FAIRMODE: A FORUM FOR AIR QUALITY MODELLING IN EUROPE

FAIRMODE (Forum for AIR quality MODelling in Europe) is an air quality modelling network that was established as a joint initiative of the European Environment Agency (EEA) and European Commission’s Joint Research Centre (JRC). In a common effort EEA and JRC aim at responding to the requirements of the new Air Quality Directive, with particular focus on the introduction of modelling as a necessary tool for air quality assessment and air quality management. The main aim of the modelling network is to bring together air quality modellers and model users in order to promote and support harmonised use of modelling for the assessment of air quality by EU and EEA member countries. The network will thus encourage synergy – at a local, national and European level - through the development and implementation of a common infrastructure based on best practices for reporting and storing information relevant to air quality modelling. A major objective of the FAIRMODE initiative is to provide guidance to present and future air quality model users in EEA’s EIONET partnership network. FAIRMODE also aims to enhance awareness of model usefulness, reliability and accuracy through model validation and intercomparison exercises at a national or European level. The JRC has taken on a leading role in the co-ordination of the latter activities gaining from its experience in leading the “Eurodelta” and “CityDelta” intercomparison exercises. A centralised web portal has been created in support of FAIRMODE, which is currently being used for internal communication purposes of the network participants, but will also provide the means for exchange of relevant material and experiences between all interested modellers and model users. The initial activities of the network will be organised by two main Work Groups, focusing on the preparation of a Guidance Document for model use and on model QA/QC procedures (input data, other uncertainties) respectively. The progress of the preparation of these documents as well as of the rest of the regular activities of the network will be reviewed and discussed within the frame of annual Plenary meetings and Steering Committee meetings

CLIMEX project: Response of runoff chemistry after 2 years of elevated CO2 and temperature

CLIMEX is an integrated, whole-ecosystem research project studying the response of entire forested catchments to increased CO2 and temperature. KIM catchment receives clean rain, elevated CO2 and elevated air temperature. EGIL catchment receives ambient acid rain and soil warming. During the first 2 years of treatment (April 1994 - April 1996) runoff from both catchments had increased concentrations of nitrate and ammonium relative to undtreated reference catchments and to pre-treatment period. Increased loss of nitrogen from the systems may be due to increased decomposition of soil organic matter induced by the higher temperatures. This increase might lead to acidification in acid-sensitive freshwaters.European Commissio

Deposisjon av fosfor i Norge - status, vurdering av behovet for kartlegging og forslag til gjennomføring. Forprosjekt

I Norge blir det idag ikke gjennomført overvåking av atmosfærisk fosfordeposisjon. De koeffisientene som brukes idag er basert på eldre målinger med variabel metodikk. Undersøkelser viser at der nedbørfeltet er lite i forhold til innsjøens overflate, kan P-deposisjonen spille en avgjørende betydning. Videre viser undersøkelser en klar årstidsvariasjon med høyest konsentrasjoner om sommeren og lavest konsentrasjoner om vinteren. De regionale koffisientene som brukes idag ser ut til å ligge høyere enn det som er observert i andre skandinaviske land. Det anbefales å måle P-deposisjonen både for tørr- og våtdeposisjon på utvalgte steder i Norge gjennom en årssyklus. Det bør også studeres i hvilken grad deposisjonen av fosfor påvirker algeveksten i vassdrag og på land, og mer generelt hvordan fosfordeposisjonen kan virke inn på forsuring og eutrofiering i ferskvann.Norsk institutt for vannforskning (NIVA) Norsk institutt for luftforskning (NILU

Measured and modelled retention of inorganic sulfur in soils and subsoils (Harz Mountains, Germany)

