SOLAR RADIATION OBSERVATIONS AT, APIA, SAMOA

Solar coronal observations at high frequencies

The Solar Eclipse Coronal Imaging System (SECIS) is a simple and extremely fast, high-resolution imaging instrument designed for studies of the solar corona. Light from the corona (during, for example, a total solar eclipse) is reflected off a heliostat and passes via a Schmidt-Cassegrain telescope and beam splitter to two CCD cameras capable of imaging at 60 frames a second. The cameras are at...

Parametrisation of solar radiation at the surface under cloudless conditions and its validation against observations

Radiative transfer is one of the most important physical processes in the atmosphere and must be treated accurately in numerical weather prediction (NWP) and climate models. In recent decades there have been many efforts aimed at improving the accuracy of radiation measurements and modelling (for example Murcray et al. 1996; Edwards and Slingo 1996; Mlawer et al. 1997; Sun and Rikus 1999; Li an...

High-sensitivity observations of solar flare decimeter radiation

A new acousto-optic radio spectrometer has observed the 1 – 2 GHz radio emission of solar flares with unprecedented sensitivity. The number of detected decimeter type III bursts is greatly enhanced compared to observations by conventional spectrometers observing only one frequency at the time. The observations indicate a large number of electron beams propagating in dense plasmas. For the first...

The Larger Results of 20 Years of Solar Radiation Observations.

Absorption of solar radiation by clouds: observations versus models.

There has been a long history of unexplained anomalous absorption of solar radiation by clouds. Collocated satellite and surface measurements of solar radiation at five geographically diverse locations showed significant solar absorption by clouds, resulting in about 25 watts per square meter more global-mean absorption by the cloudy atmosphere than predicted by theoretical models. It has often...