The “Missing Piece” - University of Colorado Bouldercires1.colorado.edu/science/groups/pielke/classes/atoc...The “Missing Piece” COULD IT: ¾Explain Why “It’s Not so Hot…yet”?

May 2007May 2007 Marcia WyattMarcia Wyatt 11

The The ““Missing PieceMissing Piece””

COULD IT:COULD IT:Explain Why Explain Why ““ItIt’’s Not so Hots Not so Hot……yetyet””??

Validate Model Design & Climate Sensitivity?Validate Model Design & Climate Sensitivity?Support a New Metric for Radiative Imbalance?Support a New Metric for Radiative Imbalance?

Provide Clues for a Provide Clues for a ““Heat RegulatorHeat Regulator”” for Earth Systems?for Earth Systems?

THE STORY OF OCEAN HEAT

Marcia WyattMarcia Wyatt

May 2007May 2007


Outline of Presentation:Outline of Presentation:

Why IsnWhy Isn’’t it Hotter??? t it Hotter??? –– a look at modelsa look at models

Revelations on radiative imbalanceRevelations on radiative imbalance

And how the ocean heats and how it is measuredAnd how the ocean heats and how it is measured

Do patterns reveal a regulatory mechanism?Do patterns reveal a regulatory mechanism?


Part I:Part I:

Why IsnWhy Isn’’t it Hotter?t it Hotter?Looking for EarthLooking for Earth’’s s ““Missing HeatMissing Heat””

If found, what does it mean?If found, what does it mean?


FirstFirst……Why IsnWhy Isn’’t it Hotter?t it Hotter?Determining the expected Ts increaseDetermining the expected Ts increase::

1.1. Assess Climate Sensitivity (CS)Assess Climate Sensitivity (CS)•• ∆∆T/T/∆∆F = 1/F = 1/λλ = CS= CS

Where Where λλ has been assigned values: 0.9 to 3.6 W/m^2 Khas been assigned values: 0.9 to 3.6 W/m^2 K2.2. Consider the projected Radiative Forcing (Rf)Consider the projected Radiative Forcing (Rf)

•• 2xCO2 ~ 4 W/m^22xCO2 ~ 4 W/m^23.3. Evaluate Expected TsEvaluate Expected Ts--increase based on CSincrease based on CS

4.54.5°°C to 1.2C to 1.2°°C for 2*CO2C for 2*CO2= 0.3 to 1.12 = 0.3 to 1.12 °°C/W/m^2 = climate sensitivityC/W/m^2 = climate sensitivity

4.4. Assess total ghg Assess total ghg RfRf to date:to date:1880 to 2003 ~ 3.05 W/m^21880 to 2003 ~ 3.05 W/m^2

This is > than 75% of expected Rf with 2xCO2This is > than 75% of expected Rf with 2xCO25.5. Conclude: should expect to observe Ts ~ 3.38Conclude: should expect to observe Ts ~ 3.38°°C to 0.9C to 0.9°°CC

•• Observed Ts Increase ~ 0.7Observed Ts Increase ~ 0.7°°CC

Why doesnWhy doesn’’t it add up?t it add up?A few possibilities A few possibilities →→


Possible Explanations:Possible Explanations: Not mutually exclusiveNot mutually exclusiveClimate sensitivity has been overestimated.Climate sensitivity has been overestimated.

CS = CS = ∆∆Ts/ Ts/ ∆∆ F = 1/F = 1/λλ∆∆Ts = Ts = ∆∆ F/F/λλFeedback parameter, Feedback parameter, λλ, would be larger, CS lower, would be larger, CS lower……a possibilitya possibility

Reflective aerosols mask heating more than thought.Reflective aerosols mask heating more than thought.Maybe they explain a larger Maybe they explain a larger λλ……also a possibilityalso a possibility

Heat is Heat is ““hidinghiding””S = S = ∆∆Ts/ Ts/ ∆∆ F = 1/F = 1/λλ –– ““hiding heathiding heat””∆∆Ts = Ts = ∆∆ F/F/λλ –– ““hiding heathiding heat””...and yet another possibility...and yet another possibility

Or maybe all threeOr maybe all three……


Considering All Three PossibilitiesConsidering All Three PossibilitiesFrom Hansen et al. 2005From Hansen et al. 2005

Aerosols considered: assigned a Rf = Aerosols considered: assigned a Rf = --1.391.39““subjective estimated uncertainties 50%subjective estimated uncertainties 50%””

Combined Combined RfRf estimates made: solar, ghgestimates made: solar, ghgtt, ghg, ghgss, O, O33↓↓& aerosols& aerosols

Net Rf = 1.88 W/m^2 (1880 to 2003)Net Rf = 1.88 W/m^2 (1880 to 2003)Assessed climate sensitivity = 0.67Assessed climate sensitivity = 0.67°°C per W/m^2C per W/m^2With these model inputs:With these model inputs:

Concluded that 1.03W/m^2 = Concluded that 1.03W/m^2 = ““realizedrealized”” with 0.7with 0.7°°C increaseC increaseConcluded 0.85W/m^2 = Concluded 0.85W/m^2 = ““unrealizedunrealized””

•• Concluded Concluded ““unrealizedunrealized”” heat in oceans.heat in oceans.Invoke Levitus et al. Invoke Levitus et al. ’’00, 00, ‘‘05 studies on ocean heat 05 studies on ocean heat Use models to assess heat gain of 0Use models to assess heat gain of 0--750 m 1993 750 m 1993 -- 2003 ; found it = .86W/m^22003 ; found it = .86W/m^2

•• Expect another 0.6Expect another 0.6°°C of C of ““commitment warmingcommitment warming””: : ““in the pipelinein the pipeline”…”…

Case closedCase closed…….???.???


Increasing Ocean Heat: Confirmation of Global Increasing Ocean Heat: Confirmation of Global WarmingWarming……but model design???but model design???

Enormous heat capacityEnormous heat capacity•• Heat in upper 2 m ocean = all heat in atmosphereHeat in upper 2 m ocean = all heat in atmosphere

Lithosphere, atmosphere, and cryosphere = minor reservoirsLithosphere, atmosphere, and cryosphere = minor reservoirs

Levitus et al. 2005

83.8% of heat delivered to

Earth system over last ~ 50

years has gone into oceans

~ volume mean

warming = 0.037°C

= radiative imbalance ~

0.2 W/m^2 for 43 years

Estimates of Earth’s heat balance components for 1955 to 1955 to 19981998 in (10^22 joules)

Levitus changes his ocean-heat values downward from ’00 to ’01 to ’05; no explanation or acknowledgement of these changes is given.


Invoking Levitus et alInvoking Levitus et al’’s Findings:s Findings:Hansen et alHansen et al’’s Reasoned:s Reasoned:

••Findings:Findings:

••Adjusted model Adjusted model conclusions ~ 6Wyr/m^2 conclusions ~ 6Wyr/m^2 radiative imbalance radiative imbalance between 1993 and 2003between 1993 and 2003

••Conclusion:Conclusion:

••Energy imbalance TOA Energy imbalance TOA

••Commitment warmingCommitment warming

••~0.6~0.6°°C C ““in pipelinein pipeline””

••agrees well with agrees well with LevitusLevitus’’ workwork

Converted to energy flux from joules from Levitus et alConverted to energy flux from joules from Levitus et al’’s s ’’05 OHCA values05 OHCA values

1 Wyr/m^2 = 1.61 x 10^22 joules averaged over Earth1 Wyr/m^2 = 1.61 x 10^22 joules averaged over Earth’’s surface;s surface;

10 22 joules = 0.62 Wyr/m^2 10 22 joules = 0.62 Wyr/m^2

OHCA IN Wyr/m 2̂ for 0 to 750 meters for 1993 to 2003

0

1

2

3

4

5

6

7

8

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003

YEAR

Hea

t-C

onte

nt In

crea

se in

Wyr

/m2̂ OHCA IN Wyr/m^2 for 0 to 750

meters for 1993 to 2003

OCEAN-HEAT CONTENT (upper 750 m) IN Wyr/m^2 1993 to 2003

OCEANOCEAN--HEAT CONTENT (upper 750 m) IN Wyr/m^2 HEAT CONTENT (upper 750 m) IN Wyr/m^2 1993 to 20031993 to 2003

Energy imbalance at TOA evidenced by accumulated ocean heat.

Energy imbalance at TOA Energy imbalance at TOA evidenced by accumulated evidenced by accumulated ocean heat.ocean heat.


Critiquing HansenCritiquing Hansen’’s Conclusions ConclusionCan Several Unknowns Be Solved with one Known Can Several Unknowns Be Solved with one Known

((assumingassuming it is a it is a ““knownknown””)?)?

