FN Archimer Export Format
PT J
TI An assessment of marine atmospheric boundary layer roll detection using Sentinel-1 SAR data
BT 
AF Wang, Chen
   Vandemark, Douglas
   Mouche, Alexis
   Chapron, Bertrand
   LI, Huimin
   Foster, Ralph C.
AS 1:1,2;2:3;3:1;4:1;5:4;6:5;
FF 1:PDG-ODE-LOPS-SIAM;2:;3:PDG-ODE-LOPS-SIAM;4:PDG-ODE-LOPS-SIAM;5:PDG-ODE-LOPS-SIAM;6:;
C1 IFREMER, Univ. Brest, CNRS, IRD, Laboratoire d'Oceanographie Physique et Spatiale (LOPS), Brest, France
   IMT Atlantique, Lab-STICC, UBL, Brest, France
   Ocean Processes Analysis Laboratory, University of New Hampshire, Durham, NH, USA
   School of Marine Sciences, Nanjing University of Information Science and Technology, Nanjing, China
   Applied Physics Laboratory, University of Washington, Seattle, WA, USA
C2 IFREMER, FRANCE
   IMT ATLANTIQUE, FRANCE
   UNIV NEW HAMPSHIRE, USA
   UNIV NANJING, CHINA
   UNIV WASHINGTON, USA
SI BREST
SE PDG-ODE-LOPS-SIAM
UM LOPS
IN WOS Ifremer UMR
   copubli-france
   copubli-int-hors-europe
   copubli-sud
IF 10.164
TC 12
UR https://archimer.ifremer.fr/doc/00643/75497/80065.pdf
LA English
DT Article
DE ;Marine atmospheric boundary layer rolls;Surface wind perturbation;Synthetic aperture radar (SAR);Sentinel-1 wave mode;Imaging sensitivity
AB The ability of high-resolution synthetic aperture radar (SAR) to detect marine atmospheric boundary layer (MABL) roll-induced roughness modulation of the sea surface wave field is well known. This study presents SAR measurements of MABL rolls using global coverage data collected by the European Space Agency's C-band Sentinel-1A satellite in 2016–2017. An automated classifier is used to identify likely roll events from more than 1.3 million images that were acquired at two incidence angles of 23° and 36.5° in either VV or HH polarization. Characteristics of the detected rolls are examined for different wind speeds, polarizations, incidence and relative azimuth angles. Roll detection counts are much higher at the higher incidence angle and nearly equivalent for VV and HH polarizations. Detection depends strongly on the relative azimuth with roll detection rates at crosswind being 3–10 times lower than for up- or downwind. All data show a low wind speed threshold near 2 m s−1 and that rolls are most commonly observed at wind speeds near 9 m s−1. For all viewing configurations, we find that rolls induce a wide range of mean surface wind speed modulation with the most frequent value being 8% (±3.5%). Roll detection at crosswind is associated with stronger roll-induced surface wind enhancement. Dependencies of roll detection on the incidence and relative azimuth angles are consistent with rapid short-scale wind-wave adjustments to the roll-induced surface wind gusts. These cm-scale waves are highly directional and provide limited crosswind backscatter at shallower incidence angles. The same roll-induced surface forcing is thus not equally detectable at all viewing geometries or polarizaions. Stronger and possibly longer-duration wind forcing is likely needed to produce detectable roll-induced modulations at crosswind. 
PY 2020
PD DEC
SO Remote Sensing Of Environment
SN 0034-4257
PU Elsevier BV
VL 250
UT 000585305400007
DI 10.1016/j.rse.2020.112031
ID 75497
ER

EF