scholarly journals NOx Release from Snow and Ice Covered Surface in Polar Regions and the Tibetan Plateau

2011 ◽  
Vol 2 (3) ◽  
pp. 141-148 ◽  
Author(s):  
Feng Wang ◽  
Weili Lin ◽  
Junxia Wang ◽  
Tong Zhu
2020 ◽  
Vol 9 (1) ◽  
pp. 231-250
Author(s):  
Birendra Prasad Sharma ◽  
Subash Adhikari ◽  
Ganesh Paudel ◽  
Namita Paudel Adhikari

Microorganisms, as successive members of the food web, play a major role in biological processes. They are found in environments ranging from extremely hot to harsh cold temperatures. Thus, the study of bacterial communities in various ecosystems is of great concern around the world. The glacier is one of the parts of the cryosphere, which is the key component and sensitive indicator of climatic and environmental changes. A glacial ecosystem is a habitat for various microorganisms, i.e., autotrophic and heterotrophic. Different physicochemical parameters like temperature, pH, electrical conductivity, the input of nutrient concentration, precipitation, ions concentrations, etc. influence the microbial diversity in the glacial ecosystem for their metabolic processes. Successive studies of bacterial communities in the Himalayan glacial ecosystem are reliable proxies to know the relationships between microbial biodiversity and climate change since the Himalayan glaciers are free from anthropogenic activities. After the study of the relevant literature, it is clear that the researches. have been carried out in the Polar Regions, and the Tibetan plateau mainly focused on the glacial ecosystem. This review concluded that Proteobacteria, Bacteroidetes, Cyanobacteria, Firmicutes, Verrucomicrobia, and Actinobacteria were the most dominant bacterial phyla via 16S rRNA clone libraries and Illumina MiSeq. Alter in landscapes, nutrient cycles, exposure of light, shifting on the concentration of different elements, glacier retreats were the major components for survival strength of dominant bacterial phyla. However, limited studies on the glacial ecosystem of the Himalayas have been published. Thus, the study of bacterial abundance, diversity, and community in the Himalayas will help plug this research gap.


2006 ◽  
Vol 43 ◽  
pp. 257-262 ◽  
Author(s):  
Baiqing Xu ◽  
Tandong Yao ◽  
Xianqin Liu ◽  
Ninglian Wang

AbstractIn this study, an optimized two-step heating-gas chromatography system is used to measure elemental carbon (EC) and organic carbon (OC) content in snow and ice, with the ability to quantify the elemental and organic carbon species in a snow or ice sample of 60−80 g. In this system, OC and EC are transformed into CO2 in a stream of oxygen at 340°C and 650°C, respectively. The resulting CO2 is accumulated in two molecular-sieve traps, and then put into a gas chromatograph equipped with a flame ionization detector by heating the traps to 200°C in a helium stream. Background contamination (mainly caused by impurities in the oxygen stream) and accuracy are dominated by the variability of the blank loads on the pre-cleaned filters, which are 0.50 ± 0.04 (1σ) μgC for OC, and 0.38 ± 0.04 (1σ) μgC for EC. The system is suitable for snow and ice sample measurements, with the same precision as shown for the blank tests. EC and OC concentrations have been measured in snow samples collected from different glaciers on the Tibetan Plateau. The results allow quantification for the first time of the different carbonaceous particle contents on the Tibetan Plateau and other regions. The concentrations of EC and OC particles in snow show a clearly decreasing trend from east to west and from north to south on the plateau, excluding the Pamirs region. The highest mean EC content, 79.2 ngg-1, was found in the northeast region, and the lowest, 4.3 ngg-1, was found in the western Himalaya. We note that even slight surface melting results in fresh snow getting dirtier, especially in regions with higher pollution such as seen on a glacier in the Qilian Shan. Here, the EC and OC concentrations in the fresh snow average 6.6 and 87.5 ngg-1, but after 2 days of surface melting they increased to 52.6 and 195.5 ngg-1. This suggests that surface snow melting can reduce snow albedo due to the accumulation of carbonaceous particles.


