Climate data for Saddle chart recorder, 1981 - 1982.

Climatological data were collected from a Niwot Ridge climate station (Saddle, 3525 m) throughout the year. Parameters measured were temperature, relative humidity, solar radiation, and precipitation. Although wind speed, wind direction, and barometric pressure were originally listed as parameters for this data set, no values were actually found to be present in the data and these columns were therefore removed from the data set. 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 is oriented with the door facing north. The station was instrumented with a recording precipitation gauge. Precipitation was caught in a bucket containing ethylene glycol (to melt snow) and light oil (to prevent evaporation). As the weight of the bucket increased, a pen moved up via a spring mechanism and recorded on a rotating chart. A snow fence was placed around the gauge to give more accurate precipitation measurements during windy conditions. 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. Wind speed (peak gust) was measured with a 3-cup, AC-generating anemometer that continuously recorded onto an Esterline Angus strip chart recorder. Wind direction was recorded as a pen position on a continuously recording strip chart. The thermohygrograph, rain gauge, and actinometer 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 instrum