Preliminary evaluation of CESM 1.0 20th century and select future climate runs within the Intra-Americas Sea region

Several studies point out the critical role that orography plays in present day mid-latitude and tropical storm tracks. Recent work also suggests that the Madden-Julian Oscillation (MJO) and Caribbean low-level jet (CLLJ) influence storm track activity within the IAS, including eastern N. Pacific and N. Atlantic tropical cyclone activity. Studies of tropical storm tracks for the projected warmer conditions of the 21st century find reduced storm track activity in the N. Atlantic and a shift of the eastern N. Pacific storm track southward. The intensity of tropical storms overall appears to remain unchanged in studies that have accounted for a mean shift in the tropical mean sea surface pressure due to warmer temperatures. However, storm intensity is more dependent on model resolution than storm frequency making these predictions more difficult. We present preliminary analyses of the Community Earth System Model (CESM) 1.0 20th century and future climate runs to examine the general characteristics of the tropical storm track in the IAS during boreal summer for both the 1979-2005 and 2005-2100 time periods. Future analyses will dynamically downscale these, as well as other AR5 future climate runs, to assess changes in the location of the tropical storm track in the region and any affects on tropical storm frequency and intensity.