The water temperature in lakes, rivers and streams has significant impacts on water quality, fish habitats, and local economies and is linked to regional/large-scale climate variability. This project analyzed Jun-Aug average water temperatures at seven rivers/streams situated along the southern coast of Alaska and one in arctic Alaska. These sites were selected primarily due to data availability (decades of data are needed for climate-scale analysis). The summer season was selected because potential temperature-related tipping points for the aquatic ecosystem occur in the warm season and mechanisms of summer climate variability in Alaska are generally the least understood of any season. Analysis showed that all streams tend to have warmer temperatures when local near-surface temperatures were warmer than average. Reduced cloud cover under persistent high pressure aloft generally was the catalyst for warmer temperatures. A potential link between sea surface temperatures, the Pacific Decadal Oscillation and stream temperatures was identified but a conclusive physical mechanism linking the two could not be established. The summer atmospheric circulation around Alaska generally lacks the active storm tracks/clear centers of action of the cold season and further study will be needed to explain the linkage between the broader climate and stream temperature variability.
Temperature data was collected for 8 different sites (7 stream/rivers, and 1 lake) and is available for download.
