Publisher : Bulletin of Marine Science
Place of publication :
Publication year : 2001
Thematic : Coral Reef
Language : English
Note
A multi-year study was undertaken to evaluate the relationship between sea surface
temperatures (SSTs) derived from two methodologies: Advanced Very High Resolution
Radiometer (AVHRR on NOAA satellites) and in situ instrumentation. Comparisons within
sites were made at six widely distributed locations in the Galapagos Archipelago: Academy
Bay, Santa Cruz, Bartolome, Champion, Punta Espinosa, Fernandina, and Wolf.
Comparisons were made at monthly (1982.1998) and weekly (1997.1998) resolution.
Results of within-site comparisons indicated that the differences in monthly SSTs for the
two methods, at four primary sites, ranged from a mean difference of -0.62‡C to a high
of +1.39oC. Weekly comparisons made during the very strong 1997.1998 ENSO event
revealed smaller differences between methodologies (-0.33 to + 0.99) due to the widespread
warming resulting from ENSO conditions. While a statistical evaluation of the
data revealed few overall differences between sites and methods, two sites, Champion
and Urvina Bay, showed consistent differences between the two methodologies. At Urvina
Bay in situ data were consistently higher than satellite measurements, and vice versa at
Champion. These differences could be explained by heating in the shallow nearshore
waters of Urvina Bay, and at Champion by the placement of the in situ instrument below
the depth of a shallow thermocline. Lastly, a comparison of AVHRR-derived SSTs from
1982.1998 at six widespread sites was used to evaluate patterns of seasonal SST variability
within the archipelago. Although several distinct temperature zones were identified,
average differences between zones previously suggested by Harris (1969) were found
to be lower than proposed.
Go to source
Keywords : coastal management
Encoded by : Pauline Carmel Joy Eje