October 2004
December
2001
UNH
UNHEnvironmental
EnvironmentalSeminar
SeminarSeries
Series5:
5:
Solar
’s Climate
Solar Forcing
Forcing of
of Earth
Earth’s
Climate
Robert F. Cahalan
Head, NASA/Goddard Climate and Radiation
Chair, Climate Change Observations Working Group
Thanks to : North, Rottman, Harder, Kopp, McClintock, Woods, Lean, Rind, Huang, Rabin, Radick
1. Solar Variability from Galileo to SOHO &
SORCE
2. Earth’s Variability from Budyko to CCSP &
IPCC
3. Explorations of Sun & Earth, past, present, future
4. Puzzles and Prospects
October 2004, University of New Hampshire
Environmental Seminar Series
Robert Cahalan, Page 1
Sunspot Cycles
October 2004
December
2001
Johannes Hevelius: 1647
www.sr.bham.ac.uk
SOHO (L1): launched 1995
sohowww.estec.esa.nl
200
SOHO MDI
Sunspot
Number
100
Modern
Maximum
Maunder
Minimum
…21 22 23 …
1234…
1843:
Schwabe
discovered 11year cycle
October 2004, University of New Hampshire
Environmental Seminar Series
Robert Cahalan, Page 2
October 2004
December
2001
Maunder’s Butterfly
Sunspots … Appear first at ±35° latitude, then drift equatorward
October 2004, University of New Hampshire
Environmental Seminar Series
Robert Cahalan, Page 3
October 2004
December
2001
Hale’s Laws
Magnetic Field from Zeeman splitting
Average ~ 1 Gauss, Spots ~ 3000 Gauss
Hα (656 nm)
Ca K (393 nm)
Magnetogram
± magnetic pairs
Polarity reversals:
across equator
every 11 years
October 2004, University of New Hampshire
Environmental Seminar Series
Robert Cahalan, Page 4
October 2004
December
2001
Solar Energy Variations
Greg Kopp, UCO/LASP
TIM Instrument Scientist
TIM
4.3/1361 = 3000 ppm
~ 3 X 11-yr amplitude
Total Solar Irradiance
Active region passages:
1362
1362
June
2003:
Sun
highly
active.
Nov 1, ‘03
1361
TSI in Watts per meter-squared
1360
1360Feb 27
2/26/03
TRACE
3/26/03
4/23/03
June 10, ‘03
5/21/03
Apr 23
6/18/03
Date
Jun 18
7/16/03
8/13/03
Aug 13
LHS - magnetic
field in EUV. RHS
- He 380 nm “S”
precedes CME.
October 2004, University of New Hampshire
Environmental Seminar Series
Robert Cahalan, Page 5
October 2004
December
2001
Oct-Nov 2003 Flares
Tom Woods, XPS Instrument Scientist, UCO/LASP
QuickTime™ and a
YUV420 codec decompressor
are needed to see this picture.
X-class flares 11/1 - 11/4
– Nov 4 saturated
GOES
– 0-7 nm nearly 100
– Comm satellite lost
– Aurora in Boulder
October 2004, University of New Hampshire
Environmental Seminar Series
Robert Cahalan, Page 6
October 2004
December
2001
Solar Radiative Inputs to Earth
Some Solar impacts Earth does
not feel near the surface
Coronal Mass Ejection
~70% TSI absorbed
near surface
Cloud-free A~16%
All-sky A~20%
Source: DoE/ARM
Incoming Shortwave Absorption:
O2,3
O2
H2O
H2O H O
2
H2O
UV stratosphere ~1%
NIR troposphere ~20%
Visible land/ocean~50%
October 2004, University of New Hampshire
Environmental Seminar Series
Robert Cahalan, Page 7
October 2004
December
2001
SIM – Spectral Irradiance Monitor
Jerry Harder, SIM Instrument Scientist, UCO/LASP
ultraviolet
visible
infrared
October 2004, University of New Hampshire
Environmental Seminar Series
Robert Cahalan, Page 8
October 2004
December
2001
Composite TSI: ACRIM vs PMOD
?
Brightening
Is the Sun
Or NOT?
Next Min 2006 -->
October 2004, University of New Hampshire
Environmental Seminar Series
Robert Cahalan, Page 9
October 2004
December
2001
Solar Irradiance Measurement Program
TSI Observations
SORCE may overlap GLORY during solar min
Solar min crucial for trend
Glory less likely to overlap NPOESS
Glory so far includes only TSI, no SSI
UV Observations
First full spectral Observations
October 2004, University of New Hampshire
Environmental Seminar Series
Robert Cahalan, Page 10
October 2004
December
2001
Venus Transits the Sun, June 8, 2004 (G. Kopp, UCA/LASP)
1.36/1360 = 1000 ppm
October 2004, University of New Hampshire
Environmental Seminar Series
Robert Cahalan, Page 11
October 2004
December
2001
Activity of Sun & Stars
Magnetic Cycles
Everything oscillates!
