Flashcard library · Earth & Climate Science · PaperFren

OSNAP: subpolar overturning peaks in spring

A 6-year OSNAP record shows the subpolar AMOC maximum in spring and minimum in winter, mostly from the eastern subpolar gyre.

Keep what you just learned

Save these 11 cards to your NoteFren library. Your first review starts right away, and each card links back to the study it came from.

Which section dominates subpolar overturning?

OSNAP East (eastern subpolar gyre), not OSNAP West (Labrador).

What is the seasonal MOC range across the full array?

Spring 21.1 Sv versus winter 12.3 Sv, peak-to-trough 8.8 Sv.

How much monthly MOC variance is seasonal?

About 40% over the 6-year record.

When does overturning peak relative to transformation?

May, 3–5 months after maximum winter transformation.

How long is the time series used here?

71 months, August 2014 to June 2020.

What monthly MOC range was observed?

About 10–25 Sv, standard deviation 3.7 Sv.

When did the full-array MOC hit 26.4 Sv?

May 2020, comparable to 2015’s 25.6 Sv.

Did OSNAP West change in the last two years?

Mean 3.9 Sv versus 2.5 Sv in the first two years; May 2019 hit 8.1 Sv.

How large is mean Ekman transport versus mean MOC?

−1.5 Sv, less than 10% of the 16.6 Sv mean MOC.

How many moorings does OSNAP use?

60 total: 24 West, 36 East.

When were continuous subpolar MOC observations lacking until?

Prior to 2014, when OSNAP was deployed.