Based on the merged measurements from the TRMM Precipitation Radar and Visible and Infrared Scanner,refined characteristics（intensity,frequency,vertical structure,and diurnal variation） and regional differences of t...Based on the merged measurements from the TRMM Precipitation Radar and Visible and Infrared Scanner,refined characteristics（intensity,frequency,vertical structure,and diurnal variation） and regional differences of the warm rain over the tropical and subtropical Pacific Ocean（40°S-40°N,120°E-70°W）in boreal summer are investigated for the period 1998-2012.The results reveal that three warm rain types（phased,pure,and mixed） exist over these regions.The phased warm rain,which occurs during the developing or declining stage of precipitation weather systems,is located over the central to western Intertropical Convergence Zone,South Pacific Convergence Zone,and Northwest Pacific.Its occurrence frequency peaks at midnight and minimizes during daytime with a 5.5-km maximum echo top.The frequency of this warm rain type is about 2.2%,and it contributes to 40%of the regional total rainfall.The pure warm rain is characterized by typical stable precipitation with an echo top lower than 4 km,and mostly occurs in Southeast Pacific.Although its frequency is less than 1.3%,this type of warm rain accounts for 95%of the regional total rainfall.Its occurrence peaks before dawn and it usually disappears in the afternoon.For the mixed warm rain,some may develop into deep convective precipitation,while most are similar to those of the pure type.The mixed warm rain is mainly located over the ocean east of Hawaii.Its frequency is 1.2%,but this type of warm rain could contribute to 80%of the regional total rainfall.The results also uncover that the mixed and pure types occur over the regions where SST ranges from 295 to 299 K,accompanied by relatively strong downdrafts at 500 hPa.Both the mixed and pure warm rains happen in a more unstable atmosphere,compared with the phased warm rain.展开更多
The Keriya River Basin is located in an extremely arid climate zone on the southern edge of the Tarim Basin of Northwest China,exhibiting typical mountain-oasis-desert distribution characteristics.In recent decades,cl...The Keriya River Basin is located in an extremely arid climate zone on the southern edge of the Tarim Basin of Northwest China,exhibiting typical mountain-oasis-desert distribution characteristics.In recent decades,climate change and human activities have exerted significant impacts on the service functions of watershed ecosystems.However,the trade-offs and synergies between ecosystem services(ESs)have not been thoroughly examined.This study aims to reveal the spatiotemporal changes in ESs within the Keriya River Basin from 1995 to 2020 as well as the trade-offs and synergies between ESs.Leveraging the Integrated Valuation of Ecosystem Services and Trade-offs(InVEST)and Revised Wind Erosion Equation(RWEQ)using land use/land cover(LULC),climate,vegetation,soil,and hydrological data,we quantified the spatiotemporal changes in the five principal ESs(carbon storage,water yield,food production,wind and sand prevention,and habitat quality)of the watershed from 1995 to 2020.Spearman correlation coefficients were used to analyze the trade-offs and synergies between ES pairs.The findings reveal that water yield,carbon storage,and habitat quality exhibited relatively high levels in the upstream,while food production and wind and sand prevention dominated the midstream and downstream,respectively.Furthermore,carbon storage,food production,wind and sand prevention,and habitat quality demonstrated an increase at the watershed scale while water yield exhibited a decline from 1995 to 2020.Specifically,carbon storage,wind and sand prevention,and habitat quality presented an upward trend in the upstream but downward trend in the midstream and downstream.Food production in the midstream showed a continuously increasing trend during the study period.Trade-off relationships were identified between water yield and wind and sand prevention,water yield and carbon storage,food production and water yield,and habitat quality and wind and sand prevention.Prominent temporal and spatial synergistic relationships were observed between differe展开更多
