Spread-F during the magnetic storm of 22 January 2004 at low latitudes: Effect of IMF-Bz in relation to local sunset time
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The paper describes the results of spread-F at low latitude stations around the world during the magnetic storm starting at 0130 UT on 22 January 2004. The storm can be divided into two phases, first phase up to 1000 UT when interplanetary magnetic field IMF-Bz was highly fluctuating around a small positive value and the second phase after a sudden large southward turning of IMF-Bz at 1030 UT. The first phase produced strong spread-F at Jicamarca, Sao Luis, and Ascension Island and caused complete inhibition of spread-F at Thumba and Waltair in India. It generated weak spread-F at Ho Chi Minh City in Vietnam and strong spread-F at Hainan and Chung Li. The strong spread-F at Hainan and Chung Li were caused by the positive IMF-Bz during the first phase of the storm and not by the negative pulse of IMF-Bz at 1000 UT.
KeywordsEquatorial ionosphere space weather geomagnetic storm
Authors thank Physical Research Laboratory, Ahmedabad and Indian Space Research Organization for the facilities for the analysis of datasets recorded by various research centers. RGR is thankful to the Indian National Science Academy for the honorary scientist position. Thanks are due to Indian Institute of Geomagnetism, Navi Mumbai; Space Physics Laboratory, Thiruvanathapuram; Physics Department, Andhra University, Waltair; Institute de Geophysics, Peru; Vietnam Academy of Sciences, Vietnam for providing the data. Thanks are also due to J H King and N Papitasbvilli at Advel Systems NASA, GSFC and CDA web for the solar wind data and to Space Physics Interactive Data Resources (SPIDR), Boulder, USA; World Data Center for Geomagnetism, Kyoto, Japan; National Institute of Information and Communication Technology, Tokyo, Japan; Digital Ionogram database, Digisonde International, Lovell, USA.
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