FIGURE 2.2 Range of spatial scales addressed by the First ISLSCP Field Experiment (FIFE). SOURCE: Sellers et al. (1992). Courtesy of the American Geophysical Union.

NSF Arctic System Science program's Land-Atmosphere-Ice Interaction Study, and the importance of disturbance processes (such as large-scale fires) in land surface water and carbon exchange. They are also likely to make major contributions to understanding isotopic exchanges between ecosystems and the atmosphere. ²³ Completion of the final planned experiment, the Brazilian-led Large-Scale Biosphere Experiment in the Amazon, will lead to a broad understanding of ecosystem-climate interactions in boreal, temperate, and tropical ecosystems. This work has had, and will continue to have, a major impact on our understanding of paleoclimate, contemporary weather and climate, weather forecasting, and climate projections.²⁴

The need for comprehensive information on the land surface has also spawned a large effort to develop remote sensing algorithms for land surface variables. Major progress has been made in developing satellite algorithms to infer surface resistance to evaporation, temperature, soil moisture, and land cover.25 Experience