Even if we Even if we knowknow the OHCA the OHCA (if we really do) (if we really do) and assume it translates to and assume it translates to something that is comparable to Hansensomething that is comparable to Hansen’’s s ““requiredrequired”” 0.85 W/m^20.85 W/m^2……..

This is only This is only oneone knownknown

Put against Put against manymany unknownsunknownsNet radiative forcings (solar, aerosols, other)Net radiative forcings (solar, aerosols, other)Climate sensitivityClimate sensitivityDynamics of heat uptake, k, and transport in oceanDynamics of heat uptake, k, and transport in oceanThe various causes for oceanThe various causes for ocean--heat increaseheat increase

Is heat at depth from decades or centuries ago?Is heat at depth from decades or centuries ago?What role does changing cloud cover play?What role does changing cloud cover play?

•• Decrease in lowDecrease in low--cloud cover from 1987 to 2002cloud cover from 1987 to 2002•• Currently highCurrently high--cloud cover is increasing, but not lowcloud cover is increasing, but not low--cloud cover.cloud cover.

Is there a fluctuating pattern of oceanIs there a fluctuating pattern of ocean--atmosphere heat exchange?atmosphere heat exchange?


Conclusion thus farConclusion thus far……

The Heat Has Been FoundThe Heat Has Been FoundIt is in the oceanIt is in the ocean……

AndAnd……•• It does indicateIt does indicate that Earth is warmingthat Earth is warming•• It It can help explaincan help explain ““Why Earth IsnWhy Earth Isn’’t Hottert Hotter””•• Does reflectDoes reflect radiative imbalance at TOAradiative imbalance at TOA•• Does suggestDoes suggest ““commitment warmingcommitment warming””


BUTBUT……

OceanOcean--Heat ChangeHeat ChangeCannotCannot identify sources of ocean warmingidentify sources of ocean warmingCannotCannot tell how much or when tell how much or when ““commitment commitment warmingwarming”” will occurwill occur

CannotCannot confirm values of CS or Rfconfirm values of CS or RfTherefore OHC change cannot validate model designTherefore OHC change cannot validate model design


Part II:Part II:

Revelations on EarthRevelations on Earth’’s Radiative Imbalances Radiative Imbalance““RealizedRealized”” vs. vs. ““UnrealizedUnrealized”” HeatingHeating

What are the implications???What are the implications???


OceanOcean--Heat Change & Radiative ImbalanceHeat Change & Radiative ImbalanceA Different Way to Assess Climate ChangeA Different Way to Assess Climate Change

•This figure consolidates realized and unrealized heating.

•Ocean heat offers a new metric for the “unrealized”Rf

Represented as all Represented as all ““unrealizedunrealized”” forcingforcing

When, in fact, a 0.7When, in fact, a 0.7°°C increase implies some of forcing C increase implies some of forcing ““realizedrealized””


Pielke ‘03

“Unrealized” Heating

Two Points to Consider:Two Points to Consider:

1.1. How does one use oceanHow does one use ocean--heatheat--content (OHC) to assess radiation imbalance (RI)?content (OHC) to assess radiation imbalance (RI)?

2.2. How reliable is the assessment of oceanHow reliable is the assessment of ocean--heatheat--content?content?

∆∆F = F = ““unrealizedunrealized”” heat + heat + ““realizedrealized”” heatheat

∆∆FF = stored heat + = stored heat + ∆∆F/F/λλ

““unrealizedunrealized”” heat (or heat (or ““commitment warmingcommitment warming””) = change in ocean) = change in ocean--heat content (OHCA) from 0 to 3000 meters.heat content (OHCA) from 0 to 3000 meters.

Caveat: heat may be below 3000 meters

••RRNN = non= non--equilibrium equilibrium RfRf

••Q = rate of heating Q = rate of heating of reservoirof reservoir

••V = volume of V = volume of reservoirreservoir

••A = area of EarthA = area of Earth

““unrealizedunrealized””

OceanOcean--heatheat--content change = metric to evaluate unrealized forcingcontent change = metric to evaluate unrealized forcingJoules of heat converted to W/m^2 Joules of heat converted to W/m^2

No need to know climate sensitivityNo need to know climate sensitivity


Time Series for Earth's Energy Imbalance

-3-2-10123

1955

1959

1963

1967

1971

1975

1979

1983

1987

1991

1995

year

Ener

gy Im

bala

nce

in

W/m

^2Time Series for Energy Imbalance

5 per. M ov. Avg. (Time Series forEnergy Imbalance)

How to Use Ocean Heat to Reflect RI:

Observed global OHCA 0 to 3000 m

Observed atmospheric mean heat content

Modeled ocean heat for Rf chosen

Levitus et al. 2001

Based on Pielke 2003

1W/m^2/year = 1.61*10^22 Joules

1*10^22 Joules = 0.62 W*yr/m^2

OceanOcean--heatheat--change:change:••Within upper 3000 metersWithin upper 3000 meters

••To calculate radiative imbalance:To calculate radiative imbalance:

••Find annual heat content Find annual heat content changechange

••Convert to W/m^2 Convert to W/m^2

••Plot OHC changePlot OHC change

Shown with 5Shown with 5--yr yr running mean running mean



-8

-6

-4

-2

0

2

4

6

1955

1958

1961

1964

1967

1970

1973

1976

1979

1982

1985

1988

1991

1994

Ener

gy Im

bala

nce

in W

/m^2

Time Series for Energy Imbalance

Ocean Heat Content

Positive Energy Imbalance: Positive Energy Imbalance: much of 1956 much of 1956 –– 1974 1974

& 1987 & 1987 -- 19941994

Negative Radiative Negative Radiative Imbalance: Imbalance:

~ 1975 ~ 1975 -- 19861986

?

High (but how high?)High (but how high?)En

ergy

Imba

lanc

e in

W/m

^2 &

Oce

anEn

ergy

Imba

lanc

e in

W/m

^2 &

Oce

an-- H

eat

Hea

t -- Con

tent

Cha

nge

in W

yr/m

^2C

onte

nt C

hang

e in

Wyr

/m^2

Plotted With OceanPlotted With Ocean--HeatHeat--Content Change 1955 to 1998Content Change 1955 to 1998


Complications on a Simple Approach:Complications on a Simple Approach:

HeatHeat--content values changecontent values changeAccording to data set, timeAccording to data set, time--ofof--studystudy

•• LevitusLevitus’’ values change between values change between ’’00, 00, ’’01, and 01, and ’’0505No mention of why; no acknowledgement of changeNo mention of why; no acknowledgement of change

Quality of dataQuality of dataCoverage and accuracyCoverage and accuracy

Instrumentation biases and errorsInstrumentation biases and errorsWarm and cold biases problematic Warm and cold biases problematic →→


Part IIIPart III

Measuring Ocean HeatMeasuring Ocean HeatMeasuring SST Measuring SST

How Does the Ocean Heat?How Does the Ocean Heat?


Ocean Heat: Upper Ocean for World Ocean, Northern Hemisphere, and Southern Hemisphere 1956 to 2001

-10

-5

0

5

10

15

1956 1961 1966 1971 1976 1981 1986 1991 1996 2001

Year

Oce

an h

eat (

x 10

^22)

joul

es

World Ocean Heat 0 to 700 meters

Northern Hemisphere Ocean 0 to 700 meters

Southern Hemisphere Ocean 0 to 700 meters

World Ocean 0 to 300 meters

Cooling w/o ArgoCooling w/o Argo

Cooling w/ ArgoCooling w/ Argo

Continued warm bias due to XBTsContinued warm bias due to XBTs

••Introduced ~ 1966Introduced ~ 1966; became ; became increasingly dominant increasingly dominant thereafter.thereafter.

••Bias Bias = 0.2 to 0.5= 0.2 to 0.5°°CC, especially , especially 50 50 -- 250m depth & below 1000m 250m depth & below 1000m

••OHC change since midOHC change since mid--50s 50s overestimatedoverestimated by factor of 0.62by factor of 0.62

Argo spinArgo spin--up 2002; cooling bias on up 2002; cooling bias on 6% of Argo profiles.6% of Argo profiles.

••DUE TO WARM BIAS OF XBTs:DUE TO WARM BIAS OF XBTs:

••New estimates on OHC change: 4.3 toNew estimates on OHC change: 4.3 to12.8*10^22 joules 1956 to 1996 12.8*10^22 joules 1956 to 1996

••DUE TO COMPETING BIASES of XBT & Argo DUE TO COMPETING BIASES of XBT & Argo

••cancels most of cancels most of ““LymanLyman”” coolingcooling

““realreal””but lessbut less

Cooling Real Cooling Real possibly more?possibly more?

