The Agulhas Current system: its dynamics and climatic importance
|
|
- Ralf Wheeler
- 6 years ago
- Views:
Transcription
1 The Agulhas Current system: its dynamics and climatic importance BJØRN BACKEBERG 1 NANSEN-TUTU CENTRE FOR MARINE ENVIRONMENTAL RESEARCH 2 DEPTARTMENT OF OCEANOGRAPHY, UNIVERSITY OF CAPE TOWN Nansen Centers 25 years Colloquium in honour of Fridtjov Nansens 150 year anniversary 25 YEARS COLLOQUIUM, 18 TH NOVEMBER
2 Outline Introducing the Agulhas Current system Subtropical Indian Ocean Aspects of its dynamics Agulhas leakage debate Why study the Agulhas system? Recent changes observed from the satellite altimeter record. What are the drivers of these changes? In the context of previous studies? Main conclusions.
3 The Agulhas Current system van Sebille et al., 2009 Penven et al., Boebel et al., 2003 Westward propagating retroflection loop & Agulhas Ring occlusion Eddies in its source regions Lutjeharms, 2006 Sources: Recirculation SEC (incl ITF) via MZC & EMC Intense oceanic turbulence the Cape Cauldron Debate over leakage: (1) Weak AC 70 transport Sv Ł stronger leakage (2) Increased winds Ł increased Variability AC predominantly transport Ł increased leakage associated with eddies & South of Africa meanders. current retroflects Lutjeharms and van Ballegooyen, 1988b
4 Importance of the Agulhas leakage Salt injection into South Atlantic via Agulhas rings is five times larger than Mediterranean Outflow. Salinity increase into North Atlantic from 1960-present Suggested that increased warm & salty flux may compensate a slowdown of MOC due to increased freshening in North Atlantic Biastoch et al., 2009 Trajectories of virtual floats released along the GoodHope section with T 10ºC
5 Impact on the global climate Agulhas leakage now recognised as key component in global climate. Paleo-climatic record indicates that: 1. Agulhas leakage shutdown associated with extreme glacial events 2. Vigorous increase preceded shifts towards interglacials. Thought that Agulhas leakage closely associated with changes in MOC Beal et al.,
6 Intensification of the subtropical gyre? Decadal sea surface height trend ( ) SSH increase in subtropical gyre, with decrease north of Madagascar Zonal average highlights the general increase of SSH in subtropical gyre Indicates that from no southward shift of the gyre occurs Enhanced pressure gradients associated with trends imply intensification of the gyre
7 Increased trade winds and westerlies Decadal ERA-interim wind stress trend ( ) Intensification of extra-tropical westerly winds and subtropical trade winds. For the period , there does not appear to a southward shift of the westerlies. Increased winds may be related to intensification of Hadley circulation associated with increased SSTs & rainfall in Indo-Pacific warm pool causing increased pressure gradients.
8 Can winds account for SSH pattern? Sverdrup SSH derived decadal decadal trend : trend 1993 : positive trend Zonal mean wind stress curl has positive trend between 8º and 30ºS. SSH trend derived from Sverdup relation and wind stress curl in good agreement with altimetry observed SSH trend pattern. Evidence that SSH trends are determined by the long term wind changes. 25 YEARS COLLOQUIUM, 18 TH NOVEMBER
9 Impact on circulation and mesoscale variability Increased large scale pressure gradients reflected in mean surface geostrophic flow and mesoscale variability. Changes predominantly in WBC. Large positive EKE trend in MZC, SEMC, and AR. Trends are statistically significant. 25 YEARS COLLOQUIUM, 18 TH NOVEMBER
10 Quantifying changes in mesoscale variability Implement eddy-tracking scheme. Combines the Okubo-Weiss and closed-contour methods Provide information on: o Position o Amplitude o Radius o U and V component drift velocities Using these information we can study trends Detected eddies in MZC
11 Impacts on eddies in the Agulhas system Eddy kinetic energy decadal trend (cm 2 s- 2 / decade) Mozambique Channel Slight increased cyclonic eddy diameters. Significant acceleration of poleward moving anticyclones (110% of the mean) 25 YEARS COLLOQUIUM, 18 TH NOVEMBER
12 Impacts on eddies in the Agulhas system Eddy kinetic energy decadal trend (cm 2 s- 2 / decade) South of Madagascar Increased amplitudes and radii of anticyclonic & cyclonic eddies. Accelerated westward propagation of anticyclonic eddies. 25 YEARS COLLOQUIUM, 18 TH NOVEMBER
13 Impacts on eddies in the Agulhas system Mean Eddy kinetic energy decadal trend (cm 2 s- 2 / decade) Agulhas Current Increasing EKE trend with faster southwestward propagating eddies. Concurrent decreasing MKE implies energy shift. 25 YEARS COLLOQUIUM, 18 TH NOVEMBER
14 Impacts on eddies in the Agulhas system Eddy kinetic energy decadal trend (cm 2 s- 2 / decade) Agulhas retroflection Increased northward propagation velocity of anticyclonic eddies (130% of the mean). Enhanced intrusion of Agulhas rings into South Atlantic 25 YEARS COLLOQUIUM, 18 TH NOVEMBER
