Then, the other side of the gauge fills, and the bucket tips back, and so forth. Each switch activation is recorded by the datalogger and stored on the departmental UNIX system. Spent water drains out the bottom of the gauge. The pressure sensor used here is a Setra Model 276 pressure transducer. The Wind Mark IIIa wind sensor measures the wind speed and direction with separate sensors.
Wind speed is measured with the three-cup anemometer pictured above.
The frequency is proportional to wind speed. We have thus far only undertaken rough calibration of the wind direction, so there may be an error of up to 20 degrees in our currently reported values. More careful calibration will be made shortly. The rooftop weather station and the rooftop web page were set up by Prof. Gary Lackmann of the Department of the Earth Sciences . Any comments, suggestions, or questions concerning these data or instruments should be sent to the Earth Sciences Department Secretary by clicking here.