This study reconstructed the annual mass balance(MB)of Laohugou Glacier No.12 in the western Qilian Mountains during 1961–2015.The annual MB was calculated based on a temperature-index and an accumulation model with ...This study reconstructed the annual mass balance(MB)of Laohugou Glacier No.12 in the western Qilian Mountains during 1961–2015.The annual MB was calculated based on a temperature-index and an accumulation model with inputs of daily air temperature and precipitation recorded by surrounding meteorological stations.The model was calibrated by in-situ MB measurements conducted on the glacier during 2010–2015.Change in constructed annual MB had three phases.During Phase Ⅰ(1961-1984),glacier-wide MB values were slightly positive with an average MB of 24±276 mm w.e.(water equivalent).During Phase Ⅱ(1984-1995),the MB values became slightly negative with an average MB of?50±276 mm w.e..The most negative MB values were found during Phase Ⅲ(1996–2015),with an average MB of?377±276 mm w.e.Climatic analysis showed that the warming led to accelerated glacier mass loss despite a persistent increase of precipitation during the analysis period.However,an increase of black carbon deposited on the glacier surface since the 1980s could have contributed to intensified glacier melt.From simulations and measurements of MB on the Urumqi Glacier No.1,26%of glacier melt caused by black carbon could be identified.展开更多
Due to global warming, glaciers on the Tibetan Plateau(TP) are experiencing widespread shrinkage; however, the mechanisms controlling glacier variations across the TP are still rather unclear, especially on the northe...Due to global warming, glaciers on the Tibetan Plateau(TP) are experiencing widespread shrinkage; however, the mechanisms controlling glacier variations across the TP are still rather unclear, especially on the northeastern TP. In this study, a physically based, distributed surface-energy and mass-balance model was used to simulate glacier mass balance forced by meteorological data. The model was applied to Laohugou No. 12 Glacier, western Qilian Mountains, China, during2010~2012. The simulated albedo and mass balance were validated and calibrated by in situ measurements. The simulated annual glacier-wide mass balances were-385 mm water equivalent(w.e.) in 2010/2011 and-232 mm w.e. in 2011/2012,respectively. The mean equilibrium-line altitude(ELA) was 5,015 m a.s.l., during 2010~2012, which ascended by 215 m compared to that in the 1970 s. The mean accumulation area ratio(AAR) was 39% during the two years. Climatic-sensitivity experiments indicated that the change of glacier mass balance resulting from a 1.5 °C increase in air temperature could be offset by a 30% increase in annual precipitation. The glacier mass balance varied linearly with precipitation, at a rate of130 mm w.e. per 10% change in total precipitation.展开更多
The Xiying River,one of eight tributaries of the Shiyang River,located at Lenglongling,east Qilian Mountain,is formed by the confluence of Luotuo,Qingyang,Ningchan,and Shuiguan rivers.In the Xiying River Basin,where h...The Xiying River,one of eight tributaries of the Shiyang River,located at Lenglongling,east Qilian Mountain,is formed by the confluence of Luotuo,Qingyang,Ningchan,and Shuiguan rivers.In the Xiying River Basin,where have 42 glaciers which toward NE in the majority.In this study,three Landsat images and two topographic maps were used to extract boundaries by artificial vector quantization.Results show that glacier area in Xiying Basin increased slightly around 1987,since then,has been reduced considerably.From 1956/1972 to 2008,glacier area in Xiying River Basin was reduced by20.76%,nine glaciers have disappeared,and below 4,100 m a.s.l.,there is no ice cover.Variation tendency of glacier retreat was obviously controlled by orientation.Temperature increase especially after 1987 is the main reason of glacier shrinkage,where glaciers in the Xiying River Basin are more sensitive to climate change.展开更多
In July, 2009, we investigated the Ningchan River Glacier No. 3. A control network was established around the glacier and the expedition used a GPS-RTK to measure glacial area, terminal and surface altitude, and used ...In July, 2009, we investigated the Ningchan River Glacier No. 3. A control network was established around the glacier and the expedition used a GPS-RTK to measure glacial area, terminal and surface altitude, and used an EKKO GPR to measure glacier thickness. We used a topographic map based on 1972 aerial photo, two TM images in 1995, 2009, and GPS-RTK data in 2009, to analyze the change of the Ningchan River Glacier No. 3 since 1972. Through analysis we found this glacier has been seriously shrinking over the past 37 years. The glacier terminal retreated about 6%, the area was reduced about 13.1%, the volume was reduced about 35.3%, and glacier shrinkage is mainly in the form of thinning. Glacier average thickness reduced from 36.8 m in 1972, to 27.4 m in 2009. Meteorological data around the study area shows that this region in recent decades has undergone differential warming which is the main reason for rapid glacier shrinkage.展开更多
