Acidifying and Eutrophying Pollutants
Concentrations:model and measurements
| Depositions
| Exceedences
| Comparisons:measurements vs model
| Trends
| Model descriptions
| About
Concentrations in 1999 are available as modelled data computed by the EMEP
Eulerian acid deposition model and measurement data ordered by station from
1977.
Depositions in 1999 are available as modelled data computed by the EMEP
Eulerian acid deposition model and reported data as deposition maps country
by country.
Yearly accumulated exceedance of acidity and nutrient critical loads in 1999
and old trends for sulphur, nitrogen and area of exceedance of critical loads
per country from 1985-1998 are also available.
Scatterplots showing comparisons between measured and modelled data in 1999
for sulphur dioxide and nitrogen dioxide in air are the most representable
components. There is also a table showing the 1999 EMEP Eulerian deposition
model performance against observations as presented in the
EMEP Summary Report 1/01.
Concentrations: model and measurements
Depositions:
|
EMEP Eulerian acid deposition model 1999 |
S
mg/m2/yr
oxN
mg/m2/yr
NHx mg/m2/yr
|
|
Detailed reports per country - Depositions 1999 |
S/oxN/NHx
|
|
Exceedences:
Comparisons of measured versus computed concentration:
| based on the EMEP Eulerian acid deposition model for 1999 |
SO2
NO2
|
| Table of the 1999 EMEP Eulerian deposition model performance against observations |
Comp99
|
|
Trends:
| Detailed reports per country - Exceedences and trends 1985-1998 |
S/N
|
|
Model descriptions:
Acidifying and eutrophying pollutants
Acidifying and eutrophying pollutants originate primarily from
anthropogenic emissions of sulphur dioxide (SO2),
nitrogen oxides (NOx) and ammonia (NH3
). Most of SO2 and NOx is
emitted to the atmosphere under the combustion of fossil fuel in electricity
generating power stations, industrial plants, residential heating, commercial
and service sectors. Road transport, shipping and aircraft are significant
sources of NOx emissions. NH3 emissions are related to
agricultural activities such as storage of manure, soil fertilising, animal
husbandry, etc.
When emitted to the atmosphere, acidifying and eutrophying
pollutants may remain in air for several days and therefore, be dispersed
and carried over long distances by winds. They can be transported across
national boundaries and cause damaging effects far from the source of
emission. Acidifying pollutants are removed from the atmosphere by wet
("acid rain") or dry (direct uptake by vegetation and surfaces) deposition.
Effects of acid deposition are widespread and appear in a number of ways,
including e.g. acidification of freshwater systems resulting in the loss of
fisheries, impoverishment of soils, damage to forests and vegetation,
corrosion of buildings, cultural monuments and materials. The man-made
gaseous sulphur and nitrogen emissions are precursors to the formation of
small particles (PM2.5) which impact human health.
Deposition of nitrogen-containing compounds also contributes to the
eutrophication ("excess nutrient enrichment") of terrestrial and marine
ecosystems. Their eutrophying effect is associated with increased leaching of
nitrogen to ground water, streams and lakes and changes in the forest
ecosystems leading to vegetation changes favouring nitrogen-tolerant species.
Until 1998, 2-D Lagrangian Acid
Deposition model was routinely used at EMEP/MSC-W. In 1999
3-D Eulerian Acid Deposition Model
(pdf format)
was applied to calculate air concentration and deposition fields for major
acidifying and eutrophying pollutants as well as their long-range transport
and fluxes across national boundaries.
Contact persons: hilde.fagerli@met.no and svetlana.tsyro@met.no
Last update: 2001-10-24