Recent studies showed that the Himalayan glaciers are reducing alarmingly. This is attributed to global warming. Since the melt water of Himalayan glaciers and snow is the principal source of water for several rivers,...Recent studies showed that the Himalayan glaciers are reducing alarmingly. This is attributed to global warming. Since the melt water of Himalayan glaciers and snow is the principal source of water for several rivers, a decrease of this source is a calamity for the large fraction of global population living in nearby regions such as India. In Asia for the 60% global population only 36% of global water is available. Any further decrease of this vital necessity makes the very existence of billions of people doubtful. Here we show, using both observations and one IPCC-AR4 model with high horizontal resolution, that the Himalayan region in fact underwent a maximum warming of 2.5°C from 1950 to 1999 and would reach the highest temperature rise of 9°C in 2100. Temperature and rainfall variations determine a simple climate classification proposed by Köppen. We show changes that occur in climate and biosphere using this classification. Also we discussed the impact of warming and resulting changes in Köppen climates on the floods and malaria in India.展开更多
The determination of total glacial volume is important for the observation of climatic change and its consequences such as global sea-level rise. The tongue area of Glacier No. 4 of Sigong River over Mt. Bogda, easter...The determination of total glacial volume is important for the observation of climatic change and its consequences such as global sea-level rise. The tongue area of Glacier No. 4 of Sigong River over Mt. Bogda, eastern Tianshan was surveyed by ground-penetrating radar （GPR） and real time kinematic （RTK）-global positioning system （GPS） during the summer campaign 2009. In order to calculate the glacier volume, both co-kriging algorithm and estimation based on the theory of perfectly plastic material were employed. Results indicated that the ice-thickness distribution of the investigated glacier ranges from 0 to 105.0 m, with the mean thickness of 27.6 m in 2009. The corresponding ice volume was -0.076 km3 （-0.068 km3 water equivalent）. The bedrock topography shows more undulating than the glacier surface. The difference of the calculated ice volume in this study and the estimated value from the empirical formula is large. Therefore, it is urgent to validate the applicability of the ex- isting empirical formula.展开更多
Many glaciers and ice caps on the Tibetan Plateau have retreated and lost mass in recent years in response to temperature increases,providing clear evidence of the impact of climate change on the region.There is incre...Many glaciers and ice caps on the Tibetan Plateau have retreated and lost mass in recent years in response to temperature increases,providing clear evidence of the impact of climate change on the region.There is increasing evidence that many of the glaciers on the Tibetan Plateau have also shown periodically dynamic behaviour in the form of glacier surging and some even catastrophic collapse events.In this study,we examine the prevalence of glacier surging at the Geladandong ice caps,North East Tibetan Plateau,to better understand the role of surge events in the evolution of glacier mass loss budgets.Using glacier surface elevation change data over the period 1969—2018 and glacier surface velocity data from the ITS_LIVE dataset,we find that 19 outlet glaciers of the ice caps are of surge-type.Our multi-temporal measurements of glacier mass balance show that surge-type glacier mass budgets vary depending on the portion of the surge-cycle captured by geodetic data.At the regional level,pre-and post-surge glacier mass loss variability does not bias regional mass budget estimates,but enhanced,or suppressed,mass loss estimates are likely when small groups of glaciers are examined.Our results emphasise the importance of accurate surge-type glacier inventories and the need to maximise geodetic data coverage over glacierised regions known to contain surge-type glaciers.展开更多
With global warming,glaciers in the high mountains of China are retreating rapidly.However,few data have been reported on whether greenhouse gases from these glaciers are released into the atmosphere or absorbed by gl...With global warming,glaciers in the high mountains of China are retreating rapidly.However,few data have been reported on whether greenhouse gases from these glaciers are released into the atmosphere or absorbed by glacial meltwater.In this study,we collected meltwater and ice samples from Laohugou Glacier No.12 in western China and measured CH_(4)and CO_(2)concentrations.Meltwater from the glacier terminus was continually sampled between 3 and 5 August 2020 to measure CH_(4)and CO_(2)concentrations.The results demonstrated that meltwater is a source of CH_(4)because the average saturations are over 100%.It could be con eluded that CH_(4)in the atmosphere can be released by glacial meltwater.However,the CO_(2)saturations are various,and CO_(2)fluxes exhibit positive(released CO_(2))or negative(absorbed CO_(2))values because the water and atmospheric conditions are variable.More importantly,the CH_(4)and CO_(2)concentrations were higher in meltwater samples from the glacier terminus than in samples from the surface ice(including an ice core)and a surface stream.Although the meltwater effect from the upper part of the glacier cannot be excluded,we speculated that subglacial drainage systems with an anaerobic environment may represent the CH_(4)source,but it needs to be further investigated in the future.However,high mountain glaciers are currently ignored in global carbon budgets,and the increased melting of glaciers with global warming may accelerate the absorption of much more CO_(2)and lead to the release of CH_(4).展开更多
文摘Recent studies showed that the Himalayan glaciers are reducing alarmingly. This is attributed to global warming. Since the melt water of Himalayan glaciers and snow is the principal source of water for several rivers, a decrease of this source is a calamity for the large fraction of global population living in nearby regions such as India. In Asia for the 60% global population only 36% of global water is available. Any further decrease of this vital necessity makes the very existence of billions of people doubtful. Here we show, using both observations and one IPCC-AR4 model with high horizontal resolution, that the Himalayan region in fact underwent a maximum warming of 2.5°C from 1950 to 1999 and would reach the highest temperature rise of 9°C in 2100. Temperature and rainfall variations determine a simple climate classification proposed by Köppen. We show changes that occur in climate and biosphere using this classification. Also we discussed the impact of warming and resulting changes in Köppen climates on the floods and malaria in India.
