The genesis of Typhoon Nuri as observed during the Tropical Cyclone Structure 2008 (TCS08) field experiment – Part 2: Observations of the convective environment 1Department of Meteorology, Naval Postgraduate School, Monterey, CA & NOAA's Hurricane Research Division, Miami, FL, USA
04 May 2012
2Meteorological Institute, University of Munich, Munich, Germany
Received: 11 August 2011 – Published in Atmos. Chem. Phys. Discuss.: 23 November 2011 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.
Revised: 14 February 2012 – Accepted: 22 March 2012 – Published: 04 May 2012
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
Citation: Montgomery, M. T. and Smith, R. K.: The genesis of Typhoon Nuri as observed during the Tropical Cyclone Structure 2008 (TCS08) field experiment – Part 2: Observations of the convective environment, Atmos. Chem. Phys., 12, 4001-4009, doi:10.5194/acp-12-4001-2012, 2012.