Progress in utilizing altimeter ocean backscatter measurements for sea surface roughness applications
Douglas Vandemark(1) , Tanos Elfouhaily(2) , Bertrand Chapron(3) , and Ngan Tran(4)
University of New Hampshire,
Morse Halll, Rm 142,
Durham NH 03801,
(2) University of Miami, 4600 Rickenbacker Causeway, Miami FL, United States
(3) IFREMER/Centre de Brest, BP 70, Plouzane 29280, France
(4) CLS, 810 rue Hermes, 31526 Ramonville St. Agnes, France
One of the cornerstone's of ocean remote sensing is the ability to detect
changes in ocean surface waves related to different environmental conditions.
The satellite altimeter continues to build a
long-term global record of this ocean surface roughness variability from
the unique vantage point of a radar whose angle of incidence
is directly at nadir, a view that is most sensitive to the sea surface slope
statistical distribution. Moreover, the TOPEX/Poseidon, Jason-1,
and Envisat missions each carry
dual-frequency radar altimeters that have added a new wave remote sensing perspective.
This paper will provide a review of the
progress made in interpretation and application of
altimetry's ocean radar cross section measurements in the last decades.
These applications include wind speed and stress estimation, air-sea carbon dioxide
gas transfer, ocean slick detection, wave-current interaction measurements near
strong boundary currents, direct impact on altimeter sea level estimates through the
sea state bias correction, high resolution wind sampling within storms, and retrieval
of surface wave properties spanning from cm to m scale wavelengths.
Much of the recent progress has come from synergistic studies where collocated
scatterometer, wind and wave model, and in situ data are blended to gain
a more comprehensive definition of the role that sea surface waves play within the context
of the applications above. Attention will be given to climate data
record potential for the altimeter cross section measurements as well
as the absolute and relative calibration of these data within
and across satellite platforms.