XBTs XBTs introducedintroduced

Mor

e M

ore x

bts

xbts ↑↑ bia

s > 19

95

bias >

1995

(.0.5

(.0.5°°

C)C)

Loss ~ 4 to 5 * 10^22 JoulesLoss ~ 4 to 5 * 10^22 Joules

Largest biases in xbtLargest biases in xbt

Lyman et al. 06Lyman et al. 06

Based on Levitus et al. 2005 & Based on Levitus et al. 2005 & Gouretski & Koltermann 07Gouretski & Koltermann 07

Large Argo coverageLarge Argo coverage

XBT + A

rgo = zeroXB

T + Argo = zero

Loss of 3.2 * 10^22 J max Loss of 3.2 * 10^22 J max to 1.1 *10^22 J minto 1.1 *10^22 J min

Instrument Biases:Instrument Biases:


What Ramifications Are Implied by the What Ramifications Are Implied by the Problem Detected in the Data Sets?Problem Detected in the Data Sets?

Measurement problems render accurate assessment of Measurement problems render accurate assessment of RI problematic for now.RI problematic for now.

With improvement of measurements will come the ability With improvement of measurements will come the ability to use OHC change as a RI metric.to use OHC change as a RI metric.

Despite instrument biases, patterns of variability in OHC Despite instrument biases, patterns of variability in OHC can be seencan be seen


How Does the Ocean Heat?How Does the Ocean Heat?Starting at the TopStarting at the Top……

••Heating the Upper LayerHeating the Upper Layer

••Solar Solar (< 2 (< 2 µµm)m)

••Heats Heats ““bulkbulk”” to ~ to ~ 100m100m

••ClarityClarity

••Sun angleSun angle

••IR IR (greenhouse gases)(greenhouse gases)

•• Heats upper few mmHeats upper few mm

••Affects TAffects T--gradientgradient

••Surface to bulkSurface to bulk

Skin TSkin T: :

••Skin T = few tenths degree Skin T = few tenths degree cooler than bulkcooler than bulk

••Some heat diffuses across Some heat diffuses across thermoclinethermocline ( k = ?)( k = ?)

••TT--gradient b/n gradient b/n mixed layermixed layer and and skin promotes conduction skin promotes conduction upward to surfaceupward to surface

••SSTSST = heat available to be = heat available to be fluxed to atmosphere (fluxed to atmosphere (-- flux) flux)

••BulkBulk = several meters= several meters’’ depth.depth.

Role of Greenhouse Gases in Warming SST:Role of Greenhouse Gases in Warming SST:

Greenhouse gases warm skin only, reducing TGreenhouse gases warm skin only, reducing T--gradient, damping outward flow of gradient, damping outward flow of heat to atmosphere:heat to atmosphere: More solar heat More solar heat ““lockedlocked”” within.within.

GHGGHG

LW LW ““kickbackkickback””

conductionconduction

evaporationevaporationLWLW

0C 20C0C 20C

SSTSST


What is Measured?What is Measured?

••Different methods, different Different methods, different SSTs measuredSSTs measured

••Satellites measure skinSatellites measure skin

••Ships measure bulkShips measure bulk••Different ships, different Different ships, different levelslevels

••Data sets use SSTData sets use SSTfndfnd

••Complications:Complications:••Diurnal thermoclineDiurnal thermocline

••Strong insolation Strong insolation Low WindLow Wind

••Satellites must inferSatellites must infer

••Model skinModel skin

••InIn--situ must specify zsitu must specify z

••Historical changes in Historical changes in measuring and measuring and distributiondistribution

Base of diurnal Base of diurnal thermoclinethermocline

SKIN EFFECT: SKIN EFFECT: tenths of a tenths of a degree coolerdegree cooler

DIURNAL DIURNAL THERMOCLINE THERMOCLINE EFFECT: up to 3EFFECT: up to 3°°C C warm skewwarm skew

Tendency: AIR COOLS WHILE SST WARMS *Tendency: AIR COOLS WHILE SST WARMS *

AIR COOLERAIR COOLER

Desired Temperature for SSTDesired Temperature for SST

MAT < SST; yet SST used for Ts data sets (Hadley MAT < SST; yet SST used for Ts data sets (Hadley ’’70s, GISS late 70s, GISS late ’’90s)90s)

HypotheticalHypothetical

Measured by Measured by satellitesatellite

Measured by Measured by thermometer= bulkthermometer= bulk

data pointdata point


SSTs 1845 to 2006SSTs 1845 to 2006Examining the RecordExamining the Record……

GLOBALLY AVERAGED SST ANOMALIES 1845-2006reference mean 1950 - 1979

-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

1845 1855 1865 1875 1885 1895 1905 1915 1925 1935 1945 1955 1965 1975 1985 1995 2005

YEAR

Two warming periods evident in this time seriesTwo warming periods evident in this time series

How Real???How Real???

Most warming Most warming before 1940before 1940

Another trend from Another trend from ’’70s70s


Corrections or Added Error?Corrections or Added Error?GLOBALLY AVERAGED SST ANOMALIES 1845-2006

reference mean 1950 - 1979

-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

1845 1855 1865 1875 1885 1895 1905 1915 1925 1935 1945 1955 1965 1975 1985 1995 2005

YEAR

““Bias CorrectedBias Corrected””: Folland & : Folland & Parker added 0.3Parker added 0.3°°C to C to values before 1941. values before 1941. Common in data sets.Common in data sets.

Bucket to ShipBucket to Ship••Assumed 100% switch 1941Assumed 100% switch 1941

••90% bucket SST in 197090% bucket SST in 1970

••0.30.3°°C added <1940; 0.25C added <1940; 0.25°° in 1941, 0in 1941, 0°° afterafter

••Engine intake biases complexEngine intake biases complex

••Actual switch to engine added warm bias Actual switch to engine added warm bias later in series.later in series.

••1985 1985 ““crashcrash”” in sample size (fewer ships) = in sample size (fewer ships) = warmer bias due to larger ship/deeper drawwarmer bias due to larger ship/deeper draw

As switch actually As switch actually made w/ time, made w/ time, pushes T higher pushes T higher by introducing by introducing warm biaswarm bias

If corrections incorrectIf corrections incorrect……

••Is jump at ~ 1940 larger? Is jump at ~ 1940 larger? Perhaps a natural Perhaps a natural phenomenon, as yet phenomenon, as yet unexplained?unexplained?

••SST since 1970 flatter?SST since 1970 flatter?

Smith & Reynolds added b/n 0.2 Smith & Reynolds added b/n 0.2 and 0.4and 0.4°°C before 1940. Others C before 1940. Others use similar correction methods.use similar correction methods.


What Influences SSTWhat Influences SST?? ••EntrainmentEntrainment

••MixedMixed--layer depthlayer depth

••Surface fluxSurface flux

••In In western boundary currentwestern boundary current::

••OceanOcean--heat contentheat content

••In In openopen oceanocean::

••Evaporation (78W/m^2)Evaporation (78W/m^2)

••Conduction (66 W/m^2)Conduction (66 W/m^2)

••LW flux (24W/m^2)LW flux (24W/m^2)

••Net depends upon:Net depends upon:

••WindWind

••RHRH

••Latitudinal Latitudinal ““quirksquirks””

••Basin Basin ““quirksquirks””

••LW forcingsLW forcings

••SW forcingsSW forcings

Insolation Insolation distribution distribution = main = main factorfactor

JULYJULYJULY

JANUARYJANUARYJANUARY

Far more complexFar more complex……

““QuirksQuirks””

••SST along equatorial PacificSST along equatorial Pacific

••↑↑ low = low = ↑↑ QQll

••↑↑ high = high = ↓↓ QQll

••Namibia cloud coverNamibia cloud cover

••Shift gradient NShift gradient N

••Increase cloudsIncrease clouds

••↓↓SSTASSTA

••WindsWinds

••Pacific midPacific mid--lat:lat:

•• ↑↑ w/ SSTw/ SST

••Atlantic tropics, Atlantic tropics, subtropicssubtropics

•• ↓↓ w/ SSTw/ SST

••OceanOcean--heat convergenceheat convergence

••wbcwbc


Relationship Between SSTs Relationship Between SSTs and Various Forcings.and Various Forcings.

SST and Ocean-Heat Anomalies: 1956 to 2001

-0.5

-0.3

-0.1

0.1

0.3

0.5

0.7

0.9

1.1

1.3

1.5

1956

1959

1962

1965

1968

1971

1974

1977

1980

1983

1986

1989

1992

1995

1998

2001

Year

SSTA

& O

HC

A w

/ for

cing

s

SST Anomalies in degrees Celsius

Sunspot Numbers (x 10 -̂2)

greenhouse gas anomalies W/m^2

volcanics (x 10 -̂1) W/m^2

Arctic Oscillation Index

1956 to 20031956 to 2003

Volcanic signal lagged in SST response

El Nino often associated

AO negative in response (and strongly + later)

Volcanic signal Volcanic signal lagged in SST lagged in SST responseresponse

El Nino often El Nino often associatedassociated

AO negative in AO negative in response (and response (and strongly + later)strongly + later)

AO: strong influence on MOC in Atlantic, affecting N.Atlantic SSTs

AO: strong AO: strong influence on influence on MOC in MOC in Atlantic, Atlantic, affecting affecting N.Atlantic N.Atlantic SSTsSSTs

Greenhouse-gas forcing influence has become more dominant than the DIRECT influence of solar forcing.

