Regional Climate: Current Research
Developing 20th Century Precipitation and Temperature Datasets for the Pacific Northwest
The U.S. National Climate Diagnostics Center recently digitized daily time-step precipitation and temperature data from co-operative weather station records for the continental U.S. dating back to the beginning of the written records for each station. Similar records are available in Canada.
In the Pacific Northwest (PNW), the station density of these records is adequate for large scale hydrologic modeling studies back to about 1915. Preliminary studies using this data showed, however, that there were significant problems with temporal inhomogeneities in the early part of the record that limited the usefulness of the data for trend analysis and for studies of the regional impacts of natural climate variability.
This project will design statistical methods to remove these temporal inhomogeneities from the observations without resorting to extremely labor intensive station-by-station corrections. Relatively high quality monthly meteorological data sets from the Historical Climate Network (HCN) in the U.S. and the Historical Canadian Climate Database (HCCD) in Canada will be used to remove the inhomogeneities in the daily co-op data. Future work will include extending retrospective Columbia River basin hydrologic simulations back to 1916 using these corrected datasets.
- What statistical methods and sources of data can be developed to remove temporal inhomogeneities from observed daily time step temperature and precipitation records? How can these methods best be tested for effectiveness using models and observations?
- What are the long-term trends in PNW temperature and precipitation over large spatial scales?
- What are the trends in hydrologic variables such as snowpack and soil moisture associated with the trends in temperature and precipitation?
- What are the relative contributions of natural climate variability and anthropogenic climate change to these trends?