As one of typical areas in the world,northern Chinese Loess Plateau experiences serious wind-water erosion,which leads to widespread land degradation.During the past decades,an ecological engineering was implemented t...As one of typical areas in the world,northern Chinese Loess Plateau experiences serious wind-water erosion,which leads to widespread land degradation.During the past decades,an ecological engineering was implemented to reduce soil erosion and improve soil protection in this area.Thus,it is necessary to recognize the basic characteristics of soil protection for sustainable prevention and wind-water erosion control in the later stage.In this study,national wind erosion survey model and revised universal soil loss equation were used to analyze the spatiotemporal evolution and driving forces of soil protection in the wind-water erosion area of Chinese Loess Plateau during 2000–2020.Results revealed that:(1)during 2000–2020,total amount of soil protection reached up to 15.47×10^(8) t,which was realized mainly through water and soil conservation,accounting for 63.20%of the total;(2)soil protection was improved,with increases in both soil protection amount and soil retention rate.The amounts of wind erosion reduction showed a decrease trend,whereas the retention rate of wind erosion reduction showed an increase trend.Both water erosion reduction amount and retention rate showed increasing trends;and(3)the combined effects of climate change and human activities were responsible for the improvement of soil protection in the wind-water erosion area of Chinese Loess Plateau.The findings revealed the spatiotemporal patterns and driving forces of soil protection,and proposed strategies for future soil protection planning in Chinese Loess Plateau,which might provide valuable references for soil erosion control in other wind-water erosion areas of the world.展开更多
For domestic consumers in the rural areas of northern Kenya, as in other developing countries, the typical source of electrical supply is diesel generators. However, diesel generators are associated with both CO2 emis...For domestic consumers in the rural areas of northern Kenya, as in other developing countries, the typical source of electrical supply is diesel generators. However, diesel generators are associated with both CO2 emissions, which adversely affect the environment and increase diesel fuel prices, which inflate the prices of consumer goods. The Kenya government has taken steps towards addressing this issue by proposing The Hybrid Mini-Grid Project, which involves the installation of 3 MW of wind and solar energy systems in facilities with existing diesel generators. However, this project has not yet been implemented. As a contribution to this effort, this study proposes, simulates and analyzes five different configurations of hybrid energy systems incorporating wind energy, solar energy and battery storage to replace the stand-alone diesel power systems servicing six remote villages in northern Kenya. If implemented, the systems proposed here would reduce Kenya’s dependency on diesel fuel, leading to reductions in its carbon footprint. This analysis confirms the feasibility of these hybrid systems with many configurations being profitable. A Multi-Attribute Trade-Off Analysis is employed to determine the best hybrid system configuration option that would reduce diesel fuel consumption and jointly minimize CO2 emissions and net present cost. This analysis determined that a wind-diesel-battery configuration consisting of two 500 kW turbines, 1200 kW diesel capacity and 95,040 Ah battery capacity is the best option to replace a 3200 kW stand-alone diesel system providing electricity to a village with a peak demand of 839 kW. It has the potential to reduce diesel fuel consumption and CO2 emissions by up to 98.8%.展开更多
This study revealed a high positive correlation between rainfall in Korea during September and the trade wind （TW）/Arctic Oscillation （AO） index in May that combines two climate factors, low-level TWs and the AO. ...This study revealed a high positive correlation between rainfall in Korea during September and the trade wind （TW）/Arctic Oscillation （AO） index in May that combines two climate factors, low-level TWs and the AO. This correlation was identified on the basis of the difference in the 850 hPa streamline analysis between the positive and negative phases selected using the combined TW/AO index. In May, the spatial pattern of the anomalous pressure systems is similar to that in the positive AO phase. These anomalous pressure sys- tems continue in June to August （JJA） and September, but the overall spatial distribution shifts a little to the south. Particularly in September, a huge anomalous anticyclone centered over the southeast seas of Japan strengthens in most of the western north Pacific region and supplies a large volume of warm and humid air to the region near Korea. This characteristic is confirmed by the facts that during the positive TW/AO phase, the subtropical western north Pacific high （SWNPH） is more developed to the north and that the continu- ous positioning of the upper troposphere jet over Korea from May to September strengthens the anomalous upward flow, bringing warm and humid air to all layers. These factors contribute to increasing September rainfall in Korea during the positive TW/AO phase. Because the SWNPH develops more to the north in the positive phase, tropical cyclones tend to make landfall in Korea frequently, which also plays a positive role in increasing September rainfall in Korea.The above features are also reflected by the differences in average rainfall between the six years that had the highest May Nifio 3.4 indices （El Niflo phase） and the six years that had the lowest May Niflo 3.4 indices （La Nifia phase）.展开更多
