Lake Fryxell photosynthetically active radiation measurements, McMurdo Dry Valleys, Antarctica

Under-ice and water column photosynthetically active radiation (PAR) was measured in Lake Fryxell, located in the McMurdo Dry Valleys region of Antarctica, on 18 November 2012, 26 December 2022, and 17 January 2025 to track changes in irradiance transmission over time. In 2012 and 2022, a diver-deployed LI-COR LI-192R quantum sensor connected to a LI-1400 data logger recorded PAR (µmol photons m⁻² s⁻¹) beneath the ice along radial transects from the dive hole, while simultaneous measurements at the lake surface were used to calculate percent transmission. In 2025, a PME miniPAR logger (µmol photons cm⁻² s⁻¹) mounted on a Chasing M2 ProMax remotely operated vehicle (ROV) collected under-ice PAR, with concurrent surface measurements using a LI-192R sensor to calculate percent transmission.