Gauge Conversion Effects on Long-Term Precipitation Comparison and Records

Climate sites measure precipitation using a variety of methods and sensors. Each individual sensor has its own catch efficiency which varies with solid and liquid precipitation. A climate site’s precipitation record may contain data from two or more types of precipitation gauges. Using parallel data from the accumulation gauges at four SNOTEL sites in Alaska, comparisons were made of the effects gauge transitions have had on the long term record. The records of each site indicate that significant change in gauge catch can occur with gauge transitions, though the variations cannot be tied to gauge type alone. These transitions should be taken into consideration when developing long-term assessments and while comparing recent data with earlier years. (KEYWORDS: precipitation gauge, SNOTEL, long-term precipitation records)