The impact of the 11-year solar variability on climate

AG „Mittlere Atmosphäre“, Institut für Meteorologie, Freie Universität Berlin

The impact of the 11-year solar variabilityon climate

Simulations with the Freie Universität Berlin Climate Middle Atmosphere Model (FUB-CMAM)

Ulrike Langematz

„Solar variability – climate interaction“ AWI/IUP Blockseminar, Universität Bremen, 13. February 2006


Objectives

What is the contribution of solar variability to climate variability?

What is the contribution of solar variability to climate change?

Solar variability is caused by different processes (orbital parameters, magnetic processes in the Sun‘s interior).

• millenium time scale (e.g. Holocene) • centennial time scale (e.g Maunder Minimum)• decadal time scale (e.g. 11-year Schwabe cycle)• 27-day rotation period

It varies on different time scales:


IPCC, 2001

Natural and anthropogenic climate factors


Total Solar Irradiance (TSI)

1363

1364

1365

1366

1367

1368

1369

78 80 0385 90 95 00

0.1 %

Fröhlich (2000), update: http://www.pmodwrc.ch/solar_const/solar_const.html

To

tal

So

lar

Irra

dia

nce

W

/m2

Schwabe-Cycle


Solar signal in 30 hPa geopotential height

Labitzke und van Loon (1995), updated

Tem

pera

ture

sig

nal:

Obs

erva

tions

Hood (2004)

NCEP/CPC (1980-1997) SSU/MSU4 (1979-1997)

-1 K

+1 K

+2.5 K

+0.8 K

+0.25 K

Courtesy of Bill Randel (2005)

SSU/MSU4 (1979-2003)

Crooks and Gray (2005)

1.75 K

0.5 K

+0.8 K

-0.25 K

0.5 K

Scaife et al. (2000)

ERA40 (1979-2001)


Lean et al., 1997

11 year solar max minus min

0.1 % variation in TSI

Mechanisms I: Variations in UV-Radiation

>50% in 121,6 nm (Lyman-α)

5-12% in 175-240 nm

3-5% in 240-260 nm


Low energy electronsStay in thermosphereMax at solar maximum

High energy electronsStratosphere/mesosphereMax at solar minimum Solar proton events (SPEs)

Thermosphere/mesosphereMax at solar maximum

Galactic cosmic rays (GCR)Lower stratosphereMax at solar minimum

Mechanisms II: Charged Particle Precipitation


Dynamics

Δ Absorption ofsolar UV-radiation

Δ NOx / HOx

chemistry

Δ UV Δ CP

Temperature

Ozone


Transfer of the solar signal from the upper to the lower atmosphere by

• radiative coupling

• dynamical coupling

• chemical coupling

The Freie Universität Berlin Climate Middle Atmosphere Model (FUB-CMAM)

Basis: ECMWF / ECHAM (Röckner et al., 1992)

Resolution: T21 (5.6°x 5.6°), T42 (2.8°x2.8°) L19 (top at 10 hPa, ~30 km); L34, L70 (top at 0.0068 hPa, ~84

km)

Physics: • Radiation-scheme for O3, CO2 and H2O (Morcrette, 1991)

Absorption of UV/VIS by O3 in 8 bands >70 hPa (Shine&Rickaby, 1989) Absorption of UV/VIS by O2 (Strobel, 1978)

Newtonian-cooling for IR above 60 km • Hydrological cycle and vertical diffusion • Rayleigh-friction in upper mesosphere

Ozone: Variable climatologies (e.g. Fortuin & Langematz, 1994)

Ocean: Climatological or annually varying SSTs (AMIP)

Pawson et al., 1998; Langematz (2000)



FUB-CMAM editions for solar cycle studies

sunT21, L34

high resolution UV radiation

SW-radiation module• 43 bands in strato-and mesosphere• Absorption due to O3 and O2

• Lyman-alpha

sun-qboT21, L34

sun plus QBO-relaxation

QBO-modulelinear relaxation of zonal wind in the tropical lower stratosphere

sun-chemT21, L34

sun plus chemistry & transport

Chemistry modulebased on Steil et al. (2003)SLT-transport modulebased on Bräsicke, 1998; Mieth (2000)


Sensitivity studies: Impact of UV-radiation

ΔUV ΔO3

or

Model: FUBCMAM sun (Pawson and Langematz, 1998; Langematz, 2000, Matthes et al.,

2003)

11 –year cycle: • prescribed UV-changes (Lean et al., 1995)• prescribed ozone changes (J. Haigh) • perpetual january

or

Radiative coupling


sola

r U

V IC-O

3

Langematz and Matthes, 2005, in Vorbereitung

Radiation and ozone changes are both important..

Radiative Impact of UV and ozone changes FUB CMAM, max-min, perpetual January

Direct radiative solar signal in temperature in the upper stratosphere.

