Mountain lakes air and water temperature report: 2008-2011 data summary, North Coast and Cascades Network
Glesne R, Baccus W, Fradkin SC, Samora B, Lofgren R, Welch C. 2015. Mountain lakes air and water temperature report: 2008-2011 data summary, North Coast and Cascades Network. Natural Resource Report. NPS/NCCN/NRR—2015/1100. National Park Service. Fort Collins, Colorado
This report provides the first look at continuous air and water temperature data collected between 2008 and 2011, from 20 mountain lakes monitored annually as part of the North Coast and Cascades Network (NCCN) Mountain Lakes Monitoring Protocol. Of the 20 “core” reference lakes, six lakes each are at Mount Rainier National Park (MORA) and North Cascades National Park Service Complex (NOCA), and eight lakes are located at Olympic National Park (OLYM). Reference lakes were randomly selected from a target population of lakes ranging from 0.4 to 6.0 ha in surface area and at elevations (1220-2046 m) representing the upper elevation limit of the montane zone (high forest) and subalpine zones of each park. NCCN lakes located in this intermediate elevation zone are considered as ultra-sensitive to climate change due to their unusually low water temperature, and because modest increases in future air temperatures will lead to major changes in lake temperatures and ice-cover duration with consequent effects on their ecological status. This report provides an initial summary and discussion of continuous air and water temperature data collected from the core monitoring lakes at all three parks during the period of January 2008 through December 2011. This overview includes: an examination of air and water temperature patterns occurring throughout each year at each of the core lakes; a comparison of temperature patterns among lakes in the three parks; an evaluation of temperature response variables that may be useful for reporting climate changes and trends and interpreting biological, chemical, and physical parameters; and an examination of issues related to quality assurance and quality control. Lake surface water temperature response variables at all three parks were strongly influenced by substantial increases in snowpack, delayed snowmelt and colder than average June 1st air temperatures during the 2010-2011 La Niña phase. On average, summer turnover occurred 55 days later in 2011 than in 2009. Lakes with the greatest delays in summer turnover dates included most lakes at OLYM and lakes located on the west side of the Cascade Crest in NOCA. Fall turnover showed very little year-to-year variation, occurring during late October and early November at all of the NCCN lakes between 2009 and 2011. The above normal snowpack and colder air temperatures in the late springs of 2010 and 2011 delayed ice-out and, consequently, shortened the ice-free season. The average number of ice-free season days for all lakes declined from 119 days in 2009 to 66 days in 2011. Five of the NCCN lakes exceeded the 20°C threshold for Index of Thermal Stress during the 2009-2011 sampling period, with all exceedances occurring only in 2009. Results indicated that native biota at Sunup Lake (OLYM), and possibly at Upper Deadwood Lake (MORA), may be particularly vulnerable to thermal stress if climate warming occurs.
- Type
- Published Report
- Authors
- Glesne, Reed; Baccus, William; Fradkin, Steven; Samora, Barbara; Lofgren, Rebecca; Welch, Carmen
- Date of Issue
- 2015-12
- Publisher
- National Park Service
- Units
- MORA , NOCA , NRSS , OLYM
- Keywords
- Air Temperature, Climate, continuous temperature, Core, El Nino, Elevation, FDD, Freezing degree-day, HDD, Heating Degree-Day, ice-cover, Index of Thermal Stress, Lakes, Long Term Monitoring, Monitoring, Montane, Mount Rainier National Park, Mountain Lake, Mountain Lakes Monitoring, North Cascades National Park, North Coast and Cascades Network, Olympic National Park, PWR-toolkit, Subalpine, Trend, turnover, Water Quality, Water Temperature
- Subjects
- Ecological Framework: Geology and Soils | Geomorphology | Lake Features and Processes , Ecological Framework: Water | Hydrology | Surface Water Dynamics , Ecological Framework: Water | Water Quality | Water Chemistry , Ecological Framework: Biological Integrity | Focal Species or Communities | Freshwater Communities