A Global Analysis of Human Impact on Nitrate Deposition
Abstract
Human activities impact the global nitrogen budget through fertilizer use, fossil fuel burning, and biomass burning. These activities release nitrogen oxides (NOx) to the atmosphere, much of which is converted to nitric acid and deposited in precipitation. Simulating reactive nitrogen transport and chemistry with the NOAA Geophysical Fluid Dynamics Laboratory Global Chemical Transport Model (GFDL GCTM), we determine the current contributions of natural [ ~10TgN/yr] and anthropogenic [ ~30TgN/yr] nitrogen oxide emissions to nitrogen deposition. A comparison of simulated annual nitrate wet deposition with recent observations from 236 sites around the world finds that 175 agree within +-50% with 30 significant outliers. The only systematic GCTM bias [+20%] was found over the U.S. After presenting a global analysis of human impact, we quantify specific source contributions for those regions most influenced by anthropogenic emissions.
- Publication:
-
AGU Spring Meeting Abstracts
- Pub Date:
- May 2001
- Bibcode:
- 2001AGUSM...H51C01L
- Keywords:
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- 0322 Constituent sources and sinks;
- 0330 Geochemical cycles;
- 1615 Biogeochemical processes (4805);
- 1803 Anthropogenic effects