GreenhouseGreenhouse--gas gas forcing forcing influence has influence has become more become more dominant than dominant than the DIRECT the DIRECT influence of influence of solar forcing.solar forcing.

SSTASSTASSTA

Solar forcing dominated early in century

Solar forcing Solar forcing dominated early dominated early in century in century


Part IV:Part IV:

CorrelationsCorrelationsPatternsPatterns

Does a Does a ““regulatoryregulatory”” heatheat--pump mechanism pump mechanism play a role in Earthplay a role in Earth’’s heat budget?s heat budget?


Tropospheric Anomalies 1979 to 2006

-1.5-1

-0.50

0.5

11.5

22.5

3

1979

1981

1983

1985

1987

1989

1991

1993

1995

1997

1999

2001

2003

2005

Year

Ano

mal

ies

in 1

0^21

Jou

les

t ropospheric anomalies

SST Anomalies 1979 to 2006

00.05

0.10.150.2

0.250.3

0.350.4

0.450.5

1979

1981

1983

1985

1987

1989

1991

1993

1995

1997

1999

2001

2003

2005

Year

SST

Anom

alie

s in

D

egre

es C

elsi

us

SST Anomalies 1979 to 2006

SST, Troposphere, and OceanSST, Troposphere, and Ocean--HeatHeat--Content AnomaliesContent Anomalies

ocean ocean usually warms atmosphereusually warms atmosphere

Atmosphere Atmosphere usuallyusuallydamps SSTsdamps SSTs……..

but not alwaysbut not always

Factors other than SSTs Factors other than SSTs can influence can influence atmospheric response.atmospheric response.

Ocean Heat Change: 1979 to 2001

-10123456789

Year

Oce

an-H

eat A

nom

alie

s in

Jo

ules

(x10

^22)

OHC appears OHC appears unrelated to either unrelated to either atmosphere or SSTsatmosphere or SSTs

??


How Do OceanHow Do Ocean--Heat Anomalies Compare to Heat Anomalies Compare to SST Anomalies?SST Anomalies?


-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

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Ocean-heat-content 0-700manomalies

••Subsurface ocean contains memory of past changes in wind stress Subsurface ocean contains memory of past changes in wind stress and is and is not in equilibrium with overlying atmosphere.not in equilibrium with overlying atmosphere.

••Rossby waves significant transport mechanism of heat.Rossby waves significant transport mechanism of heat.

SSTs are a boundary condition

•Heat available to be fluxed from ocean to atmosphere (or)

•Amount of heat that blocks flux into ocean.

SSTs are a boundary conditionSSTs are a boundary condition

••Heat available to be fluxed Heat available to be fluxed from ocean to atmosphere (or)from ocean to atmosphere (or)

••Amount of heat that blocks Amount of heat that blocks flux into ocean.flux into ocean.

R2 SST w/ OHC: 0.32

R2 OHC w/ SST: .21

RR22 SST w/ OHC: 0.32SST w/ OHC: 0.32

RR22 OHC w/ SST: .21OHC w/ SST: .21

OHC mostly decoupled from OHC mostly decoupled from surface; speaks to energysurface; speaks to energy--imbalanceimbalance

SSTs = large driver of weatherSSTs = large driver of weather


Surface heatSurface heat--flux anomalies developflux anomalies developAtmosphere fails to dampen Atmosphere fails to dampen

SST anomalies evolveSST anomalies evolve (usually in winter)(usually in winter)

Some Some rere--emergeemerge at surface following winterat surface following winter•• PersistencePersistence

Some are carried into thermoclineSome are carried into thermocline or or belowbelow•• Specific regions subduct anomalies:Specific regions subduct anomalies:

Subtropical Gyres (winter event)Subtropical Gyres (winter event)•• ““central watercentral water”” (near(near--surface to ~ 1100 m)surface to ~ 1100 m)

ACCACCCold Tongue (especially Pacific)Cold Tongue (especially Pacific)Intermediate Water Formation (550 to 1500 m) Intermediate Water Formation (550 to 1500 m) Deepwater Formation (>1500 m)Deepwater Formation (>1500 m)

Governing Processes:Governing Processes:•• WindWind--Stress and CurlStress and Curl•• Annular Modes Annular Modes •• SeaSea--Ice FormationIce Formation•• Freshwater AdditionFreshwater Addition

SST SST ––

OH

C R

elationship: Getting

OH

C R

elationship: Getting

the heat into the oceanthe heat into the ocean


Global Distribution of Net Heat Loss/GainGlobal Distribution of Net Heat Loss/GainHow Heat Enters the OceanHow Heat Enters the Ocean

ACC In So.Ocean ACC In So.Ocean intermediate and deepintermediate and deep

JULYJULY

JANUARYJANUARY

Subtropical Gyres Subtropical Gyres central watercentral water

Cold tongue PacificCold tongue PacificLSW & NADW LSW & NADW intermediate & deep intermediate & deep

ACCACC

Mediterranean Mediterranean intermediate waterintermediate water

Tropical shallowTropical shallow

4040°°S, LSW, & NADW deeperS, LSW, & NADW deeper

1993 to 20031993 to 2003

4040°°S significant warmingS significant warming


Temporal Temporal

Patterns of OHC VariabilityPatterns of OHC Variability

55--year composites: 0 to 3000 myear composites: 0 to 3000 m

0 0 –– 300 meters300 meters

••Indian, Pacific, and Global Indian, Pacific, and Global ““in syncin sync””

••At 300m, Pacific and Global in syncAt 300m, Pacific and Global in syncDecadal variability: ~5.6*10^22J Decadal variability: ~5.6*10^22J Interdecadal variability: ~3.0*10^22J Interdecadal variability: ~3.0*10^22J

Heat loss all basinsHeat loss all basins

Climate ShiftClimate Shift


Current cooling in subarctic gyreCurrent cooling in subarctic gyre

Med = Med = warmingwarming

Warming at depth earlier in centuryWarming at depth earlier in century Cooling at depth more recentlyCooling at depth more recently

Two components to deep warmingTwo components to deep warming: along isopycnals and displacement of isopycnals: along isopycnals and displacement of isopycnals

Old: decades to centuryOld: decades to century Recent: years to decadeRecent: years to decade

In N. Atlantic During 1950s to 1980s: warming at intermediate, cooling deeper, especially along subtropics. N. Atlantic mostly “new” warming. S. Atlantic mostly “old”.

Since 70s, cooling in sub-polar gyre and progressively more in east at intermediate level.Warming at intermediate due to Mediterranean Outflow and AAIW.

In N. Atlantic During 1950s to 1980s: warming at intermediate, cIn N. Atlantic During 1950s to 1980s: warming at intermediate, cooling deeper, especially along ooling deeper, especially along subtropics. N. Atlantic mostly subtropics. N. Atlantic mostly ““newnew”” warming. S. Atlantic mostly warming. S. Atlantic mostly ““oldold””..

Since 70s, cooling in subSince 70s, cooling in sub--polar gyre and progressively more in east at intermediate level.polar gyre and progressively more in east at intermediate level.Warming at intermediate due to Mediterranean Outflow and AAIW.Warming at intermediate due to Mediterranean Outflow and AAIW.

A. (1970A. (1970--1974) 1974) –– (1955(1955--1959)1959) B. (1988B. (1988--1992) 1992) –– (1970(1970--1974)1974)


Negative NAO:Negative NAO: (mostly late 1930s to 1971)(mostly late 1930s to 1971)

••1950s and 1960s most pronounced1950s and 1960s most pronounced

••High GSDW High GSDW

••Low LSWLow LSW

••Warming of intermediate N. AtlanticWarming of intermediate N. Atlantic

••High High ““1818°° waterwater”” ventilationventilation

••Subtropical gyreSubtropical gyre

Positive NAO:Positive NAO:

••Abrupt switch ~ 1971Abrupt switch ~ 1971

••Low GSDWLow GSDW

••High LSWHigh LSW

••Cooling of intermediate N. AtlanticCooling of intermediate N. Atlantic

••Especially in 1990sEspecially in 1990s

••Cool, fresh layerCool, fresh layer

••Low ventilation in subtropical gyreLow ventilation in subtropical gyre

NAO NAO --

NAO+NAO+

More More ventilation ventilation of of ““1818°°waterwater””

GSDW = GSDW = cold; in cold; in Nordic SeaNordic Sea

Cool, Cool, fresh fresh LSW LSW formation formation strongstrong

Through its influence on storm tracks, Through its influence on storm tracks, the phase of NAO dictates intensity of the phase of NAO dictates intensity of deepdeep--water formation, and thus governs water formation, and thus governs oceanocean--heat gain in the North Atlantic.heat gain in the North Atlantic.

