Downward spectral solar irradiance as measured in different depths under sea ice (transmitted irradiance) at ROV station PS81/566-1

Abstract

Measurements of solar radiation over and under sea ice have were carried out during the expedition ANT-29/7 of the German ice-breaker R/V Polarstern during the 'Winter studies on sea ice and key species' (WISKEY) project in the northern Weddell Sea. The given data were collected during the second ice camp from 18 to 26 September 2013 on a 100m-by-100m grid during 17 dives of the Remotely Operated Vehicle (ROV). All radiation measurements have been performed with Ramses spectral radiometers (Trios, Rastede, Germany). All data are given in full spectral resolution interpolated to 1.0 nm, and integrated over the entire wavelength range (broadband, total: 320 to 950 nm). One irradiance sensor (cos-collector) was mounted on the ROV and one radiometer was installed on the sea ice for surface reference measurements (solar irradiance). Along with the radiation measurements, ROV positions were obtained from a long baseline positioning system (LBL) consisting of a Woods Hole Oceanographic Institution (WHOI) FSK micro-modem equipped with an ITC 3013 transducer (mounted on the ROV) and interrogating four Benthos XT-6001 transponders (15 m depth) which were coupled to surface GPS units and spaced around the survey site in a rectangle with 400 m side length. All times are given in UTC.