Indications of a strong dynamical coupling between the polar and tropical regions during the sudden stratospheric warming event January 2009, based on COSMIC/FORMASAT-3 satellite temperature data

• A significant change in temperature was observed in the stratosphere and tropopause region during a major SSW
• A clear descending cold phase at polar region was seen similar to that of warming phase after the SSW event passed
• A warm motion appeared over the tropical region during the cold phase at polar region
• Cross equatorial response (from northern to southern hemisphere) up to 40°S due to the SSW was also observed

A significant change in temperature in the tropopause and stratosphere, from pole to the tropics, was observed during a major Sudden Stratospheric Warming (SSW) occurring in January 2009. The SSW event strongly modified the pattern of polar and tropical stratospheric circulation. After termination of SSW, a new pattern emerged that prevailed for ~ 2–3 months. After SSW, a clear descending cold phase completely replaced the warm phase in the polar regions. During the warm phase, temperature increased to ~ 40 °C in stratosphere (> 30 km altitude) in the polar region (80°N–90°N), then it dropped down to − 80 °C during the cold phase. Interestingly, new warm anomalies appeared over the tropical region during the cold phase at polar regions. Possible implications of these unusually warm and cold phases are demonstrated in this study. These phases altered significantly the cold point tropopause temperature and its height. SSW also affected the tropical atmospheric stability. Cross equatorial response (from northern to southern hemisphere) up to 40°S was observed in the form of persisting anomalies as a consequence of the SSW event.