Version 2 data of the National Science Foundation's Ultraviolet Radiation Monitoring Network: South Pole

摘要: [1] Spectral ultraviolet (UV) and visible irradiance has been measured at the South Pole between 1991 2003 by a SUV-100 spectroradiometer, which is part of U.S. National Science Foundation’s UV Monitoring Network. Here we present new data edition, labeled ‘‘Version 2.’’ The version was corrected for wavelength shift errors deviations spectroradiometer from ideal cosine response. A comprehensive uncertainty budget set established. Below 400 nm expanded standard (coverage factor 2) varies 4.6 7.2%, depending on sky condition. biologically relevant irradiances approximately 6%. Compared to previously published set, Version 2 are higher 5–14%, wavelength, solar zenith angle (SZA), year observation. By comparing with results radiative transfer model, good consistency homogeneity were confirmed. used establish climatology Pole, focusing effects aerosols, clouds, total column ozone. Clouds predominantly optically thin; 71% all clouds have an optical depth 0 1. average attenuation 345 less than 5% no attenuations greater 23% observed. Attenuation homogeneous generally larger in UV. dependence cloud quantitatively explained wavelength-dependent radiance distribution top incidence-angle transmittance. Largest radiation levels occur late November early December when low stratospheric ozone amounts coincide relatively small SZAs. Owing large effect ‘‘ozone hole,’’ short- long-term variability during austral spring very high. When hole disappears, DNA-damaging can decrease more two within days. Typical summer index values range 3.5 vary ±30% (±1s) different years. Linear regression analyses did not indicate statistically significant trends owing year-to-year fact that network established only after first occurrence hole. Current measurements therefore document elevated level. INDEX TERMS: 0360 Atmospheric Composition Structure: Transmission scattering radiation; 0394 Instruments techniques; 3359 Meteorology Dynamics: Radiative processes; KEYWORDS: radiation, UV, Antarctica, uncertainty,