Kelan River is a branch of the Ertix River, originating in the Altay Mountains in Xinjiang, northwestern China. The upper streams of the Kelan River are located on the southern slope of the Altay Mountains; they arise...Kelan River is a branch of the Ertix River, originating in the Altay Mountains in Xinjiang, northwestern China. The upper streams of the Kelan River are located on the southern slope of the Altay Mountains; they arise from small glacial lakes at an elevation of more than 2,500 m. The total water-collection area of the studied basin, from 988 to 3,480 m, is about 1,655 km2. Almost 95 percent of the basin area is covered with snow in winter. The westerly air masses deplete nearly all the moisture that comes in the form of snow during the winter months in the upper and middle reaches of the basin. That annual flow from the basin is about 382 mm, about 45 percent of which is contributed by snowmelt. The mean annual precipitation in the basin is about 620 mm, which is primarily concentrated in the upper and middle basin. The Kelan River system could be vulnerable to climate change because of substantial contribution from snowmelt runoff. The hydrological system could be altered significantly because of a warming of the climate. The impact of climate change on the hydrological cycle and events would pose an additional threat to the Altay region. The Kelan River, a typical snow-dominated watershed, has more area at higher elevations and accumulates snow during the winter. The peak flow occurs as a result of snow-melting during the late spring or early summer. Stream flow varies strongly throughout the year because of seasonal cycles of precipitation, snowpack, temperature, and groundwater. Changes in the temperature and precipitation affect the timing and volume of stream-flow. The stream-flow consists of contributions from meltwater of snow and ice and from runoff of rainfall. Therefore, it has low flow in winter, high flow during the spring and early summer as the snowpack melts, and less flows during the late summer. Because of the warming of the current climate change, hydrology processes of the Kelan River have undergone marked changes, as evidenced by the shift of the maximum flood peak discharge from May to June; the largest monthly runoffs also have an increment of about 15 percent related to before 1980; April-June runoff increased from the 60 percent of the annual runoff before 1980 to nearly 70 percent after 1990. The long-term trend shows temperature and precipitation increased mainly in the winter, but the rainfall declined in summer; hydrological process is manifested by the rising runoff in May and decreasing in June. Warming and the increase of winter and spring snowcover would lead to increased snowmelt, increasing the spring-flood hazards and the maximum flood discharge with disastrous consequences. The changed hydrological patterns caused by climate change have already impacted the urban water supply and agricultural and livestock production along the river.展开更多
Quantitative estimation of the influence of various factors,such as black carbon,snow grain,dust content,and water con tent on albedo is essential in obtaining an accurate albedo.In this paper,field measurement data,i...Quantitative estimation of the influence of various factors,such as black carbon,snow grain,dust content,and water con tent on albedo is essential in obtaining an accurate albedo.In this paper,field measurement data,including snow grain size,density,liquid water content,and snow depth was obtained.Black carbon and dust samples were collected from the snow surface.A simultaneous observation using ASD(Analytical Spectral Devices)spectral data was employed in the Qiyi glacier located on Qilian Mountain.The measurements were compared with results obtained from the Snow,Ice,and Aerosol Radiation(SNICAR)model.Additionally,a HYbrid Single-Particle Lagrangian Integrated Trajectory(HYSPLIT)air mass backward trajectory model was used to track the source of black carbon.The simulation was found to correlate well with observed data.Liquid water content was the most influential factor of albedo among the several influencing fac tors,followed by black carbon content and snow grain size.Finally,snow density change had the least toward albedo.HYSPLIT atmospheric trajectories model can only approximately show the source of black carbon and not clearly indicate the source region of black carbon.展开更多
