RTTOV-gb v1.0 – updates on sensors, absorption models, uncertainty, and availability

D. Cimini; D. Cimini; J. Hocking; F. De Angelis; A. Cersosimo; F. Di Paola; D. Gallucci; S. Gentile; E. Geraldi; S. Larosa; S. Nilo; F. Romano; E. Ricciardelli; E. Ripepi; M. Viggiano; L. Luini; C. Riva; F. S. Marzano; F. S. Marzano; P. Martinet; Y. Y. Song; M. H. Ahn; P. W. Rosenkranz

doi:10.5194/gmd-12-1833-2019

Geoscientific Model Development (May 2019)

RTTOV-gb v1.0 – updates on sensors, absorption models, uncertainty, and availability

D. Cimini,
D. Cimini,
J. Hocking,
F. De Angelis,
A. Cersosimo,
F. Di Paola,
D. Gallucci,
S. Gentile,
E. Geraldi,
S. Larosa,
S. Nilo,
F. Romano,
E. Ricciardelli,
E. Ripepi,
M. Viggiano,
L. Luini,
C. Riva,
F. S. Marzano,
F. S. Marzano,
P. Martinet,
Y. Y. Song,
M. H. Ahn,
P. W. Rosenkranz

Affiliations

D. Cimini: National Research Council of Italy, Institute of Methodologies for Environmental Analysis, Potenza, 85050, Italy
D. Cimini: Center of Excellence CETEMPS, University of L'Aquila, L'Aquila, 67100, Italy
J. Hocking: Met Office, Exeter, UK
F. De Angelis: Center of Excellence CETEMPS, University of L'Aquila, L'Aquila, 67100, Italy
A. Cersosimo: National Research Council of Italy, Institute of Methodologies for Environmental Analysis, Potenza, 85050, Italy
F. Di Paola: National Research Council of Italy, Institute of Methodologies for Environmental Analysis, Potenza, 85050, Italy
D. Gallucci: National Research Council of Italy, Institute of Methodologies for Environmental Analysis, Potenza, 85050, Italy
S. Gentile: National Research Council of Italy, Institute of Methodologies for Environmental Analysis, Potenza, 85050, Italy
E. Geraldi: National Research Council of Italy, Institute of Methodologies for Environmental Analysis, Potenza, 85050, Italy
S. Larosa: National Research Council of Italy, Institute of Methodologies for Environmental Analysis, Potenza, 85050, Italy
S. Nilo: National Research Council of Italy, Institute of Methodologies for Environmental Analysis, Potenza, 85050, Italy
F. Romano: National Research Council of Italy, Institute of Methodologies for Environmental Analysis, Potenza, 85050, Italy
E. Ricciardelli: National Research Council of Italy, Institute of Methodologies for Environmental Analysis, Potenza, 85050, Italy
E. Ripepi: National Research Council of Italy, Institute of Methodologies for Environmental Analysis, Potenza, 85050, Italy
M. Viggiano: National Research Council of Italy, Institute of Methodologies for Environmental Analysis, Potenza, 85050, Italy
L. Luini: DEIB – Politecnico di Milano, IEIIT – CNR, Milan, Italy
C. Riva: DEIB – Politecnico di Milano, IEIIT – CNR, Milan, Italy
F. S. Marzano: Center of Excellence CETEMPS, University of L'Aquila, L'Aquila, 67100, Italy
F. S. Marzano: University of Rome La Sapienza, Rome, Italy
P. Martinet: CNRM, Université de Toulouse, Météo-France, CNRS, Toulouse, France
Y. Y. Song: School of Engineering, Ewha Womans University, Seoul, South Korea
M. H. Ahn: School of Engineering, Ewha Womans University, Seoul, South Korea
P. W. Rosenkranz: Massachusetts Institute of Technology, Cambridge, MA 02139, USA

DOI: https://doi.org/10.5194/gmd-12-1833-2019
Journal volume & issue: Vol. 12
pp. 1833 – 1845

Abstract

Read online

This paper describes the first official release (v1.0) of RTTOV-gb. RTTOV-gb is a FORTRAN 90 code developed by adapting the atmospheric radiative transfer code RTTOV, focused on satellite-observing geometry, to the ground-based observing geometry. RTTOV-gb is designed to simulate ground-based upward-looking microwave radiometer (MWR) observations of atmospheric downwelling natural radiation in the frequency range from 22 to 150 GHz. Given an atmospheric profile of temperature, water vapor, and, optionally, cloud liquid water content, and together with a viewing geometry, RTTOV-gb computes downwelling radiances and brightness temperatures leaving the bottom of the atmosphere in each of the channels of the sensor being simulated. In addition, it provides the sensitivity of observations to the atmospheric thermodynamical state, i.e., the Jacobians. Therefore, RTTOV-gb represents the forward model needed to assimilate ground-based MWR data into numerical weather prediction models, which is currently pursued internationally by several weather services. RTTOV-gb is fully described in a previous paper (De Angelis et al., 2016), while several updates are described here. In particular, two new MWR types and a new parameterization for the atmospheric absorption model have been introduced since the first paper. In addition, estimates of the uncertainty associated with the absorption model and with the fast parameterization are given here. Brightness temperatures (TB) computed with RTTOV-gb v1.0 from radiosonde profiles have been compared with ground-based MWR observations in six channels (23.8, 31.4, 72.5, 82.5, 90.0, and 150.0 GHz). The comparison shows statistics within the expected accuracy. RTTOV-gb is now available to licensed users free of charge from the Numerical Weather Prediction Satellite Application Facility (NWP SAF) website, after registration. Coefficients for four MWR instrument types and two absorption model parameterizations are also freely available from the RTTOV-gb support website.

Published in Geoscientific Model Development

ISSN: 1991-959X (Print); 1991-9603 (Online)
Publisher: Copernicus Publications
Country of publisher: Germany
LCC subjects: Science: Geology
Website: https://www.geoscientific-model-development.net/

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