Big Bear Solar Observatory

1
Big Bear Solar Observatory

• Philip R. Goode
• Big Bear Solar Observatory
• New Jersey Institute of Technology

2

• Irradiance Changes
• Blue curve is solar cycle
• Red curve adds purported long-term variation
• Temperature changes from NCAR model
• Yellow line limit from physics of irradiance
  change

3
Origin of Suns Variable Output

• Seismic data from SoHO/MDI provide most precise
  measure of solar variability
• Physical picture is that rising solar activity
  blocks heat and convective flows, while
  corregating the solar surface making it a more
  effective radiator
• Active sun is cooler, corregated, slightly
  smaller and more irradiant
• Inactive sun is warmer, smoother, slightly larger
  and minimally irradiant

4
Implications of Limit

• Earth is responding to more subtle changes in
  Sun, which imprint the solar cycle and longer
  term wanderings of solar activity
• Changes in solar wind induces some unknown
  changes at the Earth
• A new burden on the climate models

5
Can Earths Reflectance Increase while Earth
Warms?

• Earthshine and other results point to an
  increasing reflectance over the past five years,
  which reverses a fifteen year trend of decline
• Taken in isolation, less sunlight would imply a
  reversal of global warming
• Recently updated NASA ISCCP data reveal a change
  in clouds, so both reduced sunlight and increased
  global warming are possible
• Results also confirm earlier Earthshine results
  of an increasing Earth albedo

6
Cloud Amount Distribution

• Cloud Amount from ISCCP
• Five year Bands of higher clouds (red) and lower
  clouds (blue)
• Unexplained change in last five years

7
Earths Reflectance in Time

• Earthshine (blue)
• Regression from ES and ISCCP (shaded area)
• Global reflectance from reconstruction
• Global warming since 1850 (red)

8
Earthshine Plus ISCCP Conclusions

• Earths Reflectance has increased over the last
  five years
• Clouds have re-arranged themselves in the same
  period so that their net cooling effect is
  reduced.
• Earth can warm with less sunlight