Estimation of the influence of snow grain size and black carbon on albedo is essential in obtaining the accurate albedo. In this paper, field measurement data, including snow grain size, snow depth and density was obt...Estimation of the influence of snow grain size and black carbon on albedo is essential in obtaining the accurate albedo. In this paper, field measurement data, including snow grain size, snow depth and density was obtained. Black carbon samples were collected from the snow surface. A simultaneous observation using Analytical Spectral Devices was employed in the Qiyi Glacier located in the Qilian Mountain. Analytical Spectral Devices spectrum data were used to analyze spectral re- flectance of snow for different grain size and black carbon content. The measurements were compared with the results obtained from the Snow, Ice, and Aerosol Radiation model, and the simulation was found to correlate well with the ob- served data. However, the simulated albedo was near to 0.98 times of the measured albedo, so the other factors were as- sumed to be constant using the corrected Snow, Ice, and Aerosol Radiation model to estimate the influence of measured snow grain size and black carbon on albedo. Field measurements were controlled to fit the relationship between the snow grain size and black carbon in order to estimate the influence of these factors on the snow albedo.展开更多
Based on the data observed at two sites (site H1, 4,473 m a.s.l., and site H2, 4,696 m a.s.l.) on Qiyi Glacier in Qilian Mountains, China, by automatic weather station and spectral pyranometer during the period of Jun...Based on the data observed at two sites (site H1, 4,473 m a.s.l., and site H2, 4,696 m a.s.l.) on Qiyi Glacier in Qilian Mountains, China, by automatic weather station and spectral pyranometer during the period of June 9 through September 27, 2006, we investigated the temporal and spatial variations in surface albedo and spectral reflectance on the glacier. At site H1, the daily mean surface albedos fluctuated between 0.233 and 0.866, which were significantly affected by the air temperature on the glacier. It was found that the albedos clearly showed a diurnal cycle with the lowest value at noon at the two observation sites over the study period, and the difference of albedos between the upper site H2 and the lower site H1 also showed diurnal cycle but with the highest value at noon. The reflectance on the glacier was higher in the ultraviolet (0.28–0.4 μm) and visible (0.4–0.76 μm) wavelengths, lower in the near infrared wavelength (0.76–3 μm), which is quite contrary to the spectral reflectance on other ground surfaces. At the two observation sites, the spectral reflectance declined in all wavelengths with the ablation of snow generally. However, it declined drastically in ultraviolet (0.28–0.4 μm) and 0.6–0.7 μm wavelength, and declined less in 0.4–0.5 μm wavelength. On fresh snow surface, the spectral reflectance had the high values of 0.983 and 0.815 in the ultraviolet and visible (0.4–0.76 μm) wavelengths, respectively; but it had a relatively lower value of 0.671 in near infrared (0.76–3 μm) wavelengths. However, on dirty and melting ice surfaces, the reflectance had the very low values of 0.305 and 0.256 in the ultraviolet and visible wavelengths, with the lowest value of 0.082 in near infrared wavelengths. The spectral reflectance also showed a diurnal cycle like that of albedo. The diurnal variations of spectral reflectance on snow surface in ultraviolet and visible wavelength changed to a greater degree than that on ice surface. The diurnal variation curves were asymmetrical before and after the local noontime, but the curves on ice surfaces in every wavelength were relatively flat and symmetrical. Especially, the surface reflectance in near infrared wavelength was flat and symmetry on both snow and ice surfaces. The studies of relations between the snow albedo and snow density and impurity, and the impact of glacier albedo on the glacier runoff are also described in this paper.展开更多
Based on the glacier mass balance and meteorological data of air temperature and precipitation on the Qiyi Glacier from June 30 to September 5, 2010, we used a degree-day mass balance model to simulate the change of m...Based on the glacier mass balance and meteorological data of air temperature and precipitation on the Qiyi Glacier from June 30 to September 5, 2010, we used a degree-day mass balance model to simulate the change of mass balance during this period. Our results indicate that the current value of the mass balance is -856.2 mm w.e. Subjected to the strong influences of air temperature and precipitation, the mass balance process can be divided into three stages： accumulating exiguously ~ melting intensively melting exiguously. The variation trends of the mass balance according to the degree-day mass balance model and the observed values are similar and wholly reflect the spatial distribution characteristics of the glacier mass balance, which increases with the increase of altitude. Our experiment on climate sensitivity of the mass balance showed that mass balance was very sensitive to the change of temperature; air temperature is the key factor which influences mass balance; and a slight increase in precipitation will have a negligible effect on mass balance when the air temperature increases continuously.展开更多
