Global Warming (and cooling 20 years ago)

Hello Radsafers:

This is from: jpreisig@aol.com .

This e-mail concerns the message sent by W. Prestwich which said:

"As regards predictions, aren't the folks who now warn us about global

warming the same ones who predicted global cooling some twenty years

ago."

That's a very nice thought, W. Prestwich. There may be geophysical

phenomena which cause the global warming and cooling to happen. (I've

written previous messages to radsafe which explain these phenomena at

greater length). In addition to the Earth's daily spin, there are longer

period polar motions, which are commonly termed Earth wobbles. The primary

wobbles are an annual wobble and a roughly 14 month wobble called the

Chandler Wobble. A geometric axis attached to the Earth (say the North

pole) wobbles with respect to the Earth's spin axis (and the angular momentum

axis of the Earth). The annual wobble and Chandler wobble have sum and

difference frequencies, and create a "beating" phenomena (see your mechanics,

i.e. physics , book for information about beating, etc.) of the wobble

amplitude. Basically the wobble amplitude increases and decreases

in a sinusoidal manner. The wobble amplitude maxima have occurred in

roughly 1910, 1954 and 1998. From 1954 to roughly 1976, the wobble

amplitude was decreasing (thus generating the observed global cooling) and

from roughly 1976 to 1998 the wobble amplitude was increasing (thus

generating the global warming). This would explain what you are talking

about.

So, I guess what I am saying, is some part of the global warming (and

some

part of the earlier global cooling) are due to the beating of the two wobble

frequencies. I don't think these phenomena are being modelled into

global warming data. I will not say that other global warming phenomena

don't exist. Good references on the Earth's wobble are a book by Munk and

MacDonald and several more recent books by Kurt Lambeck.

Regards, J.R. Preisig, Ph.D.

************************************************************************

You are currently subscribed to the Radsafe mailing list. To unsubscribe,

send an e-mail to Majordomo@list.vanderbilt.edu Put the text "unsubscribe

radsafe" (no quote marks) in the body of the e-mail, with no subject line. You can view the Radsafe archives at http://www.vanderbilt.edu/radsafe/