Sunday, October 24, 2010

Orbital forcing 135 kya

I'm building a viewer that will show orbital configurations with climate data from the Vostok ice core (and from other sources when I get to them). Below is an orbital configuration from 135 kya. Assuming I've reconstructed this time correctly, it shows an orbital configuration that puts the solstices at right angles to the Earth's semi-major axis (blue line connecting perihelion to the sun). Such a configuration should cancel out the effect of eccentricity, an effect that can heat the hemispheres unequally. In this configuration, no hemisphere gets its peak summer at perihelion, where it would otherwise get significantly more solar energy. Notice how the insolation graphs of 60 degrees N and 60 degrees South cross at this time. Click the illustration to enlarge it.

I'm sharing for the fun of learning about climate, especially the astronomical component of Earth's glacial and interglacial phases. This illustration is an elaboration of one used in my Earth, Orbit, and Climate presentation, which I've recently updated. I claim no scientific credentials; just an enthusiasm to learn and share, while inviting criticism.

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