12,000

We have over 12,000 students, from over 100 countries, within one of the safest campuses in the UK

93%

93% of Lancaster students go into work or further study within six months of graduating

Home > Research > Publications & Outputs > Nitrogen and sulfur deposition on regional and ...
View graph of relations

« Back

Nitrogen and sulfur deposition on regional and global scales: a multimodel evaluation

Research output: Contribution to journalJournal article

Published

  • F. Dentener
  • J. Drevet
  • J. F. Lamarque
  • I. Bey
  • B. Eickhout
  • A. M. Fiore
  • D. Hauglustaine
  • L. W. Horowitz
  • M. Krol
  • U. C. Kulshrestha
  • M. Lawrence
  • C. Galy-Lacaux
  • S. Rast
  • D. Shindell
  • D. Stevenson
  • T. Van Noije
  • C. Atherton
  • N. Bell
  • D. Bergman
  • T. Butler
  • J. Cofala
  • B. Collins
  • R. Doherty
  • K. Ellingsen
  • J. Galloway
  • M. Gauss
  • V. Montanaro
  • J. F. Mueller
  • G. Pitari
  • J. Rodriguez
  • M. Sanderson
  • F. Solmon
  • S. Strahan
  • M. Schultz
  • K. Sudo
  • S. Szopa
???articleNumber???GB4003
Journal publication date28/10/2006
JournalGlobal Biogeochemical Cycles
Journal number4
Volume20
Number of pages21
Pages-
Original languageEnglish

Abstract

[1] We use 23 atmospheric chemistry transport models to calculate current and future (2030) deposition of reactive nitrogen (NOy, NHx) and sulfate (SOx) to land and ocean surfaces. The models are driven by three emission scenarios: ( 1) current air quality legislation (CLE); ( 2) an optimistic case of the maximum emissions reductions currently technologically feasible ( MFR); and ( 3) the contrasting pessimistic IPCC SRES A2 scenario. An extensive evaluation of the present-day deposition using nearly all information on wet deposition available worldwide shows a good agreement with observations in Europe and North America, where 60 - 70% of the model-calculated wet deposition rates agree to within +/- 50% with quality-controlled measurements. Models systematically overestimate NHx deposition in South Asia, and underestimate NOy deposition in East Asia. We show that there are substantial differences among models for the removal mechanisms of NOy, NHx, and SOx, leading to +/- 1 sigma variance in total deposition fluxes of about 30% in the anthropogenic emissions regions, and up to a factor of 2 outside. In all cases the mean model constructed from the ensemble calculations is among the best when comparing to measurements. Currently, 36 - 51% of all NOy, NHx, and SOx is deposited over the ocean, and 50 - 80% of the fraction of deposition on land falls on natural (nonagricultural) vegetation. Currently, 11% of the world's natural vegetation receives nitrogen deposition in excess of the "critical load'' threshold of 1000 mg(N) m(-2) yr(-1). The regions most affected are the United States (20% of vegetation), western Europe ( 30%), eastern Europe ( 80%), South Asia (60%), East Asia 40%), southeast Asia (30%), and Japan (50%). Future deposition fluxes are mainly driven by changes in emissions, and less importantly by changes in atmospheric chemistry and climate. The global fraction of vegetation exposed to nitrogen loads in excess of 1000 mg(N) m(-2) yr(-1) increases globally to 17% for CLE and 25% for A2. In MFR, the reductions in NOy are offset by further increases for NHx deposition. The regions most affected by exceedingly high nitrogen loads for CLE and A2 are Europe and Asia, but also parts of Africa.