North Temperate Lakes LTER: High Frequency Water Temperature Data - Trout Lake Buoy 2004 - current

The instrumented buoy on Trout Lake is equipped with a thermistor chain that measures water temperature from thermistors placed throughout the water column. From 2004 to mid-summer 2006, thermistors were placed every 0.5-1m from the surface through 14m, and every 2 to 4m from 14m to the bottom of the water column at 31m. The surface temperature sensors are attached to floats so that they are as close to the surface as feasible. In July 2006, a new thermistor chain was deployed with sensors placed every meter from the surface through a depth of 19 meters. This configuration lasted through 2008 and was used again 2012-2014. In the period 2009-2011, thermisters were place every meter down to 20m and then every two meters to a final depth of 32m. From 2015 to present, thermistors are spaced 0.25 meters from the surface to 1m, 0.5 meters down to 4 meters depth, and 1m spacing to 14 meters. Four more thermisters are at depths of 16, 20, 25 and 30 meters. Sampling frequency was 10 minutes in 2004-2005 and again 2007-2010. It was 2 minutes in 2006. Since 2011, sampling frequency has been every minute.
The Trout Lake buoy is also equipped with a dissolved oxygen sensor and meteorological sensors that provide fundamental information on lake thermal structure, weather conditions, and lake metabolism. After correcting for flux to or from the atmosphere and vertical mixing within the water column, high frequency measurements of dissolved gases such as carbon dioxide and oxygen can be used to estimate gross primary productivity, respiration, and net ecosystem productivity, the basic components of whole lake metabolism. Number of sites: 1. Hourly and daily averages are computed from the high resolution data.