The increasing resolution of atmospheric models, and the use of ``tiling'' to represent multiple land surfaces within a grid box, mean that a rapidly increasing number of lakes must be observed, and modelled, if their regional climate impact is to be represented. Retrievals of lake surface temperature and ice cover using the Along Track Scanning Radiometer 2 (ATSR2) are presented.

Radiative transfer modelling results suggest that the sea surface temperature retrieval algorithm used is sufficiently accurate for lake altitudes up to 4000m. However, lakes frequently have large temperature gradients across their relatively small areas and this makes cloud clearing more difficult than over oceans. The modifications made to the standard cloud detection algorithm are presented. Ice detection uses a comparison of near infra-red (1.6 micron) and visible reflectances, but this is not straightforward for images with low solar elevations angles. To make maximum use of the retrievals a lake model that resolves the variations over the lake may be used, as for any one retrieval only a small part of a lake is normally visible.