Northern Oscillations and the Great Climate Flip-FlopPoorna Pal Poorna Pal MS MBA Ph.D.MS MBA Ph.D.

Professor of GeologyProfessor of GeologyGlendale Community CollegeGlendale Community College

The Great Climate Flip-flop

by

WILLIAM H. CALVIN

When 'climate change' is referred to in the press, it

normally means greenhouse warming, which, it is predicted, will cause

flooding, severe windstorms, and killer heat waves. But warming could also lead,

paradoxically, to abrupt and drastic cooling — a

catastrophe that could threaten the end of

civilization.

Observed Sea Surface Temperatures (°C) 7-day average centered on Jan 10, 2001

Observed Sea Surface Temperature Anomalies (°C)

1981 1982 1983

1 Gulf Stream2 N. Atlantic Drift3 Labrador current4 W. Greenland Drift5 E. Greenland Drift6 Canary current

7 N. Equatorial current8 N. Equatorial CC9 S. Equatorial current10 S. Equatorial CC11 Equatorial CC12 Kuroshio current

13 N. Pacific Drift14 Alaska current15 Oyashio current16 California current17 Peru (Humbolt) current18 Brazil current

19 Falkland current20 Benguela current21 Agulhas current22 West Wind Druft23 W.Australian current24 E. Australian current

2324

Strong Negative PhaseStrong Negative Phase

• reflects subnormal heights and reflects subnormal heights and pressures at high latitudes, ab-pressures at high latitudes, ab-normal heights and pressures normal heights and pressures over central North Atlantic, over central North Atlantic, eastern US and western Europe;eastern US and western Europe;

• tends to be associated withtends to be associated with

ColderColdereastern US, eastern US, western Europewestern Europe

WarmerWarmerGreenland, Greenland, southern Europesouthern Europe

DrierDriernorthern Europe,northern Europe,ScandinaviaScandinavia

WetterWettersouthern and southern and central Europecentral Europe

Strong Positive PhaseStrong Positive Phase

• reflects abnormal heights and reflects abnormal heights and pressures at high latitudes, sub-pressures at high latitudes, sub-normal heights and pressures normal heights and pressures over central North Atlantic, over central North Atlantic, eastern US and western Europe;eastern US and western Europe;

• tends to be associated withtends to be associated with

WarmerWarmereastern US, eastern US, western Europewestern Europe

ColderColderGreenland, Greenland, southern Europesouthern Europe

WetterWetternorthern Europe,northern Europe,ScandinaviaScandinavia

DrierDriersouthern and southern and central Europecentral Europe

-4

-2

0

2

4

Jan-50 Jan-60 Jan-70 Jan-80 Jan-90 Jan-00

No

rth

ern

Osc

illat

ion

Ind

exN

ort

her

n O

scill

atio

n In

dex

Monthly DataMonthly DataAnnually Annually Averaged Averaged DataData

0

2

4

6

0 16 32 48 64

Wave NumberWave Number

Rel

ativ

e E

ner

gy

Rel

ativ

e E

ner

gy

85.3

yea

rs85

.3 y

ears

9.5 years9.5 years

2.7 years2.7 years

2.5 years2.5 years5.7 years5.7 years

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

50 100 150 200

Lag (Months)Lag (Months)

Au

toco

rrel

atio

nA

uto

corr

elat

ion

96 months96 months

The Spectral (below) and The Spectral (below) and Correlogram (alongside) Correlogram (alongside) Analyses of Monthly NOI Analyses of Monthly NOI Data since 1950Data since 1950

The Global Conveyor Belt

Broecker, W.S. "The great ocean conveyor," Oceanography,4:79-89 (1991).

Atlantic meridional section at 25°W: TemperatureAtlantic meridional section at 25°W: Temperature

Atlantic meridional section at 25°W: SalinityAtlantic meridional section at 25°W: Salinity

Atlantic meridional section at 25°W: DensityAtlantic meridional section at 25°W: Density

Stream functions of meridional ocean transport in the Atlantic for the present climate (left).

Stream functions of meridional ocean transport in the Atlantic for the last glacial maximum (right),

13.5

14.0

14.5

15.0

1880 1920 1960 2000 A.D.

