The MSA and nssSO 2- 4 concentration data from the ice cores and from atmospheric aerosols of the regions surrounding Weddell Sea have been analyzed in the present paper. The results suggest that the high concen...The MSA and nssSO 2- 4 concentration data from the ice cores and from atmospheric aerosols of the regions surrounding Weddell Sea have been analyzed in the present paper. The results suggest that the high concentration of biogenic sulphur in the snow and ice as well as in the atmospheric aerosols reflects the proximity of the Weddell Sea even though a distinct strength discrepancy exists in the productivity among the areas. The snow/ice shows that the production seems to be higher in the middle of the Antarctic Peninsula than near the Filchner Ronne ice shelf. Despite the factors impacting on the transportation and deposition processes of biogenic surlphur, the concentration of MSA and nssSO 2- 4 in snow and ice shows a regular spatial distribution: decreasing with the distance from the open sea and the altitude above sea level. Nevertheless, below a certain height, the “altitude effect” is no longer significant. The “displacement” of seasonality for MSA concentration observed in ice cores of the regions has been discussed. The “out of phase” pattern in surface layer is attributed to the modification by prevailing meteorological condition to the transport and deposition process; while “relocation” in the deep layers may be caused by migration, a mechanism for which is to be further investigated.The comparative study of the atmospheric and snow/ice samples implies that at the high altitude like the Weddell Sea the atmospheric signal of SO 2- 4 and MSA could be somewhat muted in the snow samples. But the seasonal variations in the airborn sulphate and MSA are reasonably well reproduced in the surface snow, for temporal and spacial distribution. The very close ratio of MSA to nssSO 2- 4 (or to SO 2- 4) of atmospheric aerosol and snow/ice sample is indicative of weak, if any, fraction between the two species during the scavenging and deposition processes. This could serve as the internal cause to explain the relative stable MSA/nssSO 2- 4 ratio, both for atmosphere and snow, an important regional specificity for the study of marine biogenic sulphur.展开更多
Snow/ice stratigraphic profile is one of the traditional and important research fields in glaciology. The profile drawn by hand, however, is a tough job. Using the Object Oriented Programming (OOP) Visual Basic (VB), ...Snow/ice stratigraphic profile is one of the traditional and important research fields in glaciology. The profile drawn by hand, however, is a tough job. Using the Object Oriented Programming (OOP) Visual Basic (VB), we developed a Drawing Software for Snow/Ice Stratigraphic Profile (DSSISP). This paper introduces the functions, designing process and realizing methods of the drawing software. It presents the key techniques and aspects that should be payed attention to during the software development. Moreover, it also proposes the ideas for complete development of this drawing system. Legend database is a key aspect in the software designing. The major functions of the software include the stratigraphic profile drawing, edition and data management, which can help researchers draw the stratigraphic profile (including the scale, stratigraphic figure, text note and legend) quickly in a computer. In addition, the database technique is used to manage drawing data, which makes the figure drawing convenient and efficient. The drawing data is also convenient to be preserved, exchanged, processed and used.展开更多
The radiative forcing and climate response due to black carbon（BC） in snow and/or ice were investigated by integrating observed effects of BC on snow/ice albedo into an atmospheric general circulation model（BCC AGC...The radiative forcing and climate response due to black carbon（BC） in snow and/or ice were investigated by integrating observed effects of BC on snow/ice albedo into an atmospheric general circulation model（BCC AGCM2.0.1） developed by the National Climate Center（NCC） of the China Meteorological Administration（CMA）.The results show that the global annual mean surface radiative forcing due to BC in snow/ice is ＋0.042 W m 2,with maximum forcing found over the Tibetan Plateau and regional mean forcing exceeding ＋2.8 W m 2.The global annual mean surface temperature increased 0.071 C due to BC in snow/ice.Positive surface radiative forcing was clearly shown in winter and spring and increased the surface temperature of snow/ice in the Northern Hemisphere.The surface temperatures of snow-covered areas of Eurasia and North America in winter（spring） increased by 0.83 C（0.6 C） and 0.83 C（0.46 C）,respectively.Snowmelt rates also increased greatly,leading to earlier snowmelt and peak runoff times.With the rise of surface temperatures in the Arctic,more water vapor could be released into the atmosphere,allowing easier cloud formation,which could lead to higher thermal emittance in the Arctic.However,the total cloud forcing could decrease due to increasing cloud cover,which will offset some of the positive feedback mechanism of the clouds.展开更多
