Monthly NMC Mean Sea Surface Temperatures (SST) Anomaly from JCOMMProducts Bulletin at LDEO/IRI Climate Data Library

The monthly optimum interpolation (OI) fields are derived by a linear
interpolation of the weekly OI fields to daily fields then averaging
the daily values over a month. The monthly fields are in the same
format and spatial resolution as the weekly fields.

The anomalies (SSTA) are computed from these monthly fields.

Data from the Joint World Meteorological
Organization/Intergovernmental Oceanographic Commission Technical
Commision for Oceanography and Marine Meteorology (JCOMM) Products
Bulletin Data Products. The organization was formally known as the
Integrated Global Ocean Services System (IGOSS) Data Products
Bulletin.

For further data products see:
"http://ingrid.ldeo.columbia.edu/SOURCES/.IGOSS/"

"http://ingrid.ldeo.columbia.edu/SOURCES/.IGOSS/.data_products.html"

and
"http://iri.ldeo.columbia.edu/climate/monitoring/ipb/"