基金Supported by the National Natural Science Foundation of China(41230419,91337213,40730950,and 40375018)China Meteorological Administration Special Public Welfare Research Fund(GYHY201306077)
文摘Based on the merged measurements from the TRMM Precipitation Radar and Visible and Infrared Scanner,refined characteristics（intensity,frequency,vertical structure,and diurnal variation） and regional differences of the warm rain over the tropical and subtropical Pacific Ocean（40°S-40°N,120°E-70°W）in boreal summer are investigated for the period 1998-2012.The results reveal that three warm rain types（phased,pure,and mixed） exist over these regions.The phased warm rain,which occurs during the developing or declining stage of precipitation weather systems,is located over the central to western Intertropical Convergence Zone,South Pacific Convergence Zone,and Northwest Pacific.Its occurrence frequency peaks at midnight and minimizes during daytime with a 5.5-km maximum echo top.The frequency of this warm rain type is about 2.2%,and it contributes to 40%of the regional total rainfall.The pure warm rain is characterized by typical stable precipitation with an echo top lower than 4 km,and mostly occurs in Southeast Pacific.Although its frequency is less than 1.3%,this type of warm rain accounts for 95%of the regional total rainfall.Its occurrence peaks before dawn and it usually disappears in the afternoon.For the mixed warm rain,some may develop into deep convective precipitation,while most are similar to those of the pure type.The mixed warm rain is mainly located over the ocean east of Hawaii.Its frequency is 1.2%,but this type of warm rain could contribute to 80%of the regional total rainfall.The results also uncover that the mixed and pure types occur over the regions where SST ranges from 295 to 299 K,accompanied by relatively strong downdrafts at 500 hPa.Both the mixed and pure warm rains happen in a more unstable atmosphere,compared with the phased warm rain.
基金financially supported by the Natural Science Foundation of Xinjiang Uygur Autonomous Region(2022D01C77)the PhD Programs Foundation of Xinjiang University(BS202105).
文摘The Keriya River Basin is located in an extremely arid climate zone on the southern edge of the Tarim Basin of Northwest China,exhibiting typical mountain-oasis-desert distribution characteristics.In recent decades,climate change and human activities have exerted significant impacts on the service functions of watershed ecosystems.However,the trade-offs and synergies between ecosystem services(ESs)have not been thoroughly examined.This study aims to reveal the spatiotemporal changes in ESs within the Keriya River Basin from 1995 to 2020 as well as the trade-offs and synergies between ESs.Leveraging the Integrated Valuation of Ecosystem Services and Trade-offs(InVEST)and Revised Wind Erosion Equation(RWEQ)using land use/land cover(LULC),climate,vegetation,soil,and hydrological data,we quantified the spatiotemporal changes in the five principal ESs(carbon storage,water yield,food production,wind and sand prevention,and habitat quality)of the watershed from 1995 to 2020.Spearman correlation coefficients were used to analyze the trade-offs and synergies between ES pairs.The findings reveal that water yield,carbon storage,and habitat quality exhibited relatively high levels in the upstream,while food production and wind and sand prevention dominated the midstream and downstream,respectively.Furthermore,carbon storage,food production,wind and sand prevention,and habitat quality demonstrated an increase at the watershed scale while water yield exhibited a decline from 1995 to 2020.Specifically,carbon storage,wind and sand prevention,and habitat quality presented an upward trend in the upstream but downward trend in the midstream and downstream.Food production in the midstream showed a continuously increasing trend during the study period.Trade-off relationships were identified between water yield and wind and sand prevention,water yield and carbon storage,food production and water yield,and habitat quality and wind and sand prevention.Prominent temporal and spatial synergistic relationships were observed between differe
基金funded by the National Key Research and Development Program of China(2023YFF1305304)the National Natural Science Foundation of China(41801007)+3 种基金the Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK0201)the Science Technology Project of Hebei Academy of Sciences(2024PF11)the Basic Research Program of Shanxi Province(202203021211258,202103021223248)the Science and Technology Strategy Project of Shanxi Province(202304031401073).