The Tibetan Plateau（TP） is recognized as ＂Water Tower of Asia＂. Yet our understanding of mechanisms influencing incorporation of mercury（Hg） into freshwater in mountain glaciers on the TP remains quite limited. ...The Tibetan Plateau（TP） is recognized as ＂Water Tower of Asia＂. Yet our understanding of mechanisms influencing incorporation of mercury（Hg） into freshwater in mountain glaciers on the TP remains quite limited. Extensive sampling of environmental matrices（e.g., snow/ice）were conducted on the East Rongbuk glacier on Mt. Everest and Zhadang glacier on Mt.Nyainqentanglha for Hg speciation analysis. Speciated Hg behaved quite different during snowmelt： a preferential early release of DHg（dissolved Hg） was observed at the onset of snowmelt, whereas PHg（particulate-bound Hg） and THg（total Hg） become relatively enriched in snow and released later. Small fraction of Hg in snow was lost during a snowmelt day（18.9%–34.7%） with a large proportion（58.1%–87.3%） contributed by PHg decrease, indicating that the deposited Hg is most likely retained in glacier snow/ice. Furthermore, THg were positively correlated with PHg and crustal major ions（e.g., Ca2＋, Mg2＋） during snowmelt, indicating that Hg is mainly migrated with particulates. The main pathway of Hg loss during snowmelt was most probably associated with release of PHg with meltwater, which was greatly influenced by ablation intensity of snow/ice. This should be paid particular concern as Hg preserved in mountain glaciers will mostly enter aquatic ecosystem as climate warms, impacting on downstream ecosystems adversely. Obvious decrease of THg during the downstream transport from glacier was observed with a large proportion contributed by PHg decrease. The main removal mechanism of Hg was associated with sedimentation of PHg during the transport process.展开更多
To evaluate isotopic tracers at natural abundances by providing basic isotope data of the hydrological investigations and assessing the impacts of different factors on the water cycle, a total of 197 water samples wer...To evaluate isotopic tracers at natural abundances by providing basic isotope data of the hydrological investigations and assessing the impacts of different factors on the water cycle, a total of 197 water samples were collected from the Laohugou Glacial catchment in the Shule River basin northwestern China during the 2013 ablation seasons and analyzed their H- and O-isotope composition. The results showed that the isotopic composition of precipitation in the Qilianshan Station in the Laohugou Glacial catchment was remarkable variability. Correspondingly, a higher slope of δ180-δD diagram, with an average of 8.74, is obtained based on the precipitation samples collected on the Glacier No.la, mainly attributed to the lower temperature on the glacier surface. Because of percolation and elution, the bottom of the firn the isotopic composition at is nearly steady. The 6180 /altitude gradients for precipitation and melt water were -o.37%o/100 m and -o.34%o/100 m, respectively Exposed to the air and influenced by strong ablation and evaporation, the isotopic values and the 6180 vs 6D diagram of the glacial surface ice show no altitudinal effect, indicating that glacier ice has the similar origins with the firn. The variation of isotopic composition in the melt water, varying from -l0.7‰ to -16.9‰ （8180） and from -61.1%o to -122.1%o （6D） indicates the recharging of snowmelt and glacial ice melt water produced at different altitudes. With a mean value of -13.3‰ for 8180 and -89.7‰ for 8D, the isotopic composition of the stream water is much closer to the melt water, indicating that stream water is mainly recharged by the ablation water. Our results of the stable isotopic compositions in natural water in the Laohugou Glacial catchment indicate the fractionations and the smoothing fluctuations of the stable isotopes during evaporation, infiltration and mixture.展开更多
