Wednesday, May 14, 2014

New paper finds 'relatively high climate sensitivity' to tiny 0.1% changes in solar activity

A paper published in Climate Dynamics finds the climate may be highly sensitive to tiny 0.1% changes in solar activity over solar cycles, producing temperature variations of as much as 0.5 to 1.0°C at the Antarctic "Vostok" station nearest the South Pole. By way of comparison, the globe has warmed only 0.7C over the past 164 years. 

According to the authors, 
"Antarctic “Vostok” station works most closely to the center of the ice cap among permanent year-around stations. Climate conditions are exclusively stable: low precipitation level, cloudiness and wind velocity. These conditions can be considered as an ideal model laboratory to study the surface temperature response on solar irradiance variability during 11-year cycle of solar activity." 
"Using meteorological temperature record during (1958–2011) we calculated the HFD [heat flux density] variation about 0.2–0.3 W/m2 in phase with solar activity cycle. This HFD variation is derived from 0.5 to 1 °C temperature variation and shows relatively high climate sensitivity per 0.1 % of solar radiation change. This effect can be due to the polar amplification phenomenon, which predicts a similar response 0.3–0.8 °C/0.1 % (Gal-Chen and Schneider in Tellus 28:108–121, 1975)."

Climate Dynamics
May 2014, Volume 42, Issue 9-10, pp 2469-2475

Central antarctic climate response to the solar cycle

D. M. Volobuev

Antarctic “Vostok” station works most closely to the center of the ice cap among permanent year-around stations. Climate conditions are exclusively stable: low precipitation level, cloudiness and wind velocity. These conditions can be considered as an ideal model laboratory to study the surface temperature response on solar irradiance variability during 11-year cycle of solar activity. Here we solve an inverse heat conductivity problem: calculate the boundary heat flux density (HFD) from known evolution of temperature. Using meteorological temperature record during (1958–2011) we calculated the HFD variation about 0.2–0.3 W/m2 in phase with solar activity cycle. This HFD variation is derived from 0.5 to 1 °C temperature variation and shows relatively high climate sensitivity per 0.1 % of solar radiation change. This effect can be due to the polar amplification phenomenon, which predicts a similar response 0.3–0.8 °C/0.1 % (Gal-Chen and Schneider in Tellus 28:108–121, 1975). The solar forcing (TSI) is disturbed by volcanic forcing (VF), so that their linear combination TSI + 0.5VF empirically provides higher correlation with HFD (r = 0.63 ± 0.22) than TSI (r = 0.50 ± 0.24) and VF (r = 0.41 ± 0.25) separately. TSI shows higher wavelet coherence and phase agreement with HFD than VF.

3 comments:

  1. A warmist (who believes humans cause 100% of the climate) wrote this in a recent ongoing debate about the "faint sun" and how solar radiance is so weak compared to anthropogenic forcings:

    "Current variability over the 11 year solar cycle is measured at about 0.7 w/m2, while the steady forcing from anthropogenic causes is now about 2.3 w/m2 and taking averaging out the cyclic variability in the solar irradiance to get a secular trend the contribution of changes in the sun is 0.05 w/m2 (0 to .1 range).
    That's some difference.... 340 w/m2 less energy than present vs 0.05 w/m2 for current contributions from solar variability."

    Would you be willing to possibly address the different w/m2 numbers between this paper that shows very high climate sensitivity to solar variability (0.1 = 0.5 - 1 C changes) and the above statement which purports to show the sun has little to no impact compared to anthropogenic CO2?

    Also, the same person wrote this about how it is the earth's biosphere survived 2,000 to 4,000 ppm...because of the "faint, young sun"...

    "The faint young sun....the earth received about 340 w/m2 less energy than now [100s of millions of years ago], making it necessary to have 3000 ppm of CO2 in the atmosphere to keep the earth from being an iceball."

    I would really appreciate an explanation/source on how to respond to these comments. Thanks!

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  2. 1. TSI variability is 2-3W/m2 over solar cycles, not 0.7

    http://www.acrim.com/RESULTS/Earth%20Observatory/earth_obs_ACRIM_Composite.jpg

    2. Even though TSI only changes .1% over solar cycles, the spectral composition e.g. UV changes up to 100% over solar cycles and greatly affects stratospheric ozone, penetrates deeper into the ocean, etc.

    3. The proper way to determine solar forcing is accumulated anomalies, a time-integral, since the oceans are a huge lagging heat sink. The time integral of solar activity explains 95% of climate change over past 400 years

    http://hockeyschtick.blogspot.com/2013/11/the-sun-explains-95-of-climate-change.html

    4. The "steady forcing from anthropogenic causes" he claims of 2.3 W/m2 is theoretical, based upon models, based upon the false assumption of positive water feedback, etc. and is bogus.

    5. How the Faint Sun hypothesis is explained without CO2:

    http://hockeyschtick.blogspot.com/2013/01/faint-young-sun-paradox-resolved-by.html

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  3. It's been established (here) that a .1% change in solar radiance can yield a 1 C change in temperature, we could also conclude that a .01% change in solar radiance could yield a 0.1 C change in temperature.

    Below is a paper that shows there was a +0.037% change (per decade) in TSI during solar cycles 21-22 (1976-1996), which directly corresponds with the warming of that period, establishing solar forcing as an integral physical mechanism for late 20th century warming.

    http://link.springer.com/article/10.1007/s10509-013-1775-9
    Our analysis provides a first order validation of the ACRIM TSI composite approach and its 0.037 %/decade upward trend during solar cycles 21–22. The implications of increasing TSI during the global warming of the last two decades of the 20th century are that solar forcing of climate change may be a significantly larger factor than represented in the CMIP5 general circulation climate models.

    Here's another paper that establishes a connection between TSI and temperature since the 1970s.

    http://people.duke.edu/~ns2002/pdf/soon_legate.pdf
    Using thermometer-based air temperature records for the period 1850–2010, we present empirical evidence for a direct relationship between total solar irradiance (TSI) and the Equator-to-Pole (Arctic) surface temperature gradient (EPTG). Overall, evidence suggests that a net increase in the TSI, or in the projected solar insolation gradient which reflects any net increase in solar radiation, has caused an increase in both oceanic and atmospheric heat transport to the Arctic in the warm period since the 1970s.

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