CADIC   02618
CENTRO AUSTRAL DE INVESTIGACIONES CIENTIFICAS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
UV Irradiance and AOD Variation in the Nahuel Huapi National Park (Patagonia, Argentina) After the Eruption of Puyehue- Cordon Caulle (Chile)
Autor/es:
S. B. DIAZ; A. A. PALADINI; H. G. BRAILE; M. C. DIEGUEZ; G. A. DEFERRARI; M. VERNET ; J. VRSALOVIC
Lugar:
Natal
Reunión:
Simposio; Joint 13th Quadrennial iCACGP Symposium and 13th IGAC Science Conference; 2014
Institución organizadora:
IGACGP IGAC
Resumen:
On June 4th, 2011, the Puyheue-Cordon Caulle volcanic
complex (40°35′25″S 72°07′02″W, Chile)
started eruption, sending ash 45,000 feet into the atmosphere. After the initial period,
the eruption continued for several months, with less intensity. Changes in global irradiance in the
UV-B and UV-A, and direct irradiance and AOD in the UV-A, as consequence of the
eruption, were studied. Global irradiance has been permanently measured at the
Laboratory of Photobiology (LPh) (41.13S, 71.42W, 804m.s.l.) since 1998. In
addition, in the frame of a project to study altitude
effect on direct and global irradiance, field campaigns were performed during
September 17th to 23rd, 2010 and September 14th
to 18th, 2011, in the region of the Nahuel Huapi
National Park, near 100
km from the eruption. In those periods, simultaneous measurements of direct and global irradiance
and aerosol optical depth (AOD) were carried out at three sites: Laboratory of
Photobiology (LPh), Mt Otto (41.15S, 71.38W, 1386m.s.l.) and Mt Catedral
(41.17S, 71.48W, 1930m.s.l.). The analysis of aerosols in 2011, three to four
month after the eruption started, showed the presence of larger particles and
more variability than in 2010, at all sites. Global irradiance, at LPh, also
exhibited larger variability, compared to 1999, when no
eruption or any other event that could have produced major changes in aerosols occurred. The mean decrease, as consequence of the
volcano activity, at LPh, was around 20%, at 305 nm and closed to 10%, at 320
nm. At 380 nm, the decrease was very small and not statistically significant,
although in particular days, with large aerosol load, a significant decrease
was observed. Direct irradiance, in the UV-A, showed larger decrease than
global irradiance. The effect of the eruption was more pronounced at the low
altitude site. This study did not use GAW data, but shows the importance of collecting
background data, as is the case for GAW stations.