The freezing-thawing variation of permafrost active layer increases the complexity of rainfall-runoff processes in alpine river basins,Northwest China.And alpine meadow is the prominent ecosystem in these basins.This ...The freezing-thawing variation of permafrost active layer increases the complexity of rainfall-runoff processes in alpine river basins,Northwest China.And alpine meadow is the prominent ecosystem in these basins.This study selected a small alpine meadow watershed in the upper reaches of the Shule River Basin,China.We investigated alpine rainfall-runoff processes,as well as impacts of summer thaw depth of active layer,soil temperature and moisture variation on streamflow based on in-situ observations from July 2015 to December 2020.Some hydrologic parameters or indices were calculated using statistical methods,and impacts of permafrost change on river runoff were assessed using the variable infiltration capacity model(VIC).In the alpine meadow,surface soil(0–10 cm depth)of the active layer starts to freeze in mid-October each year,and begins to thaw in early April.Also,the deeper soil(70–80 cm depth)of the active layer starts to freeze in late October,and begins to thaw in late June.Moisture content in shallow soils fluctuates regularly,whereas deeper soils are more stable,and their response to rainstorms is negligible.During active layer thawing,the moisture content increases with soil depth.In the alpine meadow,vertical infiltration only occurred in soils up to 40 cm deep,and lateral flow occurred in0–20 and 60–80 cm deep soils at current rainfall intensity.Summer runoff ratios were 0.06–0.31,and runoff floods show lags of 9.5–23.0 h following the rainfall event in the study area.The freeze–thaw process also significantly impacts runoff regression coefficients,which were 0.0088–0.0654 per hour.Recession coefficient decrease negatively correlates with active layer thawing depth in summer and autumn.Alpine river basin permafrost can effectively increase peak discharge and reduce low flow.These findings are highly significant for rainfall–runoff conversion research in alpine areas of inland rivers.展开更多
The interaction between the cryosphere and atmosphere is an essential and extremely sensitive mutual action process on the earth.Due to global warming and the cryospheric melting,more and more attention has been paid ...The interaction between the cryosphere and atmosphere is an essential and extremely sensitive mutual action process on the earth.Due to global warming and the cryospheric melting,more and more attention has been paid to the interaction process between the cryosphere and atmosphere,especially the feedback of the cryosphere change to the atmosphere.A comprehensive review of the studies on the interaction between the cryosphere and atmosphere is conducted from two aspects:(1)effects of climate change on the cryosphere or responses of the cryosphere to climate change;and(2)feedback of the cryosphere change to the climate.The response of the cryosphere to climate change is lagging.Such a lagging and cumulative effect of temperature rise within the cryosphere have resulted in a rapid change in the cryosphere in the 21st century,and its impacts have become more significant.The feedback from cryosphere change on the climate are omnifarious.Among them,the effects of sea ice loss and snow cover change,especially the Arctic sea ice loss and the Northern Hemisphere snow cover change,are the most prominent.The Arctic amplification(AA)associated with sea ice feedback is disturbing,and the feedback generated by the effect of temperature rise on snow properties in the Northern Hemisphere is also of great concern.There are growing evidence of the impact of the Arctic cryosphere melting on mid-latitude weather and climate.Weakened storm troughs,steered jet stream and amplified planetary waves associated with energy propagation become the key to explaining the links between Arctic cryosphere change and atmospheric circulation.There is still a great deal of uncertainty about how cryosphere change affects the weather and climate through different atmospheric circulation processes at different spatial and temporal scales due to observation and simulation problems.展开更多
Differentialiy expressed polypeptides in the brain of a BALB/c mouse model infected with scrapie strain 22L were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The results sh...Differentialiy expressed polypeptides in the brain of a BALB/c mouse model infected with scrapie strain 22L were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The results showed that 21 peptides were down-regulated, with peptides of mass-to-charge ratio 758.772 5 and mass-to-charge ratio 5 432.206 9, demonstrating the most significant decreases. These finding suggest that these peptides are candidate biomarkers and may play an important role in the pathogenesis of prion disease.展开更多
