The Second Tibetan Plateau Scientific Expedition and Research Program tasked a research team with the“Investigation of the water vapor channel of the Yarlung Zsangbo Grand Canyon(INVC)”in the southeastern Tibetan Pl...The Second Tibetan Plateau Scientific Expedition and Research Program tasked a research team with the“Investigation of the water vapor channel of the Yarlung Zsangbo Grand Canyon(INVC)”in the southeastern Tibetan Plateau(TP).This paper summarizes the scientific achievements obtained from the data collected by the INVC observation network and highlights the progress in investigating the development of heavy rainfall events associated with water vapor changes.The rain gauge network of the INVC can represent the impacts of the Yarlung Zsangbo Grand Canyon(YGC)topography on precipitation at the hourly scale.The microphysical characteristics of the precipitation in the YGC are different than those in the lowland area.The GPM-IMERG(Integrated MultisatellitE Retrievals for Global Precipitation Measurement)satellite precipitation data for the YGC region should be calibrated before they are used.The meridional water vapor flux through the YGC is more important than the zonal flux for the precipitation over the southeastern TP.The decreased precipitation around the YGC region is partly due to the decreased meridional water vapor flux passing through the YGC.High-resolution numerical models can benefit precipitation forecasting in this region by using a combination of specific schemes that capture the valley wind and water vapor flux along the valley floor.展开更多
Glaciers in the Tianshan Mountains are an essential water resource in Central Asia,and it is necessary to identify their variations at large spatial scales with high resolution.We combined optical and SAR images,based...Glaciers in the Tianshan Mountains are an essential water resource in Central Asia,and it is necessary to identify their variations at large spatial scales with high resolution.We combined optical and SAR images,based on several machine learning algorithms and ERA-5 land data provided by Google Earth Engine,to map and explore the glacier distribution and changes in the Tianshan in 2001,2011,and 2021.Random forest was the best performing classifier,and the overall glacier area retreat rate showed acceleration from 0.87%/a to 1.49%/a,while among the sub-regions,Dzhungarsky Alatau,Central and Northern/Western Tianshan,and Eastern Tianshan showed a slower,stable,and sharp increase rates after 2011,respectively.Glacier retreat was more severe in the mountain periphery,low plains and valleys,with more area lost near the glacier equilibrium line.The sustained increase in summer temperatures was the primary driver of accelerated glacier retreat.Our work demonstrates the advantage and reliability of fusing multisource images to map glacier distributions with high spatial and temporal resolutions using Google Earth Engine.Its high recognition accuracy helped to conduct more accurate and time-continuous glacier change studies for the study area.展开更多
基金funded by the Second Tibetan Plateau Scientific Expedition and Research Program[grant numbers 2019QZKK0105 and 2019QZKK0103]the National Natural Science Foundation of China[grant number 41975009].
文摘The Second Tibetan Plateau Scientific Expedition and Research Program tasked a research team with the“Investigation of the water vapor channel of the Yarlung Zsangbo Grand Canyon(INVC)”in the southeastern Tibetan Plateau(TP).This paper summarizes the scientific achievements obtained from the data collected by the INVC observation network and highlights the progress in investigating the development of heavy rainfall events associated with water vapor changes.The rain gauge network of the INVC can represent the impacts of the Yarlung Zsangbo Grand Canyon(YGC)topography on precipitation at the hourly scale.The microphysical characteristics of the precipitation in the YGC are different than those in the lowland area.The GPM-IMERG(Integrated MultisatellitE Retrievals for Global Precipitation Measurement)satellite precipitation data for the YGC region should be calibrated before they are used.The meridional water vapor flux through the YGC is more important than the zonal flux for the precipitation over the southeastern TP.The decreased precipitation around the YGC region is partly due to the decreased meridional water vapor flux passing through the YGC.High-resolution numerical models can benefit precipitation forecasting in this region by using a combination of specific schemes that capture the valley wind and water vapor flux along the valley floor.
基金National Natural Science Foundation of China,No.41830105,No.42011530120。
文摘Glaciers in the Tianshan Mountains are an essential water resource in Central Asia,and it is necessary to identify their variations at large spatial scales with high resolution.We combined optical and SAR images,based on several machine learning algorithms and ERA-5 land data provided by Google Earth Engine,to map and explore the glacier distribution and changes in the Tianshan in 2001,2011,and 2021.Random forest was the best performing classifier,and the overall glacier area retreat rate showed acceleration from 0.87%/a to 1.49%/a,while among the sub-regions,Dzhungarsky Alatau,Central and Northern/Western Tianshan,and Eastern Tianshan showed a slower,stable,and sharp increase rates after 2011,respectively.Glacier retreat was more severe in the mountain periphery,low plains and valleys,with more area lost near the glacier equilibrium line.The sustained increase in summer temperatures was the primary driver of accelerated glacier retreat.Our work demonstrates the advantage and reliability of fusing multisource images to map glacier distributions with high spatial and temporal resolutions using Google Earth Engine.Its high recognition accuracy helped to conduct more accurate and time-continuous glacier change studies for the study area.
