GNSS Radio Ocultation: a tool for Climate Investigations

Paper number

IAC-15,B1,IP,37,x31219

Author

Dr. Francesco Vespe, Agenzia Spaziale Italiana (ASI), Italy

Coauthor

Dr. Catia Benedetto, Agenzia Spaziale Italiana (ASI), Italy

Year

2015

Abstract

Tropopause is a transition layer between the troposphere and the stratosphere. The exchanges of air mass, water vapor, trace gas and energy between the troposphere and the stratosphere occur through this layer. Accurate and continuous observations of the tropopause heights on a global scale are crucial for monitoring stratosphere-troposphere exchange and understanding the balance of atmospheric tracers in the upper troposphere and lower stratosphere. In our work, we propose  to measure  tropopause by using  bending angles (BA) profiles provided by the Radio Occultation technique applied using Global Navigations Satellite Systems. The proposed method fits the BA profiles with the dry  Hopfield model. Through  the layers in which  tropopause is contained,  the residuals have an anomalous trend. The plot of residuals in this zone form indeed a positive bump that we will try to exploit just to determine the relevant parameters of the tropopause.  We will use the huge amount of data provided by several space missions devoted to RO (COSMIC, METOP, GRACE etc.) for tuning the algorithms, perform a validation of the approach and compare our results with those achieved applying different  techniques. Furthermore an analysis of GNSS-RO tropopause behavior on global scale in the period 2006-2011 will be performed in order to detect climate signatures.
Finally with  the same GNSS-RO observations  we have reconstructed the Mapping Function in the same fashion, commonly applied in geodetic applications.
 We deem that the global  mapping function built with GNSS-RO  and its evolution in time can be  a parameter suitable for  climate investigations as well

Abstract document

IAC-15,B1,IP,37,x31219.brief.pdf

Manuscript document

IAC-15,B1,IP,37,x31219.pdf (🔒 authorized access only).

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