Climate data for C1 chart recorder, 1982 - 1988.

Climatological data were collected from a Niwot Ridge climate station (C1 at 3018 m) throughout the year. Parameters measured were temperature, relative humidity, solar radiation, barometric pressure, wind speed, and run of wind. The station was instrumented with a thermohygrograph (regularly calibrated and checked with maximum and minimum thermometers and psychrometers), which was equipped with a Bourdon tube (to measure temperature) and a banjo-spread hair element (to measure relative humidity). The thermohygrograph was situated in a white, all wood, louvered Stevenson screen which was oriented with the door facing north. Solar radiation was recorded on a bimetalic strip mechanical actinometer. Ninety percent of solar radiation from 360 to 2000 nm was transmitted through the instrument's glass dome. Barometric pressure was recorded on a Friez microbarograph at the Mountain Research Station at 2880 m. The instrument was calibrated against a full-range mercurial, Fortin-type barometer. Wind speed (peak gust) was measured with a 3-cup, AC-generating anemometer that continuously recorded onto an Esterline Angus strip chart recorder. Average wind speed was calculated from the peak gust trace. Run of wind was measured with a Belford totalizing cup anenometer with a counter (at a height of approximately 3 meters above ground). The thermohygrograph, actinometer, and microbarograph all used wind-up or battery-driven clock drives that rotated the recording chart on a right cylindrical drum with a fixed period between 24 h and 861 h depending on the gears used. These clock mechanisms were virtually identical and therefore completely interchangeable among the instruments.