VHF/UHf

摘要

Solar activity continues to decline steadily. In the 30 days to 5 September, the daily average 10.7cm solar flux was 85.4 units (about 5% lower that last month) with the maximum of 112 occurring on 23 August and the minimum of 74 on 3 September. Eleven new sunspot regions were recorded. Geomagnetic activity was quite lively in high latitudes but at the mid-latitude observatory at Fredericksburg, the A-index was in single figures for 19 days. It rose to a storm level of 72 on 24 August with the K-index reaching 8, resulting in auroral activity.