FN Archimer Export Format
PT J
TI A satellite altimeter model for ocean slick detection - art. no. C04004
BT 
AF TOURNADRE, Jean
   CHAPRON, Bertrand
   REUL, Nicolas
   VANDEMARK, D
AS 1:1;2:1;3:1;4:2;
FF 1:PDG-DOP-DCB-OPS-LOS;2:PDG-DOP-DCB-OPS-LOS;3:PDG-DOP-DCB-OPS-LOS;4:;
C1 Inst Francais Rech Exploitat Mer, Oceanog Lab, F-29280 Plouzane, France.
   NASA, Goddard Space Flight Ctr, Wallops Isl, VA 23337 USA.
C2 IFREMER, FRANCE
   NASA, USA
SI BREST
SE PDG-DOP-DCB-OPS-LOS
IN WOS Ifremer jusqu'en 2018
   copubli-int-hors-europe
IF 2.8
TC 28
UR https://archimer.ifremer.fr/doc/2006/publication-1353.pdf
LA English
DT Article
DE ;Slick;Sigma blooms;Altimeter waveforms
AB [1] About 5% of Ku-band altimeter ocean data are degraded by the occurrence of high radar return cross sections (sigma(0)), usually called sigma(0) blooms. During blooms, which occur during no or low wind conditions, the mean altimeter waveform can significantly depart from the expected shape. In about 60% of the cases the waveforms are distorted to such an extent that either the range tracker loses lock or the off-nadir angle estimate becomes unrealistic. The analysis of high data rate altimeter waveforms during bloom events reveals the presence of V-shaped patterns similar to the ones observed during rain events. These patterns trace small-scale (i.e., smaller than the altimeter footprint) changes in surface backscatter. Such variations of surface roughness are commonly observed in SAR images under low wind conditions. On the basis of the experience gained through the analysis of high-resolution altimeter waveforms in the presence of rain cell, a model is developed to analyze the altimeter response to phenomena whose length scale is smaller than the altimeter footprint. The model is applied to simple patterns ( linear slicks and circular patches) as well as to realistic surface sigma(0) estimated by SAR. It is also used to analyze bloom events in terms of surface slicks. The model results shows that the small-scale sigma(0) variations explain the behavior of altimeter waveforms in bloom events. The results also show that a good proportion of data during bloom events are still valid for estimating geophysical parameters as the Brown model remains valid. Use of high-resolution altimeter waveforms may also offer an interesting mean to study marine slick occurrence rates and type.
PY 2006
PD APR
SO JGR - Oceans
SN 0148-0227
PU American Geophysical Union
VL 111
IS C4
UT 000237282600001
DI 10.1029/2005JC003109
ID 1353
ER

EF