores for the eastern Lesotho reveal a bimodal-shoulder,meaning the peak climatic conditions are in the regional summer months(December to February).This conflicts with the peak tourist seasons of summer and winter,which align with South African school holidays,and the timing of the most profitable tourism activity(skiing)which occurs during the winter months of June,July and August.Lesotho is landlocked by South Africa.TCI analysis for South Africa reveals more suitable climatic conditions for tourism than Lesotho,with significantly higher scores of 80-89.
基金National Natural Science Foundation of China(41571044,41001283)Climate Change Special Fund of the China Meteorological Administration(CCSF201716)China Clean Development Mechanism(CDM) Fund Project(2012043)
文摘The spatial and temporal variations of daily maximum temperature(Tmax), daily minimum temperature(Tmin), daily maximum precipitation(Pmax) and daily maximum wind speed(WSmax) were examined in China using Mann-Kendall test and linear regression method. The results indicated that for China as a whole, Tmax, Tmin and Pmax had significant increasing trends at rates of 0.15℃ per decade, 0.45℃ per decade and 0.58 mm per decade,respectively, while WSmax had decreased significantly at 1.18 m·s^(-1) per decade during 1959—2014. In all regions of China, Tmin increased and WSmax decreased significantly. Spatially, Tmax increased significantly at most of the stations in South China(SC), northwestern North China(NC), northeastern Northeast China(NEC), eastern Northwest China(NWC) and eastern Southwest China(SWC), and the increasing trends were significant in NC, SC, NWC and SWC on the regional average. Tmin increased significantly at most of the stations in China, with notable increase in NEC, northern and southeastern NC and northwestern and eastern NWC. Pmax showed no significant trend at most of the stations in China, and on the regional average it decreased significantly in NC but increased in SC, NWC and the mid-lower Yangtze River valley(YR). WSmax decreased significantly at the vast majority of stations in China, with remarkable decrease in northern NC, northern and central YR, central and southern SC and in parts of central NEC and western NWC. With global climate change and rapidly economic development, China has become more vulnerable to climatic extremes and meteorological disasters, so more strategies of mitigation and/or adaptation of climatic extremes,such as environmentally-friendly and low-cost energy production systems and the enhancement of engineering defense measures are necessary for government and social publics.
基金National Basic Research Program of China(2009CB421501)National Natural Science Foundation of China(40921160381)Geographic Information Science Key Laboratory Foundation for Ministry of Education(LGISEM0606)
文摘The intensity, landing time, track trend and intensity variation of tropical cyclones (TCs) afterlandfall are analyzed using the TCs data (of best track from the China Meteorological Administration)between 1949 and 2006 for the western North Pacific and South China Sea. The trend differences of trackand intensity between the TCs that directly land in East China and those making the second landfall in EastChina after landing in Taiwan Island are categorically discussed. The results show that the first kind oflanding TCs are more likely to go northward or turn while the second kind of TCs have a larger tendency tokeep going northwest. The intensity of the first kind of TCs is more persistent than the second one. There isa higher percentage for the intensity to be weakened significantly if the TCs keep going west to northwest orsouthwest after landing.
基金National Natural Science Foundation grant 49833010.
文摘The authors investigated lacustrine chemical sediments on terrace-I of Dong Co---a salt lake in the interiorof the northern Tibetan Plateau and firstly discovered borax and a complete sedimentary section with five pure mirabilitebeds. According to the sedimentary characteristics of rhythmic layering, palaeotemperatures for the formation of the cold-phase mineral-mirabilite-at the profiles and 14C dating, the authors applied the theory and method of comparativesalinology in the study of the history of the palaeoclimate and palaeoenvironment of Dong Co in the early and middleHolocene and drew the conclusion that the salt lake had experienced the following climatic evolution: the warm and moiststage (>8470 a BP and possibly to 10500 a BP)→cold and dry stage (8470-8170 a BP)→warm and moist stage (8170-7590a BP)→stage of repeated climatic oscillations (7590-7400 a BP, alternation of three dry oscillations and three moist os-cillations in a generally cold climatic background)→cold and dry stage (7400-6940 a BP)→warm and moist stage (6940-6620 a BP)→cold and dry stage (6620-6410 a B P)→ warm and moist stage (after 6410 a BP).
基金The study is supported by the National Key Project ( No. 19980 40 80 0 ) and National Natural Science Foundation of China( Nos.
文摘According to the marine records from the Bay of Bengal, northeastern Indian Ocean, and the continental records from the South China, the authors make a detailed discussion in this paper about the correlation between them and their implication of rapid climatic change. The marine records show its good response to the high latitudes both for cold events and for warm ones while the continental records mainly mirror those cold Heinrich events corresponding to the North Atlantic but bear strongly a local color in reflecting warm events. The authors assume that the heat transmission style may cause the unbalanced coupling relationship.