Short wave heating rates (K/day)

Radiative coupling


Matthes et al., 2003

Temperature signal due to UV and ozone FUB CMAM, max-min, annual mean

Significantly higher temperatures at solar maximum in the stratosphere

Strongest temperature signal at the equatorial stratopause (> 1K)


Early Winter Anomalies

Theoretical concepts

Kodera and Kuroda (2002)

1. Initial radiative solar signal in upper stratosphere

2. Positive feedback between waves and zonal wind with poleward-downward“ movement of wind anomalies (Kodera, 1995)

3. Modulation of Mean Meridional Circulation (MMC)

4. Temperature changes in equatorial lower stratosphere

Dynamical coupling


Labitzke (2003)

Observations: Solar cycle QBO30 hPa height (m), Feb 1958-2003, NCEP/NCAR

Dynamical coupling

Major stratospheric warmings in solar maximum/QBO west (Labitzke and van Loon, 1988)

max-minPhase of tropicalstratospheric winds

is important.


Matthes et al. (2004)

QBO WestQBO East

11 – year cycle: Prescribed UV- and ozone changes

Solar sensitivity studies: QBO

Model: FUBCMAM sunqbo plus QBO relaxation: (Pawson and Langematz, 1998; Langematz, 2000, Matthes et al.,

2004)

Dynamical coupling



JNMC Data (1979-1998)

J

J

J

JNov

Dec

Jan

Feb0.4 hPa

850 hPa

Zon

al w

ind(max – min)

NH – winter circulationDynamical coupling

Model

Poleward-downward movement of zonal wind anomalies only with QBO-feedback

Major stratospheric warmings in solar solar maximum/QBO west (Labitzke and van Loon, 1988)


stratospheric response

tropospheric response

Solar signal in the troposphere Ihigh latitudes

NH zonal wind anomalies (max-min) in winter

0 km

80 km


Downward propagation of wind anomalies from stratosphere to the troposphere throughout the winter

Dynamical coupling


Nov Dec Jan Feb

no significant surface signal significant surface signal (pos. AO) surface signal disappears

monthly mean geop. height differences (max-min) – 900hPa

Solar signal in the troposphere IIhigh latitudes

Matthes et al. (2004, 2006)

Significant solar signal in lower troposphere in December and January

Dynamical coupling


w max-min January w max-min (mm/s) precipitation max-min (mm/d)

monthly mean differences in vertical motion and precipitation (max-min)

Solar signal in the tropospherelow latitudes

Matthes et al. (2004, 2006)

Significant changes in vertical motion, precipitation/cloud cover

Dynamical coupling

Lagged to changes in upper stratosphere by about 2 months


2d CTMs, annual mean (%), max-min

IC (Haigh, 1994) GISS (Shindell et al., 1999)

2d- chemical models do not reproduce the observed minimum in the equatorial middle stratosphere

Solar sensitivity studies: OzoneCalculated 2d-ozone change vs. observed ozone

change?

Chemical coupling

Ozo

ne s

igna

l: O

bser

vatio

nsSBUV/SBUVII (1980-1997)

Lee and Smith (2003)

SBUV/SBUV II (1979-1989)SAGEI/II (1984-1998)

Lee and Smith (2003)

%

Shindell et al. (1999)

Hood (2004)

6 %


Changes in chemistry module:

• Changes of TOA fluxes in photolysis scheme (Landgraf and Crutzen, 1998)

• Changes of Lyman- flux by 53.88% between solar min and max.• NOx sources > 55° lat on top 3 levels (>72 km) were reduced in sol max

and enhanced in sol min (Callis et al., 1999, 2001).

Prescribed UV changes

Calculated ozone changes NOx-sources for REP precipitation

11 – year cycle:

Solar sensitivity studies: ozone II

Model: FUBCMAM chemsun (Langematz et al., 2005)

(Pawson and Langematz, 1998; Langematz, 2000, Matthes et al., 2003)

plus interactive chemistry

Chemical coupling


Ozone [%]

Mesospheric ozone decrease (max-min)H2O [ppmv]

OH [molec/cm3]

Mesospheric ozone decrease is due to stronger catalytic destruction by HOx.

–

+ Lyman- photolysis

+

+ OH production

January

Chemical coupling

(Langematz et al., 2005)


NO2 [ppbv]

NO [ppbv]

Stratospheric ozone increase due to weaker catalytic destruction by NOx.

–

–

– thermospheric NOx source due to weaker EEP

Ozone [%]

January

High latitude ozone increase (max-min)

Chemical coupling


Polar ozone measurements confirm ozone changes due to REP(Sinnhuber et al., 2005).


Ozone decrease in lower tropical stratosphere partially due to chemical effect.

annual mean

Ozone [%]

50 hPa, Equator:

Ozone (max-min): = -5.8 %

Reaction dO3/dt (Min) dO3/dt (Max)

O3 + HO2 –297.74 –375.09NO2 + O3P –137.35 – 74.25OH + HO2 – 20.52 – 26.96ClO + O3P – 27.76 – 36.31

Chemical sinks: –29.23 ppt/day

But also radiative self-healing-effect ?Or effect of dynamical change ?

Ozone increase in tropical lower stratosphere (max-min)

Chemical coupling



Conclusions

Direct radiatively induced solar signal in the upper atmosphere is well understood.

