Abstract
Abstract. Analyses of thermodynamic data gathered from airborne dropwindsondes during the Tropical Cyclone Structure (2008) experiment are presented for the disturbance that became Typhoon Nuri. Although previous work has suggested that Nuri formed within the protective recirculating "pouch" region of a westward propagating wave-like disturbance and implicated rotating deep convective clouds in driving the inflow to spin up the tangential circulation of the system-scale flow, the nature of the thermodynamic environment that supported the genesis remains a topic of debate. During the genesis phase, vertical profiles of virtual potential temperature show little variability between soundings on a particular day and the system-average soundings likewise show a negligible change. There is a tendency also for the lower and middle troposphere to moisten. However, the data show that, on the scale of the recirculating region of the disturbance, there was no noticeable reduction of virtual temperature in the lower troposphere, but a small warming (less than 1 K) in the upper troposphere. Vertical profiles of pseudo-equivalent potential temperature, θe, during the genesis show a modestly decreasing deficit of θe in the vertical between the surface and the height of minimum θe (between 3 and 4 km), from 17.5 K to 15.2 K. The findings reported here are consistent with those found for developing disturbances observed in the Pre-Depression Investigation of Cloud Systems in the Tropics (PREDICT) experiment in 2010. Some implications of the findings are discussed.
Highlights
Understanding the dynamics and thermodynamics of tropical cyclogenesis remains one of the great unsolved problems in tropical meteorology
One prominent study of tropical cyclogenesis in the eastern Pacific basin was that of Bister and Emanuel (1997; hereafter BE97), which was an outcome of the TEXMEX experiment
This work was carried out to determine the salient thermodynamic characteristics of the “pouch region” of developing Typhoon Nuri (2008) that was identified in Part 1
Summary
Understanding the dynamics and thermodynamics of tropical cyclogenesis remains one of the great unsolved problems in tropical meteorology. 3. Influenced by the results of the TEXMEX experiment, Raymond and Sessions (2007) proposed an alternative thermodynamic view of tropical cyclogenesis that is linked with the changes of the thermal stability of the tropical atmosphere (“warming at upper levels and cooling at low levels”, their page 3, right column). Influenced by the results of the TEXMEX experiment, Raymond and Sessions (2007) proposed an alternative thermodynamic view of tropical cyclogenesis that is linked with the changes of the thermal stability of the tropical atmosphere (“warming at upper levels and cooling at low levels”, their page 3, right column) They simulated a radiativeconvective equilibrium state in the absence of ambient rotation and in a two-dimensional (zonal-height) cloud-resolving model.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
