Shedding light on the adaptive infrared iris hypothesis Academic Article uri icon


  • Visible and Infrared Scanner (VIRS) brightness temperature data and precipitation radar (PR) rain-rate data from the Tropical Rainfall Measuring Mission (TRMM) were used to investigate the suggested mechanism of the adaptive infrared iris hypothesis. The relationship between the size of convective clouds, their precipitation, and the underlying sea surface temperatures (SSTs) was examined. Little evidence of an iris effect for deep convection was found. When restricting the analysis to warm convective clouds with brightness temperatures above 270 K, a 5% decrease in cloud size normalized by rainfall with increasing SST was observed. Results suggest that interactions between precipitation and cloud amount with SST are acting on shallow, warm clouds not deep convection.

author list (cited authors)

  • Rapp, A. D., Kummerow, C., Berg, W., & Griffith, B.

publication date

  • December 2005