Thermal structure of intense convective clouds derived from GPS radio occultations 1DTU Space, National Space Institute, Copenhagen, Denmark
18 Jun 2012
2NCAR, National Center for Atmospheric Research, Boulder CO, USA
3NCAR-UCAR/COSMIC, Boulder CO, USA
4DMI, Danish Meteorological Institute, Copenhagen, Denmark
Received: 19 September 2011 – Published in Atmos. Chem. Phys. Discuss.: 27 October 2011 Abstract. Thermal structure associated with deep convective clouds is investigated
using Global Positioning System (GPS) radio occultation measurements. GPS
data are insensitive to the presence of clouds, and provide high vertical
resolution and high accuracy measurements to identify associated temperature
behavior. Deep convective systems are identified using International
Satellite Cloud Climatology Project (ISCCP) satellite data, and cloud tops
are accurately measured using Cloud-Aerosol Lidar with Orthogonal
Polarization (CALIPSO) lidar observations; we focus on 53 cases of
near-coincident GPS occultations with CALIPSO profiles over deep convection.
Results show a sharp spike in GPS bending angle highly correlated to the top
of the clouds, corresponding to anomalously cold temperatures within the
clouds. Above the clouds the temperatures return to background conditions,
and there is a strong inversion at cloud top. For cloud tops below 14 km,
the temperature lapse rate within the cloud often approaches a moist adiabat,
consistent with rapid undiluted ascent within the convective systems.
Revised: 31 March 2012 – Accepted: 02 June 2012 – Published: 18 June 2012
Citation: Biondi, R., Randel, W. J., Ho, S.-P., Neubert, T., and Syndergaard, S.: Thermal structure of intense convective clouds derived from GPS radio occultations, Atmos. Chem. Phys., 12, 5309-5318, doi:10.5194/acp-12-5309-2012, 2012.