15 Modelled increase of Agulhas leakage in recent years Altimetry observation are consistent with previous modelling studies. Increased leakage attributed to poleward shift of Southern Hemisphere westerlies. Not observed between Subtropical Indian Ocean gyre needs to be considered together with Southern Hemisphere westerlies. Studies of the leakage have relied heavily on ocean models. Biastoch et al., 2009 Increased westward transport in Agulhas leakage
16 Sensitivity of numerical models Model simulations are sensitive to numerical choices. In the Agulhas this is due to the high levels of oceanic turbulence. Models are not able to accurately represent the retroflection. Snapshot of model vorticity Eddy kinetic energy in different models Backeberg et al., 2009 Barnier et al., 2006
17 Summary and conclusions Agulhas system is a highly turbulent region. Through the Agulhas leakage it is recognised to be a key component in the global climate. Models and now observations indicate that the leakage has increased in recent years. A changing leakage has been shown to have implications for glaciations associated with the MOC. It has now been shown that changes in the subtropical Indian Ocean need to be considered in addition to the Southern Hemisphere westerlies when studying the Agulhas leakage and the MOC. Models and observations need to be combined in order to advance our understanding of this complicated system. The Agulhas is the perfect natural laboratory in which to test state-of-the-art advancements in modelling and observations
18 Acknowledgements Natural laboratory Large signals High velocities Co-authors: Pierrick Penven and Mathieu Rouault Marine-Research Institute at the University of Cape Town for travel support. This work has been supported by the Nansen-Tutu Centre for Marine Environmental Research and the International Centre for Education, Marine Strong gradients and Atmospheric Sciences over Africa. Challenging to model Eddy rich The altimeter data products were produced by Ssalto/Duacs and distributed by Aviso, with support from Cnes ( The ERA-interim data was obtained from
19
Hydrodynamic changes in the Agulhas Current and associated changes in the Indian and Atlantic Ocean
Hydrodynamic changes in the Agulhas Current and associated changes in the Indian and Atlantic Ocean Mathieu Rouault Department of Oceanography, Mare Institute, University of Cape Town Nansen-Tutu Center
More informationArne Biastoch Helmholtz Centre for Ocean Research Kiel. Modelling the Agulhas Current and its Coupling with the Atlantic Circulation
Arne Biastoch Helmholtz Centre for Ocean Research Kiel Modelling the Agulhas Current and its Coupling with the Atlantic Circulation The Agulhas System as a Key Region of the Global Oceanic Circulation
More informationArnold L. Gordon Retroflections and Bifurcations Johann Lutjeharms Memorial Lecture
The Agulhas System and its Role in Changing Ocean Circulation, Climate & Marine Ecosystems Spier Hotel, Stellenbosch, Western Cape, South Africa 8 12 October 2012 Brazil/Malvinas Agulhas Retroflection
More informationInvited paper on the South Atlantic J. Lutjeharms
AGU Chapman Conference on the Agulhas System Stellenbosch South Africa October 8 12, 2012 With regard to the thermohaline circulation, we identify some key locations where very important processes occur,
More informationAgulhas Leakage in the CCSM4. Wilbert Weijer (LANL, Los Alamos) Erik van Sebille (UNSW, Sydney)
Agulhas Leakage in the CCSM4 Wilbert Weijer (LANL, Los Alamos) Erik van Sebille (UNSW, Sydney) Slide 1 Agulhas Leakage Exchange of water between South Indian and Atlantic Oceans Takes part in Supergyre
More informationAtmospheric driving forces for the Agulhas Current in the subtropics
Click Here for Full Article GEOPHYSICAL RESEARCH LETTERS, VOL. 34, L15605, doi:10.1029/2007gl030200, 2007 Atmospheric driving forces for the Agulhas Current in the subtropics A. Fetter, 1 J. R. E. Lutjeharms,
More informationOn the fast decay of Agulhas rings
Click Here for Full Article JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 115,, doi:10.1029/2009jc005585, 2010 On the fast decay of Agulhas rings Erik van Sebille, 1,2 Peter Jan van Leeuwen, 1,3 Arne Biastoch,
More informationClimate Change Research Centre
2S On Agulhas rings and leakage (and whether it all matters) All trajectories of observational Agulhas buoys 3S 4S Erik van Sebille 1E 2E 3E 4E With input from Lisa Beal, Arne Biastoch, Matthew England,
More informationOcean Mixing and Climate Change
Ocean Mixing and Climate Change Factors inducing seawater mixing Different densities Wind stirring Internal waves breaking Tidal Bottom topography Biogenic Mixing (??) In general, any motion favoring turbulent
More informationUpper Ocean Circulation
Upper Ocean Circulation C. Chen General Physical Oceanography MAR 555 School for Marine Sciences and Technology Umass-Dartmouth 1 MAR555 Lecture 4: The Upper Oceanic Circulation The Oceanic Circulation
