EARTH SUN JUPITER SATURN Our Home in Space: The Sun-Earth System Judith Lean Naval Research...

EARTHEARTH

SUNSUN

JUPITER

SATURN

Our Home in Space: Our Home in Space: The Sun-Earth SystemThe Sun-Earth System

Judith LeanNaval Research Laboratory, Washington DC

AASM, 11APR06

Variability in the Space Era – Variability in the Space Era – past 30 yearspast 30 years Total Irradiance – Climate … where we live UV Irradiance – Ozone … our protective atmosphere EUV Irradiance, particles, plasma – Space Weather … technology

Sun-Earth System – Sun-Earth System – an overviewan overview The Sun, a Star, is our energy source The Earth, a planet, is our home

Relationships in the PastRelationships in the Past - last century - last millennium - last 10,000 years –the Holocene …… our current interglacial

radiated photons

photons

radiative zonecore

convection zone

surfaceatmosphere

4.5 billion years

surface

SUN EARTH

photons

not to scale

1,391,980 km 12,742 km149,597,900 km1 Astronomical Unit

5770 K 288 K

atmosphere

Troposphere

Stratospheredeep space 4K100,000 K 1,000 K

reflected photonsreflected photonsradiated photons

T T

Thermosphere

StratosphereStratosphere

TroposphereTroposphere

MesosphereMesosphere

ThermosphereThermosphereIonosphereIonosphere

SUN (255 K) + GHG (33 K) = 288 K

wavelengths 100-300 nm

wavelengths < 100 nm

Alt

itu

de

- km

wavelengths > 300 nm

Solar Radiation Establishes the Thermal Solar Radiation Establishes the Thermal Structure of the Earth and its AtmosphereStructure of the Earth and its Atmosphere

T

surface

particles (mainly protons)

and magnetic fields

SUN EARTH

photons

core

convection zoeradiative zone

surface atmosphere

magnetosphere

sunspotfaculae, plage

coronal mass ejection

bow shock

plasmasphere

not to scale

solar wind

heliosphere

atmosphere

galactic cosmic rays

coreradiative zoneconvection zone

photosphere

chromospheretransition regioncorona

magnetosphere

plasmasphere

thermosphere/Ionospheremesospherestratosphere

troposphere

mixed layer

deep ocean

Sun’s surface

Earth’s surface

OC

EAN

EAR

TH

ATM

OSP

HER

EEA

RTH

SPA

CE

ENVI

RO

NM

ENT

SOLA

R

ATM

OSP

HER

ESO

LAR

INTE

RIO

RH

ELIO

SPH

ERE

HEL

IOSP

HER

E

5-12

0 nm

120-

300

nm

1000

-100

00 n

m

0.00

32

0.00

09

14.9

0.1

414.

2

0.

05

0.00

065

0.

000

35

electromagnetic radiation

energetic particles

plasma wind

300-

1000

nm

936.

3

0.

45

ENERGY FLOWENERGY FLOW

W m

-2

1.5

108

km

0.00

000

07

galactic cosmic rays

0.00

2

0.00

2

Ener

gy F

lux

Cycle

Am

plitu

deEn

ergy

Flu

x

Cy

cle A

mpl

itude

Wav

elen

gth

Wav

elen

gth


Relationships in the PastRelationships in the Past - last century - last millennium - last 10,000 years –the Holocene …… our current interglacial


Heliosphere

Corona

Chromosphere-TR

KPNO magnetic flux

12DEC96

Surface Magnetic Field

31JAN0316JAN03

PhotosphereMDI

EIT

LASCO

The Sun’s Activity Drives The Sun’s Activity Drives the Sun-Earth Systemthe Sun-Earth System

sunspots have an 11-year cycle

232221

SOHO/MDI29 Mar 2001

SOHO

sunspot cycle amplitudes have increased from the Maunder Minimum … to the Modern Maximum

SOHO: 1996 ACRIMSAT: 1999 SORCE: 2003

The Solar “Constant” The Solar “Constant” Varies! Varies!

