1 / 9

North Atlantic Oscillation Joseph Papapietro

North Atlantic Oscillation Joseph Papapietro. Outline. What is NAO? Atmospheric changes. The Atmosphere/Ocean connection. Biological/Ecological Effects. North Atlantic Oscillation.

bianca-clark
Télécharger la présentation

North Atlantic Oscillation Joseph Papapietro

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. North Atlantic OscillationJoseph Papapietro

  2. Outline • What is NAO? • Atmospheric changes. • The Atmosphere/Ocean connection. • Biological/Ecological Effects

  3. North Atlantic Oscillation A decade-scale processes that appears to play a major role in regional and global climate dynamics, resulting in weather changes in North America and Europe. The oscillation ranges are due to variability in the permanent pressure system in the sub tropics and in the northern region of the Atlantic.

  4. A positive NAO index occurs when there is a large pressure gradient between the Sub-tropic permanent high pressure system and North Atlantic Low pressure system. This results in relatively strong westerlies that run across the Atlantic, carrying warm air from North America to Northern Europe.

  5. A negative NAO index occurs when there is a small pressure difference between the Sub-tropic permanent high pressure system and North Atlantic Low pressure system. This results in relatively weak westerlies that drop from Iceland and drag cold air to Northern Europe.

  6. Negative NAO Cool Eastern North America [More snow?] Warmer than usual in Iceland [Ice melt?] Cool/dry in Northern Europe Warm/Moist in Mediterranean Weather • Positive NAO: • Warm in Eastern North America • Cold in Iceland • Warm/Wet in Northern Europe • Cool/Dry in Mediterranean

  7. warm Sea Surface Temperature maps for Positive NAO (top), and Negative NAO (bottom). cool cool warm

  8. Some Biological Effects • relatively Positive NAO for ~40 years • The Labrador Sea snow crab have flourished in cooler sea temperatures. • Cod larvae • low tolerance to warm waters of NE Atlantic. • NE N. America - positive NAO brings rain and increased warmth – fresher/nutrient deficient water blocks upwelling of deep salty/nutritious water. Less productivity.

  9. Thank You! • References: • - Pearson, Aria; New Scientist; 1/3/2009, Vol. 200 Issue 2688, p32-35, 4p • - http://en.wikipedia.org/wiki/North_Atlantic_oscillation [photos] • - http://www.whoi.edu/page.do?pid=12455&tid=282&cid=10146 [photos]

More Related