基金supported by the National Key R&D Program of China(2021YFC3201102-02)the National Natural Science Foundation of China(Grant No.42171028,41877156,and 41730751)+1 种基金the State Key Laboratory of Frozen Soil Engineering Foundation(SKLFSE202110)the Science and Technology Program of Gansu Province,China(20JR5RA545)。
文摘The freezing-thawing variation of permafrost active layer increases the complexity of rainfall-runoff processes in alpine river basins,Northwest China.And alpine meadow is the prominent ecosystem in these basins.This study selected a small alpine meadow watershed in the upper reaches of the Shule River Basin,China.We investigated alpine rainfall-runoff processes,as well as impacts of summer thaw depth of active layer,soil temperature and moisture variation on streamflow based on in-situ observations from July 2015 to December 2020.Some hydrologic parameters or indices were calculated using statistical methods,and impacts of permafrost change on river runoff were assessed using the variable infiltration capacity model(VIC).In the alpine meadow,surface soil(0–10 cm depth)of the active layer starts to freeze in mid-October each year,and begins to thaw in early April.Also,the deeper soil(70–80 cm depth)of the active layer starts to freeze in late October,and begins to thaw in late June.Moisture content in shallow soils fluctuates regularly,whereas deeper soils are more stable,and their response to rainstorms is negligible.During active layer thawing,the moisture content increases with soil depth.In the alpine meadow,vertical infiltration only occurred in soils up to 40 cm deep,and lateral flow occurred in0–20 and 60–80 cm deep soils at current rainfall intensity.Summer runoff ratios were 0.06–0.31,and runoff floods show lags of 9.5–23.0 h following the rainfall event in the study area.The freeze–thaw process also significantly impacts runoff regression coefficients,which were 0.0088–0.0654 per hour.Recession coefficient decrease negatively correlates with active layer thawing depth in summer and autumn.Alpine river basin permafrost can effectively increase peak discharge and reduce low flow.These findings are highly significant for rainfall–runoff conversion research in alpine areas of inland rivers.
基金This work is supported by the National Natural Science Foundation of China(41730751,41421061)the Strategic Priority Research Program of the Chinese Academy of Sciences,No.XDA23060700.The authors thank two anonymous reviewers for their suggestions leading to significant improvement in the paper.We thank all persons for their help to us.
文摘The interaction between the cryosphere and atmosphere is an essential and extremely sensitive mutual action process on the earth.Due to global warming and the cryospheric melting,more and more attention has been paid to the interaction process between the cryosphere and atmosphere,especially the feedback of the cryosphere change to the atmosphere.A comprehensive review of the studies on the interaction between the cryosphere and atmosphere is conducted from two aspects:(1)effects of climate change on the cryosphere or responses of the cryosphere to climate change;and(2)feedback of the cryosphere change to the climate.The response of the cryosphere to climate change is lagging.Such a lagging and cumulative effect of temperature rise within the cryosphere have resulted in a rapid change in the cryosphere in the 21st century,and its impacts have become more significant.The feedback from cryosphere change on the climate are omnifarious.Among them,the effects of sea ice loss and snow cover change,especially the Arctic sea ice loss and the Northern Hemisphere snow cover change,are the most prominent.The Arctic amplification(AA)associated with sea ice feedback is disturbing,and the feedback generated by the effect of temperature rise on snow properties in the Northern Hemisphere is also of great concern.There are growing evidence of the impact of the Arctic cryosphere melting on mid-latitude weather and climate.Weakened storm troughs,steered jet stream and amplified planetary waves associated with energy propagation become the key to explaining the links between Arctic cryosphere change and atmospheric circulation.There is still a great deal of uncertainty about how cryosphere change affects the weather and climate through different atmospheric circulation processes at different spatial and temporal scales due to observation and simulation problems.
基金the National Natural Science Foundation of China,No. 30972197 and 31072148Science and Technology Plan Program of Jilin Province,No. 201105038
文摘Differentialiy expressed polypeptides in the brain of a BALB/c mouse model infected with scrapie strain 22L were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The results showed that 21 peptides were down-regulated, with peptides of mass-to-charge ratio 758.772 5 and mass-to-charge ratio 5 432.206 9, demonstrating the most significant decreases. These finding suggest that these peptides are candidate biomarkers and may play an important role in the pathogenesis of prion disease.