Warm tropicsWarm tropics

Cool tropicsCool tropics

LSW weak, LSW weak, thin, warmthin, warm

GSDW & GSDW & 1818°°water water weakweak

Decadal Decadal ““seesee--sawsaw”” between between deepdeep--water formation sites.water formation sites.


I.W. MedI.W. Med

D.W. AABW & D.W. AABW & IW AAIWIW AAIW

Deep Pacific (from Deep Pacific (from NADW, ~800 yrs NADW, ~800 yrs old)old)

New (decades), New (decades), some oldsome old

Mostly old Mostly old (centuries)(centuries)

newnew

newnew

Cooling in Cooling in SubSub--arctic arctic gyre N.Atl gyre N.Atl = LSW= LSW

Subtropical Subtropical gyre N.Pacifcgyre N.Pacifc

SH equator SH equator and tropics and tropics (~ 150m)(~ 150m)

S. Indian Ocean S. Indian Ocean subsurface ~ 10Ssubsurface ~ 10S

Cooling in Cooling in Abyssal Abyssal depths depths (3000(3000--4000m)4000m)

““SnapshotSnapshot”” of OHC for 2005of OHC for 2005

Spatial Patterns of OceanSpatial Patterns of Ocean--Heat Content ChangeHeat Content Change

Advected HeatAdvected Heat

Cooling in blue; Cooling in blue; red = warmingred = warming

“New” Warming in Atlantic: 1950s-1980s

“Old” Warming in Atlantic: 1900 to 1920

““NewNew”” Warming in Atlantic: 1950sWarming in Atlantic: 1950s--1980s1980s

““OldOld”” Warming in Atlantic: 1900 to Warming in Atlantic: 1900 to 19201920


Ocean Heat Anomalies: Global Ocean compared to North Pacific Ocean Anomalies

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North Pacif ic Ocean Heat Anomalies 0 to 700 meters

North Pacif ic Ocean Heat Anomalies 0 to 300 meters

Ocean Heat Anomalies: Global Ocean compared to South Pacific Ocean Heat Anomalies

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World Ocean OHCA 0 to 700 meters

South Pacif ic OHCA 0 to 300 meters

South Pacif ic OHCA 0 to 700 meters

Ocean Heat Anomalies: Global Ocean compared to North Atlantic Ocean Anomalies

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World Ocean Heat Anomalies 0 to 700 meters (10^22) joules

North At lant ic Ocean Heat Anomalies 0 to 700 meter (10^22) joules

North At lant ic Ocean Heat Anomalies 0 to 300 meters (10^22) joules

Global Ocean Heat Anomalies Compared to South Atlantic Ocean Heat Anomalies

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South At lant ic Ocean Heat Anomalies 0 to 300 meters

South At lant ic Ocean Heat Anomalies 0 to 700 meters

Ocean Heat 0 to 700 meters for Global Ocean

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Decadal Signal Pronounced in These Basins?Decadal Signal Pronounced in These Basins?

Indian Ocean 0 – 700mIndian Ocean 0 Indian Ocean 0 –– 700m700m

N.Pacific 0 – 700mN.Pacific 0 N.Pacific 0 –– 700m700m

S. Pacific 0 - 700S. Pacific 0 S. Pacific 0 -- 700700

Plotted w/ World OceanPlotted w/ World Ocean

N & S Atlantic: N & S Atlantic: little decadal little decadal variability in variability in OHC (whereas OHC (whereas SST decadal SST decadal variability does variability does exist)exist)

Relationship between Relationship between Indian Ocean and Indian Ocean and tropical Pacific.tropical Pacific.


SAMW carries thermal signature to tropical Pacific (the “heat pump”)??? Paleo-evidence

SAMW SAMW carries thermal carries thermal signature to tropical Pacific (the signature to tropical Pacific (the ““heat pumpheat pump””)??? Paleo)??? Paleo--evidenceevidence

Significant amplification of heat uptake in ACC: AAIW, AABW

Significant Significant amplification of amplification of heat uptake in heat uptake in ACC: ACC: AAIW, AABWAAIW, AABW

Atlantic: a “mixed bag”

DWF and advection

Atlantic:Atlantic: a a ““mixed bagmixed bag””

DWF and advectionDWF and advection

La Nina: enormous uptake; shallow signature

El Nino: export through atmosphere and especially through ocean

La NinaLa Nina: enormous uptake; shallow : enormous uptake; shallow signaturesignature

El NinoEl Nino: export through atmosphere : export through atmosphere and especially through ocean and especially through ocean

Kuroshio Current:transports from tropics and subtropical gyres.

Further N after El Nino (lag <10 ys).

Kuroshio Kuroshio Current:Current:transports transports from tropics from tropics and and subtropical subtropical gyres. gyres.

Further N Further N after El Nino after El Nino (lag <10 ys).(lag <10 ys).

••DWF and IWF in Atlantic put heat into longDWF and IWF in Atlantic put heat into long--term storage at depth.term storage at depth.••The Tropical Pacific, working in tandem w/ Southern Ocean, the IThe Tropical Pacific, working in tandem w/ Southern Ocean, the Indian Ocean, and the North ndian Ocean, and the North

Pacific Subtropical Gyre, moves heat to higher latitudes (and toPacific Subtropical Gyre, moves heat to higher latitudes (and to space?) via the Kuroshio space?) via the Kuroshio Current (decadal scale). Furthermore, the tropical Pacific mightCurrent (decadal scale). Furthermore, the tropical Pacific might control the AABW, the MOC control the AABW, the MOC

and DWF on timeand DWF on time--scales of a decade or two.scales of a decade or two.

2005 OHC Upper 750 m2005 OHC Upper 750 m

Global CircuitryGlobal Circuitry

Anomalies subducted in subtropical gyre to wbc & tropics

Anomalies Anomalies subducted in subducted in subtropical gyre subtropical gyre to wbc & tropicsto wbc & tropics

SH Subtropical gyre to tropics

SH SH Subtropical Subtropical gyre to gyre to tropicstropics

HEAT PUMPHEAT PUMP INVENTORYINVENTORY

Indian Ocean: related to ENSOIndian Ocean: Indian Ocean: related to ENSOrelated to ENSO


ReRe--Cap on Cap on ““Heat PumpHeat Pump””Heat subductedHeat subducted

North Pacific subtropical gyreNorth Pacific subtropical gyreCold tongue of tropical PacificCold tongue of tropical PacificSouth Pacific subtropical gyreSouth Pacific subtropical gyre

•• SAMWSAMW•• AAIWAAIW

Ultimately ushered to Kuroshio CurrentUltimately ushered to Kuroshio CurrentDirect pathDirect path

•• North Pacific subtropical gyreNorth Pacific subtropical gyreAlternate pathAlternate path

•• Tropical Pacific = collection pool and Tropical Pacific = collection pool and ““pumppump””

““RhythmRhythm”” on decadal scaleon decadal scaleWith interannual With interannual ““pulsespulses””Underpinned by multiUnderpinned by multi--decadal undulation of intensitydecadal undulation of intensity


PDO: PDO: Does it Set the MultiDoes it Set the Multi--Decadal Pace of Heat Pump?Decadal Pace of Heat Pump?

••During a + PDODuring a + PDO (warm tropics):(warm tropics):

••The Aleutian Low is The Aleutian Low is deepened (+PNA)deepened (+PNA)

••Westerly wind anomalies Westerly wind anomalies and curl dominate the NP and curl dominate the NP basinbasin

••Cold SSTs dominate the Cold SSTs dominate the central basincentral basin

••Cold SSTA subducted Cold SSTA subducted

••strengthened subtropical strengthened subtropical gyregyre

••The tropics are warmThe tropics are warm

••El Ninos more intense, El Ninos more intense, more frequentmore frequent

••During a During a –– PDOPDO (cool tropics):(cool tropics):

••Everything is oppositeEverything is opposite

••Warm SSTA subductedWarm SSTA subducted

PDO PDO ––

PDO +PDO +PDO +PDO +

ENSO varies with PDOENSO varies with PDO PDO +PDO +



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PDO shift from PDO shift from ““uptakeuptake”” phase to phase to ““exportexport”” phasephase

SSTs higher; OHC lowerSSTs higher; OHC lower

PDO PDO ““coolcool”” phase = uptakephase = uptake PDO PDO ““warmwarm”” phase = exportphase = export

PDO “cool”:Uptake dominant

•Warmer SSTs•Accumulating OHC

PDO PDO ““coolcool””::Uptake dominantUptake dominant

••Warmer SSTsWarmer SSTs••Accumulating OHCAccumulating OHC

PDO “warm”:Export dominant

•Cooler SSTs

•Releasing OHC

PDO PDO ““warmwarm””::Export dominantExport dominant

••Cooler SSTsCooler SSTs

••Releasing OHCReleasing OHC

SST and OceanSST and Ocean--Heat Anomalies: 1956 to 2001Heat Anomalies: 1956 to 2001

SSTs lower; OHC higherSSTs lower; OHC higher

??