Atmospheric deposition has resulted in an accumulation of inorganic sulfur (S) in many forest soils. At Sosemulde (Hart Mountains) samples from 5-240 cm depth were analysed. Most sulfate (SO4) is accumulated at about 30-60 cm depth: 8.5-9.5 mmol(c) kg(-1). Large amounts can also be retained in < 100 cm. To assess changes in SO4 dynamics in time,adsorption isotherms have been included in several process-oriented models, e.g., in MAGIC. The Lange Bramke (LB) Model is the first model used on the catchment scale containing solubility products for the hydroxosulfate minerals jurbanite and alunite. By reconstructing the long-term acidification history (140 years) both models were successfully calibrated to a 14-year deposition, soil and streamwater data set at Lange Bramke catchment (Harz Mountains). According to MAGIC the present accumulation of SO4 in 0 - 80 cm is 8.7 mmol(c) kg(-1), while according to the LB-Model 10.2 mmol(c) kg(-1) are stored as jurbanite. Both models predicted 4.5 mmol(c) kg(c) SO4 in the subsoil layer, retained as alunite in the LB Model. These values correspond to the amounts measured in soil and subsoil samples at Sosemulde, respectively. However, for future scenarios with decreasing S inputs the models show different developments in SO4 concentrations. Changes in MAGIC are gradual whereas the LB model predicts stepwise decreasing SO4 values as soon as previously stored hydroxosulfates are fully dissolved. Such concentration "jumps" have not been observed

Reversibility of Soil Acidification by Reduction of Acid Input: An Experiment with Undisturbed Soil Columns

The acidification of soils has affected many forest ecosystems in the industrialized regions of the world. Data from ion budget studies indicate that there may be a remarkable retention of inorganically bound sulfate in these soils. It remains uncertain how previously adsorbed sulfate will react when sulfur loading is decreased. In this regard, desorption of previously adsorbed SO42- may affect the sulfate concentration in the soil solution

Describing soil SO42- dynamics in the Solling roof project with 4 two different modelling approaches

The release of previously stored soil SO42- is tightly connected with the reversibility of soil and water acidification. Thus soil SO42- dynamics have to be included when predicting the reversibility acidification. Our aim was to compare two modelling approaches: The model MAGIC (Cosby ct at, 1985) describes SO42- dynamics with the Langmuir sorption isotherme. In the SO-MODEL (Prenzel, 1991) a precipitation/dissolution of jurbanite is defined. Even though it was possible to calibrate both models to lysimeter data of the Selling D1 site in 1 m depth, the prognosis for SO42- concentrations in the soil solution differed significantly. While MAGIC predicted the observed gradual decrease of SO42- concentration with decreasing deposition, the SO-MODEL calculated stable concentrations up to the year 2026 followed by a sudden drop. Because the prognosis established with the SO-MODEL is incompatible with observed field data, we concluded that the predicted SO42- dynamic of the SO-MODEL was unrealistic

The Nine year report: Acidification of surface water in Europe and North America. Long-term Developements (1980s and 1990s) (ICP Waters report)

The International Cooperative Programme on Assessment and Monitoring of Acidification of Rivers and Lakes (ICP Waters) is designed to assess the degree and geographical extent of acidification of surface waters. During the last ten years international emission reduction measures in Europe and Northe America have resulted in a decrease in atmospheric sulphur deposition of up to 50%. Nitrogen deposition has stayed almost constant. Trends in surface water chemistry at the ICP Waters sites were calculated by applying the Nonparametric Seasonal Kendal Test and, on a regional scale, by Trend Meta-Analyses. Empirical relationships between nitrogen deposition and stages of nitrogen saturation were used to assess the importance of nitrogen leaching at the sites. To show effects of acidification on aquatic fauna (geographic extent and long-term trends) presence/absence studies, acidification indexes and correlation analysis were used. Trends in water chemistry indicate that sulphate concentrations are decreasing at almost all ICP Waters sites, and in almost all cases the decreases in the 1990s are larger than in the 1980s. This is partly also reflected in a recovery of the invertebrate fauna at many sites. Decreasing sulphate concentrations emphasize the importance of nitrate as the second important acidifying anion. Besides nitrogen deposition, the overall nitrogen status of ecosystems, changes in climate extremes and hydrology can have strong influences on leaching of excess nitrate (and ammonium) from a watershed.Norwegian Pollution Control Authority-SF