Ice and snow chemistry of alpine glaciers is crucial for the research of regional atmospheric environment change. Fresh snow samples were weekly collected from Urumqi Glacier No.1 in the Tianshan Mountains, Xin- jiang...Ice and snow chemistry of alpine glaciers is crucial for the research of regional atmospheric environment change. Fresh snow samples were weekly collected from Urumqi Glacier No.1 in the Tianshan Mountains, Xin- jiang, China, and the chemical characteristics and seasonal variations of major ions, mineral dust, δ18O and trace metals were measured. Results show that the concentrations of major ions in the snow are Ca2+ > SO42-> NH4+ > NO3-> Cl-> Na+ > Mg2+ > K+, in which Ca2+ is the dominant cation, and SO42-is the dominant anion. All major ions have close positive correlations with each other except NO3-. δ18O shows positive correlation with air temperature change during the study period. Mineral dust particle and major ionic concentrations in fresh snow have obvious seasonal change, with high concentration in spring but low concentration in summer and autumn, which indicates that the chemical mass input from Asian dust activity to snow is very significant. Temporal changes of trace metals in fresh snow, e.g., Cd, Pb, Zn, Al, Fe, have shown that human-induced pollution of central Asian region also has large contribution to the snow chemistry on alpine glaciers of the Tianshan Mountains.展开更多
The fresh snow density was observed with snow analyzer (Snow Fork) at Tianshan Station for Snowcover and Avalanche Research, Chinese Academy of Sciences from February 21 to March 5, 2009. Results show that fresh snow ...The fresh snow density was observed with snow analyzer (Snow Fork) at Tianshan Station for Snowcover and Avalanche Research, Chinese Academy of Sciences from February 21 to March 5, 2009. Results show that fresh snow density increases from the 5th h to the 291st h after the snowfall, with an average rate of increase of 4.0×10-4 g/(cm3·h) (R2 = 0.943). Analysis shows that fresh snow density is negatively correlated with the compac-tion rate of fresh snow (R2 = -0.960). Inversely, it is positively correlated with fresh snow viscosity (R2 = 0.896). In relation to meteorological factors, ground temperature rising at a depth of 40 cm is the major driving factor of snow density increase. The temperature increase in fresh snow layer and the decrease in depth hoar layer have the most prominent impacts on the snow density increase in the afternoon. Principal component analysis shows that the de-terminant factors of fresh snow density change can be grouped into 3 types as follows: 1) dynamic factor contributes about 69.71% to fresh snow density change, with a significant effect from the 5th h to the 106th h after the snowfall; 2) exogenous energy factor contributes about 20.91% to it, with a significant effect at the 130th h; and c) endoge-nous energy factor contributes about 9.38% to it, with a significant effect at the 130th h and the 195th h.展开更多
During 1997 summer, fresh snow samples were collected from the high elevation region (5400－ 7000 m) of Dasuopu Galcier on the northern slope of Mt. Xixabangma (28° 33’N, 85° 44’E). Compared with other rem...During 1997 summer, fresh snow samples were collected from the high elevation region (5400－ 7000 m) of Dasuopu Galcier on the northern slope of Mt. Xixabangma (28° 33’N, 85° 44’E). Compared with other remote regions in the world, major ion concentrations in fresh snow are very low during summer in Mt. Xixabangma, suggesting that the atmosphere is very clean and may represent background value for the middle/upper troposphere in the middle/low latitude area. During summer at Mt. Xixabangma the fresh snow chemistry is minimally influenced by anthropogenic pollutants as revealed by the snow pH (mean value of 6.0). Conductivity of fresh snow are low and constant. A multi regression curve of pH vs conductivity shows a strong correlation; snow pH is negatively correlated with conductivity when pH < 6.0, and positively correlated when pH > 6.0. This suggests that the dominant chemical species of snow are interchanging between acid anions (e.g.) and crustal cations.展开更多
