Titolo Mediterranean climate: trends and projections Piero Lionello, University of Salento, Italy International workshop On Climate Change in the Mediterranean.

titolo

Mediterranean climate: trends and projections

Piero Lionello, University of Salento, Italy

International workshopOn Climate Change in the Mediterranean and the Middle East

University of Cairo, 9-11 June 2008

Sommario

Contents• Remarks on the Mediterranean climate• A review of present trends• Information from climate projections

University of Cairo, 9-11 June 2008 International workshopOn Climate Change in the Mediterranean and the Middle East


koeppen

Vladimir Petrovič Köppen Russian geographer , botanist and climatologist(S. Petersburg, 1846 – Graz, 1940)

Classificazone 1

Main groupsA tropical climateB arid climate: C mid latitude temperate climateD mid latitude cold climateE polar climateH mountain climate

Sub-groups :S steppe W desert f wet w winter dry seasons summer dry season m: rain forest

Af, Am: monsoon, tropical rain forest. Aw: savannahBS: steppe. BW: desert. Cw: temperate mid latitude with dry winter Cf: temperate mid latitude without dry season Cs: temperate mid latitude with dry summer. Df: cold rainy during the whole year. ET: tundra. EF: frost

3rd level classificationa, b,c hot summer (T warmest month > 22°C), warm summer (warmest month < 22°C), cold summer (T less than 4 months > 10°C (climates C and D). d: very cold winter (T coldest month < -38°C (climate D). h, k: hot, cold (average year temperature higher/lower than 18°C < (climate B).

Koeppen global

Updated world map of the Köppen-Geigerclimate classificationM. C. Peel, B. L. Finlayson, and T. A. McMahonHydrol. Earth Syst. Sci. Discuss., 4, 439–473, 2007

The 30 possible climate types are divided (without accounting for H)into: 3 tropical (Af, Am and Aw), 4 arid (BWh, BWk, BSh and BSk), 9 temperate (Csa,Csb, Csc, Cfa, Cfb, Cfc, Cwa, Cwb and Cwc), 12 cold (Dsa, Dsb, Dsc, Dsd, Dfa, Dfb,Dfc, Dfd, Dwa, Dwb, Dwc and Dwd) and 2 polar (ET and EF).

Med climate

What is the Mediterranean Climate ?



Koeppen eu

10 out of 30 Köppen climate types are present around the Mediterranean Sea

Koeppen considerazioni

Large areas of the Mediterranean region do not have the “CsA/Csb Mediterranean” climate

… and there is some Mediterranean climate outside the Mediterranean region

•Csa/Csb temperate climate with dry hot/warm summer season•Cfa/Cfb temperate climate without dry season and with hot/warm•Dsa, Dfb cold climate, without dry season but warm summer and with hot dry summer•BWh BWk hot and cold desert, BSh BSk hot and cold steppe

Tise T past

Past winter temperature (DJF)

Luterbacher J. et al. (2005), Mediterranean climate variability over the last centuries: a review In P.Lionello, P.Malanotte-Rizzoli, R.Boscolo (eds) Mediterranean Climate Variability. Amsterdam: Elsevier (NETHERLANDS).

Warmest-coldest

Luterbacher J. et al. (2005),

Tise prec past

Past winter precipitation (DJF)


Driest-wettest


Considerazioni: time variabiity

Large variability at inter-annual and inter-decadal scale is a basic characteristic of the Mediterranean region

…However, the temperature increase during the second half of the 20th century in unprecedented in historical records


Tendenze 20mo secolo

Focus on 20th century

Graphics based on CRU climatology, interpolated from station data to 0.5 degree lat/lon grid ( New, M., M. Hulme and P. Jones, 1999: Representing twentieth-century space-time climate variability. Part I: Development of a 1961-90 mean monthly terrestrial climatology. J. Climate, 12, 829-856.


Pre_season 1901-1925

Precipitation 1901 - 1925

DJF

SONJJA

MAM

Pre_season_19

75_2000

Precipitation 1975 -2000

DJF

SONJJA

MAM

Pre_MK 1901-2000

Precipitation trends 1901 - 1925

DJF

SONJJA

MAM

Pre_MKmsk 1901-1925


DJF

SONJJA

MAM

Pre_MK 1975-2000


DJF

SONJJA

MAM

Pre_MKmsk 1975-2000


DJF

SONJJA

MAM

Pre_MK_msk 1901-2000

Precipitation trends 1901 -2000

DJF

SONJJA

MAM

mm/50years

Acknowledgement: Xoplaki, 2002; Xoplaki et al., 2004

Wet season precipitation trend (1950-1999)

Elena wet season

mm/50years

Acknowledgement: Xoplaki, 2002; Xoplaki et al., 2004

Dry season precipitation trend (1950-1999)

Elena dry season

tmp_season_19

01_1925

DJF

SONJJA

MAM

Temperature 1901 - 1925

tmp_season_19

01_2000

DJF

SONJJA

MAM

Temperature 1975 - 2000

tmp_MKmsk_19

01_1975

DJF

SONJJA

MAM

Temperature trend 1901 - 1925

tmp_MKmsk_19

75_2000

DJF

SONJJA

MAM


Tmp_MKmsk-1901-2000

DJF

SONJJA

MAM


Comment tmp and pre

Though there is a possibly widespread over-perception of precipitation trends, reduction of (winter) precipitation is observed over large areas of the Mediterranean region. The signal for temperature is much clearer than for precipitation: there is positive trend with an acceleration during the last part of the 20th century involving the whole Mediterranean region


Models

FAQ 1.2, Figure 1Schematic view of the components of the climate system, their processes and interactions.

