In this paper, we introduce a bending angle radio occultationclimatology (BAROCLIM) based on Formosat-3/COSMIC (F3C)data. This climatology represents the monthly-mean atmospheric statefrom 2006 to 2012. Bending angles from radio occultation (RO)measurements are obtained from the accumulation of the change in theraypath direction of Global Positioning System (GPS) signals. Bestquality of these near-vertical profiles is found from the middletroposphere up to the mesosphere. Beside RO bending angles we alsouse data from the Mass Spectrometer and Incoherent Scatter Radar(MSIS) model (modified for RO purposes) to expand BAROCLIM in a spectral model, which(theoretically) reaches from the surface up to infinity. Due to thevery high quality of BAROCLIM up to the mesosphere, it can be usedto detect deficiencies in current state-of-the-art analysis andreanalysis products from numerical weather prediction (NWP) centers.For bending angles derived from European Centre for Medium-RangeWeather Forecasts (ECMWF) analysis fields from 2006 to 2012, e.g.,we find a positive bias of 0.5 to 1% at40 km, which increases to more than 2% at50 km. BAROCLIM can also be used as a priori information inRO profile retrievals. In contrast to other a priori information(i.e., MSIS) we find that the use of BAROCLIM better preserves themean of raw RO measurements. Global statistics of statisticallyoptimized bending angle and refractivity profiles also confirm thatBAROCLIM outperforms MSIS. These results clearly demonstrate theutility of BAROCLIM.
展开▼