With the advancement of industry and bio-agriculture,the effective management of CO_(2) has emerged as a critical challenge for humanity.This study systematically explores multiple CO_(2) assimilation pathways using t...With the advancement of industry and bio-agriculture,the effective management of CO_(2) has emerged as a critical challenge for humanity.This study systematically explores multiple CO_(2) assimilation pathways using the comb-FBA algorithm,aiming to identify efficient artificial carbon fixation pathways.By extracting 49 CO_(2) and HCO3involved reactions and combining them with 6,529 reactions from MetaCyc,we constructed the computational set for analysis.These 16 core reactions give rise to 136 carbon fixation pathways for single C2 targets(such as acetyl-CoA,glyoxylate,and oxalate)and 576 carbon fixation pathways for single C3 targets(including glyceraldehyde-3-phosphate or pyruvate).Based on these core reactions,we identified four principal carbon fixation modes.Through systematic assessments,we identified 12 promising CO_(2) fixation pathways,each comprising no more than 20 reaction steps and demonstrating thermodynamic feasibility.Through further analysis of enzyme oxygen sensitivity and availability,we identified three novel and promising pathways.By examining metabolite conversion relationships,we also identified alternative carbon fixation reaction modules,offering flexibility for pathway optimization and experimental design.In conclusion,this study provides a diverse library of artificial carbon fixation pathways,demonstrating the power of the comb-FBA algorithm in designing carbon assimilation pathways and laying the foundation for more efficient CO_(2) fixation strategies.展开更多
基金The work were supported by the Chinese Academy of Sciences(No.QYZDJ-SSW-DQC039)the National Natural Science Foundation of China(Nos.41630754,41721091)+2 种基金the Science and Technology planning Project of Gansu Province(No.18JR4RA002)the Project of the State Key Laboratory of Cryospheric Sciences(Nos.SKLCS-OP-2018-06,SKLCS-OP-2019-01)Open Foundation of State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering(No.2017490711).
文摘This study reconstructed the annual mass balance(MB)of Laohugou Glacier No.12 in the western Qilian Mountains during 1961–2015.The annual MB was calculated based on a temperature-index and an accumulation model with inputs of daily air temperature and precipitation recorded by surrounding meteorological stations.The model was calibrated by in-situ MB measurements conducted on the glacier during 2010–2015.Change in constructed annual MB had three phases.During Phase Ⅰ(1961-1984),glacier-wide MB values were slightly positive with an average MB of 24±276 mm w.e.(water equivalent).During Phase Ⅱ(1984-1995),the MB values became slightly negative with an average MB of?50±276 mm w.e..The most negative MB values were found during Phase Ⅲ(1996–2015),with an average MB of?377±276 mm w.e.Climatic analysis showed that the warming led to accelerated glacier mass loss despite a persistent increase of precipitation during the analysis period.However,an increase of black carbon deposited on the glacier surface since the 1980s could have contributed to intensified glacier melt.From simulations and measurements of MB on the Urumqi Glacier No.1,26%of glacier melt caused by black carbon could be identified.
基金supported by the Chinese Academy of Sciences(KJZD-EW-G03-04)the National Natural Science Foundation of China(41721091,41671071)Open Foundation of State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering(No.2017490711)
文摘Due to global warming, glaciers on the Tibetan Plateau(TP) are experiencing widespread shrinkage; however, the mechanisms controlling glacier variations across the TP are still rather unclear, especially on the northeastern TP. In this study, a physically based, distributed surface-energy and mass-balance model was used to simulate glacier mass balance forced by meteorological data. The model was applied to Laohugou No. 12 Glacier, western Qilian Mountains, China, during2010~2012. The simulated albedo and mass balance were validated and calibrated by in situ measurements. The simulated annual glacier-wide mass balances were-385 mm water equivalent(w.e.) in 2010/2011 and-232 mm w.e. in 2011/2012,respectively. The mean equilibrium-line altitude(ELA) was 5,015 m a.s.l., during 2010~2012, which ascended by 215 m compared to that in the 1970 s. The mean accumulation area ratio(AAR) was 39% during the two years. Climatic-sensitivity experiments indicated that the change of glacier mass balance resulting from a 1.5 °C increase in air temperature could be offset by a 30% increase in annual precipitation. The glacier mass balance varied linearly with precipitation, at a rate of130 mm w.e. per 10% change in total precipitation.