CH_(4) emission rates followed an increased pattern during the growing season at Tibetan Plateau.•Unique genes carried by abundant species were positively correlated with CH_(4) emission rates.•Climate factors influen...CH_(4) emission rates followed an increased pattern during the growing season at Tibetan Plateau.•Unique genes carried by abundant species were positively correlated with CH_(4) emission rates.•Climate factors influenced CH_(4) emission rates by regulating microbial community and their genes.Microorganisms play pivotal roles in soil methane(CH_(4))emissions and their functional genes are origins of a key mechanism for soil CH4-cycling.However,understanding of the roles of specific genes(e.g.,unique or shared genes carried by species)underlying CH_(4)-cycling remains elusive.Here,we measured CH_(4) emission rates and investigated variations in microbial community and the abundance of genes carried by species during the growing season in alpine meadow on the Tibetan Plateau.We discovered that CH_(4) emission rates increased from 394.4,745.9,and 1092.7µg CH4 m−2 h−1,in April,June,and August,respectively,and had a positive correlation with unique genes carried by abundant species during the growing season.Moreover,we found that unique genes carried by abundant species involved in methanogenesis processes have a higher abundance than methanotrophic processes.Further analysis indicated that climate factors(i.e.,mean monthly temperature(MMT)and mean monthly precipitation(MMP))influenced microbial community and their functional genes,and therefore affected the CH_(4) emission rates.Overall,the present study provides a novel insight into the variation of soil CH4 emissions from a functional gene perspective,highlighting the important roles of unique genes carried by abundant species in CH4 emissions in the Tibetan Plateau under seasonal variation.展开更多
0 INTRODUCTION Global warming not only exacerbates the instability of the climate system,causing more weather extremes but also has far-reaching impacts on surface systems,changing disaster environments(Qiu et al.,202...0 INTRODUCTION Global warming not only exacerbates the instability of the climate system,causing more weather extremes but also has far-reaching impacts on surface systems,changing disaster environments(Qiu et al.,2024;Ye et al.,2024).The key medium between climate warming and the mountain environment is the cryosphere,whose recession increases the occurrence of chain disasters such as rock-ice avalanches and other flow events(Yang et al.,2023).展开更多
The time series of accumulation in recent 300 years correlated well with solar activity in Dasuopu ice core. Results of spectrum analysis on the accumulation time series of the Dasuopu ice core shows that there are so...The time series of accumulation in recent 300 years correlated well with solar activity in Dasuopu ice core. Results of spectrum analysis on the accumulation time series of the Dasuopu ice core shows that there are some periods that coincide with the periods of solar activity. By comparing the long-time change trend of the accumulation in the Dasuopu ice core with various kinds of indexes of solar activity intensity, a negative correlation is found between the trend and solar activity.展开更多
Three ice cores distributed across Dasuopu glacier in Himalayas were recovered. A 400-year net annual accumulation record reconstructed from one of the cores reflects the major precipitation trend in the central Himal...Three ice cores distributed across Dasuopu glacier in Himalayas were recovered. A 400-year net annual accumulation record reconstructed from one of the cores reflects the major precipitation trend in the central Himalayas. This record is related closely to the Indian monsoon precipitation. Wavelet and moving T-test were applied to the 400-year-long Dasuopu accumulation record, and significant staggered variability and abrupt change of the record on interannual to centennial time scales are identified. Finally the possible reason for abrupt change of the accumulation record is discussed.展开更多
高亚洲山地冰川变化影响着周边数亿人的水源供给.以往研究表明,高亚洲各个地区冰川物质平衡存在较大的空间差异,但这种差异的原因尚不明确.本文提出了一种基于雷达卫星冰川积雪观测的新指数,以区分高亚洲地区冬季积累型和夏季积累型冰川...高亚洲山地冰川变化影响着周边数亿人的水源供给.以往研究表明,高亚洲各个地区冰川物质平衡存在较大的空间差异,但这种差异的原因尚不明确.本文提出了一种基于雷达卫星冰川积雪观测的新指数,以区分高亚洲地区冬季积累型和夏季积累型冰川.结合物质平衡数据进一步研究发现,夏季积累型冰川消融速度是冬季积累型冰川的4倍(2000~2018年间消融速度分别为-0.43±0.12 m w.e/a和-0.10±0.06 m w.e/a).研究结果表明了季节性积累对冰川物质平衡的重要性,强调了准确的降水观测对该地区未来冰川变化估算至关重要.展开更多
In the context of global warming,glaciers in the Asian High Mountains(AHMs)are shrinking at an accelerating rate.Projecting their future change is helpful for understanding the hydrological and climatic effects relate...In the context of global warming,glaciers in the Asian High Mountains(AHMs)are shrinking at an accelerating rate.Projecting their future change is helpful for understanding the hydrological and climatic effects related to glacier retreat.Here,we projected glacier change in the AHMs from 1979 to 2100 under shared socioeconomic pathway(SSP)scenarios from the perspective of temperature,equilibrium-line altitude(ELA),and accumulation area.The annual mean temperature in the AHMs increased by 1.26℃ from 1979 to 2014,corresponding to an increase of 210 m in the mean ELA