KUROSHIO WBC

KUROSHIO WBC

N. P. Subtropical GyreN. P. Subtropical Gyre

Heat from SAMW Heat from SAMW transported to tropicstransported to tropics

Heat uptake Heat uptake during La Nina during La Nina (some to gyre)(some to gyre)

PDOPDO--cold = warm cold = warm thermal anomaliesthermal anomalies

Time Series of Kuroshio TransportTime Series of Kuroshio Transport

1955 1955 -- 2000 2000

Surface fluxes contribute to heatSurface fluxes contribute to heat--content changes on monthly timecontent changes on monthly time--scale;scale;

Largest Kuroshio Largest Kuroshio transport in 30 transport in 30 years occurred years occurred early 90searly 90s..

PDOPDO--shiftshift

~1942 to 1976 = PDO cool~1942 to 1976 = PDO coolPDO cool ~ weak Aleutian LowPDO cool ~ weak Aleutian Low

Indian Indian Ocean: Ocean: relationshirelationship depends p depends upon PDO upon PDO phase; phase; monsoon monsoon influencedinfluenced

PDO cool 1942 PDO cool 1942 -- 19761976 PDO warm after 1976PDO warm after 1976

Going from Going from cool PDO to cool PDO to warm PDOwarm PDO

Periods of Periods of heat loss heat loss in OHC in OHC recordrecord

Transport enhanced

Transport enhancedFuture heat Future heat loss expected?loss expected?

Lateral fluxes dominate for interannual and decadal timeLateral fluxes dominate for interannual and decadal time--scales of heatscales of heat--content changes.content changes.



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??

Comparing OHC Loss with Kuroshio TransportComparing OHC Loss with Kuroshio Transport

??

Kuroshio Transport (in Sv) Time Series: 1955 to 2000Kuroshio Transport (in Sv) Time Series: 1955 to 2000

May 2007May 2007 Marcia WyattMarcia Wyatt 4343PDO

shi

ft (to

PD

O s

hift

(to ““

war

mw

arm

””

Warm thermal anomalies central PacificWarm thermal anomalies central Pacific

PDOPDO--””coolcool””

PDO PDO ““coolcool”” = More La Ninas. Warm subducted into gyres: = More La Ninas. Warm subducted into gyres:

Time of greater heat uptake???Time of greater heat uptake???

PDO PDO ““warmwarm”” = More OHC leads to greater = More OHC leads to greater Kuroshio transport and more OHC loss. Kuroshio transport and more OHC loss.

Increased transport in KuroshioIncreased transport in Kuroshio

FLU

X to

ATM

OSP

HER

EFL

UX

to A

TMO

SPH

ERE

Lateral Advection Lateral Advection of Heat to Regionof Heat to Region

Heat uptakeHeat uptake Heat uptakeHeat uptake

Heat Export Heat Export from Tropicsfrom Tropics

Heat ExportHeat Export

Lateral Advection of Lateral Advection of Heat into Region Heat into Region (decadal process (decadal process related to winds related to winds (geostrophic)(geostrophic)

Flux from wbc Flux from wbc from ocean (to from ocean (to space???)space???)

BEGIN

BEGIN ↓↓ OHCOHC

BEGIN

BEGIN ↑↑

OHC

OHC


Established thus far:Established thus far:Within the Within the ““heat pumpheat pump”” region (the Pacific and Indian Oceans), heat is region (the Pacific and Indian Oceans), heat is subducted into the ocean through the ACC, the cold tongue, and ssubducted into the ocean through the ACC, the cold tongue, and subtropical ubtropical gyres in the Pacific. Through the formation of these central andgyres in the Pacific. Through the formation of these central and intermediate intermediate mode waters, SST anomalies are delivered to the upper ocean. mode waters, SST anomalies are delivered to the upper ocean. Subduction of SST anomalies is most favorable during periods of Subduction of SST anomalies is most favorable during periods of PDOPDO--cool cool (negative phase) (weak Aleutian Low and strengthened easterly tr(negative phase) (weak Aleutian Low and strengthened easterly trades). ades). The SST anomalies are reThe SST anomalies are re--distributed within the upper ocean layer, much of the distributed within the upper ocean layer, much of the rere--distribution accomplished though the subtropical gyre.distribution accomplished though the subtropical gyre.Some of the subducted heat is carried to the southern end of theSome of the subducted heat is carried to the southern end of the Kuroshio.Kuroshio.Lateral advection of heat into the Kuroshio Current is governed Lateral advection of heat into the Kuroshio Current is governed by a decadal by a decadal rhythm. Transport is greatest during PDOrhythm. Transport is greatest during PDO--warm (positive) phases. Transport warm (positive) phases. Transport increases coincide with El Nino events. Displacement of the Kuroincreases coincide with El Nino events. Displacement of the Kuroshio Current shio Current Extension by about five degrees latitude coincides with strong EExtension by about five degrees latitude coincides with strong El Nino events.l Nino events.The heat accumulates within the westernThe heat accumulates within the western--boundary current, swelling the region boundary current, swelling the region (detectable by satellite). Surface flux to the atmosphere from t(detectable by satellite). Surface flux to the atmosphere from the ocean in the he ocean in the wbcwbc increases with increased oceanincreases with increased ocean--heat content in the heat content in the wbcwbc..Heat loss from the ocean has been found to correlate with flux tHeat loss from the ocean has been found to correlate with flux to space at the o space at the top of the atmosphere. That thread follows.top of the atmosphere. That thread follows.


Evidence for OHC Evidence for OHC ↓↓ w/ w/ ↑↑Flux to AtmosphereFlux to Atmosphere

Ellis et al. 1978Ellis et al. 1978

““World oceans apparently store and release heat inWorld oceans apparently store and release heat in--phase with the phase with the annual variation in net radiation balance.annual variation in net radiation balance.””

••Net Net losslossof LW @ of LW @ TOA to TOA to spacespace

••Net Net losslossof heat of heat from from ocean ocean storagestorage

Sampling error or real?

••Net Net gaingain(storage) (storage) into into oceanocean

••Net Net gaingain@ TOA@ TOA

Extremes in atmospheric heat storage related to land cover NH

Ellis et al. suggest that a causeEllis et al. suggest that a cause--andand--effect relationship appears likely; yet they offer no effect relationship appears likely; yet they offer no ideas on mechanism, only urging further study on the matter.ideas on mechanism, only urging further study on the matter.


““CARSCARS””: : ((ForcingsForcings: : solar, ghg, volcanics)

EXIT A EXIT A (subtropical gyres, cold tongue, ACC, mode-water form; all vary in strength and heat-uptake ability in concert with wind stress and wind-stress curl)

TOLL BOOTH I

EXIT B

SPILL-OVER LOT(deep ocean)

(upper ocean)“HOLDING PATTERN”

(Deep-w

ater formation) as in N

orth Atlantic

(shallow subduction) as in North Pacific

(higher latitudes and lost to space on quasi-decadal time scale) [OHC ↓ w/ ↑ flux TOA]

(heat re-imprinted on atmosphere, SSTs)

“MAIN HIGHWAY” (atmosphere, SSTs)

EXIT

C

(diffuses through thermocline (small amount))

(to western boundary current) Lag ~ 4 – 10 yrs

(wind-stress curl & ghg influence amount of heat into ocean)

SST

winte

r

anom

aly re

-

emer

genc

e)

follo

wing

winter

AN ANALOGY TO ILLUMINATE THIS IDEA:


If One Accepts That:If One Accepts That:

Warm atmospheric anomalies are subductedWarm atmospheric anomalies are subductedparticularly during the PDOparticularly during the PDO--cool (negative) phase (and La Nina)cool (negative) phase (and La Nina)

And if heat is more efficiently exported out of the And if heat is more efficiently exported out of the ocean ocean

Especially during the PDOEspecially during the PDO--warm (+) phasewarm (+) phase

And if flux outward from the TOA increases with And if flux outward from the TOA increases with heat buildheat build--up and transport within the wbcup and transport within the wbc

Then what might facilitate its exit?Then what might facilitate its exit?


