Study of extra tropical and higher latitude cyclone tracks in Northern Hemisphere

Extra tropical cyclones (also sometimes called middle-latitudes cyclones outside of tropics) in the Northern Hemisphere are generally generated from 30 to 60 degrees North latitudes. Higher latitudes cyclones, also called Arctic cyclones, are generally generated from 60 to 90 degrees North latitudes. It has been felt that there is an uptrend of these extra tropical cyclones moving North over time during their movement from starting latitudes to the ending latitudes. In this research, an attempt has been made to investigate this uptrend of the cyclones based on the data called ERA40 North Hemispheric cyclone tracking data provided by Environment Canada for 44 years (1958-2001). The present study has been concentrated in the North American Region.