Forbush decreases in November 6-20, 2004 observed by the Muon Detector Network

In this paper we study the relationship between Interplanetary Coronal Mass Ejections (ICMEs) and the count rate muon decrease detected by the muon detector network in November 6-20, 2004. The Muon Detector Network is composed by the detectors installed in Nagoya (Japan), Hobart (Australian) and the prototype detector installed in the “Observatorio Espacial do Sul – OES/CRSPE/INPE-MCT”, located in Sao Martinho da Serra, RS, Brazil. With the muons count rate observed by the Muon Detector Network, we will be able to observe, in the future,the direction in which a given ICME moves, and with that, we will be able to calculate the angle which they reach the Earth. Also, with this muon network, we will be able to send alerts of up to 12 hours before the arrival of a shock or an ICME. The Space Weather forecast method using cosmic rays will be a very important tool because it provides a forecast with good antecedence.