TSI from Magnetograms
Poor correlation with
global magnetic field
Excellent correlation with
Spots + Faculae + Quiet Sun
☺
October 2004, University of New Hampshire
Environmental Seminar Series
Robert Cahalan, Page 12
October 2004
December
2001
Magnetic Cycles are Common
Not Mass, but Age Matters
Spin-Cycles Slow down
Other Stars Cycle Too !
HK periods & amplitudes
similar to Sol’s ☺
Some stars
are more
variable
Sun’s “twin” SCO 18
o
October 2004, University of New Hampshire
Environmental Seminar Series
Robert Cahalan, Page 13
October 2004
December
2001
Sun brightened 30% during past 4.6 Billion Yrs BP
Stellar Life Cycles on
Hertzprung-Russell Diagram
Present climate
“Faint Young Sun Paradox!”
O B
A
F
G
K
M
Sin(IceL)
Climate Sensitivity in “Budyko-Sellers” Energy Balance Climate Model
Budyko, 1969: The effect of solar radiation variations on the climate of the earth,
Tellus 21, 611-619.
North, Cahalan & Coakley, 1981: “Energy Balance Climate Models,”
Rev. Geophys. Space Phys. 19, 91-121.
unstable
Snowball Earth!
TSI -->
October 2004, University of New Hampshire
Environmental Seminar Series
Robert Cahalan, Page 14
October 2004
December
2001
Faint Young Sun Paradox Solved by Greenhouse Warming
Elevated atmospheric CO2, resulting
in “greenhouse warming”
occurs in the early Earth due to
volcanism, during Interglacial
Periods from oceans, and has
steadily increased in modern
times from human activities,
observed in detail since 1957.
Detectability of Solar in 1000 year GCM runs,
with 2°C/2XCO2
October 2004, University of New Hampshire
Environmental Seminar Series
Robert Cahalan, Page 15
October 2004
December
2001
NOT from sunspots, but from
cosmogenic isotopes,
geomagnetic activity
Sun-like stars
Multi-centennial TSI Variations?
Reconstructions of past
Geomagnetic activity
Lockwood & Stamper, GRL, 1999
Sun-like stars
Lean , GRL, 2000
October 2004, University of New Hampshire
Environmental Seminar Series
Robert Cahalan, Page 16
October 2004
December
2001
Past Solar Forcing Scenario
dominant
solar
forcing
dominant
volcanic
forcing
Tamboora Coseguina
October 2004, University of New HampshireLean,
Environmental Seminar Series
anthropogenic
plus
solar forcing
Krakatoa
Beer & Bradley, GRL, 22, 3195, 1995
Lean, Annual Rev. Astron. Astrophys., 35, 33, 1997
Robert Cahalan, Page 17
October 2004
December
2001
GISS GCM Simulation
Solar-induced global temperature variations since 1600
model ocean
heat flow
dampens
decadal
response
20thC temperature changes of ~0.2o in response
to adopted
o
totalSeries
solar irradiance variations & 0.45 C since 1700
Environmental Seminar
October 2004, University of New Hampshire
Robert Cahalan, Page 18
October 2004
December
2001
Response to Solar due to Climate Feedbacks
water vapor: 35%
sea-ice/
snow cover: 10%
cloud cover: 20%
October 2004, University of New Hampshire
Environmental Seminar Series
Robert Cahalan, Page 19
October 2004
December
2001
Future Solar Irradiance Scenarios
•Predictions from 10.7cm radio emission
•Baseline from past changes
IS92a Total
IPCC, 1995
Net Anthropogenic
Hansen et al, 2000
Sun’s role in future
climate change depends
on irradiance cycles and
trends relative to
anthropogenic scenarios
October 2004, University of New Hampshire
Environmental Seminar Series
Robert Cahalan, Page 20
October 2004
December
2001
Estimated Forces Acting on Present Climate
2)
2
(Watts/meter
F( W
/ m)
3
greenh ous e g ases
0
-1
n atural forcin gs
2 .3
N20
2
1
oth er anthro pog enic forcin gs
CFC s
CH4
CO 2
w ell-m ixed
greenh ous e
gas es
0.4
tropo sph eric
o zo ne
strato sph eric
ozone
-0.2
trop osp heric
aero sols
fo rced
cloud
ch anges
vegetation
and other
su rface
alteration s
-0.2
-0.4
0 .4
su n
(in direct via 0 ) 3
-1
vo lcan ic
aerosols
(0 .2 ,-0 .5)
C o n fid en ce Lev els
T im e L ine
pre-sate lli te
M oder ate
Ver y Low
Ver y Low
Ver y Low
V ery Low
1979-1999
High
Low
Low
Ver y Low
Ver y Low
2000-2010
High
M oder ate
High
M ode ra te
High
Ver y Low
Ver y Low
Low
Low
Low
M oder a te