本文主要利用美国冰雪资料中心(The National Snow and Ice Data Center)提供的卫星反演积雪资料和ERA40土壤温度再分析资料,采用相关分析,对欧亚北部冬季新增雪盖面积(冬季TFSE)与我国夏季气候异常关系的可能物理途径进行了初步研究。...本文主要利用美国冰雪资料中心(The National Snow and Ice Data Center)提供的卫星反演积雪资料和ERA40土壤温度再分析资料,采用相关分析,对欧亚北部冬季新增雪盖面积(冬季TFSE)与我国夏季气候异常关系的可能物理途径进行了初步研究。结果表明,春夏季陆面季节演变异常是上述"隔季相关"的重要纽带:当冬季TFSE偏大时,欧亚北部大范围积雪—冻土自西向东、由南向北的融化进程明显减慢,受其影响,至夏季,东亚中高纬区积雪和地表冻土的融化异常强烈,土壤温度明显偏低,这种夏季陆面异常可能通过自身的冷却作用,通过加强东亚中高纬异常北风对东亚中纬区夏季变冷产生直接影响,进而与西太平洋副热带高压,乃至与我国江南夏季降水异常产生关联;冬季TFSE偏小时相反。分析表明,冬季TFSE信号在东亚中高纬局地的春季积雪—冻土融化过程中被加强,并在夏季达到显著。展开更多
利用美国冰雪资料中心(National Snow and Ice Data Center)提供的近40年逐周的卫星反演雪盖资料,定义了各季节新增(融化)雪盖面积指数(fresh snow extent),即增/融雪覆盖率PFSE、增/融雪面积AFSE、欧亚大陆北部增/融雪面积之和TFSE,针...利用美国冰雪资料中心(National Snow and Ice Data Center)提供的近40年逐周的卫星反演雪盖资料,定义了各季节新增(融化)雪盖面积指数(fresh snow extent),即增/融雪覆盖率PFSE、增/融雪面积AFSE、欧亚大陆北部增/融雪面积之和TFSE,针对欧亚大陆各季节平均的雪盖面积本身(snow extent,PSE、ASE、TSE)和其增(融)雪盖面积,分析比较了二者的变化特征。结果表明,欧亚大陆各季节平均的雪盖面积和相应增(融)雪盖面积不论是气候态分布还是其年际、十年际变化均有明显不同,其中以冬、春季差别更为明显;夏、秋季二者虽有较好的一致性,但增(融)雪盖面积的变率明显强于雪盖面积本身;另外,冬季欧洲新增雪盖对欧亚北部冬季雪盖面积以及其后的春季雪盖都有较显著的影响,而春季欧洲和中纬度亚洲地区的融雪则受到冬、春两季雪盖情况的影响。进一步分析欧亚大陆冬、春两季增(融)雪盖与ENSO关系显示,二者除在个别地区(西伯利亚北部、欧洲中东部以及青藏高原)存在较明显关系外,整体上,欧亚大陆北部雪盖变化既不受控于ENSO,也不会显著影响ENSO。展开更多
Aerosol and snow samples were collected at ablation zone of Baishui （白水） Glacier No. 1, Mt. Yulong （玉龙）, from May to June, 2006. The concentrations of Cl^-, NO3^-, SO4^2-, Na^＋, K^＋, Mg^2＋, and Ca^2＋ were ...Aerosol and snow samples were collected at ablation zone of Baishui （白水） Glacier No. 1, Mt. Yulong （玉龙）, from May to June, 2006. The concentrations of Cl^-, NO3^-, SO4^2-, Na^＋, K^＋, Mg^2＋, and Ca^2＋ were determined by ion chromatograph both in aerosol and snow samples. The average total aerosol loading is 25.45 neq.scm^-1, NO3^- and Na^＋ are the dominant soluble ions in the aerosol, accounting for 39% and 21% of average total aerosol loading, respectively. Monsoon circulation reduces the concentration of most ions, indicating that wet scavenging is effective for aerosol particles. In snow samples, SO4^2- and Ca^2＋ are the dominant anion and cation, respectively. A lower Na^＋/Cl^- ratio was found in fresh snow samples compared to the higher ratio that was found in aerosol samples. Analyzing the difference in SO4^2- and NO3^- in air and fresh snow indicated that the aerosol was influenced by local circulation, but the components in fresh snow samples were from long-distance transport. Enrichment of NO3^- in aerosol samples is attributed to motor exhaust emissions from tourism by calculating the SO4^2-/NO3^- ratio in aerosol and fresh snow samples. The temporal variation and correlation coefficients between soluble species in aerosol samples suggest that Cl^-, Na^＋ and K^＋ come from sea-salt aerosol, and SO4^2-, Mg^2＋ and Ca^2＋ are from continental crust sources.展开更多
基金Under the auspices of Major State Basic Research Development Program of China(No.2010CB951003)Knowledge Innovation Programs of the Chinese Academy of Sciences(No.KZCXZ-YW-127)National Natural Science Foundation of China(No.40631001,40571033,40701034,40371028,J0630966,40701035)
文摘Ice and snow chemistry of alpine glaciers is crucial for the research of regional atmospheric environment change. Fresh snow samples were weekly collected from Urumqi Glacier No.1 in the Tianshan Mountains, Xin- jiang, China, and the chemical characteristics and seasonal variations of major ions, mineral dust, δ18O and trace metals were measured. Results show that the concentrations of major ions in the snow are Ca2+ > SO42-> NH4+ > NO3-> Cl-> Na+ > Mg2+ > K+, in which Ca2+ is the dominant cation, and SO42-is the dominant anion. All major ions have close positive correlations with each other except NO3-. δ18O shows positive correlation with air temperature change during the study period. Mineral dust particle and major ionic concentrations in fresh snow have obvious seasonal change, with high concentration in spring but low concentration in summer and autumn, which indicates that the chemical mass input from Asian dust activity to snow is very significant. Temporal changes of trace metals in fresh snow, e.g., Cd, Pb, Zn, Al, Fe, have shown that human-induced pollution of central Asian region also has large contribution to the snow chemistry on alpine glaciers of the Tianshan Mountains.
