Variation of the Ultraviolet Solar Radiation from South Pole to the Capricorn Tropic

SUSANA DIAZ; CAROLINA CAMILION; GUILLERMO DEFERRARI; CHARLES BOOTH; ROY AMSTRONG; SERGIO CABRERA; CLAUDIO CASSICCIA; HUMBERTO FUENZALIDA; CHARLOTTE LOVENGREEN; DON NELSON; ALEJANDRO PALADINI; JORGE PEDRONI; HORACIO ZAGARESE; MARIA VERNET

Buenos Aires

Taller; Primer Encuentro de la Red de Investigadores Argentinos en Cs. de la Heliosfera (RIARCHE); 2006

Instituto de Astronomia y Fisica del Espacio

After the discovery of the ozone hole many efforts have been performed to install instruments capable of measuring the effect of ozone variations on the UV-B radiation at ground level. In 1988 the National Science Foundation (EEUU) initiated the activities of the NSF UV Radiation Monitoring Network installing four spectro-radiometers SUV-100 in Antarctic and Sub-Antarctic stations (South Pole, Mc Murdo, Palmer and Ushuaia).  This network was lately improved with instruments installed at Barrow (Alaska), San Diego (California) and Summit (Greenland). The time series of the data of this network is one of the longest in the planet. South-America is also a region of particular interest for studies related to ozone depletion. During spring, when the area of the ozone hole increases and the vortex elongates, the southern tip of South–America is under the influence of the ozone hole. On the other hand, after the vortex break up, air mases poor in ozone coming from Antartica, overpasses the region. For that reason, at the early 90`s two networks of multi-channel radiometers (GUV-511) were installed, one in Chile (Santiago, Valdivia and Punta Arenas) and the other in Argentina (Jujuy, Buenos Aires, Trelew and Ushuaia), to study the latitudinal irradiance variation. In 1997 the Inter-American Institute for Global Change (IAI) approved a project to generate consistent databases of these instruments and to keep these instruments calibrated under the same standards. This task is being performed by the Laboratorio de UV y Ozono, CADIC, Ushuaia. In 1999 a new project was approved by the IAI , and three more instruments were added to the network (Two in Argentina, Trelew2 and Bariloche) and one in Puerto Rico (Las Lajas). These spectral and narrow band measurements allow to determine the effect of ozone variation on the surface irradiance, and also to compare climatological values at different sites. Since the multi-channel instruments are calibrated against the spectro-radiometer of the NSF network installed in San Diego, the measurements of both networks are consistent, allowing the determination of climatologies and latitudinal variability in a region that extends from South Pole to the Tropics.