文摘The MSA and nssSO 2- 4 concentration data from the ice cores and from atmospheric aerosols of the regions surrounding Weddell Sea have been analyzed in the present paper. The results suggest that the high concentration of biogenic sulphur in the snow and ice as well as in the atmospheric aerosols reflects the proximity of the Weddell Sea even though a distinct strength discrepancy exists in the productivity among the areas. The snow/ice shows that the production seems to be higher in the middle of the Antarctic Peninsula than near the Filchner Ronne ice shelf. Despite the factors impacting on the transportation and deposition processes of biogenic surlphur, the concentration of MSA and nssSO 2- 4 in snow and ice shows a regular spatial distribution: decreasing with the distance from the open sea and the altitude above sea level. Nevertheless, below a certain height, the “altitude effect” is no longer significant. The “displacement” of seasonality for MSA concentration observed in ice cores of the regions has been discussed. The “out of phase” pattern in surface layer is attributed to the modification by prevailing meteorological condition to the transport and deposition process; while “relocation” in the deep layers may be caused by migration, a mechanism for which is to be further investigated.The comparative study of the atmospheric and snow/ice samples implies that at the high altitude like the Weddell Sea the atmospheric signal of SO 2- 4 and MSA could be somewhat muted in the snow samples. But the seasonal variations in the airborn sulphate and MSA are reasonably well reproduced in the surface snow, for temporal and spacial distribution. The very close ratio of MSA to nssSO 2- 4 (or to SO 2- 4) of atmospheric aerosol and snow/ice sample is indicative of weak, if any, fraction between the two species during the scavenging and deposition processes. This could serve as the internal cause to explain the relative stable MSA/nssSO 2- 4 ratio, both for atmosphere and snow, an important regional specificity for the study of marine biogenic sulphur.
基金This study is supported by Ministry of Science and Technology of the People's Republic of China(2001DLA50040)Shanghai Natural Science Foundation(02ZA14107)National Natural Science Foundation(40231013).
文摘Snow/ice stratigraphic profile is one of the traditional and important research fields in glaciology. The profile drawn by hand, however, is a tough job. Using the Object Oriented Programming (OOP) Visual Basic (VB), we developed a Drawing Software for Snow/Ice Stratigraphic Profile (DSSISP). This paper introduces the functions, designing process and realizing methods of the drawing software. It presents the key techniques and aspects that should be payed attention to during the software development. Moreover, it also proposes the ideas for complete development of this drawing system. Legend database is a key aspect in the software designing. The major functions of the software include the stratigraphic profile drawing, edition and data management, which can help researchers draw the stratigraphic profile (including the scale, stratigraphic figure, text note and legend) quickly in a computer. In addition, the database technique is used to manage drawing data, which makes the figure drawing convenient and efficient. The drawing data is also convenient to be preserved, exchanged, processed and used.
基金supported by the National Basic Research Program of China (Grant Nos. 2010CB955608 and 2011CB403405)the Public Meteorology Special Foundation of MOST (Grant No.GYHY200906020)
文摘The radiative forcing and climate response due to black carbon（BC） in snow and/or ice were investigated by integrating observed effects of BC on snow/ice albedo into an atmospheric general circulation model（BCC AGCM2.0.1） developed by the National Climate Center（NCC） of the China Meteorological Administration（CMA）.The results show that the global annual mean surface radiative forcing due to BC in snow/ice is ＋0.042 W m 2,with maximum forcing found over the Tibetan Plateau and regional mean forcing exceeding ＋2.8 W m 2.The global annual mean surface temperature increased 0.071 C due to BC in snow/ice.Positive surface radiative forcing was clearly shown in winter and spring and increased the surface temperature of snow/ice in the Northern Hemisphere.The surface temperatures of snow-covered areas of Eurasia and North America in winter（spring） increased by 0.83 C（0.6 C） and 0.83 C（0.46 C）,respectively.Snowmelt rates also increased greatly,leading to earlier snowmelt and peak runoff times.With the rise of surface temperatures in the Arctic,more water vapor could be released into the atmosphere,allowing easier cloud formation,which could lead to higher thermal emittance in the Arctic.However,the total cloud forcing could decrease due to increasing cloud cover,which will offset some of the positive feedback mechanism of the clouds.
