Unless there is a large change in salinity the world’s oceans have a higher temperature at the surface than in deeper water. If a wind blows the warm surface to one side it will be replaced by cold water rising. The air over the warm area will rise and this will have to be replaced by air from somewhere colder so leading to self-perpetuating temperature differences across the ocean. These have large effects on the rates of evaporation and the flow of nutrients which can continue for months or a year or two. Water that has come from evaporation must come down somewhere so that there are floods as well as droughts on opposite sides. In the Pacific the cycling effect is called El Niño or La Niña Southern Oscillation abbreviated ENSO. In the Indian Ocean it is called the Indian Ocean Dipole or IOD. The map below is from Wikipedia. Sometimes the Pacific and Indian Ocean events get into phase and this led to the 2010 to 2011 floods in Queensland with strong droughts and fires on one side and floods on the other.

Unless there is a large change in salinity the world’s oceans have a higher temperature at the surface than in deeper water. If a wind blows the warm surface to one side it will be replaced by cold water rising. The air over the warm area will rise and this will have to be replaced by air from somewhere colder so leading to self-perpetuating temperature differences across the ocean. These have large effects on the rates of evaporation and the flow of nutrients which can continue for months or a year or two. Water that has come from evaporation must come down somewhere so that there are floods as well as droughts on opposite sides. In the Pacific the cycling effect is called El Niño or La Niña Southern Oscillation abbreviated ENSO. In the Indian Ocean it is called the Indian Ocean Dipole or IOD. The map below is from Wikipedia. Sometimes the Pacific and Indian Ocean events get into phase and this led to the 2010 to 2011 floods in Queensland with strong droughts and fires on one side and floods on the other.