Thanks to Bill Temmink for providing us with this narrative.
Every day, several NASA satellites circle the globe from the North to the South Pole. As the earth turns, these satellite routes will cross over the entire planet, one swath at a time. Some of these satellites take pictures of the ever-changing waters of the earth. The Gunpowder Riverkeeper organization has been asked to help determine exactly what these pictures mean for our tidal rivers, including the Gunpowder River, and for the Chesapeake Bay.
The earth’s waters change. Many of these changes can be captured by the pictures these satellites take. Depending on the time of day or night, as well as on cloud cover or other weather conditions, the waters can show their different
faces. From space, the waters can be various shades of blue, green, brown, red, or yellow. But, what exactly do each of these colors signify?The program, with partners including the Smithsonian Environmental Research Center, City University of New York, NASA, and several Anne Arundel River Associations are trying to figure this out. The Gunpowder Riverkeeper Organization has been asked to help.
Different satellite cameras have different resolutions. Some can only distinguish an area approximately one kilometer round. Others, can narrow the focus to as little as sixty meters. Of course, it takes the cameras with narrower foci many more revolutions around the planet to take pictures covering the entire planet. The program is designed to compare data sampled directly from the water, with the data from the satellite imagery. Volunteers will test for suspended sediment, water color, a measure of decaying vegetation, and reflectivity, a measure of chlorophyllic activity. These tests from the waters will be compared to the satellite data to determine how precisely the space images conform to reality.
Is there a ninety percent correlation, or barely forty percent? At this stage, no one is quite sure. However, with the combination of ground-based and space-based testing, this can be made clear.
If the correlation is quite good, the data can be compared to other data, such as storm-water run-off, agricultural chemical run-off, or development-related sediment spillage. Then, it can be used for policy-making decisions concerning tidal rivers and estuaries. As they say, “Good data makes for good policy.” Once the data is tested and validated, the same process can be used for tidal rivers and bays around the world. Thus, we will be in on the ground floor of space-based estuarine science. We will have helped create the model for how to measure water quality.
It is anticipated this year’s focus for testing will be in the waters around Anne Arundel County. By 2023 the plan is to expand the data collection into the tidal areas of the northern Chesapeake. The Gunpowder Riverkeeper Organization is enthused about the potential for taking part in what is, literally, a grand experiment.
