Capturing Size and Intensity Changes of Hurricanes Irma and Maria (2017) from Polar-Orbiting Satellite Microwave Radiometers

Abstract

A recently refined hurricane warm-core retrieval algorithm was applied to data from multiple polar-orbiting satellites that carry the Advanced Technology Microwave Sounder (ATMS) and the Advanced Microwave Sounding Unit-A (AMSU-A) to examine the diurnal variability of the warm cores of Hurricanes Irma and Maria. These hurricanes occurred during the 2017 hyperactive Atlantic hurricane season. Compared with data gathered by dropsondes within 100–1700 km of Hurricanes Irma and Harvey, the means and standard deviations of the differences between ATMS-derived and dropsonde-measured temperature profiles were less than 0.7 and 1 K, respectively, in the vertical layer between ~180 and 750 hPa. The temporal evolutions of the ATMS-derived and AMSU-A-derived maximum warm-core temperature anomalies followed more closely that of the minimum mean sea level pressure and slightly less closely that of the maximum sustained wind. The radii of the ATMS-derived warm cores at 4 and 6 K compared favorably with the 34- and 50-kt-wind radii, respectively, of Hurricane Irma (1 kt = 0.51 m s−1). The vertical extent of the warm core toward lower levels increased with increasing intensity when Hurricane Irma experienced a strong intensification because of an enhanced latent heat release associated with diabatic processes. The tropical cyclone (TC) inner cores at upper-tropospheric levels (~250 hPa) were characterized by a single-peaked diurnal cycle with a maximum around midnight. This warm-core cycle may be an important element of TC dynamics and may have relevance to TC structural and intensity changes.

Diurnal Variation of Overshooting Tops in Typhoons Detected by Himawari‐8 Satellite

“…Observations by multiple polar-orbiting satellites showed that the warm core of hurricane Maria (2017) at 250 hPa was stronger at night than during the day (Tian & Zou, 2018). To determine the possible impact of the typhoon warm core in the upper troposphere on OT occurrences, we analyzed the most prominent day-night contrast of the radial distribution of the OTD for RI typhoons.…”

Comparison of TC Temperature and Water Vapor Climatologies between the Atlantic and Pacific Oceans from GPS RO Observations

“…The results obtained in this study using COSMIC and MetOp-A/MetOp-B GPS RO-retrieved temperature and moisture to construct a climatology of the TC structures are complementary to those results obtained from other types of observations, such as polar-orbiting satellite microwave, geostationary satellite infrared, airborne radar, and aircraft dropsonde data. The TC warm-core temperature retrievals from satellite microwave temperature sounding observations are accurate in the upper troposphere but not good in the low and midtroposphere due to rain contamination in regions of heavy precipitation in TCs (Kidder et al 2000;Tian and Zou 2018).…”

The Intensification of Hurricane Maria 2017 in the Antilles

“…It is suspected that the simulation may not produce enough graupel in the upper clouds, even though the WSM6 scheme included graupel. [53] used satellite microwave sounders to measure Hurricane Maria's warm core anomaly and found upper tropospheric values of 8-12 °C from 19 to 25 September 2017. Hurricane Maria's structure was analyzed by cross sections on 66.5 W at 18Z 20 September (Figure 10a,b).…”

“…It is suspected that the simulation may not produce enough graupel in the upper clouds, even though the WSM6 scheme included graupel. [53]…”