5-min oscillation ~ 0.003%27-day solar rotation ~ 0.2% 11-year solar cycle ~ 0.1% longer-term variations not

yet detectable – ……do they occur?

cycle 21 cycle 23data: Fröhlich & Lean,AARev,2004 http://www.pmodwrc.ch

Past Solar Activity

cycle 22

Total Solar Irradiance:Total Solar Irradiance:

http://lasp.colorado.edu/sorce/

- dark sunspots 2 AUG 6 AUG

solar photosphere

near UV,VIS,IR radiation

climate

1366 Wm1366 Wm-2-2

Sources of Solar Sources of Solar Irradiance Variations:Irradiance Variations:

- bright faculae

faculae dominate sunspots during solar cycle

sunspots dominate faculae during solar rotation

17 OCT 0317 OCT 03 30 OCT 0330 OCT 03

25 FEB 0225 FEB 0216 JUN 9616 JUN 96

Anthropogenic Forcings• atmospheric GH gases - CO2, CH4, CFCs, O3, N2O• tropospheric aerosols - direct and indirect effects of soot, sulfate, carbon, biomass burning, soil dust

• Climate Change Science,“An Analysis of Some Key Questions”, National Research Council, 2001• IPCC, 1992, 1995, 2001Natural Forcings

• solar variability - direct and indirect effects• volcanic eruptions - stratospheric aerosols

Internal Oscillations• atmosphere-ocean couplings - El Niño Southern Oscillation (ENSO) - North Atlantic Oscillation (NAO)

Causes of Recent Climate ChangeCauses of Recent Climate Change

Land Cover Changes

Solar and Anthropogenic Climate SignalsSolar and Anthropogenic Climate Signals

greenhouse gasesindustrial aerosols

volcanic aerosols

monthly means

El NinoLa Nina

http://data.giss.nasa.gov/

GISS Land+Ocean Global Temperature

Climate Response to Radiative ForcingClimate Response to Radiative Forcing

ΔT = F

Solar Irradiance Cycle ΔT = 0.1oC F = 0.15 Wm-2 (0.850.7/4)

= 0.67oC per Wm-2

BUT…. response to cyclic decadal forcing is assumed to be attenuated by 5

compared with “equilibrium” response

surface temperature change

forcing

climate sensitivity IPCC range: 0.2-1oC per Wm-2

paleoclimate: 0.75oC per Wm-2

Hansen, 2004

FE

ED

BA

CK

S

water vaporwater vapor

sea-ice/ sea-ice/ snow coversnow cover

cloud covercloud coverhttp://visibleearth.nasa.govhttp://www.hpl.umces.edu/~lzhong/mixed_layer/sml.htm

mix

ed l

ayer

El Chichon Pinatubo

SURFACE MIDDLETROPOSPHERE

El Nino

La Nina

LOWERSTRATOSPHERE

Tem

per

atur

e A

nom

aly

(K)

Solar Cycle Signals in Earth’s AtmosphereSolar Cycle Signals in Earth’s Atmosphere

solar increase warmingCO2 increase warmingvolcanoes cooling

solar increase warmingCO2 & CFC increase cooling

volcanoes warming

0 km8 km 20 km

O3 destruction


unit optical depth

UV radiation(λ < 315 nm)

20 Wm-2

O2 photodissociation

O3 production

Sun, Sun, Stratosphere,Stratosphere,

OzoneOzone

near UV,VIS,IR Radiation(λ > 315 nm)1346 Wm-2

Sun

Pittock (1978): Sun-ozone correlations …“experiments in autosuggestion”

The Ozone Layer:The Ozone Layer:

EP/TOMS Total Ozone Sep 16, 2001

GSFC TOMS Total Ozone Sep 16, 2001

2.2%

Total Ozone 50S-50N ~ 280 DU

Recent VariationsRecent Variations

Nimbus 7

solar upper photosphere/ chromosphere2000-02-252000-02-25

1996-06-161996-06-16 UV radiation:200-295 nm+1.2%

4%

Stratosphere – Climate CouplingStratosphere – Climate Coupling

Radiative Coupling via Absorption and Emission

Rad

iativ

e Fo

rcin

g Se

nsiti

vity

NORTH ATLANTIC OSCILLATIONNORTH ATLANTIC OSCILLATION

Positive NAOPositive NAO Negative NAONegative NAO

•solar irradiance cycle modulatesstratospheric polar vortex• tropospheric circulation•NAO (solar min) AO (solar max)

Kodera, 2003

Lacis et al., 1979

Dynamical Coupling via Wind-Wave InteractionsChange Ozone & Temperature

Change Winds & Planetary Waves

Change Temperature Advection &Temperature

Change Winds & Planetary Waves

Change ClimateLo

wer

A

tmos

pher

eM

iddl

eA

tmos

pher

eShindell et al., 2003; Rind et al., 2004


TroposphereTroposphere

ThermosphereThermosphereIonosphereIonosphere

solar EUV radiation λ< 100 nm

Alt

itu

de

solar increase warming CO2 increase warming

solar increase warmingCO2 increase cooling

solar increase warmingCO2 increase cooling

SPACE WEATHER

climate change

ozone depletionGLOBAL CHANGE

TOMS UV radiation exposure: January

solar min maxSun = +0.1KGHG = +0.2K

solar min maxSun = +0.3KGHG = -0.4K

solar min maxSun = 400KGHG = -3K

T

spacecraft drag

communication,navigation

solar EUV photon energy

solar wind kinetic energy (~protons)

