Mouth of Columbia Wind Spring and Fall Transition

Each year, along the Pacific Coast of North American between San Francisco (38 North Latitude) and the Queen Charlotte Islands (52 North Latitude), the coastal winds switch from the southerly winds of winter to the northerly winds of summer producing a transition in wind called the spring transition. Conversely, the yearly switch back from the northerly winds of summer to the southerly winds of winter produce a fall transition. The summer winds, which occur after the spring transition and prior to the fall transition, are known to be favorable for upwelling -- a process that transports the nutrients to the ocean surface, feeding the near-shore food chain. Estimates of the transition dates were derived from smoothed synthetic winds computed by the ocean surface currents model OSCURS (Ingraham and Miyihara 1988), which used daily sea level atmospheric pressure fields for years 1946 to 1994 as input. The spring and fall transition dates were calculated for the latitude of the Columbia's mouth (46 deg 12' North Latitude). The data set is provided courtesy of the U.S. Army Corps of Engineers, Northwestern Division, North Pacific Region, Engineering and Technical Services, Water Management Division. The Mouth of the Columbia Wind Spring and Fall Transition Dates data set is featured at the University of Washington, School of Aquatic and Fisheries Sciences, Data Access Real Time (DART) program. DART provides an interactive data resource designed for research and management purposes relating to the Columbia Basin salmon populations and river environment. Currently, daily data plus historic information dating back to 1910 is accessible online. DART focuses on the Columbia Basin dams and fish passage. Detailed information is brought in daily from federal, state and tribal databases to provide a comprehensive information tool. DART generates user-specified data files which can be saved to a user's personal directory in a variety of formats designed to be compatible with most spreadsheet programs. In addition, DART has graphing capabilities which allow for the visual comparison of multiple variables on one plot. These output formats are available for the following data resources related to fish passage, PIT tags and the river environment. [ Reference: PICES Scientific Report No. 18 2001, Proceedings of the PICES/CoML/IPRC Workshop on "Impact of Climate Variability on Observation and Prediction of Ecosystem and Biodiversity Changes in the North Pacific", http://www.pices.int/publications/scientific_reports/Report18/default.aspx. ] Deposited content: descriptive metadata only; underlying research data are not included.