THE MAMMOTH MOUNTAIN COOPERATIVE SNOW STUDY SITE: DATA ACQUISITION, . MANAGEMENT, AND DISSEMINATION Thomas H. Painter, Deborah Donahue, Jeffrey C. Dozier, Weimin Li, Richard Kattelmann, Daniel Dawson University of California, Santa Barbara, California Robert E. Davis, John Fiori, Bryan Harrington Cold Regions Research and Engineering Laboratory, US Army Engineer Research and Development Center, Hanover, New Hampshire PaulPugner Sacramento District, US Army Corps of Engineers, Sacramento, California ABSTRACT: The University of California, the U.S. Army Corps of Engineers and Mammoth Mountain Ski Area collaborate in a snow study site located at 2960 m on Mammoth Mountain in the Sierra Nevada of California. At this site we monitor virtually all of the important processes and properties of snow cover representative of the sub-alpine to alpine transition zone of a maritime snow cover. Measured components of the surface energy exchange include incoming direct and diffuse solar radiation, red-band solar radiation, longwave radiation, wind speed at two levels, air temperature and humidity. They also include reflected solar and red-band radiation and surface temperature. Measurements of the snow include precipitation via a gage, standard snow boards and a prototype digital snow board, the total snow water equivalent of the pack, its depth and the temperature profile across the soil-snow interface. A set of Iysimeters collects meltwater that reaches the soil surface. A digital camera collects hourly images of the array of pyranometers and the site surroundings to check for rime. In 1999, we established a data and communication protocol to assure data quality and continuity and to facilitate real time data availability. We have automated hourly data retrieval, quality checking, and ingestion into the UCSB Snow Hydrology database. Data and communication errors activate automatic email notification to site operators and database managers. Users may acquire the hourly data via the Internet in ASCII format, input format for the CRREL SNTHERM.89 snow model, and for the Utah Energy Balance model. KEYWORDS: Snow, Energy Balance, Measurement, Database INTRODUCTION The University of California at Santa Barbara, the U.S. Army Corps of Engineers, and Mammoth Mountain Ski Area collaborate in a snow study site located at 2960 m on Mammoth Mountain in the Sierra Nevada of California. At this site we monitor virtually all of the important processes and properties of snow cover representative of the sUb-alpine to alpine transition zone of a maritime snow cover. Researchers and research staff also make a variety of manual measurements at the site, which has operated at the current location in Mammoth Mountain Ski Area since 1987. The site lies well out of the way of ski area operation and recreational ski traffic so that the snow remains undisturbed from accumulation through melting. The site's position, on the east side of the Sierra crest near the headwaters of the San Joaquin River, makes environmental conditions sensitive to different types of storms, which typically result in an enormous amount of precipitation and severe winds. These weather conditions, along with ease of winter access via the ski area, make this an ideal spot for monitoring alpine snow. In 1999, we initiated a data management plan designed to meet three data goals: data quality, data continuity, and data availability. Prior to this management protocol, data underwent quality checking and became available to users several months after acquisition. Under this system, some instrumentation lay inoperable and undetected for months, producing immense voids in the data record. In order to address these deficiencies, we set the above data goals and invested in hardware, software, and homegrown scripts. We now have an automated system of data retrieval, data domain and communication checking, email communication to site and database managers, ingestion into the UCSB Snow Hydrology database, and near-real time distribution of the data via the World Wide Web. Additionally, we manually review all data fields on a sub-weekly basis for enhanced quality assurance. b Corresponding Author: Thomas H. Painter, Institute for Computational Earth System Science, University of Califomi a, Santa Barbara, CA, 93106, phone: (805) 893-8116, fax: (805) 893-2578, E-mail: painter@icess.ucsb.edu 447