Abstract
We present a relatively simple method to estimate tropical cyclone (TC) surface wind structure (34-, 50-, and 64-kt wind radii) and intensity [maximum wind speed (MWS)] from wind fields acquired from the L-band SMAP radiometer and C-band Sentinel-1A/B and RADARSAT-2 synthetic aperture radar (SAR) between 2015 and 2020. The radiometer and SAR-derived wind radii and MWS are systematically compared with the best-track estimates. The root-mean-square errors (RMSEs) of R34, R50, and R64 are 31.2, 21.8, and 17.0 nmi (1 nmi = 1.852 km) for radiometer, and 21.7, 16.5, and 16.3 nmi for SAR, respectively. These error values are smaller than the averaged best-track uncertainty estimates for the three wind radii. Compared with the best-track reports, the bias and RMSE for the MWS estimates are -0.2 m/s and 5.8 m/s for radiometer, and 4.4 m/s and 9.1 m/s for SAR, respectively. These results are for the wind speeds in the range of 17-80 m/s. For the two typical TCs (Lionrock and Noru) in the Northwest Pacific Ocean, our results show that a combination of the radiometer and SAR wind data acquired within a very short time interval has the potential to simultaneously obtain reasonable measurements of the wind radii and intensity parameters. Moreover, for a TC with a long lifecycle, such as Typhoon Noru, we demonstrate that the high-resolution and multitemporal synergistic observations from SAR and radiometer are valuable for studying fine-scale features of the wind field and characteristics of wind asymmetry associated with intensity change, as well as the evolution of TC surface wind structure and intensity.
Highlights
T ROPICAL cyclone (TC) surface wind structure includes the maximum extents for three important indicators of wind intensity, namely gale-force winds (34 kt), destructive winds (50 kt), and hurricane-force winds (64 kt), as measured radially in the four geographic quadrants of a storm
For a tropical cyclone (TC) with a long lifecycle, such as Typhoon Noru, we demonstrate that the high-resolution and multitemporal synergistic observations from synthetic aperture radar (SAR) and radiometer are valuable for studying fine-scale features of the wind field and characteristics of wind asymmetry associated with intensity change, as well as the evolution of TC surface wind structure and intensity
To estimate TC surface wind structure and intensity parameters, we interpolate the international best-track archive for climate stewardship (IBTrACS) best-track data to the time of soil moisture active/passive (SMAP) radiometer, S1-A/B and RS-2 SAR observations in order to determine the location of a given TC center, for each observation
Summary
T ROPICAL cyclone (TC) surface wind structure includes the maximum extents for three important indicators of wind intensity, namely gale-force winds (34 kt), destructive winds (50 kt), and hurricane-force winds (64 kt), as measured radially in the four geographic quadrants of a storm. Satellite remote sensing observations have been used to estimate TC intensity and wind structure, either using the original satellite data or resulting derived wind fields. Rain-induced scattering can be nearly ignored because the electromagnetic wavelength of the L-band is much larger than the size of rain droplets Due to these advantages, L-band radiometers can provide the accurate measurements of high winds with large coverage under extreme weather conditions and, provide the estimates of TC size [20], [21]. For the first time, we use both spaceborne radiometer and SAR wind fields to estimate TC surface wind radii and intensity, and systematically evaluate the associated errors against the international best-track archive for climate stewardship (IBTrACS) data.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