and a decrease of 1.7×10^(4)km^(2) in the glacier accumulation area.Under the SSP2-4.5(SSP5-8.5)scenario,the annual mean temperature in the AHMs would increase by 2.84℃(3.38℃)in 2040–2060 relative to that in 1850–1900,leading to the mean ELA reaching an elevation of5661 m(5777 m).The accumulation area in the AHMs decreased by 46.3%from 1995 to 2014 and was projected to decrease by60.1%in 2040–2060.Moreover,the annual mean temperature in the AHMs was projected to increase by 3.76℃(6.44℃)in2080–2100 relative to that in 1850–1900,corresponding to the ELA reaching an elevation of 5821 m(6245 m)and the accumulation area decreasing to 1.8×10^(4)km^(2)(0.5×10^(4)km^(2)).These data suggest that the conditions for glacier development will disappear in most of the AHMs,except for extreme high-altitude regions in the Tianshan,Pamir,and Himalaya Mountains.Under the SSP2-4.5(SSP5-8.5)scenario,when the global mean temperature increases 1.5℃(2℃)above pre-industrial levels,the annual mean temperature will increase by 2.12℃(2.86℃)and the accumulation area will decrease by 15%(48%)in the AHMs compared with that in 1995–2015.Therefore,a 1.5℃ increase in global warming would keep 40%more of the glacial accumulation area(1.5×10^(4)km^(2))in the AHMs compared to a 2℃ increase in global warming.展开更多
The variations of NO\+-\-3 concentration in the Guliya ice core are reconstructed for recent about 1 000 a. Spectrum analysis of NO\+-\-3 indicates significant periodicities in the variations of NO\+-\-3 concentration...The variations of NO\+-\-3 concentration in the Guliya ice core are reconstructed for recent about 1 000 a. Spectrum analysis of NO\+-\-3 indicates significant periodicities in the variations of NO\+-\-3 concentration, which coincide with the periodicities of the solar activity. Therefore, a positive correlation between the variations of NO\+-\-3 concentration and the solar activity is found.展开更多
基金supported by the State Key Science Research Programme for Global Change Research of China (Grant Nos. 2010CB951402 and 2010CB951404)the State Key Basic Research Development Program of China (973 Pro-gram) (Grant No. 2007 CB411507)the National Natu-ral Science Foundation of China (Grant No. 40771047)
文摘Kelan River is a branch of the Ertix River, originating in the Altay Mountains in Xinjiang, northwestern China. The upper streams of the Kelan River are located on the southern slope of the Altay Mountains; they arise from small glacial lakes at an elevation of more than 2,500 m. The total water-collection area of the studied basin, from 988 to 3,480 m, is about 1,655 km2. Almost 95 percent of the basin area is covered with snow in winter. The westerly air masses deplete nearly all the moisture that comes in the form of snow during the winter months in the upper and middle reaches of the basin. That annual flow from the basin is about 382 mm, about 45 percent of which is contributed by snowmelt. The mean annual precipitation in the basin is about 620 mm, which is primarily concentrated in the upper and middle basin. The Kelan River system could be vulnerable to climate change because of substantial contribution from snowmelt runoff. The hydrological system could be altered significantly because of a warming of the climate. The impact of climate change on the hydrological cycle and events would pose an additional threat to the Altay region. The Kelan River, a typical snow-dominated watershed, has more area at higher elevations and accumulates snow during the winter. The peak flow occurs as a result of snow-melting during the late spring or early summer. Stream flow varies strongly throughout the year because of seasonal cycles of precipitation, snowpack, temperature, and groundwater. Changes in the temperature and precipitation affect the timing and volume of stream-flow. The stream-flow consists of contributions from meltwater of snow and ice and from runoff of rainfall. Therefore, it has low flow in winter, high flow during the spring and early summer as the snowpack melts, and less flows during the late summer. Because of the warming of the current climate change, hydrology processes of the Kelan River have undergone marked changes, as evidenced by the shift of the maximum flood peak discharge from May to June; the largest monthly runoffs also have an increment of about 15 percent related to before 1980; April-June runoff increased from the 60 percent of the annual runoff before 1980 to nearly 70 percent after 1990. The long-term trend shows temperature and precipitation increased mainly in the winter, but the rainfall declined in summer; hydrological process is manifested by the rising runoff in May and decreasing in June. Warming and the increase of winter and spring snowcover would lead to increased snowmelt, increasing the spring-flood hazards and the maximum flood discharge with disastrous consequences. The changed hydrological patterns caused by climate change have already impacted the urban water supply and agricultural and livestock production along the river.