基金supported by the Funds for Creative Research Groups of China (No. 41121001)the National Natural Science Foundation of China (Nos. 41301069, 91025012 and 41101066)+1 种基金the SKLCS founding (Nos. SKLCS-ZZ-2012-01-01, SKLCS-ZZ-2012-01-09)the West Light Program for Talent Cultivation of Chinese Academy of Sciences
文摘The determination of total glacial volume is important for the observation of climatic change and its consequences such as global sea-level rise. The tongue area of Glacier No. 4 of Sigong River over Mt. Bogda, eastern Tianshan was surveyed by ground-penetrating radar （GPR） and real time kinematic （RTK）-global positioning system （GPS） during the summer campaign 2009. In order to calculate the glacier volume, both co-kriging algorithm and estimation based on the theory of perfectly plastic material were employed. Results indicated that the ice-thickness distribution of the investigated glacier ranges from 0 to 105.0 m, with the mean thickness of 27.6 m in 2009. The corresponding ice volume was -0.076 km3 （-0.068 km3 water equivalent）. The bedrock topography shows more undulating than the glacier surface. The difference of the calculated ice volume in this study and the estimated value from the empirical formula is large. Therefore, it is urgent to validate the applicability of the ex- isting empirical formula.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences(XDA20100300).
文摘Many glaciers and ice caps on the Tibetan Plateau have retreated and lost mass in recent years in response to temperature increases,providing clear evidence of the impact of climate change on the region.There is increasing evidence that many of the glaciers on the Tibetan Plateau have also shown periodically dynamic behaviour in the form of glacier surging and some even catastrophic collapse events.In this study,we examine the prevalence of glacier surging at the Geladandong ice caps,North East Tibetan Plateau,to better understand the role of surge events in the evolution of glacier mass loss budgets.Using glacier surface elevation change data over the period 1969—2018 and glacier surface velocity data from the ITS_LIVE dataset,we find that 19 outlet glaciers of the ice caps are of surge-type.Our multi-temporal measurements of glacier mass balance show that surge-type glacier mass budgets vary depending on the portion of the surge-cycle captured by geodetic data.At the regional level,pre-and post-surge glacier mass loss variability does not bias regional mass budget estimates,but enhanced,or suppressed,mass loss estimates are likely when small groups of glaciers are examined.Our results emphasise the importance of accurate surge-type glacier inventories and the need to maximise geodetic data coverage over glacierised regions known to contain surge-type glaciers.
基金This research has been supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XAD19070103)the National Key Research and Development Program of China(2020YFA0608501)+2 种基金the State Key Laboratory of Cryospheric Science(SKLCS-ZZ-2021)the Youth Innovation Promotion Association,CAS(2020419)the Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK0605).
文摘With global warming,glaciers in the high mountains of China are retreating rapidly.However,few data have been reported on whether greenhouse gases from these glaciers are released into the atmosphere or absorbed by glacial meltwater.In this study,we collected meltwater and ice samples from Laohugou Glacier No.12 in western China and measured CH_(4)and CO_(2)concentrations.Meltwater from the glacier terminus was continually sampled between 3 and 5 August 2020 to measure CH_(4)and CO_(2)concentrations.The results demonstrated that meltwater is a source of CH_(4)because the average saturations are over 100%.It could be con eluded that CH_(4)in the atmosphere can be released by glacial meltwater.However,the CO_(2)saturations are various,and CO_(2)fluxes exhibit positive(released CO_(2))or negative(absorbed CO_(2))values because the water and atmospheric conditions are variable.More importantly,the CH_(4)and CO_(2)concentrations were higher in meltwater samples from the glacier terminus than in samples from the surface ice(including an ice core)and a surface stream.Although the meltwater effect from the upper part of the glacier cannot be excluded,we speculated that subglacial drainage systems with an anaerobic environment may represent the CH_(4)source,but it needs to be further investigated in the future.However,high mountain glaciers are currently ignored in global carbon budgets,and the increased melting of glaciers with global warming may accelerate the absorption of much more CO_(2)and lead to the release of CH_(4).