High
High
High
Source: J. Hansen, GISS
October 2004, University of New Hampshire
Environmental Seminar Series
Robert Cahalan, Page 21
Earth Observing Assets
TOPEX/Poseidon
Landsat 7
SORCE
Group on Earth Observations (GEO) 10 Year Plan
Aqua
Sage
QuikScat
NPP/
NPOES
S
EO-1
SeaWiFS
IceSat
TRMM
SeaWinds
ACRIMSAT
Toms-EP
ERBS
Grace
UARS
Jason
Terra
Aura
Cloudsat
CALIPSO
October 2004
December
2001
NASA Re-Organizes
for Exploration:
Sun-Earth + Solar System + Universe
SORCE Meeting:
Decadal Variability of Sun & Climate,
Durham NH, Oct 26-29, 2004
Status of current solar radiation measurements
Decadal variability in Atmosphere & Oceans
Mechanisms and modes of decadal solar variability
Climate variability modes (ENSO, NAS/AO, PDO) and nonlinear response
“Lunar regolith temperature as monitor of Earth radiation budget,” S. Huang UMI
October 2004, University of New Hampshire
Environmental Seminar Series
Robert Cahalan, Page 23
October 2004
December
2001
Apollo 15 TC22 Peaks & Valleys
H
H2200 boils
boils at
at NP
NP
Tmax varies by 6K/371K ~ 1.6% → Fmax varies by 4 * 1.6% ~ 6.4%
→ Orbit Radius varies by 3.2% → Earth Orbital Eccentricity ~ 1.6%
Solar
Solar Input
Input == 0.92
0.92 ** 1360/4
1360/4 == 313
313 W/m
W/m22
TTeff
~ 220K → IR Out = 0.92 σT eff44 ~~ 122
122 W/m
W/m22
eff ~ 220K → IR Out = 0.92 σTeff
In
In –– Out
Out == 191
191 W/m
W/m22 out
out from
from interior
interior
N
N22 freezes
freezes at
at NP
NP
October 2004, University of New Hampshire
Environmental Seminar Series
Robert Cahalan, Page 24
October 2004
December
2001
P3 – Antarctic Sea Ice
MAS – Arctic Sea Ice
200
300
Rozwadowska and Cahalan,
2002: JGR 107,
doi:10.1029/2002/JD002092
October 2004,.University of New Hampshire
Environmental Seminar Series
40
Cahalan, McGill, Kolasinski,
Varnai, Yetzer, 2004:
JAOTech, to appear.
Robert Cahalan, Page 25
October 2004
December
2001
• Rio de Janiero
CATARINA
South Atlantic hurricane.
First ever recorded !
March 2004
• Buenos Aires
March 21, 2004 Brian Thompson’s Watch Captain’s Log:
“When we arrive off Rio we will have to avoid a lowpressure area that will be parked 500 miles offshore. We can choose
to go inshore to the west, or offshore to the east. At the moment we
are undecided on the option but during the night we will have to
make the choice. As more up to date weather info comes in it should
become a clearer decision..”
Cheyenne
October 2004, University of New Hampshire
Environmental Seminar Series
Robert Cahalan, Page 26
THE FINISH
58 days, 9 hours,32 minutes, 45 seconds
Steve Fossett (skipper) USA
Adrienne Cahalan (navigator) AUS
David Scully (watch captain) USA
Brian Thompson (watch captain) GB
Jacques Vincent (watch captain) FRA
Guillermo Altadill ESP
Mike Beasley NZL
Fraser Brown NZL
Mark Featherstone GB
Damian Foxall IRE
Nick Leggatt ZA
Justin Slattery IRE
Paul Van Dyke USA
October 2004
December
2001
Nominated Woman Sailor of the Year 2004
October 2004, University of New Hampshire
Environmental Seminar Series
Robert Cahalan, Page 27
October 2004
December
2001
Puzzles & Prospects
Do spectral solar variations impact Earth convection, clouds and aerosols?
Monitor ∆TSI, and ∆SSI < 300 nm & > 300 nm
Measure ∆(solar atmos. Absorption) with cloud
Determine ∆(cloud distributions) with solar forcing
Determine ∆(aerosol distributions) with solar forcing
QuickTime™
a
Does changing “solar weather”
impactand
Earth
upper atmosphere structure?
YUV420 codec decompressor
Ozone photochemistry
are needed to see this picture.
Radiative transfer and temperature stratification
Catalytic effects (e. g. PSC’s)? Triggering “oscillations”
Can stratospheric changes affect tropospheric climate?
Stratosphere-troposphere interactions (dynamical/radiative)
Can solar and cosmic particles impact Earth’s climate?
Testable hypotheses needed!
e.g. Solar wind modulates cosmic ray flux, which impacts
cloud cover, which controls surface temperature.
October 2004, University of New Hampshire
Environmental Seminar Series
Robert Cahalan, Page 28