Oceanography The Official Magazine of
The Oceanography Society
Volume 32 Issue 02

View Issue TOC
Volume 32, No. 2
Pages 50 - 57

Deployment of the SEA-POL C-band Polarimetric Radar to SPURS-2

Steven A. Rutledge V. ChandrasekarBrody FuchsJim GeorgeFrancesc JunyentPatrick KennedyBrenda Dolan
Article Abstract

As part of the Salinity Processes in the Upper-ocean Regional Study (SPURS-2) 2017 cruise to the eastern tropical Pacific, the Colorado State University SEA-POL (SEA-going POLarimetric) C-band radar made its first ever ship deployment. Previous ship-based experiments have used Doppler radars to map rainfall and the structure of oceanic convection, but SPURS-2 marked the first time the US research community deployed a dual-polarimetric radar at sea. Dual-polarimetric radar transmits and receives electromagnetic radiation in both horizontal (H) and vertical (V) polarizations simultaneously and thereby makes additional, important measurements of precipitation compared to a single polarization radar, which normally transmits horizontal polarization only. For H-polarization, the electric field vector of the transmit pulse is horizontal to the local Earth’s surface; for V-polarization, the electric field vector is perpendicular to Earth’s surface. Polarization measurements provide information about particle size, shape, and phase (water vs. ice). As a result, superior rain rate estimates are afforded by the dual-polarimetric technology. During SPURS-2, SEA-POL produced rain maps in real time to locate freshwater lenses forming on the ocean’s surface to develop context for oceanographic measurements of surface temperature and salinity.

Citation

Rutledge, S.A., V. Chandrasekar, B. Fuchs, J. George, F. Junyent, P. Kennedy, and B. Dolan. 2019. Deployment of the SEA-POL C-band polarimetric radar to SPURS-2. Oceanography 32(2):50–57, https://doi.org/10.5670/oceanog.2019.212.

References

Bringi, V.N., and V. Chandrasekar. 2001. Polarimetric Doppler Weather Radar: Principles and Applications. Cambridge University Press, Cambridge, UK, 636 pp.

Demott, C.A., and S.A. Rutledge. 1998. The vertical structure of TOGA COARE convection: Part I. Radar echo distributions. Journal of the Atmospheric Sciences 55:2,730–2,747, https://doi.org/10.1175/1520-0469(1998)055​<2730:TVSOTC>2.0.CO;2.

Dolan, B., S.A. Rutledge, S. Lim, V. Chandrasekar, and M. Thurai. 2013. A robust C-band hydrometeor identification algorithm and application to a long-term polarimetric dataset. Journal of Applied Meteorology and Climatology 52:2,162–2,186, https://doi.org/10.1175/JAMC-D-12-0275.1.

Drushka, K., W.E. Asher, A.T. Jessup, E. Thompson, S. Iyer, and Dan Clark. 2019. Capturing fresh layers with the surface salinity profiler. Oceanography 32(2):76–85, https://doi.org/​10.5670/oceanog.2019.215.

Houze, R.A. Jr. 1977. Structure and dynamics of a tropical squall line system. Monthly Weather Review 105:1,540–1,567, https://doi.org/​10.1175/​1520-0493​(1977)105​<1540:SADOAT>2.0.CO;2.

Kennedy, P.C., and S.A. Rutledge. 2011. S-band dual polarization radar observations of winter storms. Journal of Applied Meteorology and Climatology 50:844–858, https://doi.org/​10.1175/​2010JAMC2558.1.

Rickenbach, T.M., and S.A. Rutledge. 1998. Convection in TOGA COARE: Horizontal scale, morphology and rainfall production. Journal of the Atmospheric Sciences 55:2,715–2,729, https://doi.org/​10.1175/​1520-0469(1998)055​<2715:CITCHS>​2.0.CO;2.

Ryzhkov, A.V., S.E. Giangrande, V.M. Melnikov, and T.J. Schuur. 2005. Calibration issues of dual-​polarization radar measurements. Journal of Oceanic and Atmospheric Technology 22:1,138–1,155, https://doi.org/10.1175/JTECH1772.1.

Thompson, E.J., S.A. Rutledge, B. Dolan, M. Thurai, and V. Chandrasekar. 2018. Dual-polarization radar rainfall estimation over tropical oceans. Journal of Applied Meteorology and Climatology 57:755–775, https://doi.org/10.1175/JAMC-D-17-0160.1.