Computer Science – Sound
Scientific paper
Dec 2005
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2005jgra..11012s91s&link_type=abstract
Journal of Geophysical Research, Volume 110, Issue A12, CiteID A12S91
Computer Science
Sound
22
Space Weather: Magnetic Storms (2788), Space Weather: Ionospheric Storms (2441), Ionosphere: Equatorial Ionosphere, Ionosphere: Ionospheric Dynamics, Ionosphere: Ionospheric Irregularities
Scientific paper
The intense modifications in the ionosphere-thermosphere system in the equatorial and low-latitude regions associated with the dynamic and electrodynamic coupling from high to low latitudes and chemical changes during geomagnetic storms are important space weather issues. In the second half of October 2003, the intense solar activity resulted in one intense and two major geomagnetic storms on 29 and 30 October. In this paper we present and discuss the ionospheric sounding observations carried out from Palmas and São José dos Campos, Brazil (the Brazilian sector), and Ho Chi Minh City, Vietnam, and Okinawa, Japan (the East Asian sector), during these storms. The two sectors are separated by about 12 hours in local time (so while one sector is in daytime, the other one is in nighttime) and provide valuable information related to the storm-time longitudinal differences. Copious storm-time changes were observed in both sectors. It should be pointed out that the two longitudinal sectors investigated in the present study clearly show the global nature of the storm-time effects. However, the responses to the storm-time effects are also associated with the local time in the two sectors. The present investigations show that there are both similarities and differences in the storm-time response in the two sectors. During the storm main phases, with sharp decreases of the Dst index, both sectors showed (dusk or dawn periods) fast uplifting of the F layer associated with magnetospheric electric field penetration. Although in the East Asian sector, Ho Chi Minh City and Okinawa are located fairly close in longitude, with only 2 hour difference in local lime, on occasions the storm-time responses have been very different. Some differences in the latitudinal response of the F region were also observed in the two sectors. Both positive and negative storm phases have been observed at all the four stations. A comparison of the ionospheric parameters obtained from the TIMEGCM model runs and the observed ionospheric parameters at the four stations shows a reasonable agreement during the quiet periods. During the geomagnetic disturbance period, when there were sharp decreases in Dst, some of the observed rapid uplifts of the F region peak heights are not reproduced by the model results. Also, sometimes the model foF2 results differ considerably from the observed foF2 variations. The period investigated represents an extreme storm situation for validation of the model and points to ways in which the model might be improved in the future.
Abalde José Ricardo
Becker-Guedes F.
Bittencourt J. A.
Crowley Geoff
de Jesus Rodolfo
No associations
LandOfFree
Effects of the major geomagnetic storms of October 2003 on the equatorial and low-latitude F region in two longitudinal sectors does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Effects of the major geomagnetic storms of October 2003 on the equatorial and low-latitude F region in two longitudinal sectors, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Effects of the major geomagnetic storms of October 2003 on the equatorial and low-latitude F region in two longitudinal sectors will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1611401