[home]  [Publications]  [CP-ENSO]  [New CGCM]  [ENSO]  [Monsoon]  [Indian Dipole]  [PDO]  [TIW]  [Tropics-Extratropics]  [Cloud]  [Jetstream]  [Regional] [Gap Wind]

Professor Jin-Yi Yu
Department of Earth System Science
University of California, Irvine


John Farrara and Jin-Yi Yu


The goal of our research is to investigate the roles of land-surface vegetation, soil moisture content and topography, in regional hydrologic cycle and its interannual variability using satellite-observed land-surface data in conjunction with global and regional atmospheric models interactively coupled with advanced land-surface models (LSMs). We will focus on the effects of land-surface processes on regional hydrologic cycles in the United States, especially in the southwestern region, by nesting a regioanl-scale atmospheric model within the UCLA-AGCM. The focus of regional study includes a possible link between winter precipitation and summer monsoon through snow cover and SMC, the effects of local land-surface forcing in shaping the regional circulation, and the role of significant terrain (the Sierra Nevada and the Sierra Madre) in low-level moisture transport, in the southwestern US.

We have analyzed a 20-year simulation performed with the UCLA AGCM in which climatological SSTs are used as the lower boundary condition. The precipitation difference pattern produced by the AGCM between wet and dry summer monsoons are similar in many aspects to the observed. However, the simulated amplitudes are much smaller than the observed. Another AGCM simulation using observed SSTs as lower boundary condition produces similar results. Those preliminary results imply a significant role for the land-surface, including sub-grid topography.

Related Publications

  • Farrara, J. D. and J.-Y. Yu, 2003: Interannual variations in the North American monsoon and SST anomalies: A general circulation model study. Journal of Climate, 16, 1703-1720.
  • Yu, J.-Y., 2001: Identifications and applications of coupled climate models. Invited article in The Encyclopedia of Life Support Systems, EOLSS Publisher, Oxford, UK. In Press.
  • Yu, J.-Y., 2000: A general circulation model of the atmosphere using the full-Galerkin method. Journal of Mathematics and Computers in Simulation, 52, 427-443.
  • Farrara, J. D. and J.-Y. Yu, 2000: Interannual variability of the North American Monsoon: Preliminary results of a modeling study using the UCLA AGCM. Proceeding of US CLIVAR Pan American Principal Investigators Meeting. 6-8 September 2000, Potomac, Maryland, 34-34.

    [home]  [Publications]  [CP-ENSO]  [New CGCM]  [ENSO]  [Monsoon]  [Indian Dipole]  [PDO]  [TIW]  [Tropics-Extratropics]  [Cloud]  [Jetstream]  [Regional] [Gap Wind]