Passive Microwave Quantification of Tropical Cyclone Inner-Core Cloud Populations Relative to Subsequent Intensity Change

Abstract

Characteristics of over 15 000 tropical cyclone (TC) inner cores are evaluated coincidentally using 37-and 85-GHz passive microwave data to quantify the relative prevalence of cold clouds (i.e., deep convection and stratiform clouds) versus predominantly warm clouds (i.e., shallow cumuli and cumulus congestus). Results indicate greater presence of combined liquid and frozen hydrometeors associated with cold clouds within the atmospheric column for TCs undergoing subsequent rapid intensification (RI) or intensification. RI episodes compared to the full intensity change distribution exhibit approximately an order of magnitude increase for inner-core cold cloud frequency relative to warm cloud presence. Incorporation of an objective ring detection algorithm shows the robust presence of rings associated with hydrometeors for 85-GHz polarization corrected temperatures (P 85 ) and 37-GHz vertically polarized brightness temperatures (V 37 ) for differentiating RI with significance levels $99.99%, while 37-GHz false color rings of a combined cyan and pink appearance surrounding a region that is not cyan or pink lack statistical significance for discriminating RI against lesser intensification. Rings of depressed P 85 and enhanced V 37 tied to RI suggest the combined presence of liquid and frozen hydrometeors within the atmospheric column, indicative of cold clouds. The V 37 rings also exhibit preferences for those with collocated more widespread P 85 ice scattering signatures to be more commonly associated with RI and general intensification.

Ice Water Content as a Precursor to Tropical Cyclone Rapid Intensification

“…Comparing different intensification rates in the same intensity category, the mean IWP becomes greater as the intensification rate increases. That is, rapidly intensifying TCs have the greatest mean IWP among all intensification rates, consistent with previous studies (Fischer et al, 2018; Harnos & Nesbitt, 2016). In addition, we repeated the same analysis for retrievals of IWC from CloudSat of 2C‐ICE version, which provides a better quality of IWC retrievals.…”

Rapid Intensification of Tropical Cyclones Observed by AMSU Satellites

“…Alvey et al (2015) showed that RI events have more symmetric distributions of precipitation prior to onset of intensification, as well as a greater overall areal coverage of precipitation. Harnos and Nesbitt (2016) found ©2019. American Geophysical Union.…”

“…Convective structure within the inner core of TCs also plays an important role in RI (Alvey et al, 2015;Harnos & Nesbitt, 2011;Fischer et al, 2018;Harnos & Nesbitt, 2016;Jiang, 2012;Jiang & Ramirez, 2013;Kieper & Jiang, 2012;Rogers et al, 2013;Rogers et al, 2015;Tao & Jiang, 2015;Tao et al, 2017;Zagrodnik & Jiang, 2014). Using long-term Tropical Rainfall Measurement Mission satellite data, Harnos and Nesbitt (2011) found that TCs undergoing RI have 85-GHz signatures depicting a moderately intense convective ring surrounding the storm center associated with low wind shear.…”

Potential Vorticity Mixing and Rapid Intensification in the Numerically Simulated Supertyphoon Haiyan (2013)

“…Namely, their results indicate that in the presence of a favorable environment for the TCs to intensify, there is no further distinction in synoptic conditions on whether a RI will occur or not. Harnos and Nesbitt (2016) and Tao and Jiang (2015) have suggested that the RI group of TCs also have a higher degree of axisymmetry in precipitation before and during RI. Moreover, airborne Doppler Supplemental information related to this paper is available at the Journals Online website: https://doi.org/10.1175/JAS-D-19-0219.s1.…”