Ocean currents linked to Earth's climate
In June 2005, Terrence Joyce testified before the U.S. Congress that disruptions in the ocean current system have been associated with major climate shifts of the past. Yet, he said, the role of ocean dynamics is "only poorly known."
DB: This is Earth and Sky. As ocean currents move water around the globe, they also move heat and moisture.
JB: That’s why changes in major currents can mean droughts, floods, or extremes of heat and cold, in various places on Earth. This link between ocean currents and Earth’s weather has become clear with the El Nino in the Pacific, for example.
DB: But the ocean current/ climate relationship is complicated. Exactly when, where, how, and how much ocean currents influence Earth’s atmosphere – and vice versa – still isn’t well understood. Terrence Joyce of Woods Hole Oceanographic Institution studies ocean currents.
Terrence Joyce: One of the problems that we have is our record is so short. And currents themselves have a lot of variation over the course of a year, or over the course of five to 10 years.
JB: Joyce said nowadays Earth-orbiting satellites track water speed and measure sea surface temperatures as ocean currents move around the planet. But these satellites have only been looking for about a dozen years.
Terrence Joyce: We know, for example, there’s been a lot more wind in the southern hemisphere – the Antarctic circumpolar current, which zips around the southern hemisphere, has been speeding up. But is this due to global warming? …Best I can say to you is, ask me in 10 years and I’ll be able to answer.
_DB: Thanks today to NASA explore, discover, understand. We’re Block and Byrd for Earth and Sky.
Read the complete transcript of our interview with Terrence Joyce.
Dr. Joyce testified before US Congress on June 8, 2005 about the relationship between ocean currents and climate.
Our thanks to:
Terrence M. Joyce
Senior Scientist
Woods Hole Oceanographic Institution
Woods Hole, Mass.
Director, Ocean & Climate Change Institute
Additional Teacher Resources
NASA: The Roles of the Ocean in Climate Change
Surprisingly, despite a 30 percent increase incarbon dioxide (CO2) levels, global temperatures have not risen as much as earlier models predicted. Why? Because greenhouse gases aren’t the only influence on temperature-there are many other variables, such as clouds, aerosols, and the ocean.
NOAA: Climate Change and Our Planet
Observations are fundamental to describing, understanding and predicting the Earth climate system. NOAA gathers, analyzes and archives data from the oceans, atmosphere and land surfaces from different parts of the globe. To learn more about the role of NOAA in Earth Observing Systems, go to the blue text at the bottom of this page
