Solar eclipse

About: Solar eclipse is a research topic. Over the lifetime, 2737 publications have been published within this topic receiving 22625 citations.

Ionospheric effects on the F region during the Sunrise for the annular solar eclipse over Taiwan on 21 May 2012

Abstract: On 21 May 2012 (20:56, Universal Time; UT, on 20 May), an annular solar eclipse occurred, beginning at sunrise over southeast China and moving through Japan, sweeping across the northern Pacific Ocean, and completing its passage over the western United States at sunset on 20 May 2012 (02:49 UT, 21 May) We investigated the eclipse area in Taiwan, using an ionosonde and global positioning system (GPS) satellite measurements The measurements of foF2, hmF2, bottomside scale height around the peak height (Hm), and slab thickness (B0) were collected at the ionosonde station at Chung-Li Observatory In addition, we calculated the total electron content (TEC) to study the differences inside and outside the eclipse area, using 3 receivers located at Marzhu (denoted as MATZ), Hsinchu (TNML), and Henchun (HENC) The results showed that the foF2 values gradually decreased when the annularity began and reached a minimum level of approximately 20 MHz at 06:30 LT The hmF2 immediately decreased and then increased during the annular eclipse period The TEC variations also appeared to deplete in the path of the eclipse and opposite the outside passing area Further, the rate of change of the TEC values (dTEC / dt measured for 15 min) was examined to study the wave-like fluctuations The scale height near the F2 layer peak height (Hm) also decreased and then increased during the eclipse period To address the effects of the annular eclipse in the topside and bottomside ionosphere, this study provides a discussion of the variations between the topside and bottomside ionospheric parameters during the eclipse period

Observations of Stratosphere-Troposphere Coupling During Major Solar Eclipses from FORMOSAT-3/COSMIC Constellation

Abstract: Sudden tropospheric cooling and induced stratospheric warming were found during the 22 July 2009 total solar eclipse. Can the 22 July 2009 hallmark also be seen in other major solar eclipses? Here we hypothesize that the tropospheric cooling and the stratospheric warming can be predicted to occur during a major solar eclipse event. In this work we use the FORMOSAT-3/COSMIC (F3C) Global Positioning System (GPS) radio occultation (RO) data to construct eclipse-time temperature profiles before, during, and after the passages of major solar eclipses for the years 2006–2010. We use four times a day of meteorological analysis from the European Centre for Medium Range Weather Forecast (ECMWF) global meteorological analysis to construct non-eclipse effect temperature profiles for the same eclipse passages. The eclipse effects were calculated based on the difference between F3C and ECMWF profiles. A total of five eclipse cases and thirteen non-eclipse cases were analyzed and compared. We found that eclipses cause direct thermal cooling in the troposphere and indirect dynamic warming in the stratosphere. These results are statistically significant. Our results show −0.6 to −1.2°C cooling in the troposphere and 0.4 to 1.3°C warming in the middle to lower stratosphere during the eclipses. This characteristic stratosphere-troposphere coupling in temperature profiles represent a distinctive atmospheric responses to the solar eclipses.

Ionospheric Behavior During the Solar Eclipse of 22 July 2009 and Its Effect on Positioning

Abstract: On Jul. 22nd, 2009, an exceptionally long total solar eclipse was visible within a narrow corridor that traversed the Eastern Hemisphere. A medium geomagnetic storm synchronized with solar eclipse and led to the complexity of the ionospheric variations. This work is to analyze the ionospheric behavior during this event and its effect on positioning. The used GPS data were collected by the Chongqing CORS, Wuhan CORS, IGS stations such as WUHN and SHAO in Moon's umbra, and other IGS stations in Moon's penumbra. By comparing the TEC variations of 3 consecutive days, and using high-sampling rate CORS data, we study instantaneous changes of the total electron content (TEC) during the event. The result shows that TEC declined by (1~4)TECU at places depending on different locations and times. Meanwhile, in real time point positioning, horizontal accuracy didn't have remarkable changes, but vertical accuracy declined up to several meters. And in real time baseline positioning, horizontal accuracy still reached centimeter level, and vertical accuracy remained at decimeter level in the early stage of solar eclipse. But the geomagnetic storm occurred in the latter stage of solar eclipse that led to the decline of horizontal accuracy to decimeter, and vertical accuracy to meter level.