More informationClimate Change Research Centre
Lagrangian particles to study the ocean circulation All trajectories of buoys in the Global Drifter Program Erik van Sebille With input from Matthew England, Judith Helgers, Claire Paris, Bernadette Sloyan,
More informationNorth Atlantic circulation in three simulations of 1/12, 1/25, and 1/50
North Atlantic circulation in three simulations of 1/12, 1/2, and 1/ Xiaobiao Xu and Eric Chassignet Center for ocean-atmospheric prediction studies Florida State University Motivation Numerical models
More informationSIO 210 Introduction to Physical Oceanography Mid-term examination November 3, 2014; 1 hour 20 minutes
NAME: SIO 210 Introduction to Physical Oceanography Mid-term examination November 3, 2014; 1 hour 20 minutes Closed book; one sheet of your own notes is allowed. A calculator is allowed. (100 total points.)
More informationEvaluating two numerical advection schemes in HYCOM for eddy-resolving modelling of the Agulhas Current
Ocean Sci., 5, 173 190, 2009 Author(s) 2009. This work is distributed under the Creative Commons Attribution 3.0 License. Ocean Science Evaluating two numerical advection schemes in HYCOM for eddy-resolving
More informationLecture 4:the observed mean circulation. Atmosphere, Ocean, Climate Dynamics EESS 146B/246B
Lecture 4:the observed mean circulation Atmosphere, Ocean, Climate Dynamics EESS 146B/246B The observed mean circulation Lateral structure of the surface circulation Vertical structure of the circulation
More informationLecture 8. Lecture 1. Wind-driven gyres. Ekman transport and Ekman pumping in a typical ocean basin. VEk
Lecture 8 Lecture 1 Wind-driven gyres Ekman transport and Ekman pumping in a typical ocean basin. VEk wek > 0 VEk wek < 0 VEk 1 8.1 Vorticity and circulation The vorticity of a parcel is a measure of its
More informationObservation and modeling of eddies and dipoles in the Southern Indian Ocean
Observation and modeling of eddies and dipoles in the Southern Indian Ocean Yana Bebieva 1 Utrecht University 19.06.2013 Abstract Analysis of the along track satellite data near the southern tip of Madagascar
More informationSIO 210 Final examination Answer Key for all questions except Daisyworld. Wednesday, December 10, PM Name:
SIO 210 Final examination Answer Key for all questions except Daisyworld. Wednesday, December 10, 2008 3-6 PM Name: This is a closed book exam. You may use a calculator. There are two parts: Talley (weighted
More informationSST Observations of the Agulhas and East Madagascar Retroflections by the TRMM Microwave Imager
MAY 2002 NOTES AND CORRESPONDENCE 1585 SST Observations of the Agulhas and East Madagascar Retroflections by the TRMM Microwave Imager GRAHAM D. QUARTLY AND MERIC A. SROKOSZ James Rennell Division for
More informationArchimer
Please note that this is an author-produced PDF of an article accepted for publication following peer review. The definitive publisher-authenticated version is available on the publisher Web site Deep
More information1. The figure shows sea surface height (SSH) anomaly at 24 S (southern hemisphere), from a satellite altimeter.
SIO 210 Problem Set 3 November 16, 2015 1. The figure shows sea surface height (SSH) anomaly at 24 S (southern hemisphere), from a satellite altimeter. (a) What is the name of this type of data display?_hovmöller
More informationpsio 210 Introduction to Physical Oceanography Mid-term examination November 3, 2014; 1 hour 20 minutes Answer key
NAME: psio 210 Introduction to Physical Oceanography Mid-term examination November 3, 2014; 1 hour 20 minutes Answer key Closed book; one sheet of your own notes is allowed. A calculator is allowed. (100
More informationSea level variability in the North Indian Ocean
Sea level variability in the North Indian Ocean M. Ravichandran ESSO-National Centre for Antarctic and Ocean Research (NCAOR) (Ministry of Earth Sciences, Govt. of India) Goa mravi@ncaor.gov.in U.Srinivasu
More informationMERIDIONAL OVERTURNING CIRCULATION: SOME BASICS AND ITS MULTI-DECADAL VARIABILITY
MERIDIONAL OVERTURNING CIRCULATION: SOME BASICS AND ITS MULTI-DECADAL VARIABILITY Gokhan Danabasoglu National Center for Atmospheric Research OUTLINE: - Describe thermohaline and meridional overturning
More informationFlow structure and variability in the Subtropical Indian Ocean
Chapter 4 Flow structure and variability in the Subtropical Indian Ocean 4.1 Introduction It is well known from satellite altimetry that the variability of the South Indian Ocean comprises a range of frequencies
More informationThe effect on Agulhas Rings by the Southern Ocean wind stress
UNIVERSITY OF COPENHAGEN MASTER THESIS The effect on Agulhas Rings by the Southern Ocean wind stress Author: Peder HEISELBERG Supervisor: Markus JOCHUM A thesis submitted in fulfillment of the requirements
More informationMadagascar: A pacemaker for the Agulhas Current system?
