HR: 0800h
AN: C21B-0455    [Abstracts]
TI: Potential Biases of April 1 Snow Water Equivalent Records
AU: * Montoya, E
EM: montoya@pstat.ucsb.edu
AF: University of California, Department of Statistics and Applied Probability, Santa Barbara, CA 93106-3110, United States
AU: Dozier, J
EM: dozier@bren.ucsb.edu
AF: University of California, Donald Bren School of Environmental Science and Management, Santa Barbara, CA 93106-5131, United States
AU: Meiring, W
EM: meiring@pstat.ucsb.edu
AF: University of California, Donald Bren School of Environmental Science and Management, Santa Barbara, CA 93106-5131, United States
AB: We compare snow water equivalent (SWE) measurements from snow pillows and snow courses in the Sierra Nevada. Specifically, we use daily measurements from snow pillows to study potential biases when using the April 1 snow course measurements in trend studies. We also study variation in the amplitude and phase of the seasonal cycle in pillow-based SWE profiles. SWE trend studies usually use snow course data because of the length of record, almost always employing April 1 snow course measurements as a surrogate for peak snowpack or for the total amount of precipitation. Questions arise as to whether the April 1 snow course measurements over- or underestimate the peak, thus possibly introducing biases in the trend estimation. Snow pillows provide daily records of SWE across the whole year. At snow pillows we estimate the peak and total amount of precipitation based on the SWE profile. We compare these with April 1 SWE measurements from nearby snow courses. Both amplitude and phase variability in the seasonal cycle contribute to potential biases of April 1 records. We present statistical curve registration summaries of seasonal cycle variation in daily snow pillow records, including relationships between the amplitude and timing of the seasonal peak. This provides further insight on the nature of potential biases.
DE: 0736 Snow (1827, 1863)
DE: 0740 Snowmelt
DE: 1863 Snow and ice (0736, 0738, 0776, 1827)
DE: 3299 General or miscellaneous
SC: Cryosphere [C]
MN: 2007 Fall Meeting