UV climatology at Palmer Station, Antarctica, based on version 2 NSF network data

Network. Here we present a UV climatology for Palmer Station based on the recently produced “Version 2 ” data edition. This data set will supersede the original release “Version 0”. Corrections applied to the new version increased biologically effective UV dose rates by 0-9%. Values of UV-A irradian...

Full description

Bibliographic Details
Main Authors: Germar Bernhard, Charles R. Booth, James C. Ehramjian
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
Subjects:
Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.504.9810
http://uv.biospherical.com/presentations/SPIE_588607.pdf
Description
Summary:Network. Here we present a UV climatology for Palmer Station based on the recently produced “Version 2 ” data edition. This data set will supersede the original release “Version 0”. Corrections applied to the new version increased biologically effective UV dose rates by 0-9%. Values of UV-A irradiance changed by –8 % to +10%. A comparison with results of a radiative transfer model confirmed that measurements of different years are consistent to within ±5%. Total ozone column was calculated from UV spectra and was found to agree with measurements of NASA’s Total Ozone Mapping Spectrometer (TOMS) installed on the Nimbus-7 satellite to within 1%. TOMS measurements on the Earth Probe satellite are 3 % lower than SUV-100 data. Effective surface albedo was estimated from clear sky spectra. Between August and November, albedo typically ranges between 0.6 and 0.95. After melting of snow and sea ice, albedo varies between 0.3 and 0.5. Biologically effective UV radiation is largest in November and December when low total ozone amounts coincide with relatively small solar zenith angles (SZA). During these months, the noon-time UV Index typically varies between 4 and 7, but UV indices as high as 14.8 have been observed. The largest erythemal daily dose of 8.8 kJ/m was measured on 11/10/97 and 12/7/98. Linear regression analyses did not indicate statistically significant trends in UV or visible radiation, with the exception of February when small downward trends with statistical significance were observed. On average, clouds reduce UV irradiance at 345 nm between 28 % (October and November) and 42 % (February) compared to clear sky levels. In extreme cases, reductions by clouds can be as high as 90%.