NAME grant report contribution

Using the three-dimensional S-Pol radar grids, we have been analyzing the intraseasonal variability in the microphysical structure of convection during NAME 2004.  In the Lang et al. (2007) study, two meteorological regimes were identified: A, in which there is enhanced rainfall over the Gulf of California and coastal plain; and B, in which there is enhanced northward propagation of precipitating systems.  These regimes often overlapped, and were distinct from the usual no-regime scenario which featured the diurnally forced convection only over the Sierra Madre Occidental (SMO).

During the intersection of Regimes A and B (henceforth called Regime AB), convection contains enhanced ice and water mass over the coastal plain and Gulf, but there is little change in these parameters over the SMO.  In addition, the heaviest rains over the Gulf feature smaller raindrop median volume diameters during Regime AB.  These drop-size distribution changes are significant enough to manifest themselves as changes in reflectivity-rainfall relationships, particularly over the Gulf.  Overall, the results support the conclusion that variability in meteorological regime affects the microphysical structure of convection in the NAME region, particularly at low elevations.

Journal Reference Updates

Lang, T. J., et al., 2009: On the correction of partial beam blockage in polarimetric radar data. Journal of Atmospheric and Oceanic Technology, 26, 943-957.

Nesbitt, S. W., D. Gochis, and T. J. Lang, 2008: The diurnal cycle of clouds and precipitation along the Sierra Madre Occidental during NAME-2004: Implications for warm season precipitation estimation in complex terrain. Journal of Hydrometeorology, 9, 728-743. (this is an update to our previous reference for this paper)

Conference Paper Updates

Lang, T. J., et al., 2008: Polarimetric radar analysis of convection in northwestern Mexico. 28th Conference on Hurricanes and Tropical Meteorology, American Meteorological Society, Orlando, FL.

Lang, T. J., et al., 2007: Polarimetric radar analysis of convection in the complex topography of northwestern Mexico during NAME 2004. 6th Conference of Mesoscale Meteorology and Typhoon in East Asia, Taipei, Taiwan.

Website

http://radarmet.atmos.colostate.edu/name