NORTH ATLANTIC RELATIONSHIPS BETWEEN SURFACE fCO2 AND HYDROGRAPHY, EVALUATED USING fCO2-SST RELATIONSHIPS

BY: Siv K. LauvsetAre Olsen; Ingunn Skjelvan; Alberto Borges; Wei-Jun Cai; Yves Dandonneau; Melchor Gonzalez Davila; Truls Johannessen; Arne Körtzinger; Nathalie Lefevre; Xose A. Padin; Fiz F. Perez; Aida F. Rios; J. Magdalena Santana-Casiano; Ute Schuster; Tobias Steinhoff; Taro Takahashi; Doug Wallace; Rik Wanninkhof; Andy Watson

WWW.BJERKNES.UIB.NO

STUDY We use ~250,000 data points from Jan-

Mar 1995-2007 covering the North Atlantic basin

Evaluate fCO2-SST relationships in 26 regions

Aim to increase understanding of circulation effects

The regions shown here are used to illustrate both the results and the methods used

NEC

NBC

GS AC

NAC

LC

NwACEGC

SST (ºC)

fCO

2 (a

tm)

•Overall positive trend

•Not a direct effect of temperature change

•A result of mixing of two different water masses

SST (ºC)

fCO

2 (a

tm)

•No correlation

•Two important water masses are first seen here

•These characteristics can be traced eastward across the basin

•Two regions where frontal movements have great impact on fCO2 distribution

•Both are related to shifts in NAO

CONCLUSIONS It is possible to follow a characteristic

fCO2-SST signal in a specific water mass and/or current

Mixing between water masses and across frontal regions

Circulation changes can explain many of the observed changes in fCO2 in the North Atlantic