Turns of the seasons in the Ocean

Image of the month - May 2007

Sea level variations averaged over 15 years over Northern Hemisphere Spring, Fall, Summer and Winter (from left to right and top to bottom). The water warms in Summer, and cools in Winter, thus explaining a difference of about + or - 10 cm in the sea level between the seasons, with the seasons being inversed in the Northern and Southern Hemisphere.
Moreover, ocean stays warm or cold for some time, with a roughly two months delay with the calendar seasons, thus explaining the highs or lows in Fall or Spring.


The ocean is responding to the seasons, as the atmosphere. Just now, in May, it is beginning to warm in the Northern Hemisphere, and to cool in the Southern. The amplitude of the variations in sea level due to the seasons is one of Topex/Poseidon's discoveries. This shows the quantity of heat kept in stock in the ocean, and thus its impact on the climate.

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