Earth warming might speed ocean circulation
(Credit: **jpg. Some rights reserved.)
Contrary to predictions by most climate models and even some Hollywood movies, Earth’s oceans might actually circulate faster as Earth warms.
That’s according to research led by climate scientist J.R. Toggweiler of the Geophysical Fluid Dynamics Lab in Princeton, New Jersey. He said he started by looking at levels of the greenhouse gas CO2 at the peak of ice cover during the last ice age 21,000 years ago.
J.R. Toggweiler: We know that the carbon dioxide was high when Earth was warm and the ice had retreated, and the CO2 was low when the ice sheets expanded and covered their greatest extent. And we also know that the CO2 that appears in the atmosphere as the Earth is warming is coming out of the ocean, and that’s the key.
Like a soda bottle on a warm day, warmer surface ocean waters release more CO2 than those from the cold deep ocean. Toggweiler reasoned that in order for the ocean to have released its CO2, the overturning circulation of its deep layers had to get stronger.
J.R. Toggweiler: So basically the answer that we came up with is that the wind’s forcing of the oceans’ circulation gets stronger in a warming climate.
Each time scientists build a new climate model, said Toggweiler, they increasingly show the vital role of winds. Our thanks to NOAA, the National Oceanic and Atmospheric Administration.
Copyright 2008 EarthSky Communications, Inc.
Additional Teacher Resources
NASA: Lesson Plan – Ocean Currents and Sea Surface Temperature
In this lesson, students discover the link between ocean temperatures and currents as related to our concern for current climate change. (Grades 8-12)
NOAA – Ocean Explorer – Education
This is the homepage for NOAA Ocean Explorer Education. It includes lesson plans, curriculum, ocean career profiles and video, glossary, and puzzles.
NOAA Research: Ocean Exploration and Undersea Research
As the primary research and development organization within NOAA, NOAA Research explores the Earth and atmosphere from the surface of the sun to the depths of the ocean. They conduct research in three major areas: weather and air quality, climate, and ocean and coastal resources. This webpage provides information on a variety of ocean research topics.