基金provided by the National Natural Science Foundation of China(Grant Nos.41501069,41571415)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant Nos.XDA20060201,XDA19070302)Science&Technology Basic Resource Investigation Program of China(Grant No.2017YFC0404302).
文摘Quantitative estimation of the influence of various factors,such as black carbon,snow grain,dust content,and water con tent on albedo is essential in obtaining an accurate albedo.In this paper,field measurement data,including snow grain size,density,liquid water content,and snow depth was obtained.Black carbon and dust samples were collected from the snow surface.A simultaneous observation using ASD(Analytical Spectral Devices)spectral data was employed in the Qiyi glacier located on Qilian Mountain.The measurements were compared with results obtained from the Snow,Ice,and Aerosol Radiation(SNICAR)model.Additionally,a HYbrid Single-Particle Lagrangian Integrated Trajectory(HYSPLIT)air mass backward trajectory model was used to track the source of black carbon.The simulation was found to correlate well with observed data.Liquid water content was the most influential factor of albedo among the several influencing fac tors,followed by black carbon content and snow grain size.Finally,snow density change had the least toward albedo.HYSPLIT atmospheric trajectories model can only approximately show the source of black carbon and not clearly indicate the source region of black carbon.
基金supported by "Strategic Priority Research Program (B)" of the Chinese Academy of Sciences (Grant No. XDB03030204)SKLCS (No. SKLCS-OP-2014-03)Major Research of National Natural Science Foundation of China (Grant No. 41190084)
文摘Estimation of the influence of snow grain size and black carbon on albedo is essential in obtaining the accurate albedo. In this paper, field measurement data, including snow grain size, snow depth and density was obtained. Black carbon samples were collected from the snow surface. A simultaneous observation using Analytical Spectral Devices was employed in the Qiyi Glacier located in the Qilian Mountain. Analytical Spectral Devices spectrum data were used to analyze spectral re- flectance of snow for different grain size and black carbon content. The measurements were compared with the results obtained from the Snow, Ice, and Aerosol Radiation model, and the simulation was found to correlate well with the ob- served data. However, the simulated albedo was near to 0.98 times of the measured albedo, so the other factors were as- sumed to be constant using the corrected Snow, Ice, and Aerosol Radiation model to estimate the influence of measured snow grain size and black carbon on albedo. Field measurements were controlled to fit the relationship between the snow grain size and black carbon in order to estimate the influence of these factors on the snow albedo.
基金Financial support was given by the CAS International Partnership Project "The Basic Research for Water Issues of Inland River Basin in Arid Region," (CXTD-Z2005-2)National Natural Science Funds of China for Distinguished Young Scholar (40525001)National Basic Research Program of China (2005CB422003)
文摘Based on the data observed at two sites (site H1, 4,473 m a.s.l., and site H2, 4,696 m a.s.l.) on Qiyi Glacier in Qilian Mountains, China, by automatic weather station and spectral pyranometer during the period of June 9 through September 27, 2006, we investigated the temporal and spatial variations in surface albedo and spectral reflectance on the glacier. At site H1, the daily mean surface albedos fluctuated between 0.233 and 0.866, which were significantly affected by the air temperature on the glacier. It was found that the albedos clearly showed a diurnal cycle with the lowest value at noon at the two observation sites over the study period, and the difference of albedos between the upper site H2 and the lower site H1 also showed diurnal cycle but with the highest value at noon. The reflectance on the glacier was higher in the ultraviolet (0.28–0.4 μm) and visible (0.4–0.76 μm) wavelengths, lower in the near infrared wavelength (0.76–3 μm), which is quite contrary to the spectral reflectance on other ground surfaces. At the two observation sites, the spectral reflectance declined in all wavelengths with the ablation of snow generally. However, it declined drastically in ultraviolet (0.28–0.4 μm) and 0.6–0.7 μm wavelength, and declined less in 0.4–0.5 μm wavelength. On fresh snow surface, the spectral reflectance had the high values of 0.983 and 0.815 in the ultraviolet and visible (0.4–0.76 μm) wavelengths, respectively; but it had a relatively lower value of 0.671 in near infrared (0.76–3 μm) wavelengths. However, on dirty and melting ice surfaces, the reflectance had the very low values of 0.305 and 0.256 in the ultraviolet and visible wavelengths, with the