Scott K. Johnson: Lake Science Using Remote Sensors

Ars Technica:

Rensselaer Polytechnic Institute

Rensselaer Polytechnic Institute

The largest streams that flow into Lake George are now being monitored year-round by sampling stations. Water is pulled into a heated enclosure (ice isn’t helpful) where it is analyzed by a data-logging device with probes for things like temperature, pH, dissolved oxygen, conductivity, dissolved organic matter, and algae content. Other instruments measure the water level and flow velocity of the stream. The data is periodically uploaded over a cellular Internet connection and entered into the project database. And at the same time, a carousel of sample bottles is automatically filled and periodically retrieved for additional tests in the analytical chemistry labs back at the field station.

That same kind of data-logger is also going to be active out in the lake itself, operating from a set of anchored, floating platforms. The floats raise and lower the data-loggers, allowing them to sample a vertical profile of the lake. That’s enormously useful, because the lake stratifies into a warmer surface layer and a cooler deep portion (as most lakes do). The first two floats hit the lake last summer, but five will go out this spring after the ice melts.

A number of current profilers will be placed at the bottom of the lake as well. These devices bounce acoustic waves off particles drifting by, using the slight Doppler shift of the returning waves to calculate velocities at various heights above the device. For now, they will simply store data to be downloaded when they are retrieved, but they may run cables in the future to allow near real-time access.

Very cool. Data and models will provide useful information for lake management.