Surface Temperature and Planetary
Albedo Responses to Total and Spectral
Solar Forcing on Multi Decadal Time
Scales in GISS GCMAM
Guoyong Wen1,2, Robert F. Cahalan1, David Rind3, Jeff
Jonas3, Peter Pilewskie4, Dong Wu1, Jerald Harder4,
Natalie Krivova5
1NASA/Goddard
2GESTAR/Morgan
State University
3NASA/GISS
4University
of Colorado
5Max Planck Institute
Guoyong Wen, Page 1
Well Established TSI 11-year variability (0.1%),
accuracy and uncertainty (1360.8±0.5W/m2)
From Kopp and Lean 2011
Fig. 8-10 IPCC 2013
Kopp, G., and J. L. Lean (2011), A new, lower value of total solar irradiance: Evidence and climate significance, Geophys. Res. Lett., 38,
L01706, doi:10.1029/2010GL045777.
Guoyong Wen, Page 2
Solar Variation on Centennial Time Scales
Solar forcing is
relatively small
Fig. 8-11 from IPCC 2013
Fig. 8-15 from IPCC 2013
Guoyong Wen, Page 3
Observations (Max – Min)
Positive Responses in Ozone and Temperature
Remsberg, 2008
Guoyong Wen, Page 4
Observations (Max – Climatology)
Surface Temperature and Precipitation
Most studies
focused on
finding 11-year
signals
Meehl et al., 2009
Guoyong Wen, Page 5
Mechanisms
1. The top-down stratospheric ozone mechanism
Increase of solar UV
increased ozone heating/increased ozone
amount
modified temperature and zonal wind
altered wave propagation
changed equator to pole energy transport
and circulation
enhanced tropical precipitation
(e.g. Haigh, 1996; Shindell et al., 1999;
Balachandran et al., 1999; Kodera and
Kuroda, 2002)
Guoyong Wen, Page 6
Mechanisms
2. The bottom-up coupled air-sea mechanism
Increase of TSI
increased solar
absorption in cloud-free
subtropical ocean,
increases evaporation
increased moisture
convergence and into
precipitation in ITCZ,
stronger trades, and
cooler SST in eastern
equatorial Pacific
(e.g. Meehl et al., 2003;
Van Loon et al, 2004,
Meehl et al., 2008)
[after Meehl et al., 2008]
Guoyong Wen, Page 7
Additive of the two mechanisms to
boost the climate response
observed
Bottom-up only
Top-down only
Both bottom-up and
top-down
[after Meehl et al., 2009]
Guoyong Wen, Page 8
Lagged responses but still in 11-yr cycle
Cahalan et al., GRL, 2010
Solar Variations (Lean 2000)
Solar Variations (Harder et al 2009)
And RCM Response
Identical TSI And RCM Response
TSI
TSI
VIS
UV IR
UV IR
40km
40km
25km
25km
To
Ta
Increased 11-yr in Stratosphere G
Decreased 11-yr At Surface & Oceans H
(observations see White et al. 1997, White and Liu, 2007, 2008)
Guoyong Wen, Page 9
Motivations of This Study
• How does climate
respond on multi
decadal time
scales?
• Does spectral
matter?
• Use SATIRE SSI
• SIM-based SSI
• GISS GCM
From Ermolli et al. (2013)
Ermolli et al. (2013), Atmos. Chem. Phys., 13, 3945–3977, 2013, www.atmos-chem-phys.net/13/3945/2013/doi:10.5194/acp-13-3945-2013
Guoyong Wen, Page 10
GISS Global Climate Middle
Atmosphere Model (GCMAM)
• Full Coupled OceanAtmos. Model (Rind et
al., 2007)
• 53 Layers Atmosphere
(top at mesopause), 13
layer ocean (Russell et
al., 1995)
• Interactive chemistry
• Model has a sensitivity
of 2.8C to doubling of
CO2
Global
average
surface
air
temperature response to doubling CO2.
Rind, D., J. Lerner, J. Jonas, and C. McLinden (2007), Effects of resolution and model physics on tracer transports in the NASA Goddard Institute for Space Studies
general circulation models, J. Geophys. Res., 112, D09315, doi:10.1029/2006JD007476.
