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Using CHAMP radio occultation data to determine the top altitude of the Planetary Boundary Layer
Author(s) -
von Engeln Axel,
Teixeira João,
Wickert Jens,
Buehler Stefan A.
Publication year - 2005
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2004gl022168
Subject(s) - radio occultation , altitude (triangle) , latitude , planetary boundary layer , boundary layer , longitude , meteorology , atmospheric sciences , ionosphere , environmental science , remote sensing , geology , geodesy , physics , mathematics , geophysics , geometry , turbulence , thermodynamics
A simple approach to derive the Planetary Boundary Layer (PBL) top altitude from CHAMP (CHAllenging Minisatellite Payload) radio occultation (RO) data is presented. Our RO processing cuts off at an altitude, typically ≤4 km, below which the GPS signals are affected by tracking errors. This lowest processed altitude (LPA) is assumed to coincide with the PBL top. We average LPAs for the years 2001 to 2004 over 5 Degree latitude longitude boxes and compare them to ECMWF analysis data. The ECMWF PBL top was calculated from the relative humidity gradient with respect to altitude. Agreement between the data sets is good in terms of mean PBL height, especially over sea. The CHAMP data shows the major features of PBL height with a realistic transition from stratocumulus regions to shallow and deep cumulus areas. CHAMP also shows a substantial amount of PBL height variability that may prove useful to study PBL dynamics.