lowest value of 0.082 in near infrared wavelengths. The spectral reflectance also showed a diurnal cycle like that of albedo. The diurnal variations of spectral reflectance on snow surface in ultraviolet and visible wavelength changed to a greater degree than that on ice surface. The diurnal variation curves were asymmetrical before and after the local noontime, but the curves on ice surfaces in every wavelength were relatively flat and symmetrical. Especially, the surface reflectance in near infrared wavelength was flat and symmetry on both snow and ice surfaces. The studies of relations between the snow albedo and snow density and impurity, and the impact of glacier albedo on the glacier runoff are also described in this paper.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41171056,40871038,41190080 and 40901041)the Independent Project of the State Key Laboratory of Cryospheric Science (No.SKLCS-ZZ-2010-06)+2 种基金the National Natural Science Foundation of China the Major International Cooperation Projects (Grant No. 40810019001)the Third Pole Environment Programme (Grant No. KZCX2-YW-T11)the Glacier Resources Survey Project
文摘Based on the glacier mass balance and meteorological data of air temperature and precipitation on the Qiyi Glacier from June 30 to September 5, 2010, we used a degree-day mass balance model to simulate the change of mass balance during this period. Our results indicate that the current value of the mass balance is -856.2 mm w.e. Subjected to the strong influences of air temperature and precipitation, the mass balance process can be divided into three stages： accumulating exiguously ~ melting intensively melting exiguously. The variation trends of the mass balance according to the degree-day mass balance model and the observed values are similar and wholly reflect the spatial distribution characteristics of the glacier mass balance, which increases with the increase of altitude. Our experiment on climate sensitivity of the mass balance showed that mass balance was very sensitive to the change of temperature; air temperature is the key factor which influences mass balance; and a slight increase in precipitation will have a negligible effect on mass balance when the air temperature increases continuously.
基金financially supported by the National Natural Science Foundation of China(Grant No.42277284)the 2021 first funds for central government to guide local science and technology development in Qinghai Province(Grant No.2021ZY002)the Second Tibetan Plateau Scientific Expedition and Research Program(Grant Nos.2019QZKK020102,2019OZKK0302).
文摘CH_(4) emission rates followed an increased pattern during the growing season at Tibetan Plateau.•Unique genes carried by abundant species were positively correlated with CH_(4) emission rates.•Climate factors influenced CH_(4) emission rates by regulating microbial community and their genes.Microorganisms play pivotal roles in soil methane(CH_(4))emissions and their functional genes are origins of a key mechanism for soil CH4-cycling.However,understanding of the roles of specific genes(e.g.,unique or shared genes carried by species)underlying CH_(4)-cycling remains elusive.Here,we measured CH_(4) emission rates and investigated variations in microbial community and the abundance of genes carried by species during the growing season in alpine meadow on the Tibetan Plateau.We discovered that CH_(4) emission rates increased from 394.4,745.9,and 1092.7µg CH4 m−2 h−1,in April,June,and August,respectively,and had a positive correlation with unique genes carried by abundant species during the growing season.Moreover,we found that unique genes carried by abundant species involved in methanogenesis processes have a higher abundance than methanotrophic processes.Further analysis indicated that climate factors(i.e.,mean monthly temperature(MMT)and mean monthly precipitation(MMP))influenced microbial community and their functional genes,and therefore affected the CH_(4) emission rates.Overall,the present study provides a novel insight into the variation of soil CH4 emissions from a functional gene perspective,highlighting the important roles of unique genes carried by abundant species in CH4 emissions in the Tibetan Plateau under seasonal variation.
基金funded by the National Natural Science Foundation of China(No.42271078)Key Research and Development Program of Shaanxi(No.2024SF-YBXM-669).
文摘0 INTRODUCTION Global warming not only exacerbates the instability of the climate system,causing more weather extremes but also has far-reaching impacts on surface systems,changing disaster environments(Qiu et al.,2024;Ye et al.,2024).The key medium between climate warming and the mountain environment is the cryosphere,whose recession increases the occurrence of chain disasters such as rock-ice avalanches and other flow events(Yang et al.,2023).
