Total Solar Irradiance
Composites and
the empirical analysis of the
solar contribution to global
mean air surface temperature
change
Nicola Scafetta
Duke University, Physics Department
References:
1) N. Scafetta, “Empirical analysis of the solar
Contribution to global mean air surface temperature
change,”
Journal of Atmospheric and Solar-Terrestrial Physics
71, 1916–1923 (2009), doi:10.1016/j.jastp.2009.07.007.
http://arxiv.org/abs/0912.4319
2) N. Scafetta and R. Willson, “ACRIM-gap and
Total Solar Irradiance (TSI) trend issue resolved using
a surface magnetic flux TSI proxy model”,
Geophysical Research Letter 36, L05701, (2009).
doi:10.1029/2008GL036307.
ABSTRACT
We discuss the Total Solar Irradiance satellite composites and
show that the ACRIM/PMOD controversy is still open to further
investigation. In particular we show that TSI proxy models based
on solar surface magnetic field disprove the alterations made by
PMOD of the Nimbus record during the ACRIM gap (1989-1992).
This suggest that the TSI may have increased from 1980 to 2000
as ACRIM science team has proposed.
By using alternative TSI model we evaluate the solar contribution
to global mean air surface temperature change by using an
empirical bi-scale climate model characterized by both fast and
slow characteristic time responses to solar forcing: T1 = 0.4 +/- 0.1
yr, and T2 = 8 +/- 2 yr or T2 = 12 +/- 3 yr. Since 1980 the solar
contribution to climate change is uncertain because of the severe
uncertainty of the total solar irradiance satellite composites. The
sun may have caused from a slight cooling, if PMOD TSI
composite is used, to a significant warming (up to 65% of the total
observed warming) if ACRIM, or other TSI composites are used.
The model is calibrated only on the empirical 11-year solar cycle
signature on the instrumental global surface temperature since
1980. The model reconstructs the major temperature patterns
covering 400 years of solar induced temperature changes, as
shown in recent paleoclimate global temperature records.
Figure 1:
[A] satellite Total Solar Irradiance measurements
[B] ACRIM TSI composite , PMOD composite and a TSI
Proxy reconstruction based on surface magnetic flux.
Frohlich C., 2006, Solar irradiance variability since 1978: revision of the
PMOD composite during solar cycle 21: Space Science Reviews, v. 125, p. 53–65.
Krivova N. A., L. Balmaceda, and S. K. Solanki, 2007, Reconstruction of solar total irradiance since
1700 from the surface magnetic flux: Astronomy and Astrophysics, v. 467, p. 335-346.
Willson R. C., and A. V. Mordvinov, 2003, Secular total solar irradiance trend during solar
cycles 21-23: Geophysical Research Letters, v. 30, p. 1199-1202.
Incompatibility between
the PMOD correction of
the Nimbus7 TSI satellite
Data and the TSI proxy
reconstruction based on
magnetic
flux
by
KBS[2007]
Comparison of KBS2007 and ACRIM1 and ACRIM2
Recalibration on ACRIM1 and ACRIM2 of the TSI proxy
reconstruction based on magnetic flux by KBS[2007].
Now the TSI proxy looks like the ACRIM composite.
[A] Difference between NIMBUS7 and PMOD
TSI composite during the ACRIM gap.
[B] Comparison of WSKF06 and PMOD during
the period 1978-1980 that reveals the
existence of the TSI peak in 1979.
[C] Difference between NIMBUS7, ACRIM1 and
PMOD relative to WSKF06 with the relative
trend estimates.
[D] Difference between NIMBUS7 and PMOD
relative to KBS07 with the relative trend
estimates.
[WSK06] Wenzler T., S. K. Solanki, N. A. Krivova, and C. Frohlich (2006), Reconstruction
of solar irradiance variations in cycles 21-23 based on surface magnetic fields, Astr. And
Astrophys, 460, 583-595.
Three alternative secular TSI records constructed
by merging the TSI proxy reconstruction by
Solanki's team [Krivova et al., 2007] with the three
alternative TSI satellite composites shown in
Figure 1. (units of W/m2 at 1 A.U.)
These results disagree significant
from the empirical findings in 2C
that show a peak-to-trough
amplitude of the response to the 11year solar cycle globally to be
approximately from 0.1 to 0.4 K from
the ground to the lower
stratosphere.
[A] Monthly-mean optical thickness
at 550 nm which is associated to the
volcano signal, the 10.7cm solar flux
values, and the ENSO MEI signals
used in the regression model.
[B]Regression model against MSU
temperature records: Temperature
Lower Troposphere (TLT, MSU 2);
Temperature Middle Troposphere
(TMT, MSU 2); Temperature Lower
Stratosphere (TLS, MSU 4).
[C] Solar Signatures as predicted by
the regression model.
[D] GISS ModelE solar signature
prediction from the ground (bottom)
to the lower stratosphere (MSU4)
(top). The figure shows that GISS
ModelE simulations predict a peakto-trough amplitude of the response
to the 11-year solar cycle globally to
be approximately 0.035 to 0.05 K
from the ground to the lower
stratosphere.
[A] Comparison between an energy balance model prediction (gray) [Crowley
et al., 2000] with the `hockey stick' temperature graph by Mann et al.
[1998] (black, bottom) and a more recent paleoclimate temperature
reconstruction [Loehle and Mc Culloch, 2008] (black, top).
[B] (Top) Comparison between an energy balance model prediction (gray)
[Crowley et al., 2000] and the reconstruction by Moberg et al [2005]
(black); (Bottom) the volcano, solar and GHG+Aerosol components of the
Clowley's model are rescaled to fit the temperature record.
The solar effect on climate must be amplified by 3 and the GHG+Aer
component must be reduced by 0.4.
A climate model based on two characteristic time constants
Z(11) = 0.11 K/Wm-2 :
Z1(11) = 0.047 K/Wm-2 : Z2(11) = 0.053 K/Wm-2
Phenomenological climate model for the solar
signature on climate
against the global surface temperature record