Nitrate Plus Nitrite Concentrations in a Himalayan Ice Core

The measurement of chemical constituents in glacial ice has been useful in discerning historic trends in chemical deposition and hence paleo-atmospheric records in remote areas (Thompson and Mosley - Thompson, 1981; Johnson and Chamberlain, 1981; Ng and Patterson, 1981; Neftel et al., 1982). However, delineating the sources of the deposited chemical species in question is not always straightforward. This has been especially true for nitrate. Although it is now believed that man-made emissions are responsible for a high percentage of nitrate being deposited in remote areas of the Northern Hemisphere, numerous natural sources, named and unnamed, have also contributed to the precipitated nitrate burden in these regions (Risbo et al., 1981; Herron, 1982). Most of the data available for glacial ice has been obtained from polar glaciers. We present nitrate plus nitrite data froma 16.6m core collected at 4908m on Sentik Glacier in the Nun Kun portion of the Ladakh Himalayas, India. To our knowledge this is the longest record of nitrate concentrations reported from an alpine glacie

Source and climatic implication of the reactive iron and reactive silicate concentration found in a core from Meserve Glacier, Antartica

Glaciochemistry has recently provided a useful tool in the study of snow accumulation rates (Herron and Langway, 1979; Bulter et al., 1980 Warburton and Young, 1981; Mayewski et al., in press) and the elucidation of long-term climatic change (Delmas et al., 1980; Thompson and Mosley-Thompson, 1981) as well as the definition of aerosol/precipitation source areas (Warburton and Linkletter, 1978). Recent glaciochemical work from Antarctica has suggested that although cations associated with seasalt(Na, Mg, Ca and K) decrease in concentration as one proceeds inland, crustally-derived chemical species such as Al and Fe remain relatively constant in snow and ice (Boutron and Martin, 1980; Herron and Langway, 1979; Johnson and Chamberlain, 1981; Warburton and Young, 1981). This paper presents the first data suggesting that there is in some cases a local source for the crustally-derived material that enters Antarctic precipitation

Acidity of Recent Himalayan Snow

Surface snows collected at various elevations in the Indian Himalayas were analyzed in the field for pH as part of a broader study of the chemistry. The pH values are lower than the predicted ≅5.6 for unpolluted precipitation. Analysis of NO3 + NO2, Cl, SO4 and NH4 indicate that these low pH values are not completely due to the presence of strong mineral acids. The strong correlation of pH with elevation (i.e. temperature) suggests that the low pH values are due to the snow being supersaturated with CO2

Examination of Selected Microparticles from the Sentik Glacier Core, Ladakh, Himalayas

Several characteristics and interpretive comments are reported for microparticles from selected samples in the Sentik Glacier core. Four basic morphologic groups are defined: Platy, angular, biogenic, and anomalous

Chemical composition of a high altitude fresh snowfall in the Ladakh Himalayas

Studies of the chemical constituents in Antarctic and Greenland snow and ice cores have proven to be extremely useful for determining the composition of the atmosphere during past climatic events (Boutron and Delmas, 1980; Herron, 1982) and hence provide data concerning climatic change. Despite the potential for the collection of similar types of information from high altitude temperate glacier snow and ice cores, their study has been limited. In addition, unlike polar ice sheets, high altitude temperate glaciers are not only close to populated area but have higher accumulation rates. Owing to the latter, preservation of detailed records on sub-annual and sub-seasonal scales can be extracted from high altitude temperate glacier cores. As part of the 1980 University of New Hampshire Nun Kun coring program a suite of surface snow samples were collected from one snowfall event that occurred during the field season. Determinations of deuterium, reactive phosphate, reactive silicate, reactive iron, chloride, nitrate plus nitrite, pH, and ammonium measured on the eight samples collected from this snowfall are presented in this paper. Although limited in number, these samples are unique and as such their interpretative use has been extended to define source(s) for the chemical species found within the snow samples and effects created on the distribution of these species by the mountainous terrain of Nun Kun. Results from these samples will be useful in the interpretation of the time-series record currently being analyzed from this area and in helping to improve our knowledge of the ice and snow chemistry of high altitude temperate glaciers