文摘The time series of accumulation in recent 300 years correlated well with solar activity in Dasuopu ice core. Results of spectrum analysis on the accumulation time series of the Dasuopu ice core shows that there are some periods that coincide with the periods of solar activity. By comparing the long-time change trend of the accumulation in the Dasuopu ice core with various kinds of indexes of solar activity intensity, a negative correlation is found between the trend and solar activity.
基金This work was supported by Ministry of Science and Technology of China (Grant No. G1998040807) Chinese Academy of Sciences (Grant No. KZCX2-301)+1 种基金the National Natural Science Foundation of China (Grant Nos. 40101006 and 40171020) Innovation Fund of C
文摘Three ice cores distributed across Dasuopu glacier in Himalayas were recovered. A 400-year net annual accumulation record reconstructed from one of the cores reflects the major precipitation trend in the central Himalayas. This record is related closely to the Indian monsoon precipitation. Wavelet and moving T-test were applied to the 400-year-long Dasuopu accumulation record, and significant staggered variability and abrupt change of the record on interannual to centennial time scales are identified. Finally the possible reason for abrupt change of the accumulation record is discussed.
基金supported by the National Key Research and Development Program of China(2018YFA0605403)the National Natural Science Foundation of China(41971393)+1 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(XDA20100300)the ESA-MOST(European Space Agency-Ministry of Science and Technology of China)Dragon 5 Programme(4000136930/22/I-NB)。
文摘高亚洲山地冰川变化影响着周边数亿人的水源供给.以往研究表明,高亚洲各个地区冰川物质平衡存在较大的空间差异,但这种差异的原因尚不明确.本文提出了一种基于雷达卫星冰川积雪观测的新指数,以区分高亚洲地区冬季积累型和夏季积累型冰川.结合物质平衡数据进一步研究发现,夏季积累型冰川消融速度是冬季积累型冰川的4倍(2000~2018年间消融速度分别为-0.43±0.12 m w.e/a和-0.10±0.06 m w.e/a).研究结果表明了季节性积累对冰川物质平衡的重要性,强调了准确的降水观测对该地区未来冰川变化估算至关重要.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research(STEP)Program(Grant No.2019QZKK0201)the National Natural Science Foundation of China(Grant No.41571062)。
文摘In the context of global warming,glaciers in the Asian High Mountains(AHMs)are shrinking at an accelerating rate.Projecting their future change is helpful for understanding the hydrological and climatic effects related to glacier retreat.Here,we projected glacier change in the AHMs from 1979 to 2100 under shared socioeconomic pathway(SSP)scenarios from the perspective of temperature,equilibrium-line altitude(ELA),and accumulation area.The annual mean temperature in the AHMs increased by 1.26℃ from 1979 to 2014,corresponding to an increase of 210 m in the mean ELA and a decrease of 1.7×10^(4)km^(2) in the glacier accumulation area.Under the SSP2-4.5(SSP5-8.5)scenario,the annual mean temperature in the AHMs would increase by 2.84℃(3.38℃)in 2040–2060 relative to that in 1850–1900,leading to the mean ELA reaching an elevation of5661 m(5777 m).The accumulation area in the AHMs decreased by 46.3%from 1995 to 2014 and was projected to decrease by60.1%in 2040–2060.Moreover,the annual mean temperature in the AHMs was projected to increase by 3.76℃(6.44℃)in2080–2100 relative to that in 1850–1900,corresponding to the ELA reaching an elevation of 5821 m(6245 m)and the accumulation area decreasing to 1.8×10^(4)km^(2)(0.5×10^(4)km^(2)).These data suggest that the conditions for glacier development will disappear in most of the AHMs,except for extreme high-altitude regions in the Tianshan,Pamir,and Himalaya Mountains.Under the SSP2-4.5(SSP5-8.5)scenario,when the global mean temperature increases 1.5℃(2℃)above pre-industrial levels,the annual mean temperature will increase by 2.12℃(2.86℃)and the accumulation area will decrease by 15%(48%)in the AHMs compared with that in 1995–2015.Therefore,a 1.5℃ increase in global warming would keep 40%more of the glacial accumulation area(1.5×10^(4)km^(2))in the AHMs compared to a 2℃ increase in global warming.
文摘The variations of NO\+-\-3 concentration in the Guliya ice core are reconstructed for recent about 1 000 a. Spectrum analysis of NO\+-\-3 indicates significant periodicities in the variations of NO\+-\-3 concentration, which coincide with the periodicities of the solar activity. Therefore, a positive correlation between the variations of NO\+-\-3 concentration and the solar activity is found.
