The east coast of India is prone to tropical cyclones. During pre-monsoon and post-monsoon seasons, almost every year, cyclones are developed over the Bay of Bengal and Andaman Sea. On 20 May 2020, tropical cyclone Amphan made initial landfall at Bakkhali in the West Bengal, India at 2:30 PM (local time) with wind velocity more than 175 km/h, which further intensified and moved into adjoining Bangladesh coastal areas on 21 May 2020 with highest wind speed 260 km/h. The cyclone formed on 16 May 2020 and dissipated finally on 21 May 2020. More than 22,000 houses in Coastal parts of West Bengal, and nearly 220,000 houses in Bangladesh coastal areas were damaged, and approximately 4.2 millions of people in both the countries were relocated to safe places. This cyclone affected many of the eastern states of India and 9 coastal districts of Bangladesh due to heavy rainfall that caused deadly flood. In West Bengal, Kolkata airport was flooded, and all the flights were closed. We have carried out analysis of meteorological and atmospheric parameters that helped in formation of the cyclone. Detailed analysis of multi satellite sensors, ground and Argo data have been carried out that show pronounced changes in ecological, atmospheric and ocean color parameters. The ocean parameters such as chlorophyll concentration, dissolved oxygen, salinity, sea surface and sub-surface temperature show strong changes in ocean ecology that have serious impacts on the marine life. Strong stratospheric-tropospheric exchange caused the rise in various trace gases close to the ground. A detailed damage analysis along the Eastern part of India and Bangladesh coast and major nearby cities and migration of the population from the affected region will be discussed.