Climate model projections

From IPCC 4th AR

Scenarios

CO2 emissions in SRES (Nakicenovic et al, 2000) :

•A-B rispettivamente forte e ridotto fabbisogno energetico;

•1-2 rispettivamente sviluppo mondiale omogeneo e eterogeneo.

From IPCC 4th AR

Figure TS.23

Figure TS.23. (a) Global mean surface temperature anomalies relative to the period 1901 to 1950, as observed (black line) and as obtained from simulations with both anthropogenic and natural forcings. The thick red curve shows the multi-model ensemble mean and the thin lighter red curves show the individual simulations. Vertical grey lines indicate the timing of major volcanic events. (b) As in (a), except that the simulated global mean temperature anomalies are for natural forcings only. The thick blue curve shows the multi-model ensemble mean and the thin lighter blue curves show individual simulations. Each simulation was sampled so that coverage corresponds to that of the observations. {Figure 9.5}

Model mean reliability

From IPCC 4th AR

Figure 10.5

Time series of globally averaged (left) surface warming (surface air temperature change, °C) and (right) precipitation change (%) from the various global coupled models for the scenarios A2 (top), A1B (middle) and B1 (bottom). Numbers in parentheses following the scenario name represent the number of simulations shown. Values are annual means, relative to the 1980 to 1999 average from the corresponding 20th-century simulations, with any linear trends in the corresponding control run simulations removed. A three-point smoothing was applied. Multi-model (ensemble) mean series are marked with black dots. See Table 8.1 for model details.

Mean projection

From IPCC 4th AR

Ensemble mean med

Ensemble mean projections for the Mediterranean region

Using GLOBAL models



MODEL 20C B1 A1B A2

CCMA-3-T47

CNRM-CM3

CSIRO-MK3

GISS-AOM

GFDL-CM2-0

INMCM3

MIROC3-2H

IPSL-CM4

GISS-E-R

UKMO-HADCM3

NCAR-PCM1

NCAR-CCSM3

MRI-CGCM2

MPI-ECHAM5

MIUB-ECHO-G

MIROC3-2M

GFDL-CM2-1

5 4 4 2

1 1 1 1

2 1 1 1

3 1 1 1

3 0 1 1

2 2 2 0

1 1 2 1

1 1 1 1

1 1 1 1

1 1 1 03 3 3 3

5 3 3 3

3 3 2 3

5 5 5 58 8 6 4

4 2 3 4

1 1 1 1

Grid interval

~2.7 deg

~2.8 deg

~2.3 deg

~2.3 deg

~3.2 deg

~2.2 deg

~2.2 deg

~3.5 deg

~4.5 deg

~4.5 deg

~3.0 deg

~1.2 deg

~2.8 deg

~2.8 deg

~2.8 deg

~1.4 deg

~3.0 deg

List of models, grid interval (atmosphere) and experiments used in this work. 20C indicates experiments for the 20c century, B1, A1B and A2, experiments for the 21st century under forcing deriving from the corresponding IPCC emission scenarios. The grid interval is approximate, as it may vary across latitudes and may be different in the longitude and latitude directions. More detailed information on models and experiments is available the PCMDI web site http://www-pcmdi.llnl.gov for.

List of models

risoluzione

space resolution !!!!

One obvious limitation of these simulations is resolution. This might have important consequences for the climate change signal in region where it shows a sharp gradient, likely associate with the geomorphology of the region: precipitation in the middle east in Summer and Fall, precipitation along the northern boundary of the Mediterranean region (Pyrenees, Alps, Balkans).

Risoluzione 5

5 degs

Risoluzione 4

4 degs

Risoluzione 3

3 degs

Risoluzione 2

2 degs

Risoluzione 1

1 degs

Risoluzionem 0.5

0.5 degs

Risoluzione 0.2

0.2 degs

Risoluzione 0.1

0.1 degs

Precipitation change (%, 2071-2100 minus 1961-1990), MGME ensemble average, B1 scenario

DJFDJF MAMMAM

SONSONJJAJJA

Figure 6

CC_Pre B1

from Giorgi and Lionello, 2007

Precipitation change (%, 2071-2100 minus 1961-1990), MGME ensemble average, A1B scenario

DJFDJF MAMMAM

SONSONJJAJJA

Figure 4

CC_Pre A1B


Precipitation change (%, 2071-2100 minus 1961-1990), MGME ensemble average, A2 scenario

DJFDJF MAMMAM

SONSONJJAJJA

Figure 7

CC_Pre A2


Temperature change (C, 2071-2100 minus 1961-1990), MGME ensemble average, A1B scenario

