Effects of space weather on the ionosphere and LEO satellites' orbital trajectory in equatorial, low and middle latitude. Issue 7 (1st April 2018)

• Record Type: Journal Article
• Authors: Nwankwo, Victor U.J.; Chakrabarti, Sandip K.
• Is Part Of: Advances in space research. Volume 61:Issue 7(2018)
• Page Start: 1880
• Page End: 1889
• Publication Date: 2018-04-01
• Subjects: Atmospheric drag -- Ionosphere and thermosphere -- Geomagnetic storms -- LEO satellites -- Orbital decay -- Space weather; Space sciences -- Periodicals; Astronautics -- Periodicals; Geophysics -- Periodicals; 500.505
• DOI: 10.1016/j.asr.2017.12.034
• Languages: English
• ISSNs: 0273-1177

Abstract

Abstract: We study the effects of space weather on the ionosphere and low Earth orbit (LEO) satellites' orbital trajectory in equatorial, low- and mid-latitude (EQL, LLT and MLT) regions during (and around) the notable storms of October/November, 2003. We briefly review space weather effects on the thermosphere and ionosphere to demonstrate that such effects are also latitude-dependent and well established. Following the review we simulate the trend in variation of satellite's orbital radius ( r ), mean height ( h ) and orbit decay rate ( ODR ) during 15 October–14 November 2003 in EQL, LLT and MLT. Nominal atmospheric drag on LEO satellite is usually enhanced by space weather or solar-induced variations in thermospheric temperature and density profile. To separate nominal orbit decay from solar-induced accelerated orbit decay, we compute r, h and ODR in three regimes viz. (i) excluding solar indices (or effect), where r = r 0, h = h 0 and ODR = ODR 0 (ii) with mean value of solar indices for the interval, where r = r m, h = h m and ODR = ODR m and (iii) with actual daily values of solar indices for the interval ( r, h and ODR ). For a typical LEO satellite at h = 450 km, we show that the total decay in r during the period is about 4.20 km, 3.90 km and 3.20 km in EQL, LLT and MLT respectively; the respective nominal decay ( r 0 ) is 0.40 km, 0.34 km and 0.22 km, while solar-induced orbital decay ( r m ) is about 3.80 km, 3.55 km and 2.95 km. h also varied in like manner. The respective nominal ODR 0 is about 13.5 m/day, 11.2 m/day and 7.2 m/day, while solar-induced ODR m is about 124.3 m/day, 116.9 m/day and 97.3 m/day. We also show that severe geomagnetic storms can increase ODR by up to 117% (from daily mean value). However, the extent of space weather effects on LEO Satellite's trajectory significantly depends on the ballistic co-efficient and orbit of the satellite, and phase of solar cycles, intensity and duration of driving (or influencing) solar event.