@misc{vanzadelhoff_retrieving_hurricane_2014, 
author={van Zadelhoff, G.-J.,Stoffelen, A.,Vachon, P. W.,Wolfe, J.,Horstmann, J.,Belmonte Rivas, M.},
title={Retrieving hurricane wind speeds using cross-polarization C-band measurements},
year={2014},
howpublished = {journal article},
doi = {https://doi.org/10.5194/amt-7-437-2014},
abstract = {Hurricane-force wind speeds can have a large societal impact and in this paper microwave C-band cross-polarized (VH) signals are investigated to assess if they can be used to derive extreme wind-speed conditions. European satellite scatterometers have excellent hurricane penetration capability at C-band, but the vertically (VV) polarized signals become insensitive above 25 m s−1. VV and VH polarized backscatter signals from RADARSAT-2 SAR imagery acquired during severe hurricane events were compared to collocated SFMR wind measurements acquired by NOAA's hurricane-hunter aircraft. From this data set a geophysical model function (GMF) at strong-to-extreme/severe wind speeds (i.e., 20 m s−1 < U10 < 45 m s−1) is derived. Within this wind speed regime, cross-polarized data showed no distinguishable loss of sensitivity and as such, cross-polarized data can be considered a good candidate for the retrieval of strong-to-severe wind speeds from satellite instruments. The upper limit of 45 m s−1 is defined by the currently available collocated data. The validity of the derived relationship between wind speed and VH backscatter has been evaluated by comparing the cross-polarized signals to two independent wind-speed data sets (i.e., short-range ECMWF numerical weather prediction (NWP) model forecast winds and the NOAA best estimate 1-minute maximum sustained winds). Analysis of the three comparison data sets confirm that cross-polarized signals from satellites will enable the retrieval of strong-to-severe wind speeds where VV or horizontal (HH) polarization data has saturated. The VH backscatter increases exponentially with respect to wind speed (linear against VH [dB]) and a near-real-time assessment of maximum sustained wind speed is possible using VH measurements. VH measurements thus would be an extremely valuable complement on next-generation scatterometers for hurricane forecast warnings and hurricane model initialization.},
note = {Online available at: \url{https://doi.org/10.5194/amt-7-437-2014} (DOI). van Zadelhoff, G.; Stoffelen, A.; Vachon, P.; Wolfe, J.; Horstmann, J.; Belmonte Rivas, M.: Retrieving hurricane wind speeds using cross-polarization C-band measurements. Atmospheric Measurement Techniques. 2014. vol. 7, no. 2, 437-449. DOI: 10.5194/amt-7-437-2014}}