Geoscience Reference
In-Depth Information
Maud Rise Nonlinear Equation of State Study
(MaudNESS, July-September
2005): A winter experiment in the eastern Weddell Sea designed to study upper
ocean mixing in a low stability environment, from the R/V
Nathaniel B. Palmer
.
The experiment comprised a rapid survey of upper ocean properties above and on
theflanksoftheMaudRiseseamount,twoship-supporteddriftswithvariousinstru-
mentation on the ship and adjacent floe, and a series of short drifts with all instru-
mentation,includingturbulencemeasuringequipmentdeployedfromtheship.
Svalbard Fjord Studies
Anongoingseriesofshortfieldstudiesfromfasticein
Svalbardfjords,usuallydoneincollaborationwiththeUniversityCenterinSvalbard
(UNIS).By measuringturbulenceduringtidalcyclesalongwithice characteristics,
theseexperimentsweredesignedtolookatspecificaspectsofheatandsaltexchange
nearthe ice/oceaninterface.
1.5 Roadmap
This topic is intended to serve two purposes. First, it strives to summarize our
present understanding of how sea ice and the upper ocean interact, and how that
understanding may be applied in models that predict future changes. Rapid and
apparently accelerating changes in the state of the Arctic ice pack lend a sense
of urgency: essentially, it seems that Nature is solving the equations a lot faster
thanweare.
The second major aim is to consolidate what the rather unique measurements
made from the ice-platform “laboratory” imply about the scales of turbulence and
howfluidboundarylayersworkwhenrotationandbuoyancyfluxareimportant.
Chapter 2 is a quick review of basic fluid dynamical principles, with emphasis
on the upper ocean and planetary boundarylayer. Chapter 3 is a somewhatcursory
summaryofturbulenceprinciples,withemphasisondirectmeasurementsofcovari-
ance statistics as estimators of turbulent fluxes in the IOBL, and the use of turbu-
lence spectrato infer featuresof the turbulentkinetic energycascade anddominant
scales. Chapter 4 explores concepts of fluid dynamical similarity as they apply
to the IOBL, and emphasizes connections between the oceanic and atmospheric
boundarylayers.Chapter5isthe“observationalmeat”ofthework,usingmeasure-
ments to assess the impact of stress and rotation, plus stabilizing and destabilizing
buoyancy flux, on scales of turbulence in the IOBL. Chapter 6 explores the small-
scaleprocessesthatgovernthetransferofheat,salt,andmassacrosstheimmediate
boundary at the ice/ocean interface, including double-diffusive effects when ice is
melting. Chapter 7 introduces a fairly standard, one (spatial) dimensional numeri-
calmodelsolutionapproach,alongwithanalgorithmforimplementingafirst-order
local-turbulence-closure (LTC) technique incorporating the similarity and scaling
argumentsofChapters5and6.Chapter8exercisesthetime-dependentnumericalin
threeexamples,chosentoillustrate(i)absorptionanddistributionofsolarenergyin
the IOBL near summer solstice; (ii) inertialresponse of the IOBL to rapid changes
in surface forcing; and (iii) mixing in an IOBL bounded below by a combination