2021 ◽  
Author(s):  
Weili Lin ◽  
Feng Wang ◽  
Chunxiang Ye ◽  
Tong Zhu

Abstract. NOx is released from sunlit snowpack surfaces, and this significantly influences the oxidizing capacity of the clean boundary layer atmosphere and the potential interpretation on the historical atmospheric composition recorded in the ice core. The Tibetan Plateau is an important snow-covered region in the northern midlatitudes, with strong solar radiation and relatively high NO3− in snow/ice. Released NOx on the glacier surface of the Tibetan Plateau should have a higher concentration than in Antarctic and Arctic regions. To verify this hypothesis, field observations were carried out at 4600 m asl in Qiyi Glacier in late August 2004. In late August, the surface ultraviolet-B (UVB) radiation level at 4600 m asl in Qiyi Glacier reached >4.5 W/m2 and was increased by the strong reflection of snow/ice and clouds against the sun, and strengthened by the topographical effect. The concentrations of NO3− and NH4+ in water from melting snow were hardly detected, but the average concentration (±1σ) of NO3− in snow samples was 8.7 ± 2.7 μmol/L. Strong correlations were observed between NOx (NO2) mixing ratios and UVB radiation levels in the Tibetan glacier. Vertical experiments revealed a negative gradient of NOx (NO2) mixing ratios from the glacier snow surface to a height of 30 cm. As a result of the high levels of UV radiation and high NO3− concentrations in snow/ice, the mixing ratios of NOx released by fresh snow in Qiyi Glacier in late August reached to several parts per billion (ppbv) and were approximately 1 order of magnitude higher than those observed in polar regions. This observation provides direct evidence to support the research hypothesis and confirms that the release of high concentrations of NOx in the boundary layer of highland glaciers and snow surfaces.


2018 ◽  
Vol 10 (01) ◽  
pp. 1850003
Author(s):  
Tyler C. Tucker ◽  
Samuel S. P. Shen

This research develops a toolkit for snow-cover area calculation and display (SACD) based on the Interactive Multisensor Snow and Ice Mapping System (IMS). The paper uses the Tibetan Plateau region as an example to describe the toolkit’s method, results, and usage. The National Snow and Ice Data Center (NSIDC) provides to the public IMS a well-used system for monitoring the snow and ice cover. The newly developed toolkit is based on a simple shoe-lace formula for a grid box area on a sphere and can be conveniently used to calculate the total area of snow cover given the IMS data. The toolkit has been made available as an open source Python software on GitHub. The toolkit generates the time series of the daily snow-covered area for any region over the Northern Hemisphere from 4 February 1997. The toolkit also creates maps showing snow and ice coverage with an elevation background. The Tibetan Plateau (TP) region [Formula: see text]–[Formula: see text]N)[Formula: see text][Formula: see text]–[Formula: see text]E) is used as an example to demonstrate our work on SACD. The IMS products at 24, 4, and 1[Formula: see text]km resolutions include each grid’s latitude and longitude coordinates that are used to calculate the grid box’s area using the shoe-lace formula. The total TP area calculated by the sum of the areas of all the grid boxes approximates the true spherical TP surface area bounded by [Formula: see text]–[Formula: see text]N) [Formula: see text]–[Formula: see text]E) with a difference 0.046% for the 24[Formula: see text]km grid and 0.033% for the 4[Formula: see text]km grid. The differences in the snow-cover area reported by the 24[Formula: see text]km and 4[Formula: see text]km grids vary between [Formula: see text]% and 6.24%. The temporal variations of the daily TP snow cover are displayed in time series from 4 February 1997 to present with 4[Formula: see text]km and 24[Formula: see text]km resolutions.


2021 ◽  
Vol 754 ◽  
pp. 142248
Author(s):  
Keshao Liu ◽  
Tandong Yao ◽  
David A. Pearce ◽  
Nianzhi Jiao ◽  
Yonghui Zeng ◽  
...  

2021 ◽  
Author(s):  
Chaoliu Li ◽  
Fangping Yan ◽  
shichang kang

<p>Carbonaceous matter, including organic carbon (OC) and black carbon (BC), is an important climate forcing agent and contributes to glacier retreat in the Himalayas and the Tibetan Plateau (HTP). The HTP - the so-called “Third Pole” – contains the most extensive glacial area outside of the polar regions. Considerable research on carbonaceous matter in the HTP has been conducted, although this research has been challenging due to the complex terrain and strong spatiotemporal heterogeneity of carbonaceous matter in the HTP. A comprehensive investigation of published atmospheric and snow data for HTP carbonaceous matter concentration, deposition and light absorption is presented, including how these factors vary with time and other parameters. Carbonaceous matter concentrations in the atmosphere and glaciers of the HTP are found to be low. Analysis of water-insoluable organic carbon and BC from snowpits reveals that concentrations of OC and BC in the atmosphere and glacier samples in arid regions of the HTP may be overestimated due to contributions from inorganic carbon in mineral dust. Due to the remote nature of the HTP, carbonaceous matter found in the HTP has generally been transported from outside the HTP (e.g., South Asia), although local HTP emissions may also be important at some sites. This study provides essential data and a synthesis of current thinking for studies on atmospheric transport modeling and radiative forcing of carbonaceous matter in the HTP.</p>


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