An analysis of SST gradients off the Peruvian Coast: The impact of going to higher resolution

ISI Document Delivery No.: 098JZ Times Cited: 1 Cited Reference Count: 32 Cited References: Armstrong EM, 2012, INT J REMOTE SENS, V33, P6639, DOI 10.1080/01431161.2012.692832 Belkin IM, 2003, PACIFIC OCEANOGRAPHY, V1, P90 Capet X., 2008, GEOPHYS MONOGR SER, V177, P131, DOI [DOI 10.1029/177GM10, 10.1029/177GM10] Capet X. J., 2004, GEOPHYS RES LETT, V31 Chaigneau A, 2009, PROG OCEANOGR, V83, P117, DOI 10.1016/j.pocean.2009.07.012 Chaigneau A, 2005, J GEOPHYS RES-OCEANS, V110, DOI 10.1029/2004JC002628 Chavez FP, 2008, PROG OCEANOGR, V79, P95, DOI 10.1016/j.pocean.2008.10.012 Chelton DB, 2010, OCEANOGRAPHY, V23, P52 Chelton DB, 1996, SCIENCE, V272, P234, DOI 10.1126/science.272.5259.234 Chelton DB, 2007, J PHYS OCEANOGR, V37, P495, DOI 10.1175/JPO3025.1 Chin TM, 1998, J ATMOS OCEAN TECH, V15, P741, DOI 10.1175/1520-0426(1998)0152.0.CO;2 Croquette M, 2007, GEOPHYS RES LETT, V34, DOI 10.1029/2006GL027538 Dewitte B, 2011, J GEOPHYS RES-OCEANS, V116, DOI 10.1029/2010JC006495 Dewitte B., 2012, DEEP SEA RES, VII Donlon C, 2007, B AM METEOROL SOC, V88, P1197, DOI 10.1175/BAMS-88-8-1197 Donlon CJ, 2012, REMOTE SENS ENVIRON, V116, P140, DOI 10.1016/j.rse.2010.10.017 Estrade P, 2008, J MAR RES, V66, P589 Gentemann CL, 2009, OCEANOGRAPHY, V22, P76 Gruber N, 2011, NAT GEOSCI, V4, P787, DOI [10.1038/ngeo1273, 10.1038/NGEO1273] Jacox MG, 2012, J GEOPHYS RES-OCEANS, V117, DOI 10.1029/2011JC007856 Kilpatrick K.A., 2001, J GEOPHYS RES, V106, P9 Kim W, 2011, GEOPHYS RES LETT, V38, DOI 10.1029/2011GL048521 Marchesiello P, 2003, J PHYS OCEANOGR, V33, P753, DOI 10.1175/1520-0485(2003)332.0.CO;2 Marchesiello P, 2010, J MAR RES, V68, P37 Pickett MH, 2003, J GEOPHYS RES-OCEANS, V108, DOI 10.1029/2003JC001902 Renault L., 2012, J GEOPHYS RES, V117, DOI 19.1029/2011JC007446. Reynolds RW, 2010, J CLIMATE, V23, P3545, DOI 10.1175/2010JCLI3294.1 REYNOLDS RW, 1994, J CLIMATE, V7, P929, DOI 10.1175/1520-0442(1994)0072.0.CO;2 Reynolds RW, 2002, J CLIMATE, V15, P1609, DOI 10.1175/1520-0442(2002)0152.0.CO;2 Smith R., 1994, DAHL WORKSH UPW OC B, P39 Vazquez-Cuervo J, 2010, J CLIMATE, V23, P1047, DOI 10.1175/2009JCLI2839.1 Wentz FJ, 2000, SCIENCE, V288, P847, DOI 10.1126/science.288.5467.847 Vazquez-Cuervo, Jorge Dewitte, Boris Chin, Toshio M. Armstrong, Edward M. Purca, Sara Alburqueque, Edward National Aeronautics and Space Administration at the Jet Propulsion Laboratory, California Institute of Technology The work was carried out under contract with the National Aeronautics and Space Administration at the Jet Propulsion Laboratory, California Institute of Technology. The authors gratefully thank Instituto del Mar del Peru (IMARPE) for providing both scientific and technical support. The authors also thank three anonymous reviewers for their hardwork and thoughtful reviews in significantly improving this manuscript. 1 ELSEVIER SCIENCE INC NEW YORK REMOTE SENS ENVIRONThe Peruvian Coastal Upwelling System (PCUS) is one of the most productive fisheries in the world. Upwelling events are associated with changes in the magnitude and location of frontal structures. SST gradients from four different data sets, NCDC, REMSS, OSTIA, and MUR are compared in two test areas off the PCUS: Paita (5 degrees S) and Pisco (14 degrees S). In both areas gradients derived from the MUR data set show greater magnitudes, as well as larger seasonal cycles. Off Pisco, the magnitude of the seasonal cycle of 2.2 degrees C/100 km in MUR is larger than the one derived from the lower resolution data sets. All data sets at Pisco exhibit a seasonal cycle that peaks in late Austral summer and early fall. Hovmoller diagrams calculated at 5.5 degrees S, 10.5 degrees S, and 14.5 degrees S show clearly defined offshore maxima in the cross-shore gradients for all the data sets. Upwelling scales determined by the distance to the first maxima vary depending on the data set used. At 5.5 degrees S upwelling scales vary from 10 km for MUR to 50 km for NCDC At 14.5 degrees S the scales vary from 20 km for MUR to 40 km for OSTIA. All four data sets show similar large-scale structures associated with the Peruvian upwelling. However, MUR shows finer scale structures that are most likely due to submesoscale to mesoscale eddies. Sub-sampled MUR 1 km data at the 25 km, 9 km, and 4 km resolutions compare well in magnitude and phase with the lower resolution products. Agreement in gradient magnitude between the lower resolution data sets and the MUR sub-sampled at their respective resolutions implies that the pixel-to-pixel analysis noise in MUR is at a similar level as the other data sets. (c) 2013 Elsevier Inc. All rights reserved