Click Here for Full Article GEOPHYSICAL RESEARCH LETTERS, VOL. 33, L17609, doi:10.1029/2006gl026854, 2006 Madagascar: A pacemaker for the Agulhas Current system? P. Penven, 1,2 J. R. E. Lutjeharms, 3 and
More informationSIO 210 Final Exam Dec Name:
SIO 210 Final Exam Dec 8 2006 Name: Turn off all phones, pagers, etc... You may use a calculator. This exam is 9 pages with 19 questions. Please mark initials or name on each page. Check which you prefer
More informationOcean surface circulation
Ocean surface circulation Recall from Last Time The three drivers of atmospheric circulation we discussed: Differential heating Pressure gradients Earth s rotation (Coriolis) Last two show up as direct
More informationModes of the southern extension of the East Madagascar Current
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 114,, doi:10.1029/2008jc004921, 2009 Modes of the southern extension of the East Madagascar Current Gerold Siedler, 1,2 Mathieu Rouault, 2 Arne Biastoch, 1 Bjorn Backeberg,
More information2/15/2012. Earth System Science II EES 717 Spring 2012
Earth System Science II EES 717 Spring 2012 1. The Earth Interior Mantle Convection & Plate Tectonics 2. The Atmosphere - Climate Models, Climate Change and Feedback Processes 3. The Oceans Circulation;
More informationBasic Ocean Current Systems. Basic Ocean Structures. The State of Oceans. Lecture 6: The Ocean General Circulation and Climate. Temperature.
Lecture 6: The Ocean General Circulation and Climate Basic Ocean Current Systems Upper Ocean surface circulation Basic Structures Mixed Layer Wind-Driven Circulation Theories Thermohaline Circulation Ocean
More informationWestern Boundary Currents. Global Distribution of Western Boundary Currents and their importance
Western Boundary Currents In previous chapters you have learned about the processes that cause the intensification of currents along the western boundaries of the oceans. In this chapter we will examine
More informationIPCC AR5 WG1 - Climate Change 2013: The Physical Science Basis. Nandini Ramesh
IPCC AR5 WG1 - Climate Change 2013: The Physical Science Basis Nandini Ramesh Seminar in Atmospheric Science 21 st February, 2014 1. Introduc,on The ocean exchanges heat, freshwater, and C with the atmosphere.
More informationCHAPTER 7 Ocean Circulation Pearson Education, Inc.
CHAPTER 7 Ocean Circulation 2011 Pearson Education, Inc. Types of Ocean Currents Surface currents Deep currents 2011 Pearson Education, Inc. Measuring Surface Currents Direct methods Floating device tracked
More informationAnswer the following questions using letters A through H :
SIO 210 Problem Set 3 November 10, 2014 Due Nov. 24, 2014 Answer key 1. 10 total 6 points (a) The following kinds of wave motion were mentioned in class A. light 3 x 10 9 m/sec B. sound in air (340 m/sec)
More informationclimate system and its subcomponents: the atmosphere, ocean, land surface, Prof. Jin-Yi Yu ESS200A A general description of the Earth
Earth System Climate () Course Time Lectures: Tu, Th 9:30-10:20 Discussion: 3315 Croul Hall Text Book The Earth System, Kump, Kasting, and Crane, Prentice-Hall Global Physical Climatology, Hartmann; Academic
More informationPathways in the ocean
Pathways Pathways in the in the ocean by Sybren Drijfhout Introduction The properties of water masses in the ocean are set by air-sea interactions at the surface and convective overturning. As direct transfer
More informationSIO 210: Dynamics VI (Potential vorticity) L. Talley Fall, 2014 (Section 2: including some derivations) (this lecture was not given in 2015)
SIO 210: Dynamics VI (Potential vorticity) L. Talley Fall, 2014 (Section 2: including some derivations) (this lecture was not given in 2015) Variation of Coriolis with latitude: β Vorticity Potential vorticity