El Nino:El Nino:••Subtropics dry out furtherSubtropics dry out further

••OLR enhancedOLR enhanced

••During the 82/83 El Nino, During the 82/83 El Nino, increased area of dry poolsincreased area of dry pools

••Less so during La Nina in Less so during La Nina in ’’8585

••Statistics on H2Ov:Statistics on H2Ov:

••In tropics, H2Ov In tropics, H2Ov governed by winds, governed by winds, RH, not as much by RH, not as much by SST.SST.

••If reIf re--distribute water distribute water vapor into wet and vapor into wet and dry pools, OLR dry pools, OLR increasesincreases

••50%: 87.5 and 50%: 87.5 and 12.5 = 12.5 = ↑↑3.6W/m^23.6W/m^2

••Drying from 5% to Drying from 5% to 2.5% ~ 40% to 20% for 2.5% ~ 40% to 20% for OLR increaseOLR increase

••Due to Hadley Cell Due to Hadley Cell ↑↑

El Nino:El Nino:

Dry pool area increases; OLR increasesDry pool area increases; OLR increases

La Nina:La Nina:

Water vapor more uniformly distributed; OLR lessWater vapor more uniformly distributed; OLR less

One WayOne Way…….enhanced subsidence.enhanced subsidence


86/87 = El Nino86/87 = El Nino

El Nino 82/83 moderated by El Nino 82/83 moderated by El Chichon March El Chichon March ‘‘8282

Succession of El Ninos

Succession of El Ninos ’’ 91

91 -- 9494

Weak La Nina Weak La Nina 19951995--9696

El Nino El Nino ’’97/97/’’9898

’’9898--’’99 weak 99 weak La NinaLa Nina

PDO warm phase PDO warm phase ’’77 77 –– ‘‘9999

Switch to cool?Switch to cool?

Pacific Pacific ““ShiftShift”” ’’76/7776/77El Nino El Nino ’’72/7372/73

Weak La Weak La Nina Nina ’’84/8584/85

El Nino El Nino ’’55 to 55 to ‘‘5757

El Nino El Nino ’’50/5150/51

El El Nino Nino ’’64/6564/65

El Nino El Nino 61/6261/62

El Nino 68/69El Nino 68/69

Mount Mount Pinatubo Pinatubo ‘‘9191

Strong La Nina Strong La Nina 88/8988/89

Vertically integrated waterVertically integrated water--vapor content decreases with vapor content decreases with each El Nino and w/ the shift each El Nino and w/ the shift to PDO warm (+). La Ninas to PDO warm (+). La Ninas and volcanic eruptions and volcanic eruptions coincide with higher values.coincide with higher values.


From Wielicki et al. From Wielicki et al. ’’0202Decadal Variability in Tropical Radiative Energy BudgetDecadal Variability in Tropical Radiative Energy Budget

Increasing trend of LW to space; especially w/ El Nino

Increasing trend of LW to space; especially w/ El Nino

Decreasing SW reflected, especially w/ EN

Decreasing SW reflected, especially w/ EN

Decreasing cloud cover through much of this timeDecreasing cloud cover through much of this time

Another way: decreased cloud coverAnother way: decreased cloud cover……


An Intriguing An Intriguing thought:thought:

••Van LoonVan Loon’’s s observationobservation

••Increased Increased solarsolar

••More La More La Nina Nina –– likelike

••More heat More heat uptakeuptake

••Higher sea Higher sea levellevel

↑↑ + flux + flux TOA (less TOA (less outgoing; outgoing; more more incoming)incoming)

↑↑ + flux into + flux into oceanocean

↑↑ seasea--level level height w/ height w/ thermosteric thermosteric expansion??expansion??

Steve MilloySteve Milloy’’s Climate Audit s Climate Audit showed these graphs showed these graphs 3/23/07 = Holgate plot3/23/07 = Holgate plot

SUNSPOTSSUNSPOTS

SEA LEVELSEA LEVEL

And What And What might set might set the pace of the pace of the PDO?the PDO?


Can All this be put TogetherCan All this be put Together? ?

Inventory:Inventory:DWF: NADW & AABWDWF: NADW & AABW

North and South AtlanticNorth and South AtlanticRelated to NAO, SAM, and possibly ENSO?Related to NAO, SAM, and possibly ENSO?

•• ““CappedCapped”” in Southern Ocean when warm = negative feedbackin Southern Ocean when warm = negative feedback•• Released in Southern Ocean when cold = negative feedbackReleased in Southern Ocean when cold = negative feedback

““OldOld”” heating & heating & ““newnew””•• Century vs decadeCentury vs decade

Heat Pump:Heat Pump:The correlation among the P.O., I.O, and World OceanThe correlation among the P.O., I.O, and World Ocean

QuasiQuasi--decadal pattern of oceandecadal pattern of ocean--heatheat--contentcontentSubtropical gyres, the tropical cold tongue, and the Subtropical gyres, the tropical cold tongue, and the wbcwbcThe decadal nature underlying ENSOThe decadal nature underlying ENSOThe decadal nature of the subtropical gyreThe decadal nature of the subtropical gyreThe decadal nature of transport within the wbcThe decadal nature of transport within the wbcThe decadal nature of westerly windsThe decadal nature of westerly winds

The decadal and multiThe decadal and multi--decadal nature of solar outputdecadal nature of solar outputThe decadal nature of sea levelThe decadal nature of sea levelThe decadal nature of the MOC The decadal nature of the MOC


••Intensified Aleutian LowIntensified Aleutian Low

••Weakened westerliesWeakened westerlies

••weakened SH subtropical highweakened SH subtropical high

••More El NinoMore El Nino--like (PDO warm)like (PDO warm)

••Cool anomalies subducted into gyreCool anomalies subducted into gyre

••More heat lost from oceanMore heat lost from ocean

••More flux outward at TOAMore flux outward at TOA

••Lower sea level?Lower sea level?

Intensified NH HadleyIntensified NH Hadley

Intensified SH HadleyIntensified SH Hadley

weakweak

StrongStrong

PDO coolPDO coolPDO warmPDO warm

••Weakened Aleutian LowWeakened Aleutian Low

••Weakened westerliesWeakened westerlies

••Strengthened SH subtropical highStrengthened SH subtropical high

••More La NinaMore La Nina--like (PDOlike (PDO--cool)cool)

••Warm anomalies subducted in subtropical gyreWarm anomalies subducted in subtropical gyre

••Heat uptake in cold tongueHeat uptake in cold tongue

••Less heat fluxed outward at TOA Less heat fluxed outward at TOA

••Higher sea level?Higher sea level?

HIG

H S

OLA

RH

IGH

SO

LAR

LOW

SOLA

RLO

W SO

LAR

strongstrong

weakweak

PDO warmPDO warm ??

La NinaLa Nina--likelike El NinoEl Nino--likelike

High High solarsolar

Low Low solarsolar

Lower Lower SolarSolar

Weak A.LowWeak A.Low Intensified LowIntensified LowPDO coolPDO cool

LOW

SOLA

RLO

W SO

LAR

HIG

H S

OLA

RH

IGH

SO

LAR

PDO warmPDO warmPDO warmPDO warm



-2.5-2

-1.5-1

-0.50

0.51

1.52

2.5

1955

1959

1963

1967

1971

1975

1979

1983

1987

1991

1995

year

Ene

rgy

Imba

lanc

e in

W/m

^2


PDO cold tropicsPDO cold tropics

Warm subtr.gyreWarm subtr.gyre

PDO warm PDO warm tropics; tropics; cold gyrecold gyre


-8

-6

-4

-2

0

2

4

6

1955

1958

1961

1964

1967

1970

1973

1976

1979

1982

1985

1988

1991

1994

Ene

rgy

Imba

lanc

e in

W/m

^2


Ocean Heat Content

Overall Gain of OHCOverall Gain of OHC

Overal

l Gain

of OHC

Overal

l Gain

of OHC

Loss OHC

Loss OHC

Loss OHLoss OH ??

????

Can the data support the idea? Can the data support the idea?

Solar Output HigherSolar Output HigherSolar Output WeakerSolar Output Weaker Current Current State???State???

End

Tim

e Se

ries

End

Tim

e Se

ries



-8

-6

-4

-2

0

2

4

619

55

1958

1961

1964

1967

1970

1973

1976

1979

1982

1985

1988

1991

1994

Ener

gy Im

bala

nce

in W

/m^2


Ocean Heat Content

PDO + (PDO + (warm tropicswarm tropics))

NAO NAO ––(warm tropics)(warm tropics)

NAO +NAO +(cool tropics)(cool tropics)

PDO PDO –– (cool tropics)(cool tropics)

Heat U

ptake S

trong in

gyre, c

old tongue

Heat U

ptake S

trong in

gyre, c

old tongue

NAO+NAO+NAO NAO –– (warm tropics)(warm tropics)

Active SunActive Sun Less Active SunLess Active Sun

Warm Bias , esp after 1994Warm Bias , esp after 1994

PDO PDO --

Heat Loss

Heat Loss

PDO +PDO +

Does the phase Does the phase of the NAO of the NAO affect the affect the Pacific?Pacific?