Reconnaissance Glacio-chemical Studies in the Indian Himalayas

Analysis of reactive silicate, ammonium, phosphate, iron and sodium from cores taken from three glaciers in the Kashmir portion of the Himalayas are reported as the first in a series of glacio-chemical studies designed to produce proxy paleoclimatic data for this region. This study stresses the elevation dependency of such studies and for the chemical species analyzed which are most reliable for the purpose of the study

Geochemistry of mineral dust in the McMurdo Dry Valleys Region, Antarctica

The transport and deposition of windblown materials are major processes in the ice-free areas of polar regions. The deposition of aeolian material provides connectivity within the ecosystems of these regions and is integral in understanding geochemical balances and exchanges between landscape units. We have analyzed materials deposited on glacier and permanent lake-ice surfaces as well as geomorphological features formed by aeolian processes in the largest ice-free area in Antarctica, the McMurdo Dry Valleys (~78 °S) in order to determine the source of this sediment. This presentation will focus on the materials collected from the glacier and lake surfaces. The bulk of sediment movement occurs during foehn events in the austral winter that redistribute material throughout the region. The majority of these samples were sand size (\u3e80 %) by weight. Samples containing the highest silt size were from the glaciers in the eastern portion of the Taylor Valley which is the most downwind position. Major rock-forming elements were analyzed using Standard XRF techniques. The alkali metals were depleted with respect to the Upper Continental Crust (UCC), in both the sand and silt fractions, while the alkaline earths were enriched. The TiO2, Fe2O3 and Al2O3 in the sands are similar to UCC values. The major element geochemistry of the aeolian material suggests that it is a mix of the four major rock types in the Valley itself: PreCambrian basement complex, Beacon Sandstone, Ferrar Dolerite and McMurdo Volcanics. Sr isotopic measurements of the fine grained materials from the glacier surfaces indicate the material is similar to the soils from their respective glacier/lake basins. Nd isotope values of this material lie intermediate to the rock values, indicating multiple sources of the aeolian material. The Sr and Nd isotopic data do not plot within the fields of dust from either Vostok or Dome C ice cores which has been interpreted as coming primarily from South America. All of our data suggest a local source of the majority of aeolian material deposited with Taylor Valle

Snow Chemistry from Xixabangma Peak, Tibet

[From conclusion] Although the cause of the differences in chemistry of the Xixabangma glacier fresh snow events cannot be adequately inferred from the limited number of samples available for this study, the existence of such different chemical signatures is encouraging for future studies in the region

The characterization and role of aeolian deposition on water quality, McMurdo Dry Valleys, Antarctica

The connection of ecosystems by wind-driven transport of material has become a topic of increasing interest and importance. Less than 1% of dust transported worldwide is exported to the Southern Ocean and Antarctic cryosphere; however, aeolian transport on the Antarctic continent is predominantly locally derived from the abrasion of bedrock. The deposition of the aeolian material is integral to nutrient and solute dispersal in the Antarctic ecosystem. This is particularly true in the ice-free areas of Antarctica, such as the McMurdo Dry Valleys (MDV), where aeolian material deposited in the aquatic system is solubilized during the melt season. The material is predominantly locally-derived from the abrasion of bedrock. In this study, a two-step leaching experiment simulates the melt season and we quantify the flux of solutes and nutrients to the aquatic ecosystem. Soluble salts were removed from the aeolian material first during cold water leaching followed by an increase in carbonate and silicate dissolution during freeze–thaw. Major ion fluxes on glaciers and lakes are at least two orders of magnitude greater than nutrient fluxes. However, the fluxes derived from these experiments are less than the estimated flux from streams to lakes and probably represent minima. Aeolian redistribution of local soils is important because they are the only source of new solutes and nutrients to the aquatic ecosystem of the MDV

A Preliminary Assessment of the Potential Application of Glaciochemical Investigations on Heard Island, South Indian Ocean

Analyses of fluoride, chloride, sodium, sulfate, bromide. nitrate, and iron from a 3 m snow pit on Heard Island, collected at an elevation of 2450, m are used to assess the potential of glaciochemical studies on Heard Island glaciers. Sources Cor the chemical species are identified and, in particular, chloride, sodium, and sulCate are found to be useful seasonal indication. The total record measured is believed to be less than one mass-balance year