
TY  - JOUR
A1  - Lehany, FJ 
A1  - Yabsley, DE 
T1  - Solar Radiation at 1200 MC/S., 600 MC/S., and 200 MC/S
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1949
VL  - 2
IS  - 1
SP  - 48
EP  - 62
KW  - 
UR  - https://doi.org/10.1071/CH9490048 
N2  - Daily observations of solar radiation at frequencies of 1200 Mc/s., 600 Mc/s., and 200 Mc/s. taken between August 18 and November 30, 1947, are described. The characteristics of the radiation at 200 Mc/s. were in general agreement with those observed by earlier workers. At 600 Mc/s. and 1200 Mc/s., the received intensity was normally steady on any one day but underwent long-period variations over a range of about two to one. The radiation received when the sun was almost free of sunspots corresponded to an effective black-body temperature of 0.5 million °K. at 600 Mc/s. and 0.1 million °K. at 1200 Mc/s. As sunspots appeared, the temperature rose and showed marked oar- relation with sunspot area. It is considered that radiation at these frequencies is entirely thermal in origin and that the long-period variations are at least partly due to the influence of the magnetic field of sunspots on the mechanism of thermal emission from a magneto-ionic medium.   On a few occasions, isolated disturbances were observed on 600 Mc/s. and 1200 Mc/s. some of which were associated with chromospheric flares and radio fade-outs.   The difficulties arising in the calibration of the apparatus and the steps taken to overcome them are discussed in detail. 
ER  -

