SolarCycleVariationsofTopsideElectronDensityand：的頂面電子密度的太陽周期變化-2課件

1、Solar Cycle Variations of Topside Electron Density and Temperature: Altitudinal, Latitudinal, and Seasonal Differences. D. Bilitza(1), P. Richards(2), V. Truhlik(3), T. Abe(4), L. Triskova(3) (1)Raytheon ITSS, GSFC, SPDF, Greenbelt, USA(2)NASA, Earth-Sun Systems Division, Washington DC, USA(3) Insti

2、tute of Atmospheric Physics, Praha, Czech Republic(4) Aerospace Exploration Agency (JAXA), Sagamihara, Japan第1頁，共21頁。Summary Goal: Determine Te solar cycle variation for inclusion in IRI. Source: Data base of satellite insitu measurements and FLIP model This Study: Solar activity variation of Ne and

3、 Te at 550, 900, and 2000 km, for MLT= 2, and 13, during all seasons第2頁，共21頁。Previous Studies Balan et al., 2001- MU RadarBalance of gain, loss,and transport processes for thermal energy can result in increase or decrease with solar activity.第3頁，共21頁。Previous Studies Oyama et al., 2002 - AkebonoAt h

4、igh altitudes the heat transport from the plasmasphere results in an increase with solar activity.第4頁，共21頁。Previous Studies Zhang, Holt, 2004 Millstone Hill第5頁，共21頁。DatabaseAkebono, since Feb 1989, 700 10,000 km, -75 - 75第6頁，共21頁。第7頁，共21頁。第8頁，共21頁。Altitudinal Differences Jicamarca latitude 第9頁，共21頁。

5、Altitudinal Differences Jicamarca:第10頁，共21頁。Altitudinal Differences Millstone Hill:MidnightNoon第11頁，共21頁。Averages of Akebono electron temperatures versus solar flux for different altitude ranges during daytime for summer (top) and winter (right) conditions seem to indicate an increase with solar flu

6、x at higher altitudes and a decrease for the lower height range and no significant seasonal changes. 第12頁，共21頁。Equinox, mid-latitude, noon550 km900 km2000 kmLog(Ne)Te第13頁，共21頁。Winter, mid-latitude, midnight550 km900 km2000 kmLog(Ne)Te第14頁，共21頁。600 kmNoon, Mid-lat900 km1500 km2200 kmMidnight, Mid-lat

7、Midnight, EquatorNoon, Equator第15頁，共21頁。Seasonal Differences第16頁，共21頁。Mid-latitude, noon, 550 kmEquinoxSummerWinter第17頁，共21頁。Mid-latitude, noon, 900 kmEquinoxSummerWinter第18頁，共21頁。Mid-latitude, noon, 2000 kmEquinoxSummerWinter第19頁，共21頁。SummerEquinoxWinter第20頁，共21頁。ResultsNe increases with solar acti

8、vity for all cases.Solar cycle effects are strongest at low altitudes.- Te changes over the solar cycle are generally much smaller than those of Ne and show a seasonal dependence during daytime: increases in summer, constant or small decrease in winter, decrease in equinox.FLIP generally confirms the Ne trends seen in our data base. FLIP agrees well with the Te