Recent progress in understanding downward transfer of solar signal into lower stratosphere and troposphere by indirect dynamical mechanism.

First progress in understanding chemical impact of solar variability.

Open questions remain concerning solar signal in stratospheric ozone, the troposphere and the ocean.


Current FUB activities

11-year solar signal in stratospheric ozone 11-year solar signal in the troposphere and the ocean using MA-ECHAM5-MESSy (cooperation with MPI-Chemie, Mainz) centennial solar signal (Maunder Minimum and holocene) using FUB-EGMAM

DFG-CAWSES-project ProSECCO (Project on Solar Effects on Chemistry and Climate Including Ocean Interactions)

cooperation with University Bremen (J. Notholt, M. Weber, M. Sinnhuber)

EC-project SOLVO (The Influence of Solar Variability on Climate)

11-year solar signal ↔ QBO 11-year solar signal in the troposphere NCAR WACCAM (in cooperation with NCAR (USA)


• radiation: • Decrease of TSI = 1367.0 Wm-2 by 0.1% for solar min. • Spectral UV flux variations in 43 bands based on Lean et al., 1997

• chemistry: • TOA fluxes in photolysis scheme (Landgraf and Crutzen, 1998)

were changed by (min to max)

Interval (nm) %change178.6 – 202.0 9.52202.0 - 241.0 4.00241.0 - 289.9 1.38289.9 - 305.5 0.42305.5 - 313.5 0.40313.5 - 337.5 0.20337.5 - 422.5 0.20422.5 - 752.5 0.00

• Lyman- flux was changed by 53.88% from solar min to max.

• NOx sources >55° lat on upper 3 levels (>72 km) are decreased at sol. max and increased at sol. min (Callis et al., 1999, 2001)

FUB CMAM-CHEM solar cycle experiments


Solar impact studies: GCMs with coupled chemistry

Ozone (%) and Temperature (K) solar (max-min)in FUB-CMAM-chem

Ozone [%] Temperature [K]

-3 30 10-1

annual mean

Langematz and Grenfell (2004)


Ozone [%]

-3 0

Ozone response (%) (max-min)annual mean

3 Hood, 2004

SBUV/SBUV2 satellite data1980-1997

Chemical coupling


Solar sensitivity studies: Radiation ⇔ Ozone FUB-CMAM-sun, max-min, perpetual January

sola

r U

V IC-O

3

Langematz and Matthes (2004), in preparation

Solar impact studies: Sensitivity studies

Radiation and ozone changes Between solar min and maxare equally important.


GRIPS solar cycle studies: NH winter circulationzonal wind, max–min (m/s)

Nov

Dec

Jan

Feb


GRIPS solar cycle studies: SW heating ratesannual mean, max–min (K/d)


Solar sensitivity studies: OzoneFUB CMAM, max-min, perpetual January

IC-O

3

GIS

S-O

3

Langematz and Matthes (2003), in preparation


Solar studies with coupled chemistry

MA-ECHAM4/CHEM Model • T30 L39, chemistry (Steil et al., 1998) (Manzini and Mc Farlane, 1998) • TSI and spectral solar variations in

radiation scheme and chemistry

• 20 year integration

FUB-CMAM-CHEM Model • T21 L34, chemistry (Steil et al., 1998) (Langematz, 2000; Mieth et al., 2003) • TSI and spectral solar variations in



Met. Office Unified Model • 2.5° x 3.75°, L64, with chemistry (Austin, 2002) • TSI and spectral solar variations in



SOCOL Model • T30 L39, MA-ECHAM4 + MEZON (Rozanov, pers. comm) • TSI and of spectral solar variations in




The Berlin Climate Middle Atmosphere Model

FUB-CMAM-CHEMBasis: FUB-CMAM: T21 L34

Chemistry: (Steil et al. 1998): 18 tracers I.e. CH4, N2O, H2O2, HCl, (HNO3+NAT), NOx, ClOx,Ox, CO, CH3OOH, ICE, ClONO2, F11, F12, CH3Cl, CCl4, CH3CCl3, H2; 107 gas-phase reactions (DeMore et al.,1994);

7 photolytic reactions (Landgraf and Crutzen, 1998); 4 heterogeneous reactions on PSCs and sulphate;tropospheric emissions and thermospheric NOx source

Tracer transport: Semi-Lagrangian Transport Scheme(Böttcher 1996, Braesicke 1998, modified by Mieth 2000)

Gravity waves: orographic: McFarlane (1987); Non-orographic:Hines (1997), Manzini and McFarlane (1987)

Mieth et al. (2003), in preparation.


Solar impact studies: Solar CCM-Intercomparison

Ozone (%) solar max-minCCM Intercomparisonmore ozone:

faster jO2

effect ?

less ozone: faster jH2O effect ?


Solar impact studies: Solar CCM-Intercomparison

Temperature (K) solar max-minCCM Intercomparison

The impact of the 11-year solar variability on climate

Documents

Transcript of The impact of the 11-year solar variability on climate