UV Irradiance and Albedo at Union Glacier Camp (Antarctica): A Case Study

Abstract

We report on the first spectral measurements of ultraviolet (UV) irradiance and the albedo at a Camp located in the southern Ellsworth Mountains on the broad expanse of Union Glacier (700 m altitude, 79° 46′ S; 82° 52′W); about 1,000 km from the South Pole. The measurements were carried out by using a double monochromator-based spectroradiometer during a campaign (in December 2012) meant to weight up the effect of the local albedo on the UV irradiance. We found that the albedo measured at noon was about 0.95 in the UV and the visible part of the spectrum. This high surface reflectivity led to enhancements in the UV index under cloudless conditions of about 50% in comparison with snow free surfaces. Spectral measurements carried out elsewhere as well as estimates retrieved from the Ozone Monitoring Instrument (OMI) were used for further comparisons.

Spectral Characterization, Radiative Forcing, and Pigment Content of Coastal Antarctic Snow Algae: Approaches to Spectrally Discriminate Red and Green Communities and Their Impact on Snowmelt

“…LAPs influence spectral albedo in the visible spectrum, 400 -700 nm (Warren and Wiscombe, 1980). Spectral albedo is further dependent on physical snow properties such as specific surface area, i.e., grain size and shape, e.g., (Cordero et al, 2014), liquid water content, surface roughness, snow depth, albedo of underlying ground (for thin snow packs), and snow density (Flanner et al, 2007). Aged snow that has collected LAPs, typically has an albedo around 0.5 -0.7, and in extreme cases of organic LAP content, can range below 0.2 (Khan et al, 2017).…”

Solar UV Irradiance in a Changing Climate: Trends in Europe and the Significance of Spectral Monitoring in Italy

“…In urban environments changes in aerosols may counterbalance the effect of even extremely high or low total ozone events, and lead to erythemal irradiance above or below the climatological averages respectively [35]. Surface albedo is an additional important regulatory factor for the levels of UV irradiance, since multiple reflections between the Earth's surface and the atmospheric constituents enhance UV irradiance over highly reflective (e.g., snow-or ice-covered) terrains [36,37]. Over highly reflective terrains and under broken cloud conditions short-term enhancement can be of the order of 50% [38].…”

Growth and lipid profiles of the Antarctic snow microalga Chlamydomonas sp. In response to changes in temperature, photoperiod, salinity and substrate

“…The PPF at coastal Antarctic areas varies between 0.1 µmol m -2 s -1 in winter and 2,000 µmol m -2 s -1 in the summer (Pannewitz et al 2003). Further, the springsummer seasons result in a significant increase in surface UV radiation (Cordero et al 2014). The adaptive responses of microalgae (Gomez et al 2009) and snow microalgae to photosynthetically active radiation (PAR) at this broad range of light intensity and light quality (wavelength) as well as the limiting threshold for the production of cold-response proteins and lipids with cryoprotective potential are still poorly understood (Lyon et al 2014).…”