More informationWater mass transport associated with the oceanic fronts in the northwestern Pacific Ocean HIDEYUKI NAKANO (METEOROLOGICAL RESEARCH INSTITUTE)
Water mass transport associated with the oceanic fronts in the northwestern Pacific Ocean HIDEYUKI NAKANO (METEOROLOGICAL RESEARCH INSTITUTE) How is the Kuroshio-origin water distributed in the subtropical
More informationModes of the southern extension of the East Madagascar Current
Modes of the southern extension of the East Madagascar Current Gerold Siedler 1,2, Mathieu Rouault 2, Arne Biastoch 1, Bjorn Backeberg 2,3, Chris J.C. Reason 2, and Johann R. E. Lutjeharms 2 1 Leibniz
More informationWinds and Global Circulation
Winds and Global Circulation Atmospheric Pressure Winds Global Wind and Pressure Patterns Oceans and Ocean Currents El Nino How is Energy Transported to its escape zones? Both atmospheric and ocean transport
More informationElsevier Editorial System(tm) for Deep-Sea Research Part II Manuscript Draft
Elsevier Editorial System(tm) for Deep-Sea Research Part II Manuscript Draft Manuscript Number: Title: Circulation, stratification and seamounts in the South West Indian Ocean Article Type: SW Indian Ocean
More informationEddy-resolving Simulation of the World Ocean Circulation by using MOM3-based OGCM Code (OFES) Optimized for the Earth Simulator
Chapter 1 Atmospheric and Oceanic Simulation Eddy-resolving Simulation of the World Ocean Circulation by using MOM3-based OGCM Code (OFES) Optimized for the Earth Simulator Group Representative Hideharu
More informationS11. Indian Ocean: Supplementary Materials
C H A P T E R S11 Indian Ocean: Supplementary Materials FIGURE S11.1 Indian Ocean surface circulation (Tables S11.1, S11.2 and Figure 11.1). Surface height (cm). Data from Niiler, Maximenko, and McWilliams
More informationLecture 1. Amplitude of the seasonal cycle in temperature
Lecture 6 Lecture 1 Ocean circulation Forcing and large-scale features Amplitude of the seasonal cycle in temperature 1 Atmosphere and ocean heat transport Trenberth and Caron (2001) False-colour satellite
More informationSIO 210 Problem Set 2 October 17, 2011 Due Oct. 24, 2011
SIO 210 Problem Set 2 October 17, 2011 Due Oct. 24, 2011 1. The Pacific Ocean is approximately 10,000 km wide. Its upper layer (wind-driven gyre*) is approximately 1,000 m deep. Consider a west-to-east
More informationThe Planetary Circulation System
12 The Planetary Circulation System Learning Goals After studying this chapter, students should be able to: 1. describe and account for the global patterns of pressure, wind patterns and ocean currents
More informationSE Atlantic SST variability and southern African climate
SE Atlantic SST variability and southern African climate Chris Reason Oceanography Dept, Univ. Cape Town Overview of southern African climate and tropical Atlantic SST South American monsoon, Benguela
More informationMAR 110 LECTURE #10 The Oceanic Conveyor Belt Oceanic Thermohaline Circulation
1 MAR 110 LECTURE #10 The Oceanic Conveyor Belt Oceanic Thermohaline Circulation Ocean Climate Temperature Zones The pattern of approximately parallel oceanic surface isotherms (lines of constant temperature)
More informationClimate Change Impacts on the Marine Environment
Climate Change Impacts on the Marine Environment Ken Ridgway CSIRO Marine and Atmospheric Research Wealth from Oceans National Research Flagship www.csiro.au Acknowledgements Jeff Dunn, John Church, Katy
More informationStructure and origin of the subtropical South Indian Ocean Countercurrent
GEOPHYSICAL RESEARCH LETTERS, VOL. 33, L24609, doi:10.1029/2006gl027399, 2006 Structure and origin of the subtropical South Indian Ocean Countercurrent Gerold Siedler, 1 Mathieu Rouault, 2 and Johann R.
