August 1, 2019.
The Marshall Field Site, located about ten miles southeast of Boulder, Colorado, is home to various precipitation and wind testing instruments to create data for the National Center for Atmospheric Research (NCAR). Precipitation data has been recorded for nearly 30 years using three main types of instruments, the Ott Pluvio II rain gauge, the Geonor 16” Single Alter gauge, and the Geonor double fence intercomparison reference (DFIR) gauge located in the southern region of the Marshall Site. The Ott Pluvio II gauge has data ranging back to 2012, the 16” Geonor dates back to 1994, and the DFIR Geonor dates back to 1999. The 16 inch Geonor is cheaper to install and takes up less space but the DFIR Geonor is more accurate at detecting snowfall due to its dual layer of fencing to keep the wind out. To further understand what trends the precipitation has caused over the years, data will be compared for each month of each year side by side to show the decline that has occurred over the last three decades. The data from the devices is sent to the Marshall site database, where the precipitation amounts are recorded in a Microsoft Excel spreadsheet and organized into charts or other means of visualization. The maximum and minimum amount of precipitation recorded each month is used to determine the average precipitation for the entire month. Results from the study have shown that the maximum precipitation in each month has decreased steadily over the years. Precipitation was much more spread out and normalized during the earlier years than the more recent ones. Data shows the precipitation trends for the Denver-Boulder region of Colorado, but it is likely that similar climates in the United States have followed the same patterns. Further data could show the trend the precipitation follows over the next 10 to 20 years.
National Center for Atmospheric Research (NCAR)
The 2019 STEM Teacher and Researcher Program and this project have been made possible through support from Chevron (www.chevron.com), the National Marine Sanctuary Foundation (www.marinesanctuary.org), the National Science Foundation through the Robert Noyce Program under Grant #1836335 and 1340110, the California State University Office of the Chancellor, and California Polytechnic State University with NCAR. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the funders.