2.   OVERALL AIMS OF RegClim

There are two overall aims of the project.

  • Overall aim I is to estimate probable changes in the regional climate in Northern Europe, bordering sea areas and major parts of the Arctic (“our region”), given a global climate change.

  • Overall aim II is to quantify, as far as possible, the significance of regional scale climate forcings pertaining specifically to our region.

The second includes processes determining relatively warm sea-surface-temperature (SST) and modest sea ice cover in the Nordic Seas (Overall aim IIa), and processes related to radiatively active atmospheric contaminants with a regional distribution (Overall aim IIb).

 

Climate in this connection encompass the statistical properties of the following elements:

  • air temperature

  •  precipitation amount

  • wind at 10m

  • sea state

  • (wave-height and sea-level)

Climate scenario projections of these parameters in our region will include estimations of typical seasonal variations, typical variations from year to year, and probable changes in severe weather conditions as defined by high wind speeds, large precipitation amounts and extreme sea state. We also aim at first estimates of inter-decadal variations by choosing situations with different modes of the North Atlantic Oscillation (NAO) index.

 

2.1     Major objectives and principal tasks

The project is separated into 9 Principal Tasks (PT), each with a main objective which is meant to yield a considerable contribution to the overall aims. Task 9 was included in the last extension of RegClim in December 2000. The following major objectives are specified for each Principal Task.

 

PT1.    Dynamical downscaling.

            To use a Regional Climate Model, in some cases coupled to a slab ocean model, to estimate the regional climate in Northern Europe and adjacent sea areas, given the best estimates of climate scenarios from a coupled Atmospheric-Oceanic GCM.

 

            Contributes mainly to Overall aim I.

 

PT2.    Basin scale ocean modelling of the Nordic Seas.

            To establish and validate a model tool for oceanic circulation and thermodynamics with focus on the Nordic Seas, but suitable for coupling to a global atmospheric model.

 

            Contributes mainly to Overall aim IIa.

 

PT3.    Empirical downscaling

            To establish empirically based climate change scenarios on regional and local scales, with resolution in time and space appropriate for further impact modelling.

 

            Contributes mainly to Overall aim I.

 

PT4.    The role of the Nordic Seas: Atmosphere-Ocean feedback

            To improve our understanding of the relative role of mechanisms influencing the Norwegian Atlantic Current, and to estimate its impact on sea-surface temperature (SST) and sea-ice the Nordic Seas and the climate in our region.

 

            Contributes mainly to Overall aim IIa.

 

PT5.    Indirect effects of aerosols

            To estimate indirect aerosol effects on the climate in our region, by linking aerosols to cloud microphysics, precipitation and cloud-radiation interaction.

 

            Contributes mainly to Overall aim IIb.

 

PT6.    Direct Climate Effects of Regional Contaminants

            To calculate the regional distribution of direct radiative forcing due to tropospheric ozone, sulphate and black carbon, and to estimate the effects on the climate of our region.

 

            Contributes mainly to Overall aim IIb.

 

PT7.    Air-ice-ocean interface processes and sea-state modelling

            To develop suitable dynamic boundary conditions for dynamical downscaling, to estimate the effect of atmospheric anomalies on the ocean circulation and hydrography, and to model the Nordic Seas climate with respect to storm surges and waves.

 

            Contributes to both, but mainly to Overall aim I.

           

PT8.    Data for Model Evaluation

            To establish links to data-sets for model-validation and to maintain an information page on availability of different data for model-validation in the project.

 

              Contributes to both overall aims.

 

PT9.    Advanced analysis and interpretation of climate model results and observations

            To detect forced and internal variability on different time-scales in the climate system with focus on our region, and to improve the physical interpretation of the non-linear dynamical interactions that cause the variability.

 

The major objectives and the contents of the principal tasks will be re-evaluated annually in connection with the progress reporting. This will secure a dynamic project in accordance with the progress of work.

 

2.2     Major milestones related to the IPCC third assessment report

This description defines a project to be finalized by the early year 2002, and major conclusions responding to the overall aims and the major objectives will have to wait until the end of the project. Some major intermediate results are, however, planned to appear well before the finalization. In particular several parts of RegClim are presently contributing results to the IPCC Third Assessment Report (TAR). Results reported by early autumn 1999 should be in due time for inclusion. RegClim are presently making scenario runs designed by some co-ordinating lead authors, which will be delivered and discussed in IPCC workshops (PT5 and 6).

 

Two scientists in RegClim (Prof. Ivar Isaksen and Dr.Gunnar Myhre) are elected lead authors of IPCC TAR.

 

The following major milestones for the end of 1999 was to:

*     Calculate present and projected climate in our region given the best estimate of the global climate for one mode of the North Atlantic Oscillation (NAO) index.


     Belongs to Tasks under PT1.

 

*     Obtain first results from empirical downscaling of global climate scenarios to scales suitable or input to impact modelling.


     Belongs to Tasks under PT3.

 

*     obtain first evaluations of the impacts of anomalies in SST and sea-ice in the Nordic Seas on the atmosphere, and vice versa the impacts of anomalous atmospheric states on circulations in the Nordic Seas.

 

Belongs to PT2, 4 and 7.

*     Evaluations of direct aerosol effects, and effects of tropospheric ozone on the climate in our region.


     Belongs to PT5 and 6.