Monthly Time Series
For over 20 years, oceanographers from all over the world have been riding wave after wave of amazing sea surface height (SSH) data. Orbiting from 1336 kilometers (830 miles) in space, the NASA/CNES/NOA/EUMETSAT Jason-series satellites keeps cranking out remarkable perspectives of our ocean planet. At the same time, the National Oceanic and Atmospheric Administration's (NOAA) Polar Orbiting Satellites have been measuring the sea surface temperature (SST) of the global ocean. These animations illustrate the changes in our ocean that these important satellites reveal... for scientists, it is where their path begins.
The temperature data show us the warmer and cooler than normal sea-surface temperatures that influence our atmosphere every day, while sea-surface heights are a measure of how much heat is stored in the ocean below. The differences between what we see and what is normal are called anomalies. When you put these two critical pieces of the climate puzzle together, the SST's tell us about what is influencing today's weather, and the SSH's tell us how much heat is being stored in the ocean to influence future planetary climate events.
WHAT ARE WE LOOKING AT?
On these pages you are going to be viewing anomalies! What is an anomaly? Simply, an anomaly is something that is outside of a range of what we consider to be normal. In this case, the anomalies are data points of sea-surface height and sea-surface temperature that stray away from a range of normal variations in height and temperature for the specified time of year. The normal slow, regular patterns of sea-surface height and temperature are moved up and down (warm and cool) with the normal progression of the seasons ... winter to spring to summer to fall. To better view the largest year-to-year variations of the '90's, a "normal" annual signal has been removed from these data. The years 1993 through 1996 have been chosen as "normal" because of a lack of any large El Niño or La Niña signal. This same time period was used to calculate a "normal year" for both SST and SSH maps and to calculate the monthly anomalies. Repeating what our charts are ... these SSH and SST "anomaly" maps are defined as the difference between the satellite-measured SSH and SST and the 'normal' SSH and SST for that time of year and location. This allows the best visualization of climate events such as the El Niño, La Niña and Pacific Decadal Oscillation.
Sea-surface height is shown relative to normal with normal shown as green. Blue and purple areas represent heights measuring between 8 and 24 centimeters (3 and 9 inches) lower than normal. Red and white areas represent higher than normal sea-surface heights and indicate warmer water. These areas are between 8 and 24 centimeters, (3 and 9 inches) higher than normal.
WHY NEW DATA?
These images and animations of sea surface height and sea surface temperature data are provided for information and display purposes. Research quality data, with higher accuracy and suitable for quantitative analysis, can be obtained from the Physical Oceanography DAAC (PO.DAAC). For further clarification, please email PO.DAAC at firstname.lastname@example.org.
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