| [00:00:00.00] | [ music ] |
| [00:00:03.00] | |
| [00:00:07.00] | Earth’s climate and the circulation of deep ocean currents are strongly influenced by the saltiness of the sea surface. So why don’t we have detailed maps that show its rapid changes? |
| [00:00:18.00] | |
| [00:00:19.20] | Well, now we do. |
| [00:00:21.24] | |
| [00:00:22.00] | After more than a year of continuous measurements, NASA’s Aquarius instrument aboard the Aquarius/SAC-D spacecraft has given us this new space-based view of sea surface salinity. |
| [00:00:33.25] | |
| [00:00:34.15] | A closer look at the data reveals some fascinating features. |
| [00:00:38.00] | |
| [00:00:39.10] | Our focus first turns to a salty patch of water in the North Atlantic Ocean. |
| [00:00:43.30] | |
| [00:00:45.00] | Evaporation of water from the sea surface leaves behind large amounts of salt that contribute to the active zone of high salinity water seen here. |
| [00:00:54.25] | |
| [00:01:00.10] | Conditions are different in the North Pacific Ocean. |
| [00:01:03.08] | |
| [00:01:04.00] | Near the equator, in one of the wettest regions on the planet, heavy rainfall adds an abundance of water to the sea surface. |
| [00:01:11.05] | |
| [00:01:12.00] | This results in the dark-blue band of low salinity water off the coast of South America and Central America. |
| [00:01:19.00] | |
| [00:01:23.00] | Rivers can also influence the amount of salt on the sea surface. |
| [00:01:27.10] | |
| [00:01:27.25] | Every second, millions of gallons of fresh water flows from the Amazon River into the Atlantic Ocean. |
| [00:01:34.14] | |
| [00:01:35.15] | The effect of this is a sinuous plume of low salinity water that extends from the mouth of this great river. |
| [00:01:42.02] | |
| [00:01:44.45] | At high latitudes, the seasonal melting of sea ice causes a sharp decrease in sea surface salinity. |
| [00:01:51.15] | |
| [00:01:52.00] | We see examples of this in the Labrador Sea and the coastal waters that surround Greenland. |
| [00:01:57.25] | |
| [00:01:58.00] | In spring and summer, surface currents transport the low salinity water south, where it meets warmer and saltier water carried north by the Gulf Stream. |
| [00:02:07.27] | |
| [00:02:13.20] | The contrasting patches of high salinity water to the west and low salinity water to the east of the Indian subcontinent are due to a combination of geography and climate. |
| [00:02:23.28] | |
| [00:02:24.15] | To the west, an arid climate and lack of freshwater input yields the salty waters of the Arabian Sea. |
| [00:02:31.05] | |
| [00:02:31.15] | To the east, monsoon rains and freshwater outflow from the Ganges River keep the Bay of Bengal far less salty. |
| [00:02:39.11] | |
| [00:02:42.00] | Without satellite observations, these global changes would be largely invisible to us. |
| [00:02:47.21] | |
| [00:02:48.15] | Ongoing measurements by Aquarius will help scientists better understand our vast oceans and how changes to ocean circulation and the transport of water through the atmosphere may impact Earth’s climate. |
| [00:03:01.00] | |
| [00:03:04.11] | [ beeps ] |
| [00:03:10.25] |