Are Are measurement measurement errors errors interfering?interfering?

Have Have ghgsghgschanged the changed the relationship?relationship?

Is the Is the hypothesis hypothesis unsupportedunsupported

??????????


NA

O+

= w

eak

MO

C =

PD

O+

NA

O+

= w

eak

MO

C =

PD

O+

PDO

+ Increases salinity & M

OC

= NA

OPD

O + Increases salinity &

MO

C = N

AO

--

NA

O

NA

O --

= st

rong

MO

C

= st

rong

MO

C →→

stro

ng

stro

ng

upw

ellin

g =

PDO

upw

ellin

g =

PDO

--

PDO

PDO

-- shortshort -- term

term→→

↓↓salinity salinity →→

weak M

OC

weak M

OC

NA

O+

= w

eak

MO

C

NA

O+

= w

eak

MO

C →→

PDO

+PD

O+

MAX OCMAX OC--HEAT EXPORTHEAT EXPORT MAX OH UPTAKEMAX OH UPTAKE MAX OH EXPORTMAX OH EXPORT

NAO INDEXNAO INDEX

TTSS

TTsssolarsolar

PDO+ = OH exportPDO+ = OH export

PDOPDO-- = OH uptake= OH uptake

PDO+ exportPDO+ export

NAO+ export OHNAO+ export OH

NAONAO-- OH uptakeOH uptake

NAO+ OH exportNAO+ OH export

NAO+ & PDO+ =NAO+ & PDO+ = NAONAO-- & PDO& PDO-- == NAO+ & PDO+ =NAO+ & PDO+ =

MOC strong MOC strong →→ AMOAMO--warmwarm→→ N.Atl.+SSTAN.Atl.+SSTA →→propagation via Gulf Stream propagation via Gulf Stream →→NAONAO--negative negative →↓→↓LSW; PDO to cool LSW; PDO to cool phase. MOC decreasing phase. MOC decreasing →→ AMOAMO--cool cool →→ N. Atl. N. Atl. –– SSTA SSTA →→ propagation via Gulf Stream propagation via Gulf Stream →→ NAONAO--positive positive →→ ↑↑LSW; LSW; PDO to warm phasePDO to warm phase……etc.etc.

Low-frequency solar cycle nudges ocean-atmosphere coupling on multi-decadal scales.

Positive phases of NAO/PDO → increased atmospheric T

Negative phases of NAO/PDO → decreasedatmospheric T

LowLow--frequency solar cycle frequency solar cycle nudges oceannudges ocean--atmosphere atmosphere coupling on multicoupling on multi--decadal decadal scales.scales.

Positive phases of Positive phases of NAO/PDO NAO/PDO →→ increased increased atmospheric Tatmospheric T

Negative phases of Negative phases of NAO/PDO NAO/PDO →→ decreaseddecreasedatmospheric Tatmospheric T


ReRe--Cap of:Cap of:NAO/PDO/solar/ocean heat/atmospheric TNAO/PDO/solar/ocean heat/atmospheric T

Low solar: 1900 Low solar: 1900 -- 1930 1930 NAO + NAO + PDO + PDO + Net result = strong heating of atmosphere; expulsion of heat froNet result = strong heating of atmosphere; expulsion of heat from oceanm ocean

Increasing solar: 1930 to 1942 Increasing solar: 1930 to 1942 NAO NAO -- (this mode changes first) (this mode changes first) PDO + continues in positive state PDO + continues in positive state Net result = less heating of atmosphere, more to oceans (in AtlaNet result = less heating of atmosphere, more to oceans (in Atlantic)ntic)

High solar cycles: 1942 High solar cycles: 1942 -- 1971 1971 NAO NAO -- (still negative, in ocean(still negative, in ocean--heat uptake mode) heat uptake mode) PDO PDO -- (becomes negative due to NAO (becomes negative due to NAO -- (strong MOC)) (strong MOC)) Net result = minimal heating of atmosphere; maximum heat uptake Net result = minimal heating of atmosphere; maximum heat uptake in oceans in oceans -- both shallow both shallow and deepand deep

Decreasing solar: 1971 Decreasing solar: 1971 -- 1976 1976 NAO + (transitions first) NAO + (transitions first) PDO PDO -- (remains) (remains) Net result = heating of atmosphere increases due to NAO + (due tNet result = heating of atmosphere increases due to NAO + (due to increasing LSW o increasing LSW convection); decreasing amount of heat to ocean in Atlanticconvection); decreasing amount of heat to ocean in Atlantic

Lower solar 1976 Lower solar 1976 -- 1995 1995 NAO + continues in this low oceanNAO + continues in this low ocean--heatheat--uptake mode uptake mode PDO + switch occurs as result of low MOC during NAO + PDO + switch occurs as result of low MOC during NAO + Net result = more heat to atmosphere, less uptake in oceansNet result = more heat to atmosphere, less uptake in oceans

Unclear about solar, PDO, and NAO since 1995; time will tell???Unclear about solar, PDO, and NAO since 1995; time will tell???


Conclusions:Conclusions:OceanOcean--heatheat--content increase indicates the globe is warming.content increase indicates the globe is warming.Storage in the ocean moderates atmospheric temperature, partiallStorage in the ocean moderates atmospheric temperature, partially explaining why the y explaining why the atmosphere has not heated as fast as expected.atmosphere has not heated as fast as expected.OceanOcean--heatheat--content change cannot speak to choice of climate sensitivity or content change cannot speak to choice of climate sensitivity or to model to model validity.validity.OceanOcean--heatheat--content change does reflect Earthcontent change does reflect Earth’’s radiative imbalance at the TOA.s radiative imbalance at the TOA.Measurements of OHC are plagued with biases, obviating, for now,Measurements of OHC are plagued with biases, obviating, for now, the ability to use this the ability to use this metric to accurately assess Earthmetric to accurately assess Earth’’s radiative imbalance.s radiative imbalance.SSTs correlated well with solar early in the 20SSTs correlated well with solar early in the 20thth century. The correlation has been much century. The correlation has been much lower since the 1970s. Is this due to lower since the 1970s. Is this due to ““correctionscorrections”” made in the SST data set or to a made in the SST data set or to a dominance of ghg as the Rf, or due to some other reason?dominance of ghg as the Rf, or due to some other reason?SST anomalies correlate well with tropospheric temperature anomaSST anomalies correlate well with tropospheric temperature anomalies; neither correlates lies; neither correlates well with OHCA.well with OHCA.This fact reflects nonThis fact reflects non--straightstraight--forward process of delivering heat to ocean.forward process of delivering heat to ocean.Despite uncertainties of measurements of OHC, patterns of variabDespite uncertainties of measurements of OHC, patterns of variability are evident, even if ility are evident, even if their amplitudes are now in question.their amplitudes are now in question.These patterns of variability in OHC in the upper ocean, operatiThese patterns of variability in OHC in the upper ocean, operating on a variety of different ng on a variety of different timetime--scales, give insight into a possible regulatory mechanism governscales, give insight into a possible regulatory mechanism governing global heat.ing global heat.The Pacific and Indian Oceans are key players in this quasiThe Pacific and Indian Oceans are key players in this quasi--decadal variability. Uptake decadal variability. Uptake and export of ocean heat appear orchestrated by phase of PDO, wiand export of ocean heat appear orchestrated by phase of PDO, with uptake occurring th uptake occurring mostly during PDOmostly during PDO--cool phases and export during PDOcool phases and export during PDO--warm phases. The Kuroshio warm phases. The Kuroshio Current is the Current is the ““dumping grounddumping ground”” for some of the collected heat. From this current, heat for some of the collected heat. From this current, heat flux to the atmosphere increases with increased oceanflux to the atmosphere increases with increased ocean--heat content. Evidence suggests heat content. Evidence suggests that oceanthat ocean--heat loss correlates with flux at the TOA.heat loss correlates with flux at the TOA.Variability of solar output is well correlated with the collectiVariability of solar output is well correlated with the collection of changes that, together, on of changes that, together, orchestrate oceanorchestrate ocean--heat uptake, reheat uptake, re--distribution, and expulsion from the ocean. Amplified distribution, and expulsion from the ocean. Amplified solar output correlates well with the set of processes that incrsolar output correlates well with the set of processes that increases oceaneases ocean--heatheat--uptake; uptake; decreased solar correlates with those processes that export and decreased solar correlates with those processes that export and expel ocean heat.expel ocean heat.

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