More informationExamples of Pressure Gradient. Pressure Gradient Force. Chapter 7: Forces and Force Balances. Forces that Affect Atmospheric Motion 2/2/2015
Chapter 7: Forces and Force Balances Forces that Affect Atmospheric Motion Fundamental force - Apparent force - Pressure gradient force Gravitational force Frictional force Centrifugal force Forces that
More informationLecture 14. Equations of Motion Currents With Friction Sverdrup, Stommel, and Munk Solutions Remember that Ekman's solution for wind-induced transport
Lecture 14. Equations of Motion Currents With Friction Sverdrup, Stommel, and Munk Solutions Remember that Ekman's solution for wind-induced transport is which can also be written as (14.1) i.e., #Q x,y
More informationDivergent pathways of cyclonic and anti-cyclonic ocean eddies
GEOPHYSICAL RESEARCH LETTERS, VOL. 31, L24311, doi:10.1029/2004gl020974, 2004 Divergent pathways of cyclonic and anti-cyclonic ocean eddies Rosemary Morrow and Florence Birol Laboratoire d Etudes en Géophysique
More informationAgulhas eddy fluxes in a 1/6 Atlantic model
Deep Sea Research Part II: Topical Studies in Oceanography JAN 2003; 50(1) : 251-280 http://dx.doi.org/10.1016/s0967-0645(02)00396-x Copyright 2002 Elsevier Science Ltd. All rights reserved Archimer http://www.ifremer.fr/docelec/
More informationWeather & Ocean Currents
Weather & Ocean Currents Earth is heated unevenly Causes: Earth is round Earth is tilted on an axis Earth s orbit is eliptical Effects: Convection = vertical circular currents caused by temperature differences
More informationAtmosphere, Ocean and Climate Dynamics Fall 2008
MIT OpenCourseWare http://ocw.mit.edu 12.003 Atmosphere, Ocean and Climate Dynamics Fall 2008 For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms. Problem
More informationCapabilities of Ocean Mixed Layer Models
Capabilities of Ocean Mixed Layer Models W.G. Large National Center for Atmospheric Research Boulder Co, USA 1. Introduction The capabilities expected in today s state of the art models of the ocean s
More informationChapter 6. Antarctic oceanography
Chapter 6 Antarctic oceanography The region of the world ocean bordering on Antarctica is unique in many respects. First of all, it is the only region where the flow of water can continue all around the
More informationPUBLICATIONS. Journal of Geophysical Research: Oceans
PUBLICATIONS Journal of Geophysical Research: Oceans RESEARCH ARTICLE Key Points: Interannual variations of western boundary currents along Madagascar are investigated These interannual anomalies are responses
More informationClimate sensitivity of coupled models with differing ocean components
Climate sensitivity of coupled models with differing ocean components Alex Megann, Adam Blaker and Adrian New National Oceanography Centre, Southampton, UK LOM Workshop, Miami, February 2011 Overview Introduction
More informationWind changes above warm Agulhas Current eddies
Wind changes above warm Agulhas Current eddies M. Rouault 1,2, P. Verley 1,3, B. Backeberg 2,4 1 Department of Oceanography, Mare Institute, University of Cape Town 2 Nansen-Tutu Center for Marine Environmental
More informationAn analysis of the Atlantic Meridional Overturning Circulation (MOC) in an Atmosphere-Ocean General Circulation Model
An analysis of the Atlantic Meridional Overturning Circulation (MOC) in an Atmosphere-Ocean General Circulation Model Virginie Guemas, David Salas-Mélia Centre National de Recherches Météorologiques (CNRM)
More informationSIO 210 Final examination Wednesday, December 12, :30-2:30 Eckart 227 Name:
SIO 210 Final examination Wednesday, December 12, 2018 11:30-2:30 Eckart 227 Name: Please put your initials or name on each page, especially if you pull pages apart. Turn off all phones, ipods, etc. and
More informationCANER SERTKAN ( ) WIND DRIVEN OCEAN CIRCULATION
CANER SERTKAN (517101005) WIND DRIVEN OCEAN CIRCULATION INTRODUCTION The waters of the ocean are continually moving in powerful currents like the Gulf Stream, in large gyres, in feautures visible from
More informationOcean dynamics: the wind-driven circulation
Ocean dynamics: the wind-driven circulation Weston Anderson March 13, 2017 Contents 1 Introduction 1 2 The wind driven circulation (Ekman Transport) 3 3 Sverdrup flow 5 4 Western boundary currents (western
More informationDeep-Sea Research II
Deep-Sea Research II ] (]]]]) ]]] ]]] Contents lists available at ScienceDirect Deep-Sea Research II journal homepage: www.elsevier.com/locate/dsr2 The South Atlantic and the Atlantic Meridional Overturning
More informationEstimation of the Agulhas ring impacts on meridional heat fluxes and transport using ARGO floats and satellite data
GEOPHYSICAL RESEARCH LETTERS, VOL. 38,, doi:10.1029/2011gl049359, 2011 Estimation of the Agulhas ring impacts on meridional heat fluxes and transport using ARGO floats and satellite data J. M. A. C. Souza,
More informationAgulhas Leakage Predominantly Responds to the Southern Hemisphere Westerlies
