Ice sheets and nitrogen

Wolff, Eric W.. 2013 Ice sheets and nitrogen. Philosophical Transactions of the Royal Society (B), 368 (1621). 10.1098/rstb.2013.0127

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Abstract/Summary

Snow and ice play their most important role in the nitrogen cycle as a barrier to land–atmosphere and ocean–atmosphere exchanges that would otherwise occur. The inventory of nitrogen compounds in the polar ice sheets is approximately 260 Tg N, dominated by nitrate in the much larger Antarctic ice sheet. Ice cores help to inform us about the natural variability of the nitrogen cycle at global and regional scale, and about the extent of disturbance in recent decades. Nitrous oxide concentrations have risen about 20 per cent in the last 200 years and are now almost certainly higher than at any time in the last 800 000 years. Nitrate concentrations recorded in Greenland ice rose by a factor of 2–3, particularly between the 1950s and 1980s, reflecting a major change in NOx emissions reaching the background atmosphere. Increases in ice cores drilled at lower latitudes can be used to validate or constrain regional emission inventories. Background ammonium concentrations in Greenland ice show no significant recent trend, although the record is very noisy, being dominated by spikes of input from biomass burning events. Neither nitrate nor ammonium shows significant recent trends in Antarctica, although their natural variations are of biogeochemical and atmospheric chemical interest. Finally, it has been found that photolysis of nitrate in the snowpack leads to significant re-emissions of NOx that can strongly impact the regional atmosphere in snow-covered areas.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	10.1098/rstb.2013.0127
Programmes:	BAS Programmes > Polar Science for Planet Earth (2009 - ) > Chemistry and Past Climate
ISSN:	0962-8436
Additional Keywords:	nitrogen, nox no, no2, n2o, ice sheet
NORA Subject Terms:	Meteorology and Climatology Chemistry
Date made live:	04 Jul 2012 07:10 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/18403

Item Type:

Publication - Article

Digital Object Identifier (DOI):

10.1098/rstb.2013.0127

Programmes:

BAS Programmes > Polar Science for Planet Earth (2009 - ) > Chemistry and Past Climate

ISSN:

0962-8436

Additional Keywords:

nitrogen, nox no, no2, n2o, ice sheet

NORA Subject Terms:

Meteorology and Climatology
Chemistry