Preprints
https://doi.org/10.5194/tc-2021-32
https://doi.org/10.5194/tc-2021-32

  17 Feb 2021

17 Feb 2021

Review status: this preprint is currently under review for the journal TC.

Observation of strong NOx release over Qiyi Glacier, China

Weili Lin1, Feng Wang2, Chunxiang Ye3, and Tong Zhu3 Weili Lin et al.
  • 1College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China
  • 2China Everbright International Limited, Shenzhen 518040, China
  • 3BIC-ESAT and SKL-ESPC, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China

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.

Weili Lin et al.

Status: open (until 14 Apr 2021)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse

Weili Lin et al.

Weili Lin et al.

Viewed

Total article views: 127 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
104 21 2 127 13 0 0
  • HTML: 104
  • PDF: 21
  • XML: 2
  • Total: 127
  • Supplement: 13
  • BibTeX: 0
  • EndNote: 0
Views and downloads (calculated since 17 Feb 2021)
Cumulative views and downloads (calculated since 17 Feb 2021)

Viewed (geographical distribution)

Total article views: 124 (including HTML, PDF, and XML) Thereof 124 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 01 Mar 2021
Download
Short summary
Field observations found that released NOx on the glacier surface of the Tibetan Plateau, an important snow-covered region in the northern mid-latitudes, had a higher concentration than in Antarctic and Arctic regions. Such evidence, and such high fluxes as observed here on the Tibetan plateau is novel. That such high concentrations of nitrogen oxides can be found in remote areas is interesting and important for the oxidative budget of the boundary layer.