基金Under the auspices of National R & D Project of Social Welfare, Ministry of Science and Technology Development, China (No. GYHY200706008, GYHY200806011)West Light Foundation of Chinese Academy of Sciences (No. RCPY200902)
文摘The fresh snow density was observed with snow analyzer (Snow Fork) at Tianshan Station for Snowcover and Avalanche Research, Chinese Academy of Sciences from February 21 to March 5, 2009. Results show that fresh snow density increases from the 5th h to the 291st h after the snowfall, with an average rate of increase of 4.0×10-4 g/(cm3·h) (R2 = 0.943). Analysis shows that fresh snow density is negatively correlated with the compac-tion rate of fresh snow (R2 = -0.960). Inversely, it is positively correlated with fresh snow viscosity (R2 = 0.896). In relation to meteorological factors, ground temperature rising at a depth of 40 cm is the major driving factor of snow density increase. The temperature increase in fresh snow layer and the decrease in depth hoar layer have the most prominent impacts on the snow density increase in the afternoon. Principal component analysis shows that the de-terminant factors of fresh snow density change can be grouped into 3 types as follows: 1) dynamic factor contributes about 69.71% to fresh snow density change, with a significant effect from the 5th h to the 106th h after the snowfall; 2) exogenous energy factor contributes about 20.91% to it, with a significant effect at the 130th h; and c) endoge-nous energy factor contributes about 9.38% to it, with a significant effect at the 130th h and the 195th h.
基金Under the auspices of NKBRSF Project (G1999043400), the Great Project of Chinese Academy of Sciences (KZ951 A1 402 and KZ951
文摘During 1997 summer, fresh snow samples were collected from the high elevation region (5400－ 7000 m) of Dasuopu Galcier on the northern slope of Mt. Xixabangma (28° 33’N, 85° 44’E). Compared with other remote regions in the world, major ion concentrations in fresh snow are very low during summer in Mt. Xixabangma, suggesting that the atmosphere is very clean and may represent background value for the middle/upper troposphere in the middle/low latitude area. During summer at Mt. Xixabangma the fresh snow chemistry is minimally influenced by anthropogenic pollutants as revealed by the snow pH (mean value of 6.0). Conductivity of fresh snow are low and constant. A multi regression curve of pH vs conductivity shows a strong correlation; snow pH is negatively correlated with conductivity when pH < 6.0, and positively correlated when pH > 6.0. This suggests that the dominant chemical species of snow are interchanging between acid anions (e.g.) and crustal cations.
