New continuous total ozone, UV, VIS and PAR measurements at Marambio 64° S, Antarctica

Abstract

A GUV multifilter radiometer was set up at Marambio, 64 • S 56 • W, Antarctica, in 2017. The instrument measures continuously ultraviolet (UV) radiation, visible (VIS) radiation and photosynthetically active radiation (PAR). The measurements are designed for providing high quality long-term time series which can be used to assess the impact of global climate change in the Antarctic region. The quality assurance includes regular absolute calibrations and solar comparisons performed at the site and at Sodankylä, Finland. The actual measurements continue the time series measured at Marambio with NILU-5UV radiometers during 2000-2010 as part of the Antarctic NILU-UV network. They are optimal for assessing the effects of the ongoing stratospheric ozone recovery on the ecosystem as the data products include information on radiation at various wavelengths ranging from UV to VIS so that changes on biologically effective radiation due to ozone can be separated from those due to other factors. The final data products are total ozone, PAR, VIS radiation at 555 nm, UV index, UV irradiance at 5 channels, UVB and UVA dose rate/daily dose, and biologically weighted UV dose rate/ daily dose, including 10 different 10 action spectra. The data from the last five days and the daily maximum UV index time series are plotted and updated daily on the web page fmiarc.fmi.fi/sub_sites/GUVant/. The first two years of UV measurements were very different in terms of the results: The monthly average of daily maximum UVB dose rates were clearly higher in 2018 than in 2017 during the period from October to December. The largest difference was observed in October, when the average of daily maximum UVB dose rates was 7.6 kWm −2 and 10.2 kWm −2 in 2017 and 2018, respectively. The monthly averages were close to each other for all 15

Assessment of spectral UV radiation at Marambio Base, Antarctic Peninsula

“…In the Antarctic Peninsula region, both Adhikari et al (2012), Lachlan-Cope (2010) and Scott et al (2017) found 205 the cloud cover minima in winter and maxima in summer. However, due to the large cloud cover variability, mentioned also in Aun et al (2020), the results presented in this study might have been affected by the choice of study period.…”