Dear Dr. Holan,
I am an assistant professor at the Brooklyn College in New York and I received some questions regarding the Milankovitch cycles from a colleague of mine. Could you please help out with these questions?
Thank you in advance for considering my request.
Here are the questions:
First, I assume that to favor glaciation, the key thing is to have cool summers for 65 degrees north latitude. If this is so, then will glaciation be favored by:
1. minimum axial tilt?
2. maximum orbital eccentricity with northern summer occurring at the aphelion?
Is it correct that, on a long term basis, we should now be leaving an interglacial and entering a glacial? That is, we should be at the end of a roughly 18,000 year interglacial and about to begin a 90,000 year glacial, ignoring minor wiggles in the climate curve?
Where are we now in the three M cycles? Is our axial tilt increasing or decreasing? How eccentric is our orbit and is it increasing or decreasing in ellipticity? And is our winter solstice close to the aphelion but moving towards the perihelion?
Best regards,
Constantin Cranganu, Ph.D.
Brooklyn College
Department of Geology
2900 Bedford Ave., Brooklyn, NY 11210
tel.: 718-951-4251
fax: 718-951-4753