corona

chromosphere heliosphere

16 JAN 03

Sun and Thermosphere-IonosphereSun and Thermosphere-Ionosphere

quiet Sun

response to EUV photons

response to particles, plasma, fields

500 km

temperature

neutral density

electron density

100%

Yohkoh: launched 30 AUG 1991Re-entered 12 SEPT 2005

solar EUV irradiance changes modulate upper atmospheric densities, affecting the orbits of >10,000 resident space objects

1999

Density at YOHKOH

Spacecraft DragSpacecraft Drag

International Space Station: 400 km YOHKOH Altitude

EUV Irradiance

July 1979

Space CommandRadar Fence

20031028 20:49

““Halloween” Solar StormHalloween” Solar Storm October 28th, 2003

NOAA National Weather Service http://www.sec.noaa.gov/

… at L1

SOHO/LASCO 20031028 12:42

heliosphere

X-ray photons

chromosphere-TR

EIT 30420031028 13:19

30 Rsun

8 minutes later ... X-class flare recorded by GOES

coronal mass ejection leaves the Sun ….

8 hours later... particles saturate SOHO/LASCO detector

surface

active region with big sunspot erupts ….

and reach Earth

energetic protons

SOHO/EIT 171 20031028 13:00

www.nas.edu.ssb/cover.html

Solar Variability Drives Solar Variability Drives Space WeatherSpace Weather

March 1989:Auroral Oval

solar photons & solar and magnetospheric particles

heat and ionize Earth’s atmosphere and ionosphere

Power System Events spacecraft drag, collisions, loss

aurora

currents induced in power grids

communications & navigation

spacecraft detector upsets

hazards to humans in space



Relationships in the PastRelationships in the Past - last century - last millennium - last 10,000 years – the Holocene …. our current interglacial

In early September in 1859, telegraph wires suddenly shorted out in the United States and Europe, igniting widespread fires. Colorful aurora, normally visible only in polar regions, were seen as far south as Rome and Hawaii.

1613 Galileo 1995 SOHO

Earth’s surface temperature has increased in the last century..

1900-1950

1960-2000

http://giss/nasa/gov

Sun and Climate in Recent CenturiesSun and Climate in Recent Centuries

changes are non-uniform, globally and temporally

sunspot cycle amplitudes have increased from the Maunder Minimum to the Modern Maximum

Industrial-Era Climate Forcing: IPCC 2001Industrial-Era Climate Forcing: IPCC 2001

3

2

1

0

-1

-2

-3

1750

-200

017

50-2

000

CH4

N2Ohalocarbons

stratosphericozone

troposphericozone

2.4R

adia

tive

Forc

ing

(Wm

-2)

sulphate

fossil fuel

burning

biomass burning

mineral dust

landuse(albedo)

0.35 0.25 0.3

0.2 0.4 0.1 0.25 0.23

solar

indirect aerosol

CO2

aviationcontrails & cirrus

0.05

war

min

gco

olin

g

solar forcing

volcanic forcing

anthropogenic & solar forcing

Pre-Industrial Solar Forcing

F = 0.3 Wm-2 ΔT = 0.2oC = 0.6oC per Wm-2

Tamboora Coseguina Krakatoa

(Bradley & Jones, 1993)

Lean et al., 1995

(FSUN=ΔS0.7/4)

Climate Change in Recent CenturiesClimate Change in Recent Centuries

GCM simulation: ~ 4oC for 2×CO2Robinson et al., 2001

EBM simulation: ~ 2oC for 2×CO2Crowley, 2000

forcings

omitting solar forcing .. poorer tracking of centennial

variations .. higher sensitivity to GHGs

high solar activity low 14C low 18O high rainfall

Holocene Sun-Climate ConnectionsHolocene Sun-Climate Connections

18O in stalagmites in Oman track 14C for 3,000 years in mid-Holocene Neff et al., Nature, 2001

INTERTROPICAL INTERTROPICAL CONVERGENCE CONVERGENCE ZONEZONE

NORTH ATLANTIC NORTH ATLANTIC CLIMATECLIMATE

surface winds and ocean hydrography affected by solar variability --North Atlantic Deep Water may amplify solar signals Bond et al., Science, 2001

high solar activity low 14C less drift ice southward

cosmogenic isotope changes - 14C in tree-rings, 10Be in icecores - imply long-term solar activity

Centennial-Millennial Solar VariabilityCentennial-Millennial Solar Variability

0.1%

… do they also imply long-term solar irradiance variations?

