Seagliderobservations in the Gulf of Oman: Localisededdy ...file.iocwestpac.org/upwelling/7-8 May 2018/ppts... · Seagliderobservations in the Gulf of Oman: Localisededdy-driven upwelling

Seaglider observationsintheGulfofOman:

Localised eddy-drivenupwellingandproductivity

BastienY.QuesteCentreforOceanandAtmosphericSciences,UniversityofEastAnglia,Norwich,NR47TJ,UK.

Contact ::b.queste@uea.ac.uk::www.byqueste.comIOCWestPac Meeting

Putrajaya,7th May2018

UEA owns a total of ~10 instruments7 x 1000m glidera 6000m glidera shallow glideran Autonaut surface vehicle

Standard: CTD, O2, Chlorophyll, CDOM & backscatter, currents (u, v and w)

Optional: PAR, echosounder, passive acoustic & microstructure turbulence

Testing: pH, pCO2, ADCP, N & P sensors

UEA Glider Group:5+ permanent faculty3 research staff2 engineering staff9+ PhD students

Winter(NE)monsoon Intermonsoon Summer(SW)monsoon

December– February March– MaySeptember– November June– August

P.L’Hegaret (2015)

Questeetal.(2018).PhysicalcontrolsonoxygendistributionanddenitrificationpotentialinthenorthwestArabianSea.GeophysicalResearchLetters

DatafromHydrobase 3

IIOE-1 JGOFS/ARABESQUE

PGW

Questeetal.(2018).PhysicalcontrolsonoxygendistributionanddenitrificationpotentialinthenorthwestArabianSea.GeophysicalResearchLetters

2Seaglider Deploymentsalong80km transect

- March– June2015

- December– March2016

Totalof58repeatobservationsofthetransect(twiceperweek)

Veryhighresolution:1.3kmhorz /0.5mvertRelativevorticity

PGW

Questeetal.(2018).PhysicalcontrolsonoxygendistributionanddenitrificationpotentialinthenorthwestArabianSea.GeophysicalResearchLetters

• MarchtoJune

• Standardpattern:collapseofthebloomthroughmixingandthengradualstratificationwithapersistentdeepchlorophyllmaximum.

doRosarioGom

eseta

l.(2014)

Questeetal.(2018).PhysicalcontrolsonoxygendistributionanddenitrificationpotentialinthenorthwestArabianSea.GeophysicalResearchLetters

PGW

80kmStoN

• Developingnewmethodtodirectlymeasureupwellingfluxinsitu:

𝑑(𝑏𝑢𝑜𝑦𝑎𝑛𝑐𝑦×𝑔)𝑑𝑡𝑖𝑚𝑒 ×𝑑𝑟𝑎𝑔34 −

𝑑𝑝𝑟𝑒𝑠𝑠𝑢𝑟𝑒𝑑𝑡𝑖𝑚𝑒

• Thehighintermonsoonchlorophylla isnotvisibleinremotesensing.

• Estimatesofproductivityintheregionareallbased,orvalidated,onremotesensing.

• MarchtoJune

• Standardpattern:collapseofthebloomthroughmixingandthengradualstratificationwithapersistentdeepchlorophyllmaximum.

Left. Glider calibration vs satellite showing what satellites can “see” (lines) and depth integrated chlorophyll a (black dots). Remote sensing cannot resolve the elevated biomass at the DCM

DCM(inter-monsoon)

WithcolleaguesfromthePlymouthMarineLab.

Loveday,Smyth&Queste,inprep.

• Asimilarproblemhappenslaterintheyearduringthestartofthespringbloom.

• DecembertoMarch

Temperature

Chlorophyll

Left. Glider calibration vs satellite showing what satellites can “see” (lines) and depth integrated chlorophyll a (black dots). Remote sensing cannot resolve the elevated biomass at the DCM

Bloomevent(monsoon)

WithcolleaguesfromthePlymouthMarineLab.

Loveday,Smyth&Queste,inprep.

KeyPoints:

•Primaryproductionisnotwellconstrainedbyremotesensingalgorithmsintheregion

•Submeso- andmesoscaleprocessesregulatehorizontalandverticalfluxesofChl a,CandO2

•Glidersareusefulforlinkingscales(submeso/meso)tobasinandseasonaldynamics(highresolutionandendurance)

•Candofullbiogeochemicalandphysicalobservationofupwellingfor~110kUSDat1.5km/0.5mresolutionforafullyear!

Doesn’thavetoberareand(too)expensive!

Contact ::b.queste@uea.ac.uk::www.byqueste.com

ONR GLOBAL N62909-14-1-N224/SQU SQU EG/AGR/FISH/14/01SQU IG/AGR/FISH/17/01 UK NERC NE/M005801/1UK NERC NE/N012658/1