The Character of North Atlantic Subtropical Mode Water Potential Vorticity Forcing Otmar Olsina, William Dewar Dept. of Oceanography, Florida State University.

Slides:

Advertisements

Similar presentations

The Ocean perspective on frontal air-sea exchange over the wintertime Gulf Stream or…CLIMODE Redux The separated Gulf Stream (GS) is one of the ocean hot.

Advertisements

Josh Griffin and Marcus Williams

Ocean Currents of the Eastern Gulf of Mexico Robert H. Weisberg Professor, Physical Oceanography College of Marine Science University of South Florida.

Circulation in the atmosphere

Dynamics V: response of the ocean to wind (Langmuir circulation, mixed layer, Ekman layer) L. Talley Fall, 2014 Surface mixed layer - Langmuir circulation.

Climatic impacts of stochastic fluctuations in air–sea fluxes Paul Williams Department of Meteorology, University of Reading, UK.

Using High Quality SST Products to determine Physical Processes Contributing to SST Anomalies A First Step Suzanne Dickinson and Kathryn A. Kelly Applied.

Summary from last class… Importance of large-scale ocean circulation –climate, biogeochemistry, marine resources Characteristic “Types” of Ocean Circulation.

Generalized Surface Circulation

A Voyage of Discovery Physical oceanography Instructor: Dr. Cheng-Chien LiuCheng-Chien Liu Department of Earth Sciences National Cheng Kung University.

LOW FREQUENCY VARIATION OF SEA SURFACE SALINITY IN THE TROPICAL ATLANTIC Semyon A. Grodsky 1, James A. Carton 1, and Frederick M. Bingham 2 1 Department.

Modes of Pacific Climate Variability: ENSO and the PDO Michael Alexander Earth System Research Lab michael.alexander/publications/

Lecture 7: The Oceans (1) EarthsClimate_Web_Chapter.pdfEarthsClimate_Web_Chapter.pdf, p

Wind Driven Circulation I: Planetary boundary Layer near the sea surface.

Dr. Nicholas R. Bates Bermuda Biological Station For Research Twenty Years of Oceanic CO 2 Observations in the North Atlantic Ocean at the BATS site.

Define Current decreases exponentially with depth. At the same time, its direction changes clockwise with depth (The Ekman spiral). we have,. and At the.

Monin-Obukhoff Similarity Theory

Surface wind stress Approaching sea surface, the geostrophic balance is broken, even for large scales. The major reason is the influences of the winds.

Calculating the amount of atmospheric carbon dioxide absorbed by the oceans Helen Kettle & Chris Merchant School of GeoSciences, University of Edinburgh,

The meridional coherence of the North Atlantic meridional overturning circulation Rory Bingham Proudman Oceanographic Laboratory Coauthors: Chris Hughes,

Linking sea surface temperature, surface flux, and heat content in the North Atlantic: what can we learn about predictability? LuAnne Thompson School of.

Oceanography 569 Oceanographic Data Analysis Laboratory Kathie Kelly Applied Physics Laboratory 515 Ben Hall IR Bldg class web site: faculty.washington.edu/kellyapl/classes/ocean569_.

Evaporative heat flux (Q e ) 51% of the heat input into the ocean is used for evaporation. Evaporation starts when the air over the ocean is unsaturated.

Define Current decreases exponentially with depth and. At the same time, its direction changes clockwise with depth (The Ekman spiral). we have,. and At.

Northern Hemisphere Atmospheric Transient Eddy Fluxes and their Co-variability with the Gulf Stream and Kuroshio-Oyashio Extensions Young-Oh Kwon and Terrence.

Mode (Eighteen Degree) Water V.Y. Chow EPS Dec 2005.

IORAS activities for DRAKKAR in 2006 General topic: Development of long-term flux data set for interdecadal simulations with DRAKKAR models Task: Using.

Comparison of Surface Turbulent Flux Products Paul J. Hughes, Mark A. Bourassa, and Shawn R. Smith Center for Ocean-Atmospheric Prediction Studies & Department.

Sara Vieira Committee members: Dr. Peter Webster

Impact of partial steps and momentum advection schemes in a global ocean circulation model at eddy-premitting resolution Barnier Bernard et al.

The Relations Between Solar Wind Variations and the North Atlantic Oscillation Rasheed Al-Nuaimi and Kais Al-Jumily Department of Atmospheric Sciences.

North Atlantic Oscillation (NAO) Primary forcing mechanism of the NAO: internal atmospheric dynamics How can we account for the redness in the spectrum?

