Leap Second: The Earth is Gradually Slowing Down
Today will be a little longer than normal, but only by a second. An extra second, or “leap” second will be added today June 30, 2015. Daniel MacMillan of NASA’s Goddard Space Flight Center located in Greenbelt, Maryland said, “Earth’s rotation is gradually slowing down a bit, so leap seconds are a way to account for that”. Technically speaking a day lasts 86,400 seconds, however, the mean solar day, which is the average length of a day based on how long it takes for the Earth to make one rotation, is about 86,400.002 seconds long. These 2 milliseconds are hardly noticeable at first, but each day that this happens, it adds up to almost 1 second each year.
The length of a day is influenced by many factors, our seasonal and daily weather variations can affect the length of a day by a few milliseconds. Other contributors to this include dynamics of the Earth’s inner core, variations in the atmosphere and oceans, groundwater, ice storage and atmospheric tides. Even El Nino can cause Earth’s rotation to slow down, which would increase the length of a day by as much as 1 millisecond.
How will you spend your extra second?
For WeatherNation: Brandon Thorne