Abstract
Part I of this two-part paper treats Tropical Rainfall Measuring Mission (TRMM) radar, passive microwave, and lightning observations in hurricanes individually. This paper (Part II) examines relationships between these parameters (and implications of the relationships). Quantitative relationships between lightning occurrence and 85-GHz brightness temperature, 37-GHz brightness temperature, and radar reflectivity in the mixed phase region are established separately for hurricane eyewall regions, inner rainband regions, and outer rainband regions; other tropical oceanic regions; and tropical continental regions. When any of the brightness temperature or radar parameters are held constant as controls, lightning is more frequent in hurricane outer rainbands than elsewhere over tropical oceans, and more frequent over continents than even in the outer rainbands. Reflectivity profiles associated with specific brightness temperatures are presented, demonstrating a link between high-altitude ice phase precipitation and 85-GHz scattering and a link between lower-altitude precipitation and 37-GHz scattering. Based on the combination of radar, passive microwave, and lightning observations, it is proposed that supercooled cloud water occurs preferentially in outer rainbands compared to other tropical oceanic precipitation. The suspected microphysical differences produce only subtle differences in the remote sensing parameters other than lightning.
Current affiliation: National Space Science and Technology Center, University of Alabama in Huntsville, Huntsville, Alabama
Corresponding author address: Daniel J. Cecil, National Space Science and Technology Center, University of Alabama in Huntsville, 320 Sparkman Dr., Huntsville, AL 35805. Email: Daniel.Cecil@msfc.nasa.gov