DJFDJF

SONSON

MAMMAM

JJAJJA

Figure 5

CC_tmp_A1B


-35

-30

-25

-20

-15

-10

-5

0

Pre

cip

itati

on

ch

an

ge (

%)

B1

A1B

A2

0

1

2

3

4

5

6

DJF MAM JJA SON

Tem

per

atu

re c

han

ge

(C)

B1

A1B

A2

(2081-2100) minus (1961-1980)

MGME ensemble average change in mean precipitation (upper panel) and mean surface air temperature (lower panel) for the full Mediterranean region, the four seasons and different scenario. The changes are calculated between the periods 2081-2100 and 1961-1980 and include only land points. Units are % of 1961-1980 value for precipitation and degrees C for temperature

Tmp-prec total


SLP change (mb, 2071-2100 minus 1961-1990), MGME ensemble average, A1B scenario

DJFDJF

SONSON

MAMMAM

JJAJJA

CC_SLP

500 Gph change (mb, 2071-2100 minus 1961-1990), MGME ensemble average, A1B scenario

DJFDJF

JJAJJA

MAMMAM

SONSON

Figure 3

CC_GPH500


-30

-25

-20

-15

-10

-5

0

Pre

cip

itati

on

Ch

an

ge (

%)

2001-2020

2021-2040

2041-2060

2061-2080

2081-2100

00.5

11.5

22.5

33.5

44.5

5

DJF MAM JJA SON

Tem

per

atu

re c

han

ge

(C)

2001-2020

2021-2040

2041-2060

2061-2080

2081-2100

MGME ensemble average, A1B scenario


0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

DJF MAM JJA SON

Tem

per

atu

re c

han

ge

(C)

Observed

MGME

-12

-10

-8

-6

-4

-2

0

2

4P

reci

pit

atio

n c

han

ge

(%)

Observed

MGME

(1981-2000) minus (1961-1980)

Observed (CRU data) and MGME ensemble average change in precipitation (upper panel) and surface air temperature (lower panel) for the four seasons over the full Mediterranean region (land only) 1981-2000 minus 1961-1980. Units are % of 1961-1980 value for precipitation and degrees C for temperature.

caveaut


Modelli regionali

Regional Climate models


International workshopOn Climate Change in the Mediterranean and the Middle East


RegCM experiment design

• Global Model: Hadley Centre HadAMH– Dx = 1.25 lat x 1.875 lon– SST from HadCM3 run– Coupled sulfur model

• Regional model: ICTP RegCM– Dx = 50 km– SST, GHG and sulfate from

HadAMH– aerosol effects

• Simulation periods– 1961-1990 : Reference run– 2071-2100 : Scenario run

• Scenarios: A2, B2

Giorgi, F., X. Bi and J.S. Pal , 2004 a and b

Risoluzionem 0.5

0.5 degs

CRU Observed climatology

CTR RegCM model

WET

SEASON

SEASON

DRY

Precipitation A2-CTR Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

mm

Mediterranean River basins

Ebro

Po Croatian rivers

Greek rivers

Turkish rivers

Rhone

Greece and TurkeyP

reci

pit

atio

n

Eva

po

rati

on

Wat

er b

alan

ce (

P-E

)-

=

Gr+Tu rivers

Drier autumn and (partially) spring for Greek and Turkish rivers

JAN FEB MAR

APR MAY JUN

JUL AUG SEP

OCT NOV DEC

Climate change assessment for Mediterranean agriculturalareas by statistical downscalingL. Palatella · M. Miglietta · P. Paradisi · P. Lionello (submitted)

Population growth !?!?!?!


0

10000

20000

30000

40000

50000

60000

70000

80000

90000

1 2 3 4 5 6

France

Italy

Spain

Turkey

1955 1970 1985 2000 2015 2030


0

5000

10000

15000

20000

25000

1 2 3 4 5 6

Cyprus

Gaza Strip

Israel

Lebanon

Syria

1955 1970 1985 2000 2015 2030

0

10000

20000

30000

40000

50000

60000

70000

1 2 3 4 5 6

Algeria

Egypt

Libya

Morocco

Tunisia

1955 1970 1985 2000 2015 2030

Considerazioni: time variabiity

Large variability at inter-annual and inter-decadal scale is a basic characteristic of the Mediterranean region…However, the temperature increase during the second half of the 20th century in unprecedented in historical records

Though there is a possibly widespread over-perception of precipitation trends, reduction of (mainly winter) precipitation is observed over large areas of the Mediterranean region. The signal for temperature is much clearer than for precipitation: there is positive trend with an acceleration during the last part of the 20th century involving the whole Mediterranean region

Reduced precipitation is a very likely consequence of anthropogenic climate change in large parts of the Mediterranean (including Middle east)

Evidences from global models are not flawless. They need further confirmation, possibly based on regional analysis

Regionalization techniques (dynamical versus statistical) do not always agree

Concerning impacts, other factors (such as population dynamics) are likely to have larger effects than climate change (multi-sector approach is needed)

THANK YOU for your attention



Titolo Mediterranean climate: trends and projections Piero Lionello, University of Salento, Italy International workshop On Climate Change in the Mediterranean.

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