OCTOBER 2013 D U R GADOO ET AL. 2113 Agulhas Leakage Predominantly Responds to the Southern Hemisphere Westerlies JONATHAN V. DURGADOO GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany BENJAMIN
More informationSIO 210 Introduction to Physical Oceanography Mid-term examination Wednesday, November 2, :00 2:50 PM
SIO 210 Introduction to Physical Oceanography Mid-term examination Wednesday, November 2, 2005 2:00 2:50 PM This is a closed book exam. Calculators are allowed. (101 total points.) MULTIPLE CHOICE (3 points
More informationOcean currents from altimetry
Ocean currents from altimetry Pierre-Yves LE TRAON - CLS - Space Oceanography Division Gamble Workshop - Stavanger,, May 2003 Introduction Today: information mainly comes from in situ measurements ocean
More informationTasman leakage in a fine-resolution ocean model
GEOPHYSICAL RESEARCH LETTERS, VOL. 39,, doi:10.1029/2012gl051004, 2012 Tasman leakage in a fine-resolution ocean model Erik van Sebille, 1 Matthew H. England, 1 Jan D. Zika, 1 and Bernadette M. Sloyan
More informationNorth Atlantic Deep Water Pathways and Eddy Generation Beneath the Agulhas Current System
University of Miami Scholarly Repository Open Access Theses Electronic Theses and Dissertations 2013-12-17 North Atlantic Deep Water Pathways and Eddy Generation Beneath the Agulhas Current System Joni
More informationPreliminary Cruise Report PIRATA Northeast Extension 2006 / AMMA / Sahara Dust Cruise NOAA Ship Ronald H. Brown
Preliminary Cruise Report PIRATA Northeast Extension 2006 / AMMA / Sahara Dust Cruise NOAA Ship Ronald H. Brown Leg 1: May 27-June 18, 2006 San Juan, Puerto Rico to Recife, Brazil Leg 2: June 22 - July
More informationTransient/Eddy Flux. Transient and Eddy. Flux Components. Lecture 7: Disturbance (Outline) Why transients/eddies matter to zonal and time means?
Lecture 7: Disturbance (Outline) Transients and Eddies Climate Roles Mid-Latitude Cyclones Tropical Hurricanes Mid-Ocean Eddies (From Weather & Climate) Flux Components (1) (2) (3) Three components contribute
More informationINDONESIAN THROUGHFLOW AND ITS PROXY FROM SATELLITE ALTIMETERS AND GRAVIMETERS
INDONESIAN THROUGHFLOW AND ITS PROXY FROM SATELLITE ALTIMETERS AND GRAVIMETERS R. Dwi Susanto 1, Tony Song 2, Zexun Wei 3, Jiayi Pan 4 1 Department of Atmospheric and Oceanic Science University of Maryland,
More informationComparison Figures from the New 22-Year Daily Eddy Dataset (January April 2015)
Comparison Figures from the New 22-Year Daily Eddy Dataset (January 1993 - April 2015) The figures on the following pages were constructed from the new version of the eddy dataset that is available online
More informationRelating Agulhas leakage to the Agulhas Current retroflection location
Ocean Sci., 5, 511 521, 29 www.ocean-sci.net/5/511/29/ Author(s) 29. This work is distributed under the Creative Commons Attribution 3. License. Ocean Science Relating Agulhas leakage to the Agulhas Current
More informationWinds and Currents in the Oceans
Winds and Currents in the Oceans Atmospheric Processes Density of air is controlled by temperature, pressure, and moisture content. 1. Warm air is less dense than cold air and moist air is less dense than
More informationWind Gyres. curl[τ s τ b ]. (1) We choose the simple, linear bottom stress law derived by linear Ekman theory with constant κ v, viz.
Wind Gyres Here we derive the simplest (and oldest; Stommel, 1948) theory to explain western boundary currents like the Gulf Stream, and then discuss the relation of the theory to more realistic gyres.
More informationPUBLICATIONS. Journal of Geophysical Research: Oceans
PUBLICATIONS Journal of Geophysical Research: Oceans RESEARCH ARTICLE Key Points: Local atmospheric variability modulates the structure of the ACC south of Africa Positive SAM is linked with a warmer ACC
More informationSatellite Altimetry Sea Surface Height Variability and In Situ Observations Along An Eddy Corridor Dr. Sheekela Baker-Yeboah 1
Satellite Altimetry Sea Surface Height Variability and In Situ Observations Along An Eddy Corridor Dr. Sheekela Baker-Yeboah 1 NOAA/NESDIS/National Center for Environmental Information, 2 University of
More informationLink between Hurricanes and Climate Change: SST
Link between Hurricanes and Climate Change: SST FRIDAY: PROJECT 2 Proposals due! Bring laptops on weds (at least one per group)! Discuss assessment on Weds. Roger Francois will talk on Friday about the
More informationSUPPLEMENTARY INFORMATION
SUPPLEMENTARY INFORMATION DOI: 1.138/NCLIMATE216 Recent intensification of wind-driven circulation in the Pacific and the ongoing warming hiatus (a) Observed wind trends 6N N 2N 2S S 6S 6E 12E 18E 12W
More informationSIO 210: Dynamics VI: Potential vorticity
SIO 210: Dynamics VI: Potential vorticity Variation of Coriolis with latitude: β Vorticity Potential vorticity Rossby waves READING: Review Section 7.2.3 Section 7.7.1 through 7.7.4 or Supplement S7.7
More informationWhat caused the significant increase in Atlantic Ocean heat content since the mid 20th century?