基金supported by the Project from the National Foundational Scientific and Technological Work Programs of the Ministry of Science and Technology of China (Grant No. 2013FY111400)the State Key Laboratory of Cryospheric Sciences (SKLCS-ZZ-2017)+3 种基金the Global Change Research Program of China (2013CBA01801)the Chinese Academy of Sciences (KJZD-EW-G03-01)the National Natural Science Foundation of China (41371091)the Coordinate system conversion system v1.0 (2016SR394422)
文摘The Xiying River,one of eight tributaries of the Shiyang River,located at Lenglongling,east Qilian Mountain,is formed by the confluence of Luotuo,Qingyang,Ningchan,and Shuiguan rivers.In the Xiying River Basin,where have 42 glaciers which toward NE in the majority.In this study,three Landsat images and two topographic maps were used to extract boundaries by artificial vector quantization.Results show that glacier area in Xiying Basin increased slightly around 1987,since then,has been reduced considerably.From 1956/1972 to 2008,glacier area in Xiying River Basin was reduced by20.76%,nine glaciers have disappeared,and below 4,100 m a.s.l.,there is no ice cover.Variation tendency of glacier retreat was obviously controlled by orientation.Temperature increase especially after 1987 is the main reason of glacier shrinkage,where glaciers in the Xiying River Basin are more sensitive to climate change.
基金supported by the State Natural Science Fund projects(41071046 and 41201067)the project from the State Key Laboratory of Cryospheric Sciences(SKLCS-ZZ-2012-01-05)the Project for Incubation of Specialists in Glaciology and Geocryology of Nation-al Natural Science Foundation of China(J0930003/J0109)
文摘In July, 2009, we investigated the Ningchan River Glacier No. 3. A control network was established around the glacier and the expedition used a GPS-RTK to measure glacial area, terminal and surface altitude, and used an EKKO GPR to measure glacier thickness. We used a topographic map based on 1972 aerial photo, two TM images in 1995, 2009, and GPS-RTK data in 2009, to analyze the change of the Ningchan River Glacier No. 3 since 1972. Through analysis we found this glacier has been seriously shrinking over the past 37 years. The glacier terminal retreated about 6%, the area was reduced about 13.1%, the volume was reduced about 35.3%, and glacier shrinkage is mainly in the form of thinning. Glacier average thickness reduced from 36.8 m in 1972, to 27.4 m in 2009. Meteorological data around the study area shows that this region in recent decades has undergone differential warming which is the main reason for rapid glacier shrinkage.
基金supported by the Strategic Priority Research Pro-gram of the Chinese Academy of Sciences(XDC0120201)the National Natural Science Foundation of China(12326611).
文摘With the advancement of industry and bio-agriculture,the effective management of CO_(2) has emerged as a critical challenge for humanity.This study systematically explores multiple CO_(2) assimilation pathways using the comb-FBA algorithm,aiming to identify efficient artificial carbon fixation pathways.By extracting 49 CO_(2) and HCO3involved reactions and combining them with 6,529 reactions from MetaCyc,we constructed the computational set for analysis.These 16 core reactions give rise to 136 carbon fixation pathways for single C2 targets(such as acetyl-CoA,glyoxylate,and oxalate)and 576 carbon fixation pathways for single C3 targets(including glyceraldehyde-3-phosphate or pyruvate).Based on these core reactions,we identified four principal carbon fixation modes.Through systematic assessments,we identified 12 promising CO_(2) fixation pathways,each comprising no more than 20 reaction steps and demonstrating thermodynamic feasibility.Through further analysis of enzyme oxygen sensitivity and availability,we identified three novel and promising pathways.By examining metabolite conversion relationships,we also identified alternative carbon fixation reaction modules,offering flexibility for pathway optimization and experimental design.In conclusion,this study provides a diverse library of artificial carbon fixation pathways,demonstrating the power of the comb-FBA algorithm in designing carbon assimilation pathways and laying the foundation for more efficient CO_(2) fixation strategies.