文摘As one of typical areas in the world,northern Chinese Loess Plateau experiences serious wind-water erosion,which leads to widespread land degradation.During the past decades,an ecological engineering was implemented to reduce soil erosion and improve soil protection in this area.Thus,it is necessary to recognize the basic characteristics of soil protection for sustainable prevention and wind-water erosion control in the later stage.In this study,national wind erosion survey model and revised universal soil loss equation were used to analyze the spatiotemporal evolution and driving forces of soil protection in the wind-water erosion area of Chinese Loess Plateau during 2000–2020.Results revealed that:(1)during 2000–2020,total amount of soil protection reached up to 15.47×10^(8) t,which was realized mainly through water and soil conservation,accounting for 63.20%of the total;(2)soil protection was improved,with increases in both soil protection amount and soil retention rate.The amounts of wind erosion reduction showed a decrease trend,whereas the retention rate of wind erosion reduction showed an increase trend.Both water erosion reduction amount and retention rate showed increasing trends;and(3)the combined effects of climate change and human activities were responsible for the improvement of soil protection in the wind-water erosion area of Chinese Loess Plateau.The findings revealed the spatiotemporal patterns and driving forces of soil protection,and proposed strategies for future soil protection planning in Chinese Loess Plateau,which might provide valuable references for soil erosion control in other wind-water erosion areas of the world.
文摘For domestic consumers in the rural areas of northern Kenya, as in other developing countries, the typical source of electrical supply is diesel generators. However, diesel generators are associated with both CO2 emissions, which adversely affect the environment and increase diesel fuel prices, which inflate the prices of consumer goods. The Kenya government has taken steps towards addressing this issue by proposing The Hybrid Mini-Grid Project, which involves the installation of 3 MW of wind and solar energy systems in facilities with existing diesel generators. However, this project has not yet been implemented. As a contribution to this effort, this study proposes, simulates and analyzes five different configurations of hybrid energy systems incorporating wind energy, solar energy and battery storage to replace the stand-alone diesel power systems servicing six remote villages in northern Kenya. If implemented, the systems proposed here would reduce Kenya’s dependency on diesel fuel, leading to reductions in its carbon footprint. This analysis confirms the feasibility of these hybrid systems with many configurations being profitable. A Multi-Attribute Trade-Off Analysis is employed to determine the best hybrid system configuration option that would reduce diesel fuel consumption and jointly minimize CO2 emissions and net present cost. This analysis determined that a wind-diesel-battery configuration consisting of two 500 kW turbines, 1200 kW diesel capacity and 95,040 Ah battery capacity is the best option to replace a 3200 kW stand-alone diesel system providing electricity to a village with a peak demand of 839 kW. It has the potential to reduce diesel fuel consumption and CO2 emissions by up to 98.8%.
基金A grant from "Development of Meteorolocial Resources for Green Growth" and "Research for the Meteorological and Earthquake Observation Technology and Its Application" supported by the NIMR/KMA under contract No.NIMR-2012-B-3the Korea Research Foundation Grant funded by the Korean Government (MOEHRD, Basic Research Promotion Fund) under contract No. KRF-2007-331-C00255
文摘This study revealed a high positive correlation between rainfall in Korea during September and the trade wind （TW）/Arctic Oscillation （AO） index in May that combines two climate factors, low-level TWs and the AO. This correlation was identified on the basis of the difference in the 850 hPa streamline analysis between the positive and negative phases selected using the combined TW/AO index. In May, the spatial pattern of the anomalous pressure systems is similar to that in the positive AO phase. These anomalous pressure sys- tems continue in June to August （JJA） and September, but the overall spatial distribution shifts a little to the south. Particularly in September, a huge anomalous anticyclone centered over the southeast seas of Japan strengthens in most of the western north Pacific region and supplies a large volume of warm and humid air to the region near Korea. This characteristic is confirmed by the facts that during the positive TW/AO phase, the subtropical western north Pacific high （SWNPH） is more developed to the north and that the continu- ous positioning of the upper troposphere jet over Korea from May to September strengthens the anomalous upward flow, bringing warm and humid air to all layers. These factors contribute to increasing September rainfall in Korea during the positive TW/AO phase. Because the SWNPH develops more to the north in the positive phase, tropical cyclones tend to make landfall in Korea frequently, which also plays a positive role in increasing September rainfall in Korea.The above features are also reflected by the differences in average rainfall between the six years that had the highest May Nifio 3.4 indices （El Niflo phase） and the six years that had the lowest May Niflo 3.4 indices （La Nifia phase）.