GEOPHYSICAL RESEARCH LETTERS, VOL. 38,, doi:10.1029/2011gl048856, 2011 What caused the significant increase in Atlantic Ocean heat content since the mid 20th century? Sang Ki Lee, 1,2 Wonsun Park, 3 Erik
More informationInterhemispheric climate connections: What can the atmosphere do?
Interhemispheric climate connections: What can the atmosphere do? Raymond T. Pierrehumbert The University of Chicago 1 Uncertain feedbacks plague estimates of climate sensitivity 2 Water Vapor Models agree
More informationThe seasonality of transportation in the Southern African subregion is considered. By
CHAPTER 3 RESULTS AND DISCUSSION This Chapter discusses the findings of the research. A seasonal air transport climatology for southern Africa is presented. The months of February, April, July and October
More informationIntroduction of climate monitoring and analysis products for one-month forecast
Introduction of climate monitoring and analysis products for one-month forecast TCC Training Seminar on One-month Forecast on 13 November 2018 10:30 11:00 1 Typical flow of making one-month forecast Observed
More informationNOTES AND CORRESPONDENCE. On Sverdrup Discontinuities and Vortices in the Southwest Indian Ocean
2940 J O U R N A L O F P H Y S I C A L O C E A N O G R A P H Y VOLUME 37 NOTES AND CORRESPONDENCE On Sverdrup Discontinuities and Vortices in the Southwest Indian Ocean J. H. LACASCE Institute for Geophysics,
More informationHow might extratropical storms change in the future? Len Shaffrey National Centre for Atmospheric Science University of Reading
How might extratropical storms change in the future? Len Shaffrey National Centre for Atmospheric Science University of Reading Extratropical storms Extratropical storms Strong winds, extreme waves, storm
More informationWhat is the Madden-Julian Oscillation (MJO)?
What is the Madden-Julian Oscillation (MJO)? Planetary scale, 30 90 day oscillation in zonal wind, precipitation, surface pressure, humidity, etc., that propagates slowly eastward Wavelength = 12,000 20,000
More informationThe Tswaing Impact Crater, South Africa: derivation of a long terrestrial rainfall record for the southern mid-latitudes
The Tswaing Impact Crater, South Africa: derivation of a long terrestrial rainfall record for the southern mid-latitudes T.C. PARTRIDGE Climatology Research Group, University of the Witwatersrand, Johannesburg,
More informationG. S. Pilo et al. June 30, This paper gives an overview of some eddy statistics in the 3 Southern Hemisphere
Reply to Anonymous Referee #2 regarding the paper submitted to Ocean Science entitled Eddy Surface properties and propagation at Southern Hemisphere western boundary current systems G. S. Pilo et al. June
More informationEddy-induced meridional heat transport in the ocean
GEOPHYSICAL RESEARCH LETTERS, VOL. 35, L20601, doi:10.1029/2008gl035490, 2008 Eddy-induced meridional heat transport in the ocean Denis L. Volkov, 1 Tong Lee, 1 and Lee-Lueng Fu 1 Received 28 July 2008;
More informationIs there a continuous Subtropical Front south of Africa?
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 116,, doi:10.1029/2010jc006587, 2011 Is there a continuous Subtropical Front south of Africa? Guillaume Dencausse, 1,2 Michel Arhan, 1 and Sabrina Speich 1 Received
More informationWind: Global Systems Chapter 10
Wind: Global Systems Chapter 10 General Circulation of the Atmosphere General circulation of the atmosphere describes average wind patterns and is useful for understanding climate Over the earth, incoming
More informationDecadal Variation of the Geostrophic Vorticity West of the Luzon Strait
144 The Open Oceanography Journal, 2010, 4, 144-149 Open Access Decadal Variation of the Geostrophic Vorticity West of the Luzon Strait Yinglai Jia *,1, Qinyu Liu 1 and Haibo Hu 2 1 Physical Oceanography
More informationCurrents and Mixing in the Southern Ocean. Sarah Gille
Currents and Mixing in the Southern Ocean Sarah Gille Scripps Institution of Oceanography and Department of Mechanical and Aerospace Engineering UCSD, La Jolla, CA Where might AVISO gridded fields fall
More information