Synthesis NOAA Webinar Chris Fairall Yuqing Wang Simon de Szoeke X.P. Xie "Evaluation and Improvement of Climate GCM Air-Sea Interaction Physics: An EPIC/VOCALS.

Three Lectures on Tropical Cyclones Kerry Emanuel Massachusetts Institute of Technology Spring School on Fluid Mechanics of Environmental Hazards.

Monitoring Heat Transport Changes using Expendable Bathythermographs Molly Baringer and Silvia Garzoli NOAA, AOML What are time/space scales of climate.

Icebergs, Ice Shelves and Sea Ice: A ROMS Study of the Southwestern Ross Sea for Michael S. Dinniman John M. Klinck Center for Coastal Physical.

Current Weather Introduction to Air-Sea interactions Ekman Transport Sub-tropical and sub-polar gyres Upwelling and downwelling Return Exam I For Next.

An example of vertical profiles of temperature, salinity and density.

Air-sea fluxes over the ITHACA region Grbec, B. and Matić, F. Institute of oceanography and fisheries - Split.

1 Xujing Jia Davis Graduate School of Oceanography, University of Rhode Island Lewis M. Rothstein Graduate School of Oceanography, University of Rhode.

An evaluation of satellite derived air-sea fluxes through use in ocean general circulation model Vijay K Agarwal, Rashmi Sharma, Neeraj Agarwal Meteorology.

Investigation of Mixed Layer Depth in the Southern Ocean by using a 1-D mixed layer model Chin-Ying Chien & Kevin Speer Geophysical Fluid Dynamics Institute,

Graduate Course: Advanced Remote Sensing Data Analysis and Application A COMPARISON OF LATENT HEAT FLUXES OVER GLOBAL OCEANS FOR FOUR FLUX PRODUCTS Shu-Hsien.

Typical Distributions of Water Characteristics in the Oceans.

Ekman pumping Integrating the continuity equation through the layer:. Assume and let, we have is transport into or out of the bottom of the Ekman layer.

Role of the Gulf Stream and Kuroshio-Oyashio Systems in Large- Scale Atmosphere-Ocean Interaction: A Review Young-oh Kwon et al.

Question: Why 45 o, physics or math? andare perpendicular to each other 45 o relation holds for boundary layer solution Physics: Coriolis force is balanced.

 one-way nested Western Atlantic-Gulf of Mexico-Caribbean Sea regional domain (with data assimilation of SSH and SST prior to hurricane simulations) 

A Synthetic Drifter Analysis of Upper-Limb Meridional Overturning Circulation Interior Ocean Pathways in the Tropical/Subtropical Atlantic George Halliwell,

12.808, Problem 1, problem set #2 This is a 3 part question dealing with the wind-driven circulation. At 26 o N in the N. Atlantic, the average wind stress.

Geopotential and isobaric surfaces

Contributions to SST Anomalies in the Atlantic Ocean [Ocean Control of Air-Sea Heat Fluxes] Kathie Kelly Suzanne Dickinson and LuAnne Thompson University.

One float case study The Argo float ( ) floating in the middle region of Indian Ocean was chosen for this study. In Figure 5, the MLD (red line),

Bailey Wright.  Tornadoes are formed when the vertical wind shear, vertical vorticity, and stream line vorticity conditions are favorable. ◦ Storms and.

Wind-driven circulation II ●Wind pattern and oceanic gyres ●Sverdrup Relation ●Vorticity Equation.

Water Properties Surface Tension Viscosity Changes in State.

Interannual to decadal variability of circulation in the northern Japan/East Sea, Dmitry Stepanov 1, Victoriia Stepanova 1 and Anatoly Gusev.

MICHAEL A. ALEXANDER, ILEANA BLADE, MATTHEW NEWMAN, JOHN R. LANZANTE AND NGAR-CHEUNG LAU, JAMES D. SCOTT Mike Groenke (Atmospheric Sciences Major)

Forces and accelerations in a fluid: (a) acceleration, (b) advection, (c) pressure gradient force, (d) gravity, and (e) acceleration associated with viscosity.

I. Objectives and Methodology DETERMINATION OF CIRCULATION IN NORTH ATLANTIC BY INVERSION OF ARGO FLOAT DATA Carole GRIT, Herlé Mercier The methodology.

Meteorological Variables 1. Local right-hand Cartesian coordinate 2. Polar coordinate x y U V W O O East North Up Dynamic variable: Wind.

