Lake Sunapee Instrumented Buoy: High Frequency Water Quality Data - 2007-2021

The Lake Sunapee (Global Lake Ecological Observatory Network—GLEON) instrumented buoy, operated by the Lake Sunapee Protective Association (LSPA www.lakesunapee.org), is equipped with a thermistor chain, one optical dissolved oxygen probe suspended at approximately 10 meters depth (installed in 2013), and a multi-parameter sonde (installed in 2021) at 1 meter depth. An optical dissolved oxygen (DO) probe was located at 1.5 meter prior to the 2021 deployment of the multi-parameter probe from the inception of the buoy and the deep DO sensor was at 10.5 meters depth prior to 2021 since deployment. The number of thermistors and below-surface depth of the thermistors has fluctuated throughout the years and the additional water quality sensors have changed over time. The Lake Sunapee buoy is located near Loon Island Lighthouse (43.391°N, 72.058°W) during the summer months and in the Lake Sunapee Harbor (43.386°N, 72.081°W) (2010-current). During the first few years of data collection (2007-2010), the buoy was located near Loon Island year-round. In two instances, HOBO units were deployed at the buoy's location when sensors failed. This occurred in 2015 (in place of the thermistors) and in 2018 (in place of the shallow DO sensor). All data in this data package have been QAQC'd to remove obviously errant readings, highly suspicious readings, and artifacts of buoy maintenance. Additionally, flags have been added per sensor, to indicate calibration and non-calibration of the optical DO probe, location of the buoy, and to document other potential confounding observations. Dissolved oxygen data and data from the multi-parameter probe are “raw”: they are have not been corrected for calibration issues, drift, or fouling. Additional documentation and data are provided including manual DO measurements, visual comparisons of buoy-recorded DO and manual DO measurements, and an overview of how and where DO offsets applied in the data logger program were removed.