Climate Sensitivity Illustrations

As part of my revised Earth, Orbit and Climate presentation that I delivered at the Temecula Public Library last week, I created a sequence of illustrations showing the concept of climate sensitivity, as I understand it. These images below are not the complete sequence of climate sensitivity illustration, rather, just key points.

The first image is used to show that each doubling of CO2 produces a warming of about 1.2 degrees C. Each overlaid image doubles the CO2 on the left and the bulb level rises as the graph is drawn. Below is the final image:

Next comes the H2O feedback. I set the CO2 back to one doubling and then describe the water vapor feedback of 1.5 to 2 degrees C:

The combined CO2 and H2O are enough to change ice cover, affecting the ice-albedo feedback, shown here with a reduction of snowcover:

Then I start adding a range of feedbacks such as meltwater affecting ocean currents, CO2 fertilization and rainfall disruptions:

The final image of feedbacks is not meant to be all inclusive nor is it meant to clarify the role of each. It is meant to give the viewer an appreciation that Earth is a knot of complex, inter-related systems, each reacting to changes around it:

 And then last, I show a final climate sensitivity from the combined forcings (CO2) and feedbacks (all others), giving a final climate sensitivity of 2 to 4.5 degrees C.

Other illustrations mention that the greater uncertainty is at the high end. Then I conclude that if we double the CO2 again, we repeat this process.

As with all my projects, I welcome criticism. I hope to have my revised presentation online in a couple weeks.

jg

Earth, Orbit, and Climate Presentation and Lunar Observing, Thurs., June 28

This Thursday, the Temecula Valley Astronomers will provide an indoor presentation followed by some lunar and planetary observing at the Temecula Library. The indoor presentation begins at 6:30 and observing of the moon can begin at approximately 7:45. By 8:15, Saturn will be visible in telescopes. Observing will end before 9:00 pm when the library closes.

I will present "Earth, Orbit, and Climate." My presentation is a illustrated look how the science of astronomy contributes to our understanding of climate change. I cover the Sun, the greenhouse effect, climate sensitivity, paleoclimate data, and Earth's changing orbit. Below is a sample from the section describing the greenhouse effect.

I have given this talk to middle school students, so I hope the illustrated nature and my simplifying of concepts, makes this presentation suitable for a broad range of learners. Some graphs and technical explanations are necessary, but most will have the simplicity of the above illustration.

After the presentation, the Temecula Valley Astronomers will have a few telescopes set up for some observing of the moon and Saturn until the library closes.

jg

American Medical Association reports that night light is a health hazard

The following article describes the AMA's new policy recognizing health and safety hazards of night lighting and recommending further research:

Night Light Can Harm Your Health

jg

Great group of sunspots

It is June 16 and I'm seeing a spectacular group of sunspots. My photos were taken with a white-light solar filter at about 40 and 100x magnification. I always add a little yellow, though the sun is white. And I applied unsharp masking in Photoshop to sharpen the details.

jg

Venus Transit at Borrego Springs

On June 5, I observed and photographed the 2012 transit of Venus from Borrego Springs. Though the skies were clear, it was quite windy, so most of my photos were distorted. But of these, a few serve to tell the story of this rare siting.

This isn't first contact, but rather, first presentable photo nearest to first contact:

Below shows Venus taking a bite out of the sun:

The teardrop effect can be seen here. Though, I can't claim the effect is a genuine tear drop instead of distortion from the wind.

And another, almost teardrop effect:

A few minutes into the sun:

Here is a close-up of the anti-teardrop effect. A few of my photos at second contact (the point Venus appears fully in front of the sun's disk) showed a bulge of the sun where a teardrop shadow should be. Is it my viewing conditions or something else?

As the transit progressed, the clarity of my images got worse. As of today, I've examined only a third of the photos.

UPDATE: A few more photos added:
This one is my last clear image at this magnification:

As the sun got lower in the sky, I shortened the focal length to get a smaller image. The smaller image showed less of the atmospheric distortion:

jg

Partial report on the partial eclipse

Here are a few photos I took of the partial solar eclipse yesterday. I hope to return to my photos and carefully select the best of the set.

Partial eclipse with sunspot.

 Dappled sunlight will create pinhole projections of the sun. Here you see the tree making pinhole projections of the eclipse.

Maximum coverage from my location.

Sunset with both the horizon and the moon taking a bite out of the sun.

And after a little processing and manipulation (rotating, brighten, sharpening and noise reduction), this one is my favorite:

 

jg

Volcanoes, CO2 and Temperatures

A friend has prompted me to post for reference a couple illustrations I've created for www.skepticalscience.com on estimates of emissions of CO2 by volcanoes. It is a common belief that volcanic activity produces more atmospheric CO2 that human activity, however, research shows that in the modern era, volcanoes haven't been active enough to account for the steady rise in CO2.

The first chart compares surface temperatures by the Goddard Institute for Space Studies with atmospheric CO2 and stratospheric optical thickness, which is used as a proxy for volcanic activity.

The second illustration summarizes the conclusion of Terry Gerlach of USGS publishing in the Transactions of the American Geophysical Union: Volcanic vs Anthropogenic Carbon Dioxide, EOS, 14 June 2011).

In the above diagram, the area of the clouds correspond to the emissions of each source.
jg