|
|
[求助]
關于電離層臨界頻率,大家可不可以幫我翻譯下。
The ionosphere varies greatly due to changes in the sources of ionization and because it responds to changes in the neutral part of the upper atmosphere in which it is embedded. Since it responds to solar EUV radiation the ionosphere varies in the 24-hour period between daytime and nighttime and over the 1 I-year cycle of solar activity.
In the study of the ionosphere, foF2 is taken as the main parameter that reflects the ionospheric variations as the densest ionization occurs in this layer. One of the most important quantities in High Frequency (HF) u"nications is the maximum usable frequency or MUF, which is the maximum frequency that will be reflected by the ionosphere
for a given circuis and is closely related to foF2. In rlds.paper we will investigate the behavior of foF2 values ~vhich can characterize well the F-region morphology over the equatoAl region and of the relation to the solar activity. To study the foF variation in the ionosphere in the equatorial region. we employed the ionosonde data for Singapore
from 1957 to 1971 from National Geophysical Data Center, NOAA (Space Physics Interactive Dat Resource, SPIDR for short). The data analysis is presented and summarized in the following sections. Section 2 presents the discussion of the relationship between the Sun Spot Number (SSN) and the foF2. In section 3, the teniporal variations of the ionosphere are investigated. Conclusions and discussions are made in the last section. |
|