OCEAN HEAT AND CLIMATE
I’m Jorge Vazquez-Cuervo and I am a physical
oceanographer at the Jet Propulsion Laboratory. I work
with another oceanographer, Elisa Garcia-Gorriz [Fig.
1], to understand the circulation and seasonal fluctuations in the Mediterranean Sea and off the east coast of
the United States. I use sea surface temperature data
from an Earth-orbiting satellite instrument called an
Advanced High Resolution Radiometer (AVHRR).
Figure 1. Dr. Elisa GarciaSatellites have dramatically changed the way oceanGorriz, physical oceanograographers study the world’s ocean, allowing us to observe all our oceans from
pher.
space. Prior to satellites ocean measurements were taken by people on ships; so
we only had measurements from limited locations, mostly along shipping routes. With satellite instruments we can get sea surface temperature measurements over much of the worlds oceans every day!
This allows us to determine how patterns of warm and cool water change with season and from year to
year. Because the ocean can hold a lot of heat, small variations in ocean temperature can make big differences to the weather and climate.
The temperatures in the eastern coastal states of the United States are affected by the Gulf Stream
[Fig. 2]. The Gulf Stream is a fast-moving current that carries warm waters north-eastward into the
Atlantic, eventually affecting the weather of Europe. This current is similar to fast moving winds high in
the atmosphere, known as jet streams, which steer weather systems and storms. My research on the Gulf
Stream has focused on detecting fluctuations in the Gulf Stream with a view to better understanding what
drives these fluctuations.
I am currently working with Elisa Garcia-Gorriz to understand the sea surface temperature fluctuations in the Mediterranean Sea [Fig. 3]. Using satellite data we are examining the annual fluctuation in
sea surface temperature [Movie]. We are also examining the interannual fluctuations, in other words,
how the temperatures vary from
year to year. We chose the
Mediterranean Sea as a study
site because little work has been
done there. The Mediterranean
Sea is important because it
affects climate in Europe and
North Africa, areas where many
of people live [Fig. 4].
In 1998, the Year of the
Ocean, I will be continuing to
work on the Mediterranean Sea
using a new type of sea surface
temperature data we are producing with the NASA Physical
Oceanography Distributed
Active Archive Center
Figure 2. The warm water of the Gulf Stream is seen as red with colder waters (PO.DAAC). These data, called
showing up as blue and purple. This is imagery from May 1993.
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Pathfinder SST, provide more
coverage than was previously
available. In addition, the data
have been processed with a
consistent algorithm so that
they can be used to compare
sea surface temperatures from
one year to the next.
Figure 3. The Strait of Gibraltar in the left hand side of the image is the entrance of
Atlantic Waters into the Mediterranean and the exit of Mediterranean Waters into the
Atlantic. The eastern part of the Mediterranean is a lot warmer. This partly explains
why Rome and Barcelona get almost no snow in winter while Boston, at the same
latitude, has severe winters. The Mediterranean Sea has a strong influence in Europe
and Africa climate. The data is from October 1992.
Figure 4. Fishermen harvesting shellfish in
the Mediterranean Sea.
Movie. This animation shows the seasonal change in sea surface temperature. Red is the warmest temperature and purple is the coldest.
White indicates no data in that area, mainly due to cloud cover. Month
1 is January, month 12 is December.
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