Ocean current spurred faster rotation of Earth

National Geographic : For about two weeks in November 2009, Earth took 0.1 millisecond less to make one complete rotation on its axis. A study by Steven Marcus of NASA’s Jet Propulsion Laboratory in California indicates that a slowdown in the Antarctic Circumpolar Current was strong enough to make the Earth slow its rotation to conserve angular momentum. Toward the end of 2009, the Southern Ocean also had record high surface temperatures and record high pressures at the ocean bottom. Tong Lee of JPL suggests in a separate paper that those excursions could be caused by a Modoki, an unusual version of El Niño, which generates atmospheric waves that can affect ocean circulation in the Southern Hemisphere. Although not certain, it looks like Modokis are becoming more common, which could in turn lead to more months in the future when the world turns a little faster.