Large-scale Satellite Oceanography in Eastern Pacific Upwelling Regions Andrew Thomas University of Maine Recent manuscript collaborators: Jose Luis Blanco, Mary Elena Carr, Scott Nixon, Jorge Ossus, Ted Strub Valparaiso, January 2003

Interests - Overview Coupling between wind forcing, hydrographic patterns and biological response Focus on phytoplankton biomass response Large-scale view (remote sensing data) requires collaboration - for in situ data - expert local knowledge - I don’t know much Comparisons between eastern boundary current regions California Current – Humboldt Current Benguela Current – Canary Current links to basin scale patterns & low latitude forcing (& high latitude forcing)

Background my South American efforts Older Younger Didn’t know much Still don’t know much Carr M-E., P.T. Strub, A.C. Thomas and J.L. Blanco, 2002, Evolution of La Nina and El Nino conditions off the western coast of South America: a remote sensing perspective, J. Geophys. Res. Blanco J.L., M-E. Carr, A.C. Thomas and P.T. Strub, 2002, Hydrographic conditions off northern Chile during the La Nina and El Nino, J. Geophys. Res. Thomas A.C., M.E. Carr and P. T. Strub, 2001, Chlorophyll variability in eastern boundary currents, Geophys. Res. Lett. Nixon, S.W. and A.C. Thomas, 2001, On the size of the Peru upwelling ecosystem. Deep Sea Res. I. Blanco J.L., A.C. Thomas, M-E. Carr and P.T. Strub, 2001, Seasonal climatology of hydrographic conditions in the upwelling region off northern Chile, J. Geophys. Res. Thomas A.C., J.L. Blanco, M.E. Carr, P.T. Strub and J. Ossus, 2001, Satellite-measured chlorophyll and temperature variability off northern Chile during the La Nina and El Nino, J. Geophys. Res. Thomas A.C., P. T. Strub, M.E. Carr and R. Weatherbee, Comparisons of chlorophyll variability between the four major global eastern boundary currents. Int. J. Rem. Sens. Thomas, A.C. 1999, Seasonal distributions of satellite-measured phytoplankton pigment concentration along the Chilean coast. J. Geophys. Res. Hill, A.E., B.M.Hickey, F.A.Shillington, P.T.Strub, K.H. Brink, E.D.Barton, A.C. Thomas, Eastern Boundary Currents: A Pan-Regional Review. In: The Sea. A.R. Robinson and K.H. Brink, Editors. J.Wiley and Sons Inc. Thomas, A.C., P.T. Strub and S. Levesque Satellite measured ocean color variability at large spatial and temporal scales. World Meteorological Organization, UNESCO. Thomas, A.C., P.T. Strub, F. Huang and C. James A comparison of the seasonal and interannual variability of phytoplankton pigment concentrations in the Peru and California Current System. J. Geophys. Res. Carr M-E., P.T. Strub, A.C. Thomas and J.L. Blanco, 2002, Evolution of La Nina and El Nino conditions off the western coast of South America: a remote sensing perspective, J. Geophys. Res. Blanco J.L., M-E. Carr, A.C. Thomas and P.T. Strub, 2002, Hydrographic conditions off northern Chile during the La Nina and El Nino, J. Geophys. Res. Thomas A.C., M.E. Carr and P. T. Strub, 2001, Chlorophyll variability in eastern boundary currents, Geophys. Res. Lett. Nixon, S.W. and A.C. Thomas, 2001, On the size of the Peru upwelling ecosystem. Deep Sea Res. Blanco J.L., A.C. Thomas, M-E. Carr and P.T. Strub, 2001, Seasonal climatology of hydrographic conditions in the upwelling region off northern Chile, J. Geophys. Res. Thomas A.C., J.L. Blanco, M.E. Carr, P.T. Strub and J. Ossus, 2001, Satellite-measured chlorophyll and temperature variability off northern Chile during the La Nina and El Nino, J. Geophys. Res.

Seasonal Cycles - monthly SeaWiFS composites FebruaryJuly Based on newest (2002) SeaWiFS processing

Seasonal Cycles – GRL 2001 SeaWiFS (3 years)CZCS (7 years) Summer Centered in each Hemisphere Amplitude Phase r 2 Wind CHL summer

~30 o latitudinal boundary Noted in CZCS data [Thomas 1999 JGR] Very evident in SeaWiFS / Wind / SST data [Thomas et al GRL] ….as Rubén showed yesterday with other data

Interannual Variability 3 years – GRL 2001 a preliminary view

Interannual Variability SeaWiFS (4 years) - monthly CONCENTRATIONS – 100km mean Work in progress – presented at 2002 Ocean Sciences Meeting SeaWiFS (4 years) - monthly ANOMALIES – 100km mean

Examine EL NIÑO Timing and structure Work in progress – presented at 2002 Viña El Niño Conference Compare Northern Hemisphere response to Southern Hemisphere response multi-disciplinary satellite data altimeter anomalies – ERS & TOPEX SST anomalies – NOAA AVHRR chlorophyll anomalies – SeaWiFS Ekman transport – ERS & QuikSCAT

El Nino Comparisons N & S: Timing ALTIMETER: Sea Surface Height Residuals ( ) Low latitudes Baja VS N.Chile Mid latitudes High Sea Levels SeaWiFS Data Begins

Anomaly Time Series Baja VS N. Chile (~28N-22 o S) Data: Height (SSH) N. Chile Baja

Anomaly Time Series Baja VS N. Chile (~28N-22 o S) Data: Height (SSH) & SST 21 o N N. Chile Baja

N. Chile Baja Anomaly Time Series Baja VS N. Chile (~28N-22 o S) Data: Height (SSH) & SST & CHL

N. Chile Baja Anomaly Time Series Baja VS N. Chile (~28N-22 o S) Data: Height (SSH) & SST & CHL & WIND (Ekman)

Anomaly Time Series MID Latitudes (~35 o N&S) Data: Height (SSH) California Chile

Anomaly Time Series MID Latitudes (~35 o N&S) Data: Height (SSH) & SST California Chile

Anomaly Time Series MID Latitudes (~35 o N&S) Data: Height (SSH) & SST & CHL California Chile

Anomaly Time Series MID Latitudes (~35 o N&S) Data: Height (SSH) & SST & CHL & Wind (EKMAN) California Chile

VARIABILITY ANALYSIS 21.4% year time series of monthly SeaWiFS data

September 1997October 1997November 1997 Monthly anomalies (from new [2002 processing] data)

December 1997January 1998February 1998 Monthly anomalies (from new [2002 processing] data)

July 1998June 1998May 1998 Monthly anomalies (from new [2002 processing] data)

Large Positive Anomalies off North America in 2002 !! Presented at November 2002 GLOBEC meeting (Oregon) April 2002 May 2002 EOF (pattern) EOF (time series)

Summary Data: SeaWiFS & MODIS color AVHRR & MODIS SST QuikSCAT & ERS wind TOPEX & ERS heights gracias So much to do…..so much fun….. Send students!