HWRF Ocean: The Princeton Ocean Model (POM-TC)
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1 HWRF Ocean: The Princeton Ocean Model (POM-TC) Richard M. Yablonsky University of Rhode Island WRF for Hurricanes Tutorial NCWCP, College Park, MD 14-16 January 2014
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HWRF Ocean: The Princeton Ocean Model (POM-TC). Richard M. Yablonsky University of Rhode Island WRF for Hurricanes Tutorial NCWCP, College Park, MD 14-16 January 2014. What is the Princeton Ocean Model?. - PowerPoint PPT Presentation
Transcript of HWRF Ocean: The Princeton Ocean Model (POM-TC)
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HWRF Ocean: The Princeton Ocean Model (POM-TC)Richard M. YablonskyUniversity of Rhode Island
WRF for Hurricanes TutorialNCWCP, College Park, MD14-16 January 2014#What is the Princeton Ocean Model?Three-dimensional, primitive equation, numerical ocean model (commonly known as POM; Mellor 2004)Originally developed by Alan Blumberg and George Mellor in the late 1970sInitially used for coastal ocean circulation applications Open to the community during the 1990s and 2000sMany user-generated changes incorporated into official code version housed at Princeton University#Developing HWRF Ocean (POM-TC)Available POM code version transferred to University of Rhode Island (URI) in mid-1990sPOM code changes made at URI specifically to address ocean response to hurricane wind forcingThis POM version coupled to GFDL hurricane model at URICoupled GFDL/POM model operational at NCEP in 2001Additional POM upgrades made at URI during 2000s (e.g. initialization) and implemented in operational GFDL/POMSame version of POM coupled to operational HWRF in 2007This POM version is now designated POM-TCSome further POM-TC upgrades made at URI since 2007#Why Couple POM-TC to HWRF?To create accurate SST field for input into the HWRFEvaporation (moisture flux) from sea surface provides heat energy to drive a hurricaneAvailable energy decreases if storm-core SST decreasesUncoupled hurricane models with static SST neglect SST cooling during integration high intensity biasOne-dimensional (vertical-only) ocean models neglect upwelling and horizontal advection, both of which can impact SST during integration (e.g. Yablonsky and Ginis 2009, 2013, Monthly Weather Review)#
#5Physics of Storm-Core SST ChangeVertical mixing/entrainment (Slide 7)
Upwelling (Slide 8)
Horizontal advection (Slide 9)
Heat flux to the atmosphere (small by comparison)#ATMOSPHEREOCEANWarm sea surface temperatureCool subsurface temperature1) Vertical mixing/entrainmentWind stress surface layer currentsCurrent shear turbulenceTurbulent mixing entrainment of cooler waterSea surface temperature decreasesSubsurface temperature increasesThis is a 1-D (vertical) processPOM-TC uses the Mellor-Yamada 2.5 turbulence closure submodel to parameterize vertical mixing#CyclonichurricanevortexATMOSPHEREOCEANWarm sea surface temperatureCool subsurface temperature2) UpwellingCyclonic wind stress divergent surface currentsDivergent currents upwellingUpwelling cooler water brought to surfaceThis is a 3-D process#CyclonichurricanevortexATMOSPHEREOCEANWarm sea surface temperatureCool subsurface temperature3) Horizontal advectionPreexisting cold pool is located outside storm corePreexisting current direction is towards storm coreOcean currents advect cold pool under storm coreThis is a horizontal process#9Prescribed propagation speedCyclonichurricanevortexATMOSPHEREOCEANHomogeneous initial SSTHorizontally-homogeneous subsurface temperatureWhat is the impact of varying storm translation speed?