基金supported by the National Natural Science Foundation of China (Nos.41421061,41671074)the Foundation of State Key Laboratory of Cryosphere Science (No.SKLCS-ZZ-2015-01-10)
文摘The Tibetan Plateau（TP） is recognized as ＂Water Tower of Asia＂. Yet our understanding of mechanisms influencing incorporation of mercury（Hg） into freshwater in mountain glaciers on the TP remains quite limited. Extensive sampling of environmental matrices（e.g., snow/ice）were conducted on the East Rongbuk glacier on Mt. Everest and Zhadang glacier on Mt.Nyainqentanglha for Hg speciation analysis. Speciated Hg behaved quite different during snowmelt： a preferential early release of DHg（dissolved Hg） was observed at the onset of snowmelt, whereas PHg（particulate-bound Hg） and THg（total Hg） become relatively enriched in snow and released later. Small fraction of Hg in snow was lost during a snowmelt day（18.9%–34.7%） with a large proportion（58.1%–87.3%） contributed by PHg decrease, indicating that the deposited Hg is most likely retained in glacier snow/ice. Furthermore, THg were positively correlated with PHg and crustal major ions（e.g., Ca2＋, Mg2＋） during snowmelt, indicating that Hg is mainly migrated with particulates. The main pathway of Hg loss during snowmelt was most probably associated with release of PHg with meltwater, which was greatly influenced by ablation intensity of snow/ice. This should be paid particular concern as Hg preserved in mountain glaciers will mostly enter aquatic ecosystem as climate warms, impacting on downstream ecosystems adversely. Obvious decrease of THg during the downstream transport from glacier was observed with a large proportion contributed by PHg decrease. The main removal mechanism of Hg was associated with sedimentation of PHg during the transport process.
基金the projects of National Major Scientific Research Project (2013CBA01806)National Natural Science Foundation of China (Grant Nos. 41271085,41130641)open fund project of State Key Laboratory of Cryospheric Science (SKLCS-OP2013-05)
文摘To evaluate isotopic tracers at natural abundances by providing basic isotope data of the hydrological investigations and assessing the impacts of different factors on the water cycle, a total of 197 water samples were collected from the Laohugou Glacial catchment in the Shule River basin northwestern China during the 2013 ablation seasons and analyzed their H- and O-isotope composition. The results showed that the isotopic composition of precipitation in the Qilianshan Station in the Laohugou Glacial catchment was remarkable variability. Correspondingly, a higher slope of δ180-δD diagram, with an average of 8.74, is obtained based on the precipitation samples collected on the Glacier No.la, mainly attributed to the lower temperature on the glacier surface. Because of percolation and elution, the bottom of the firn the isotopic composition at is nearly steady. The 6180 /altitude gradients for precipitation and melt water were -o.37%o/100 m and -o.34%o/100 m, respectively Exposed to the air and influenced by strong ablation and evaporation, the isotopic values and the 6180 vs 6D diagram of the glacial surface ice show no altitudinal effect, indicating that glacier ice has the similar origins with the firn. The variation of isotopic composition in the melt water, varying from -l0.7‰ to -16.9‰ （8180） and from -61.1%o to -122.1%o （6D） indicates the recharging of snowmelt and glacial ice melt water produced at different altitudes. With a mean value of -13.3‰ for 8180 and -89.7‰ for 8D, the isotopic composition of the stream water is much closer to the melt water, indicating that stream water is mainly recharged by the ablation water. Our results of the stable isotopic compositions in natural water in the Laohugou Glacial catchment indicate the fractionations and the smoothing fluctuations of the stable isotopes during evaporation, infiltration and mixture.
