Large-scale Satellite Oceanography in Eastern Pacific Upwelling Regions

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)

Backgroundmy 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 1996-1999 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 1996-1998 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 1996-1998 La Nina and El Nino, J. Geophys. Res.

 Thomas A.C., P. T. Strub, M.E. Carr and R. Weatherbee, 2003. 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, 1998. 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. 1994. 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. 1994. A comparison of the seasonal and interannual variabilityof 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 1996-1999 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 1996-1998 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 1996-1998 La Nina and El Nino, J. Geophys. Res.

Seasonal Cycles - monthly SeaWiFS composites

February JulyBased on newest (2002) SeaWiFS processing

Seasonal Cycles – GRL 2001

SeaWiFS (3 years) CZCS (7 years)

Summer Centered in each Hemisphere

Amplitude Phase r2

Wind

CHL

summer summer

summer summer

~30o latitudinal boundaryNoted in CZCS data [Thomas 1999 JGR]

Very evident in SeaWiFS / Wind / SST data [Thomas et al. 2001 GRL]

….as Rubén showed yesterday with other data

Interannual Variability

3 years – GRL 2001

a preliminary view

Interannual VariabilitySeaWiFS (4 years)

- monthly CONCENTRATIONS

– 100km mean

1997 1998 1999 2000 20011997 1998 1999 2000 2001

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 dataaltimeter anomalies – ERS & TOPEXSST anomalies – NOAA AVHRRchlorophyll anomalies – SeaWiFSEkman transport – ERS & QuikSCAT

El Nino Comparisons N & S: TimingALTIMETER: Sea Surface Height Residuals (1997-1998)

Low latitudes

Baja VS N.Chile

Mid latitudes

High Sea Levels

SeaWiFS Data Begins

1997 1998

Anomaly Time Series 1997-98

Baja VS N. Chile (~28N-22oS)

Data: Height (SSH)

N. Chile

Baja

1997 1998

Anomaly Time Series 1997-98

Baja VS N. Chile (~28N-22oS)

Data: Height (SSH) & SST

« @ 21oN

N. Chile

Baja

1997 1998

N. Chile

Baja

Anomaly Time Series 1997-98

Baja VS N. Chile (~28N-22oS)

Data: Height (SSH) & SST & CHL

1997 1998

N. Chile

Baja

Anomaly Time Series 1997-98

Baja VS N. Chile (~28N-22oS)

Data: Height (SSH) & SST & CHL & WIND (Ekman)

1997 1998

Anomaly Time Series 1997-98

MID Latitudes (~35o N&S)

Data: Height (SSH)

1997 1998

California

Chile

Anomaly Time Series 1997-98

MID Latitudes (~35o N&S)

Data: Height (SSH) & SST

California

Chile

1997 1998

Anomaly Time Series 1997-98

MID Latitudes (~35o N&S)

Data: Height (SSH) & SST & CHL

California

Chile

1997 1998

Anomaly Time Series 1997-98

MID Latitudes (~35o N&S)

Data: Height (SSH) & SST & CHL & Wind (EKMAN)

California

Chile

1997 1998

VARIABILITY ANALYSIS

21.4%

1997 1998 1999 2000 2001 2002

1997 1998 1999 2000 2001 2002

5 year time series of monthly SeaWiFS data

September 1997 October 1997 November 1997

Monthly anomalies

(from new [2002 processing] data)

December 1997 January 1998 February 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)

SummaryData:

SeaWiFS & MODIS color

AVHRR & MODIS SST

QuikSCAT & ERS wind

TOPEX & ERS heights

gracias

So much to do…..so much fun….. Send students!