Unlike albatrosses today, which avoid the tropical equatorial currents with their doldrums, Pelagornithidae were found in all sorts of climate, and records from around 40 Ma stretch from Belgium through Togo to the Antarctic.
At the beginning of the period, Australia and Antarctica remained connected, and warm equatorial currents mixed with colder Antarctic waters, distributing the heat around the world and keeping global temperatures high.
But when Australia split from the southern continent around 45 Ma, the warm equatorial currents were deflected away from Antarctica, and an isolated cold water channel developed between the two continents.
The areas of surface ocean currents move somewhat with the seasons; this is most notable in equatorial currents.
At the western edge of each of the oceans, the equatorial currents turn poleward and flow along adjacent continents.
It's where the equatorial currents meet arctic waters.
During the non-breeding season, Juan Fernández Petrels forage in the equatorial currents and counter currents, north to the Hawaiian Islands.
Moreover, warm equatorial currents run across the Atlantic from Africa to the Americas, assisting in travel.
The Atlantic NECC is unique among the equatorial currents in that basin because of its extreme seasonality.
They attribute the dark green line, which is several hundred yards wide, to an abundance of microscopic plants that thrive where cold, nutrient-rich water welling up from polar seas meets warm equatorial currents.