History of S. RI Methods
Data & Results
Publications
Bibliography
Links
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Circulation methods
ADCPAn RD Instruments Acoustic Current Doppler Profiler (ADCP) measures the speed and direction (velocity) of the currents in the pond. In order to determine the influence of the tidal flow, the entire tidal cycle needs to be measured. |
Tide gaugesIn-Situ, Inc. Troll, Model SP4000 YSI 6800 |
Weather StationA Davis weather station records wind velocity, temperature, barometric pressure, and rainfall. This station can be set up for remote access, or can be downloaded manually. |
How it works: The ADCP has a transducer and receiver. The transducer sends out an acoustic signal (75-1200 kHz frequency) which bounces off tiny particles in the water. Based on the velocity of the particle, there is a measurable Doppler shift. The receiver picks up this return signal and the computer calculates the velocity based on the Doppler shift. There are actually four transducers, so the instrument can measure the currents in the whole water column. For details click  . |
How it works: Inside of a tide gauge there is a pressure sensor. It stays anchored in one place underwater (either bolted onto a board or in a stilling well) and measures the amount of water above it--the more water, the greater the pressure. The gauge records the pressure changes internally, then gets uploaded and computer programs convert the pressure data to water level data. | How it works: This instrument has a traditional anemometer and directional flag, as well as pressure and temperature sensors. The rainfall gauge is separate. An internal computer stores the data. |