High penetration of ultraviolet radiation in the south east Pacific waters
Article first published online: 27 JUN 2007
Copyright 2007 by the American Geophysical Union.
Geophysical Research Letters
Volume 34, Issue 12, June 2007
How to Cite
2007), High penetration of ultraviolet radiation in the south east Pacific waters, Geophys. Res. Lett., 34, L12610, doi:10.1029/2007GL029823., , , , , , , and (
- Issue published online: 27 JUN 2007
- Article first published online: 27 JUN 2007
- Manuscript Accepted: 16 MAY 2007
- Manuscript Revised: 26 APR 2007
- Manuscript Received: 27 FEB 2007
- south east Pacific;
- South Pacific Gyre;
- ultraviolet radiation
 We investigated the penetration of solar ultraviolet radiation (UVR) in the surface waters of the south east Pacific (08–35°S, 142–73°W) from October to December 2004 during the BIOSOPE cruise. In the hyper-oligotrophic waters of the South Pacific Gyre (near Easter Island), diffuse attenuation coefficients for downward irradiance, Kd(λ), at 305 nm (UV-B), 325, 340 and 380 nm (UV-A) were 0.083, 0.055, 0.039 and 0.021 m−1, respectively. The corresponding 10% irradiance depths, Z10%(λ), were 28, 42, 59 and 110 m, respectively. These UVR penetrations are the highest ever reported for oceanic waters and are equal to those measured in the clearest fresh waters. UV-extended inherent optical property (IOP) and radiative transfer (RT) models allowed reliable estimations of Kd(λ) with the Case 1 water assumption when two values of chromophoric dissolved organic matter (CDOM) absorption spectral slope coefficient (S) were used, i.e. 0.017 nm−1 at 325, 340 and 380 nm, and 0.023 nm−1 at 305 nm.