R.W. Shaw

Grid point surface air temperature calculations with a fast turnaround: Combining the results of IMAGE and a GCM

This paper describes a methodology that combines the outputs of (1) the Integrated Model to Assess the Greenhouse Effect (IMAGE Version 1.0) of the Netherlands National Institute of Public Health and Environmental Protection (RIVM) (given a greenhouse gas emission policy, this model can estimate the effects such as global mean surface air temperature change for a wide variety of policies) and (2) ECHAM-1/LSG, the Global Circulation Model (GCM) of the Max-Planck Institute for Meteorology in Hamburg, Germany. The combination enables one to calculate grid point surface air temperature changes for different scenarios with a turnaround time that is much quicker than that for a GCM. The methodology is based upon a geographical pattern of the ratio of grid point temperature change to global mean values during a certain period of the simulation, as calculated by ECHAM-1/LSG for the 1990 Scenarios A and D of the Intergovernmental Panel on Climate Change (IPCC). A procedure, based upon signal-to noise ratios in the outputs, enabled us to estimate where we have confidence in the methodology; this is at about 23% to 83% of the total of 2,048 grid points, depending upon the scenario and the decade in the simulation. It was found that the methodology enabled IMAGE to provide useful estimates of the GCM-predicted grid point temperature changes. These estimates were within 0.5K (0.25K) throughout the 100 years of a given simulation for at least 79% (74%) of the grid points where we are confident in applying the methodology. The temperature ratio pattern from Scenario A enabled IMAGE to provide useful estimates of temperature change within 0.5K (0.25K) in Scenario D for at least 88% (68%) of the grid points where we have confidence; indicating that the methodology is transferable to other scenarios. Tests with the Geophysical Fluid Dynamics Laboratory GCM indicated, however, that a temperature ratio pattern may have to be developed for each GCM. The methodology, using a temperature ratio pattern from the 1990 IPCC Scenario A and involving IMAGE, gave gridded surface air temperature patterns for the 1992 IPCC radiative-forcing Scenarios C and E and the RIVM emission Scenario B; none of these scenarios has been simulated by ECHAM-1/LSG. The simulations reflect the uncertainty range of a future warming.

Assessment of wet deposition monitoring in Atlantic Canada

The precipitation chemistry stations operating in the Atlantic Provinces during the period 1980–1982 were assessed by comparing their siting characteristics and sampling procedures with the criteria recommended by the Canadian Federal‐Provincial Research and Monitoring Coordinating Committee (RMCC). The data collected at these stations were also evaluated according to standards recommended by the Unified Deposition Data Base Committee. Only one quarter of the 32 stations satisfied all of these criteria. In addition, there is evidence to suggest that some of the laboratories experienced problems analysing for nitrate or pH. Therefore, producing a coherent region‐wide data set for the major ions in precipitation was not feasible. However, the qualifying measurements were adequate to indicate an excess sulphate deposition of slightly less than 20 kg ha−1 a−1 to most of the region, with less than 10 kg ha−1 a−1 to Labrador. Although this analysis was restricted to the monitoring in Atlantic Canada, the results are of broader relevance in illustrating the potential problems inherent in merging data from several networks.

Using Science to Develop and Assess Strategies to Reduce Acid Deposition in Europe

The Regional Acidification Information and Simulation (RAINS) model that has been developed at IIASA can be used to assess the environmental effects of a given pattern of emissions in Europe or, given an environmental target, develop cost-effective international emission reduction strategies. In this paper, the RAINS model has been used to assess the effect of emissions from the United Kingdom at four receptor points in the United Kingdom, southwestern Norway, southern Sweden and the German Democratic Republic. The United Kingdom is, of course, the dominant contributor to sulfur deposition in the UK and is the largest national contributor (outside of the substantial contribution of background sulfur) to deposition in southwestern Norway. It is not important for deposition in southern Sweden or the German Democratic Republic.

Adapting the Rains Model to Develop Strategies to Reduce Acidification in the USSR

RAINS (Regional Acidification Information and Simulation) is an integrated assessment model developed at IIASA to formulate and assess emission reduction strategies to reduce regional acidification in Europe. It consists of components to develop emission scenarios for sulfur and nitrogen, simulate atmospheric transport and deposition, and calculate ecological effects. The atmospheric transport component uses a source-receptor transfer matrix produced by the long range transport model of the Norwegian Meteorological Institute. The receptors are on a 150 × 150 km grid; emissions are aggregated by country. At the present time, emissions in RAINS can be varied only on a national basis; this has not been a hindrance for developing emission reduction strategies for the geographically small countries of western and central Europe, where the RAINS model has been very useful. However, an analysis in this paper shows that most of the deposition within the USSR comes from sources within the USSR itself. To develop meaningful strategies to reduce acid deposition within the USSR, the RAINS model must be modified such that the USSR is divided into several source regions.