Cirrus Cloud and the 1997/1998 El Nino

One assertion made by Erl Happ’s theory of climate is that changes in cirrus cloud cover create tropical warming events (El Ninos).  Cirrus cloud is a cause of albedo, reflecting sunlight back into space.  Therefore, less cirrus cloud would lead to a warming event, while more cirrus cloud would lead to a cooling event.

After a lot of searching, I finally found this site: http://isccp.giss.nasa.gov/products/browsed2.html.

It is run by the International Sattelite Cloud Climatology Project, which describes itself:

“The International Satellite Cloud Climatology Project (ISCCP) was established in 1982 as part of the World Climate Research Program (WCRP) to collect weather satellite radiance measurements and to analyze them to infer the global distribution of clouds, their properties, and their diurnal, seasonal and interannual variations. The resulting datasets and analysis products are being used to study the role of clouds in climate , both their effects on radiative energy exchanges and their role in the global water cycle.

I have two pictures to show you, and they have something in common.

My point in showing the second image is that the behavior of cirrus clouds in the Pacific during October of 1996 is identical to changes in temperature seen in the Pacific during an El Nino.

This similarity between cirrus cloud and temperature trends (with the 97/98 El Nino) illustrates that cirrus cloud cover and sea surface temperature might be closely related.  Yet, we can go a step farther.  Below is a graph of sea surface temperature in the region in the Pacific that I have used before and with no smoothing.  This graph should show the first indications of an El Nino.

Note that the El Nino does not start until the first month of 1997.  This means that the decrease in cirrus cloud cover that was so consistent with sea surface temperature trends during El Ninos occured three months before the El Nino began!

The big question to answer now is this: Was the decrease in cirrus cloud responding to atmospheric changes related to the El-Nino that preceded the actual sea surface temperature rise?  Or was the El Nino responding to the decrease in cirrus cloud?

Erl Happ’s theory is truly a theory of climate and not just “global warming”; it is a way of describing terrestrial temperature trends, and it does so very well.  Some steps of the theory require more evidence than others, so I’ll continue posting as I try to confirm the various steps.

UPDATE: Backtracking….

After looking at more months and more years, it seems that the region in the Pacific of varying cirrus cloud cover always holds the same shape (with decreased cirrus cloud) as an El Nino SST trend does for some circulation-related reason during the months July through January.  Here’s a graph of the mean cirrus cloud cover for October (1983-2006).

With that said, my Oct 1996 map does hold somewhat more of a clear El Nino shape, though not significantly.  This does not mean that there is no correlation; it just means that this is more complex than I assumed when I made the post because I will have to take into account monthly means when looking for an El Nino signature.

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One Response to “Cirrus Cloud and the 1997/1998 El Nino”

  1. Chris M. Says:

    Good job, it was helpful for my Earth and Space homework.

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