Guoyong Wen, Page 11
GCM Experiments
Variation of SATIRE SSI
4
(a)
D Irradiance [W/m2]
Experiments
I. SATIRE modeled
SSI
II.SIM-based SSI
2
Mid-UV (200-300 nm)
Near-UV (300-400 nm)
Visible (400-700 nm)
SWIR (>700 nm)
TSI
0
-2
-4
Variation of SIM-Based SSI
Multi-decadal and
longer time scales
(b)
D Irradiance [W/m2]
Fixed GHGs,
aerosols
4
2
0
-2
-4
1600
1700
1800
Time [Year]
1900
2000
Guoyong Wen, Page 12
Global Average Temperature Responses
to Two Solar Forcing Scenarios
• Large multi
decadal variation
in both
scenarios, much
larger than 11year signal
(~0.1C)
SIM-based SSI
SATIRE SSI
• No clear 11-year
cycle
• Different in
trend
Guoyong Wen, Page 13
What is the cause?
Planetary Albedo Responses
0.3
SATIRE
: Da = 0.02 - (0.016/100) [t(year)-1610], n* = 370 years
• Planetary albedo
responses have
decreasing trends
D Albedo (%)
0.2
0.1
-0.0
-0.1
-0.2
-0.3
0.3
0.2
D Albedo (%)
• Large multi
decadal
variation.
SIM-based : Da = 0.023 - (0.030/100) [t(year)-1610], n* = 264 years
0.1
-0.0
-0.1
-0.2
-0.3
1600
1700
1800
Time [Years]
1900
2000
Guoyong Wen, Page 14
dT is negatively correlated with
planetary albedo
0.2
SATIRE: Da = 0.030 - 0.22DT, R = -0.50
SIM : Da = 0.009 - 0.29DT, R = -0.50
DAlbedo (%)
0.1
• Correlation
coefficients are about
the same. But the
sensitivity differs
significantly.
0.0
-0.1
-0.2
-0.6
• Cloud feedback is
positive for both
solar forcing
experiments
-0.4
-0.2
-0.0
DT (K)
0.2
0.4
• “The net radiative
feedback due to all
0.6
cloud types is likely
positive…” [IPCC 2013]
Guoyong Wen, Page 15
Compare to the Natural Variation
Control Experiment
With Solar Forcing
0.2
0.3
0.1
DAlbedo (%)
0.2
DAlbedo (%)
SATIRE: Da = 0.030 - 0.22DT, R = -0.50
SIM : Da = 0.009 - 0.29DT, R = -0.50
0.1
0.0
0.0
-0.1
-0.1
-0.2
SIM : Da = 0.21 - 0.07DT, R = -0.24
SATIRE: Da = 0.05 - 0.15DT, R = -0.29
-0.4 -0.2 0.0
0.2 0.4
DT (K)
0.6
0.8
1.0
-0.2
-0.6
-0.4
-0.2
-0.0
DT (K)
0.2
0.4
0.6
• Cloud feedback is positive for both
control and solar forcing experiments
• Cloud feedbacks in solar forcing are
much stronger
Guoyong Wen, Page 16
Summary
• Multi decadal global average surface
temperature variation is strong for
both solar forcing scenarios.
• Such strong surface temperature
variation is related to cloud
feedback.
• Spectral matters for surface
temperature response and feedback to
some extend
• Studies required to identify type of
clouds and regions response most.
Guoyong Wen, Page 17
Solar Variation on Centennial and Longer Time Scales
Kopp, G., and J. L. Lean (2011), A new, lower value of total solar irradiance: Evidence and climate significance, Geophys. Res. Lett., 38,
L01706, doi:10.1029/2010GL045777.
Guoyong Wen, Page 18
Kopp, G., and J. L. Lean (2011), A new, lower value of total solar irradiance: Evidence and climate significance, Geophys. Res. Lett., 38,
L01706, doi:10.1029/2010GL045777.
Guoyong Wen, Page 19