A Fear-Inspiring Intercomparison of Monthly Averaged Surface Forcing

The β-spiral Determining absolute velocity from density field

A Comparison of Profiling Float and XBT Representations of Upper Layer Temperature Structure of the Northwestern Subtropical North Atlantic Robert L.

Coupled atmosphere-ocean simulation on hurricane forecast

Observations of the North Atlantic Subtropical Mode Water

A Mechanistic Model of Mid-Latitude Decadal Climate Variability

Heat Transport by the Atmosphere and ocean

TALLEY Copyright © 2011 Elsevier Inc. All rights reserved

Operational Oceanography

Presentation transcript:

The Character of North Atlantic Subtropical Mode Water Potential Vorticity Forcing Otmar Olsina, William Dewar Dept. of Oceanography, Florida State University Abstract Introduction The input of potential vorticity (PV) over the North Atlantic is estimated from observations to produce a climatological map of pv flux and to study the interannual forcing variability. Particular attention is paid to the North Atlantic subtropical mode water potential temperature range from 17 to 19C. The sea surface PV flux is estimated through buoyancy and wind stress contributions and using a climatological mixed layer depth product. Wind forcing of pv is found to be weak. Attempts are made to relate the fluctuations to the North Atlantic Oscillation index NAO, a major mode of North Atlantic atmospheric variability. The purpose is to identify PV sources in Gulf Stream (GS) derived from the hydrostatic equations and estimate the PV fluxes from the available data. The focus is given to CLIMODE years ( ) determining their deviation from climatological average. CLIMODE project – is a study of the dynamics of ‘Eighteen Degree Water’ (EDW), the subtropical mode water of the North Atlantic. Started in Oct Mode water is characterized with exceptionally uniform properties over depth significantly deeper than non-mode water. In this study the subtropical mode water is in temperature range between C and it is in a region of significant air-sea exchange. The Boussinesq equations of motion describe essentially all fluid phenomena of importance in the ocean. With few exceptions, turbulence and buoyant convection are the primary instances where ocean dynamics are not adequately described by the hydrostatic approximation. The times over which non-hydrostatic contributions are significant at given location are short (~1-2 hours). Time averaging over such intervals leads to an excellent approximation: potential vorticity, neglected (small, no data available) coriolis, in this case not applicable around equator calculated as estimated by density Main resolution 1x1 ( ) High resolution 0.25x0.25 ( ) Wind stress, SST, Qnet (net heat flux)  Obtained from satellite observations provided and processed by NCAR, QSCAT, AMSRE, WHOI Measurements from ships  Ocean Mixed Layer Depth Climatology Theory 1x1 degree resolution ( ) After manipulations of the equations the PV source is established as: where Data Acquisition 1x1 Resolution QnetWHOI (1)WHOI NCAR (1.25x1.21) SSTWHOI NCAR (1.25x1.21) Wind Dir NCAR (2) (1.25x1.21)QSCAT (3) QSCAT Wind SpeedWHOI QSCAT Mixed layer depthNODC (4)NODC 2007 Results PV sources for Jun 28, 2004 generated from the source equation. PV flux for Jun 28, 2004 integrated over 0.25x0.25 grid in NA Comparing resolution difference between 1x1 (blue) and 0.25x0.25 (red) between at monthly increment. The values are obtained by integrating over NA region in C SST range and averaged over daily values. Net Heat flux (Qnet), SST, Wind Direction and Wind Speed for Jun Contribution due to H (Buoyancy flux), on Jun After creating climatological product from 22 years of data , each month (blue) is plotted against the climatological product (red). Climatology and the monthly product is calculated by integrating over NA region and averaged over monthly values within C SST region. *note – climatology product (red) is a repeating pattern Comparing NAO yearly index (green), climatology product (red) to yearly PV flux (blue). Since this is a yearly value, the climatology product is averaged into a single value. The time scale is at yearly increment. Discussion The PV flux over NA in C range indicates that CLIMODE years were slightly stronger in their forcing than climatology. Also the analysis of contribution due to buoyancy is significantly larger than contribution due to wind stress. This finding agrees with Czaja and Haussmann (2008). The main factors affecting the PV flux in Gulf Stream are the net heat flux and climatological depth of the mixed layer. References Czaja, A. and U. Hausmann, 2008: Observations of entry and exit of Potential Vorticity at the sea surface. J.of Phys. Oce. Leif, T., 2005: Destruction of Potential Vorticity by Winds. J.of Phys. Oce. Marshall, J. D. Jamous and J. Nilsson, 2000: Entry, Flux, and Exit of Potential Vorticity in Ocean Circulation. J.of Phys. Oce (1) (2) (3) (4)