However, measurements taken by airborne SFMR provide a very good connection between the sparse dropsonde data and the observed SMAP wind fields.
The SFMR measures brightness temperatures at six closely spaced C-band channels (4-8 GHz, 7.
The SFMR measurements are processed with a 10-s running mean and at a spatial sampling of approximately 3 km.
4 and depict a strong correlation between SMAP and resampled SFMR wind speeds for these eight storms.
Without SFMR flights, there is no in situ spatial information available in this case, and a direct comparison for the winds that are seen by the spaceborne sensors cannot be made.
We have computed the statistics of the SMAP-resampled SFMR matchup data in different rain-rate regimes using the rain rate measured by SFMR.
The SMAP radiometer winds show very good correlation with the airborne SFMR observations over a wide wind speed range between 15 and 65 m [s.
It is desirable to increase the validation database of SMAP high-wind retrievals with additional SFMR matchups, as they become available.
We are thankful to Philippe Caroff (Tropical Cyclone Center La Reunion) for information about Tropical Cyclone Fantala and to Brad Klotz (University of Miami/CIMAS and NOAA/HRD), Jim Carswell (Remote Sensing Solutions), Paul Chang, and Zorana Jelenak (NOAA/NESDIS/STAR) for useful discussions about the SFMR measurements.
a) NOAA SFMR flight segments through Hurricane Patricia on 23 Oct 2015.