The JIFRESSE Regional Earth System Model and its application to air quality in California

In order for comprehensive assessments of the impact of global climate change on our society and ecosystems, the UCLA Joint Institute for Regional Earth System Science and Engineering (JIFRESSE) is developing a regional earth system model (RESM). The joint UCLA-JPL effort includes the development of a coupled regional atmosphere-land-ocean model. The core of the RESM is based on the Weather Research Model (WRF) for atmospheric processes, Simplified Simple Biosphere (SSiB) model for land-surface processes and the Regional Ocean Model (ROM) for coastal ocean processes. A suite of models for air pollution, hydrology, water resources, and ecosystem are to be added to the RESM in order to comprehensively assess the impact of climate change on regional sectors. This approach for the development of the JIFRESSE RESM attempts to balance physically- based simulations of important interactive processes within the climate system and the flexibility in the application of the RESM results to a variety of impact assessment studies. In line with the preceding objective, an air pollution model, the Community Multi-scale Air Quality (CMAQ) model, is currently used to assess the impact of regional climate elements on regional air quality - an aspect that is among the most important concerns in the assessment of the impact of future climate change on human and natural sectors. We will present preliminary results from the air quality assessment study in which the impact of anthropogenic emissions on air pollutants in Southern California will be investigated. Using the fine-resolution atmospheric forcing from the JIFRESSE RESM, the CMAQ model will be run with two sets of emission data, one for natural emission sources and the other for both natural and anthropogenic sources. Results from the two simulations will be differentiated to obtain the impact of anthropogenic emissions on air pollutants in California.