Mea

n A

nn

ual

Tem

per

atu

re (

°C)

Northern Hemisphere

SouthernHemisphere

Global

1951-1980 average

Global mean temperature since 1866Global mean temperature since 1866

0

0.05

0.10

0.15

0.20

0.25

-0.04 -0.02

Annual Temperature Change (°C)Annual Temperature Change (°C)

0 0.02 0.04

Fre

qu

ency

Fre

qu

ency

1867-2000 AD1867-2000 ADGlobal Mean DataGlobal Mean Data

x = 0.000132x = 0.000132s = 0.011238s = 0.011238

-2

-1

0

1

2

1,000 1,200 1,400 1,600 1,800 2,000 AD

Southern HemisphereSouthern Hemisphere

Northern HemisphereNorthern Hemisphere

Jones, P.D., Briffa, K.R., Barnett, T.P. and Tett, S.F.B.High-resolution palaeoclimatic records for the last millennium: interpretation, integration and comparison with General Circulation Model control-run temperaturesTHE HOLOCENE, 8: 455-471 (1998)

δT

(° C)

δT

(° C)

Through most of the last millennium, though, Southern Through most of the last millennium, though, Southern Hemisphere has been generally warmer than the Northern Hemisphere has been generally warmer than the Northern HemisphereHemisphere

0.00

0.04

0.08

0.12

-0.08 -0.04 0 0.04 0.08

Annual ChangeAnnual Change

Fre

qu

ency

Fre

qu

ency

Mean Annual ChangeMean Annual ChangeStandard DeviationStandard Deviation

== 1.481.481010-5-5

== 0.01870.0187

5% Probability that annual change 5% Probability that annual change will be < -0.037 or >0.037will be < -0.037 or >0.037

Annual temperature changes in the Annual temperature changes in the past millenniumpast millennium

0.0001

0.001

0.01

0.1

1

-5 -4 -3 -2 -1 0 1 2 3 4 5

Z-ScaleZ-Scale

Cu

mu

lati

ve F

req

uen

cyC

um

ula

tive

Fre

qu

ency

Observed Observed DataData

The The Normal CurveNormal Curve

The tail probabilities exceed those predicted by the Normal distribution

model

The past millenniumThe past millennium

-8

-4

0

4

050,000100,000150,000200,000250,000

δδ1

81

8OO

Years BPYears BP

GRIPGRIP

-8

-6

-4

-2

0

2

δT

(°C)

δT

(°C)

VostokVostok

-10

-5

0

5

20,00030,00040,00050,000 δδ1

81

8OO

GRIP: GRIP: Blunier et al. NATURE, 394: 739-743 (1998)Blunier et al. NATURE, 394: 739-743 (1998)

Younger Dryas

J. Jouzel, C. Lorius, J.R. Petit, N.I. Barkov & V.M. Kotlyakov (1994): “Vostok isotopic temperature record” in TRENDS: A COMPEDIUM OF DATA ON GLOBAL CHANGE [ORNL/CDIAC-65. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, Oak Ridge, Tenn., U.S.A.]

S.J. Johnson, D. Dahl-Jensen, W. Dansgaard & N.S. Gundestrup (1995): “Greenland palaeotemperatures derived from GRIP borehole temperature and ice core isotope profiles”

TELLUS, 47B: 624-629.

0.0

0.1

0.2

-0.06 -0.03 -0.01 0.01 0.03 0.06

Annualized temperature changes as Annualized temperature changes as seen in the 10-50 Ka BP GRIP seen in the 10-50 Ka BP GRIP record record

Annualized ChangeAnnualized Change

Fre

qu

ency

Fre

qu

ency

Mean Annualized Mean Annualized ChangeChange

Standard DeviationStandard Deviation== -4.30-4.301010-5-5

== 0.01020.0102

5% Probability that annual 5% Probability that annual change will be < -0.02 or change will be < -0.02 or

>0.02>0.02

0.0001

0.001

0.01

0.1

1

-5 -4 -3 -2 -1 0 1 2 3 4 5

Z-ScaleZ-Scale

Cu

mu

lati

ve F

req

uen

cyC

um

ula

tive

Fre

qu

ency

The The Normal CurveNormal Curve

Observed Observed DataData

The tail probabilities exceed those predicted by the Normal distribution

model

10-50 Ka BP 10-50 Ka BP GRIP DataGRIP Data

The past millennium has The past millennium has been about as stable, been about as stable, temperature-wise, as the past temperature-wise, as the past 10-50 Ka BP interval that 10-50 Ka BP interval that included the Younger Dryas included the Younger Dryas Ice Age. Ice Age.

Thank You!