文摘以荷兰豆为原料,研究超声波(US)、微酸性电解水(SAEW)、超声波联合SAEW 3种处理方式对荷兰豆的保鲜效果。通过单因素试验确定最佳浸泡时间,进一步探讨不同保鲜方式对荷兰豆在贮藏期间菌落总数和品质变化的影响。结果表明,最佳浸泡时间为15 min。在相同贮藏时间内,不同处理方式的抑菌效果,超声波联合SAEW处理>SAEW处理>超声波处理>对照。超声波与微酸性电解水在荷兰豆的杀菌保鲜过程中具有良好的协同增效作用,使荷兰豆的菌落总数降低了1.71 lg CFU/g,延缓了抗坏血酸、叶绿素含量的降解及衰老的进行,有效提高了贮藏期内荷兰豆的整体品质。为荷兰豆的贮藏保鲜提供了一定的参考依据。
文摘本文主要利用美国冰雪资料中心(The National Snow and Ice Data Center)提供的卫星反演积雪资料和ERA40土壤温度再分析资料,采用相关分析,对欧亚北部冬季新增雪盖面积(冬季TFSE)与我国夏季气候异常关系的可能物理途径进行了初步研究。结果表明,春夏季陆面季节演变异常是上述"隔季相关"的重要纽带:当冬季TFSE偏大时,欧亚北部大范围积雪—冻土自西向东、由南向北的融化进程明显减慢,受其影响,至夏季,东亚中高纬区积雪和地表冻土的融化异常强烈,土壤温度明显偏低,这种夏季陆面异常可能通过自身的冷却作用,通过加强东亚中高纬异常北风对东亚中纬区夏季变冷产生直接影响,进而与西太平洋副热带高压,乃至与我国江南夏季降水异常产生关联;冬季TFSE偏小时相反。分析表明,冬季TFSE信号在东亚中高纬局地的春季积雪—冻土融化过程中被加强,并在夏季达到显著。
文摘利用美国冰雪资料中心(National Snow and Ice Data Center)提供的近40年逐周的卫星反演雪盖资料,定义了各季节新增(融化)雪盖面积指数(fresh snow extent),即增/融雪覆盖率PFSE、增/融雪面积AFSE、欧亚大陆北部增/融雪面积之和TFSE,针对欧亚大陆各季节平均的雪盖面积本身(snow extent,PSE、ASE、TSE)和其增(融)雪盖面积,分析比较了二者的变化特征。结果表明,欧亚大陆各季节平均的雪盖面积和相应增(融)雪盖面积不论是气候态分布还是其年际、十年际变化均有明显不同,其中以冬、春季差别更为明显;夏、秋季二者虽有较好的一致性,但增(融)雪盖面积的变率明显强于雪盖面积本身;另外,冬季欧洲新增雪盖对欧亚北部冬季雪盖面积以及其后的春季雪盖都有较显著的影响,而春季欧洲和中纬度亚洲地区的融雪则受到冬、春两季雪盖情况的影响。进一步分析欧亚大陆冬、春两季增(融)雪盖与ENSO关系显示,二者除在个别地区(西伯利亚北部、欧洲中东部以及青藏高原)存在较明显关系外,整体上,欧亚大陆北部雪盖变化既不受控于ENSO,也不会显著影响ENSO。
基金supported by the National Natural Science Foundation of China (Nos.40801028,40971019)the National Basic Research Program of China (No.2007CB411501)+1 种基金the West Light Foundation of Chinese Academy of Sciences (No.O828A11001)the Funds from the State Key Laboratory of Cryospheric Sciences and the Lijiang City Government
文摘Aerosol and snow samples were collected at ablation zone of Baishui （白水） Glacier No. 1, Mt. Yulong （玉龙）, from May to June, 2006. The concentrations of Cl^-, NO3^-, SO4^2-, Na^＋, K^＋, Mg^2＋, and Ca^2＋ were determined by ion chromatograph both in aerosol and snow samples. The average total aerosol loading is 25.45 neq.scm^-1, NO3^- and Na^＋ are the dominant soluble ions in the aerosol, accounting for 39% and 21% of average total aerosol loading, respectively. Monsoon circulation reduces the concentration of most ions, indicating that wet scavenging is effective for aerosol particles. In snow samples, SO4^2- and Ca^2＋ are the dominant anion and cation, respectively. A lower Na^＋/Cl^- ratio was found in fresh snow samples compared to the higher ratio that was found in aerosol samples. Analyzing the difference in SO4^2- and NO3^- in air and fresh snow indicated that the aerosol was influenced by local circulation, but the components in fresh snow samples were from long-distance transport. Enrichment of NO3^- in aerosol samples is attributed to motor exhaust emissions from tourism by calculating the SO4^2-/NO3^- ratio in aerosol and fresh snow samples. The temporal variation and correlation coefficients between soluble species in aerosol samples suggest that Cl^-, Na^＋ and K^＋ come from sea-salt aerosol, and SO4^2-, Mg^2＋ and Ca^2＋ are from continental crust sources.
