Format

Send to

Choose Destination
See comment in PubMed Commons below
Science. 2004 Apr 23;304(5670):555-9. Epub 2004 Apr 15.

Decline of subpolar North Atlantic circulation during the 1990s.

Author information

1
NASA Goddard Space Flight Center, Code 971, Greenbelt, MD 20771, USA. sirpa.hakkinen@nasa.gov

Abstract

Observations of sea surface height reveal that substantial changes have occurred over the past decade in the mid- to high-latitude North Atlantic Ocean. TOPEX/Poseidon altimeter data show that subpolar sea surface height increased during the 1990s, and the geostrophic velocity derived from altimeter data exhibits declining subpolar gyre circulation. Combining the data from earlier satellites, we find that subpolar circulation may have been weaker in the late 1990s than in the late 1970s and 1980s. Direct current-meter observations in the boundary current of the Labrador Sea support the weakening circulation trend of the 1990s and, together with hydrographic data, show that the mid- to late 1990s decline extends deep in the water column. Analysis of the local surface forcing suggests that the 1990s buoyancy forcing has a dynamic effect consistent with altimetric and hydrographic observations: A weak thermohaline forcing allows the decay of the domed structure of subpolar isopycnals and weakening of circulation.

PMID:
15087505
DOI:
10.1126/science.1094917
Free full text
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire
    Loading ...
    Support Center