04/22/23 Laurie Padman: S. O. GLOBEC P.I. Meeting,December 2002: Washington D.C.

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Southern Ocean GLOBEC: Status of ADCP and Microstructure

L. Padman1, B. Beardsley2, S. Howard1

1 Earth & Space Research, Seattle WA2 Woods Hole Oceanographic Inst., Woods Hole MA

04/22/23 Laurie Padman: S. O. GLOBEC P.I. Meeting,December 2002: Washington D.C.

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ADCP StatusCruise StatusLMG0103 Processed and editedNBP0103 Processed and edited (new version Fall ’02)LMG0104 Processed and edited

NBP0104 Reprocessing, est. 01/03LMG0106 Processed and editedLMG0201A Processed only, editing est. 02/03NBP0202 Processed and editedLMG0203 Processed only, editing est. 02/03NBP0204 Est. 01/03LMG0205 Est. Spring/03LMG0302 2003 Mooring recovery

04/22/23 Laurie Padman: S. O. GLOBEC P.I. Meeting,December 2002: Washington D.C.

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ADCP Data Access

Data are served through ESR’s web site as Matlab MAT files:

http://www.esr.org/globec/globec.html

and through the U.S. GLOBEC Data System at WHOI:

http://globec.whoi.edu/jg/dir/globec/soglobec/

where users can convert to ASCII, plot data, etc.

04/22/23 Laurie Padman: S. O. GLOBEC P.I. Meeting,December 2002: Washington D.C.

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ADCP: General comments

Data loss occurs:

in heavy sea states; and

when vessels are underway in ice: so, most winter data are just at sampling stations.

Data include high-frequency signals (mainly tides and near-inertial), with magnitudes that can at times exceed the mean circulation.

04/22/23 Laurie Padman: S. O. GLOBEC P.I. Meeting,December 2002: Washington D.C.

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CMiPS: CTD-Mounted Microstructure Profiling System

04/22/23 Laurie Padman: S. O. GLOBEC P.I. Meeting,December 2002: Washington D.C.

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CMiPS: RationaleMeasures T(z) and C(z) at ~1 cm resolution

(oversamples at 512 Hz) to look at turbulence due to– Shear instabilities

– Double diffusion

– Intrusions

to answer the question: What is the diffusivity in the pycnocline between the UCDW and the mixed layer?

04/22/23 Laurie Padman: S. O. GLOBEC P.I. Meeting,December 2002: Washington D.C.

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CMiPS Stations: NBP0204

04/22/23 Laurie Padman: S. O. GLOBEC P.I. Meeting,December 2002: Washington D.C.

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West of Marguerite Bay (CTD-044)

04/22/23 Laurie Padman: S. O. GLOBEC P.I. Meeting,December 2002: Washington D.C.

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Marguerite Trough (CTD-091)

04/22/23 Laurie Padman: S. O. GLOBEC P.I. Meeting,December 2002: Washington D.C.

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Palmer LTER Amid Icebergs (CTD-113)

04/22/23 Laurie Padman: S. O. GLOBEC P.I. Meeting,December 2002: Washington D.C.

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Anchor Stations

04/22/23 Laurie Padman: S. O. GLOBEC P.I. Meeting,December 2002: Washington D.C.

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Anchor Stations

04/22/23 Laurie Padman: S. O. GLOBEC P.I. Meeting,December 2002: Washington D.C.

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Anchor Stations

04/22/23 Laurie Padman: S. O. GLOBEC P.I. Meeting,December 2002: Washington D.C.

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Comparison of T-S

Med. Rρ

Low RρOff-shelf

Central WAP shelfSW of Palmer Stn.Gerlache Strait

04/22/23 Laurie Padman: S. O. GLOBEC P.I. Meeting,December 2002: Washington D.C.

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Summary

• Making progress on ADCP clean-up and archiving; web-serving is now compatible with other GLOBEC programs.

• Microstructure profiling on NBP0202 and NBP0204. Tentative conclusion: more mixing at main pycnocline than we thought from bulk parameterizations.

• But little evidence of mixing below 150 m except near the shelf break.

• No evidence of significant double diffusion in the GLOBEC area, but more likely in the Palmer LTER.