Land Surface Modeling and Land–Atmosphere–Ocean Interaction Studies—A Historical Perspective (Centennial)

The challenges posed by global climate and environmental variability and change research and the desire to have models that accurately simulate climate and its responses to various forcings have motivated the continued development of land surface process models over the last several decades. In the late 1970s, field measurements started becoming available to support the development of parameterizations for key land surface processes such as turbulence, heat flux, and photosynthesis. Emerging in conjunction with the land model development and associated field measurements as well as environmental and climate concern was a strong interest in land/atmosphere interaction studies, which investigate how land condition changes and land surface variability feeds back on the atmosphere. These researches have evolved since the 1970s from sub-branches of biology, hydrology, ecology, and micro-meteorology dealing with small scale phenomena into an important facet of climate science itself. Modeling land surface processes at the large scale become an important component in Earth system modeling, and is now recognized as being critical to understanding the interactions between climate, the environment and ecosystems, and the global cycles of water, energy, and carbon. The interaction between these components is one of the major interdisciplinary research topics in Earth science today.

This presentation will briefly review the history of this development. For example, we will describe early community efforts addressing land surface model evaluation and land-climate interaction, including the Project for Intercomparison of Land Surface Parameterization Schemes (PILPS) and early research into the impacts on climate of land use and land cover change (LULCC). We will highlight in particular the broad suite of relevant efforts sponsored by the international Global Energy and Water Exchanges (GEWEX) program, showing results and conclusions from such projects as the GEWEX/Global Land-atmosphere Coupling Experiment (GLACE), the GEWEX/West African Monsoon Modeling and Evaluation (WAMME) project, and the GEWEX/GASS Initiative “Impact of initialized land temperature and snowpack on subseasonal to seasonal prediction (LS4P)”.

Recent analyses based on modeling and observational data are revealing that (1) land/atmosphere interaction can have remote, continental to global scale impacts and is thus not limited to local and regional scales; and (2) the interactions between the land, the atmosphere, and the ocean help guide climate and environmental variability and change. The presentation will touch on some of these more recent results.