Satellite and Aircraft Observations of the Eyewall Replacement Cycle in Typhoon Sinlaku (2008)

Abstract

Satellite and aircraft observations of the concurrent evolution of cloud-top brightness temperatures (BTs) and the surface and flight-level wind fields were examined before and during an eyewall replacement cycle (ERC) in Typhoon Sinlaku (2008) as part of The Observing System Research and Predictability Experiment (THORPEX) Pacific Asian Regional Campaign (T-PARC) and the Tropical Cyclone Structure 2008 (TCS08) field campaign. The structural evolution of deep convection through the life cycle of the ERC was clearly evident in the radial variation of positive water vapor (WV) minus infrared (IR) brightness temperature differences over the 96-h period. Within this framework, the ERC was divided into six broadly defined stages, wherein convective processes (including eyewall development and decay) were analyzed and then validated using microwave data. Dual maxima in aircraft wind speeds and geostationary satellite BTs along flight transects through Sinlaku were used to document the temporal evolution of the ERC within the TC inner core. Negative correlations were found between IR BTs and surface wind speeds, indicating that colder cloud tops were associated with stronger surface winds. Spatial lags indicated that the strongest surface winds were located radially inward of both the flight-level winds and coldest cloud tops. Finally, timing of the ERC was observed equally in IR and WV minus IR (WVIR) BTs with one exception. Decay of the inner eyewall was detected earlier in the WVIR data. These findings highlight the potential utility of WVIR and IR BT radial profiles, particularly so for basins without active aircraft weather reconnaissance programs such as the western North Pacific.

The role of ocean‐atmosphere interaction in Typhoon Sinlaku (2008) using a regional coupled data assimilation system

“…Typhoon Sinlaku (2008) is taken up as a case example in this study. Sinlaku was intensively observed under The Observing System and Predictability Experiment (THORPEX) Pacific Asian Regional Campaign (T‐PARC) [ Elsberry and Harr , ; Chou et al ., ; Harnisch and Weissmann , ; Weissmann et al ., ; Wu et al ., ; Sanabia et al ., ]. During the observational campaign, abundant flight observations from the four aircrafts were conducted along with conventional radiosondes (Figure ) to address major scientific issues such as structure change, target observations, and extratropical transition [ Wu et al ., ].…”

Satellite Imagery-Based Cloud Classification Using Deep Learning

“…The information in satellite cloud images regarding clouds, the atmosphere, and the seas is gathered by weather satellites. Weather satellites are crucial for weather analysis and meteorological catastrophe alerts since they are mainly used to observe Earth's weather conditions [17]. Research on weather forecasting has been conducted by meteorologists utilizing numerical weather prediction (NWP) [18].…”

Inner‐Core Wind Field in a Concentric Eyewall Replacement of Typhoon Trami (2018): A Quantitative Analysis Based on the Himawari‐8 Satellite

“…After the SEF, TCs often experience an eyewall replacement cycle (ERC). In an ERC, the primary inner eyewall gradually dissipates and the secondary outer eyewall contracts (e.g., Black & Willoughby, 1992; Houze et al., 2007, 2006; Sanabia et al., 2015; Sitkowski et al., 2011; Yang et al., 2013). Coincided with the ERC, the maximum wind speed and radius of maximum wind speed (RMW) in TCs rapidly change (e.g., Black & Willoughby, 1992).…”