Mechanisms of Cosmogenic Isotope and Mechanisms of Cosmogenic Isotope and Solar Irradiance VariabilitySolar Irradiance Variability

Galactic Cosmic Ray Flux at Earth

Radial Interplanetary

Magnetic Field

open flux modulates cosmogenic isotopes

closed flux modulates irradiance

24 June 2002

EIT304

EIT284

surface magnetic fields of opposite polarity

open flux in coronal holes – extends to helio-sphere

closed flux in active regionsand network

phot

osph

ere

chro

mos

pher

eco

rona

Irradiance at Earth1365 Wm-2

0.0000007 Wm-2

MDI

Evolution of the Sun’s Surface Magnetic Field Evolution of the Sun’s Surface Magnetic Field Drives Long-Term Solar Irradiance ChangesDrives Long-Term Solar Irradiance Changes

sub-surface dynamo

surface magnetic fields of opposite polarity

www.hao.ucar.edu, Y.-M. Wang, N. Sheeley science.nasa.gov/ssl/pad/solar

diffusionpoleward meridional

flow

magnetic flux is transported by…. differential

rotation

0.08%

0.2%

Long-Term Solar Irradiance Simulated by a Flux Transport Model

magnetogram

Causes of Causes of Climate Climate ChangeChangein the in the

Recent PastRecent Past

Radiative Forcing 1750-2000

IPCC 2001: (Wm-2)Greenhouse Gases +2.4Ozone +0.15Solar +0.3Landuse -0.23Tropospheric -0.4 to -1.4 Aerosols

Hansen et al., 2001Tropospheric -0.6 Aerosols Empirical Reconstruction

+0.12

0.1K

0.9K

0.7K

Sun-Earth System:Sun-Earth System:Emerging QuestionsEmerging Questions

Long-term solar variability and terrestrial responses- solar dynamo action, irradiance and heliospheric modulation, terrestrial responses

Eruptive energy outputs and terrestrial responses- flare spectra, relative impacts of flares and CMEs, time scales of terrestrial responses

Solar-driven versus other influences on Earth- volcanic influences, internal modes (ENSO, NAO, QBO), geenhouse gasesVertical couplings of solar and other influences-radiative and dynamical up & down atmospheric couplings - surface to themosphere-radiative and plasma couplings of thermo/ionsophere and plasma/megnetosphere

Non-linear system responses-mode amplification (ENSO), stochastic resonance, frequency modulation, triggering altered stability states

Ability of models to simulate system responses-mechanisms, data assimilation, subsystem interfaces, transition to operations

In seeking answers to such questions once-disparate fields are coalescing slowly and a new paradigm is emerging –

… of the Sun and Earth as one unified system, our home in space that extends well beyond the surface where we live.

Physics Today, June 2005: “Living with a Variable Sun”

Communication, NavigationCommunication, Navigation

Meier et al., GRL, 2001

ionospheric electron density response

X-ray and EUV irradiance variation

NRL SAMI2 model(Huber and Joyce)

Bastille Day 2000 Bastille Day 2000 solar eruptionsolar eruption flares

nemax=1.24×104fo2

Yohkoh SXT

• disrupts communications • degrades radar accuracy • disrupts/degrades navigation • degrades precision targeting

Meier et al., 2000

active region evolution solar cycle

reflection, refractiontime delays, phase shiftsfades, polarization rotation

Sun – Climate - Ozone: Sun – Climate - Ozone: Future Decadal VariabilityFuture Decadal Variability

Sun’s role in future climate change depends on irradiance cycles and trends relative to anthropogenic scenarios

solar cycle

C. Jackman, GSFC

Total OzoneTotal Ozone

Radiative ForcingRadiative Forcing

IPCC, 1995

Hansen et al, 2000

NPOESS ??GLORY

SORCETotal Solar IrradianceMonitoring

Coronal Mass EjectionSOHO/LASCO 1997-11-06 solar magnetic

cloud perturbs Earth’s magnetic field lines

Particle Transport

Particle-Plasma Wave Interactions

103 c

m-1 s

ec-1 s

tr-1

Coronal Mass EjectionsCoronal Mass Ejections

affects energetic particle penetration of Earth’s atmosphere

Propagate to Earth through the Propagate to Earth through the Heliosphere Heliosphere … hours to days

EARTH SUN JUPITER SATURN Our Home in Space: The Sun-Earth System Judith Lean Naval Research...

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