Detailed horizontal and vertical structures of a typhoon core area captured by radiosonde launches at the interval of one hour from a research vessel
Abstract
Three-dimensional thermodynamic and dynamic structures of the central region of a typhoon have been still in veiled because of the difficulty of the direct measurement launched by radiosondes under a severe weather condition in the typhoon. We observed the central region of Typhoon Meari by GPS radiosonde from a research vessel at a bay of a small island in the East China Sea with the time interval of about one hour for about a half-day in 2011. During the launches, the central region of the typhoon passed over the research vessel when the central pressure of the typhoon was the minimum in this typhoon life time. The continuous launches revealed the detailed horizontal and vertical structures from near the center of the typhoon to about 200km far from the center and from the surface to the lower stratosphere. In the lower troposphere near the center of typhoon, there was a warm and dry core in the altitudes of about 2000m to 4000m. In addition, in about 2000m, outward flow was observed. The strongest tangential cyclonic flow was observed at 500m high. Three force terms, i.e., the pressure gradient force, the Coriolis force and the centrifugal force, were estimated by the observed wind and pressure distribution. In the outflow area, centrifugal force overwhelmed the inward pressure gradient force, and Corioli's force was the smallest of the three. Outflow was also observed just below the tropopause. The observed absolute angular momentum profile of this typhoon signifies the existence of subsidence over the warm and dry core. The observation indicates that some dynamic and thermodynamic structures of the typhoon are different from those of representative observations or numerical models.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2013
- Bibcode:
- 2013AGUFM.A13F0292Y
- Keywords:
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- 3372 ATMOSPHERIC PROCESSES Tropical cyclones