The Gulf Stream - June 13, 1988
Clouds are Grey.
This image is of the Gulf Stream. This is a current that begins at the
tip of Florida, where it is called the Florida Current, and ends off the
coast of Ireland. The area off of the Northeast United States is the most
interesting, dynamically speaking. Here, warm water breaks away from the
stream in masses that are called eddies or rings (orange/red circular
features). The Gulfstream also begins to meander, curving like a giant
snake through the north Atlantic.
The Gulfstream picture shows three different types of data. The most obvious is the
AVHRR
satellite image of sea surface temperature (sst). In this image dark
red indicates temperatures near 28 C, green colors represent temperatures near 18 Celsius and violet colors are near
10 degrees Celsius. This data is available directly to us from the satellite
dish on our roof. Each pixel that makes up this image is 4x4 kilometers, but
the spatial resolution of the data we get from our satellite dish is 1.1x1.1 kilometers.
The satellite to the right is known as the NOAA/TIROS polar orbiting platform, and houses the AVHRR sensor.
The second type of data plotted on the Gulfstream image is from the Geosat Satellite Altimeter. This
satellite measures ocean height.
The straight white lines running southeast
to northwest on the Gulfstream image are the groundtracks of the satellite passes, and the topography of the
ocean is plotted perpendicular to these straight lines as curving white lines.
Heights above "average" height are plotted to the right of the straight line, and
heights below mean sea surface height are plotted to the left of the groundtrack.
The scale of this topography is +/- 60 centimeters on either side of the
groundtrack line. In other words, the drop across the Gulf Stream's northern
edge, or North Wall (black line) is approximately 1.1 meters.
The third type of data is XBT data.
This is temperature data taken below the surface of the ocean by a torpedo like
instrument (right). From previous research, we know that at a depth of 200 meters,
any temperature above 15 degrees C is Gulfstream water. The yellow squares and
circles are measurements above 15 degrees, and the yellow +'s and *'s are measyurements
below this temperature at a depth of 200 meters.
These three types of data help us locate the rings and Northwall, which
is important for the United States military and commercial fisherman.
We would tell you more about the Navy's concerns, but this information is
top secret, and important for National Security reasons.
flounder@arctic.rutgers.edu