The Groundhog Oscillation: Evidence of Global Change

The following is an article from the Annals of Improbable Research.

by Andrew J. Gerrard,* Christina M. Gerrard,* Mark A. London,* Keith A. Soldavin,* Timothy J. Kane,* and Alan Freed**

*The Pennsylvania State University, University Park, Pennsylvania, **Ambridge, Pennsylvania

Figure 2. Phil (Image Credit: Flickr user pennstatelive)

There is a fierce debate about whether the earth's climate is changing. In this paper we describe an overlooked -- but reliable -- remote sensing instrument that can provide crucially pertient information. We also describe an extensive long-term data set that was obtained by using the instrument.

A Shadowy Observer

Every year on Groundhog Day (February 2), Phil the groundhog emerges from his burrow in Punxsutawney, Pennsylvania, after a long winter's sleep. Legend has it that if Phil sees his shadow (that is, if Groundhog Day is sunny), he dives back into his burrow, because he knows that there will be six more weeks of winter. If Phil doesn't see his shadow (that is, if the Groundhog Day is cloudy), he (and his adoring public) expect spring to arrive early.

By analyzing the more-than-century-long record of Phil's observations of his shadow, we discovered that there has been a dramatic change in the data pattern over the past two decades. We speculate that this new pattern, which we call the "Groundhog Oscillation," is evidence that the global climate is indeed changing.

This new pattern also suggests that mankind should pay closer attention to what our furry friends are telling us.

The Climate Change Question: Some Background

The scientific community has for many years been investigating the question of climate change. The main objectives have been (a) to prove or disprove the existence of global-scale climate change; (b) to understand the nature and implications of such change if it is occurring; and (c) to determine the extent to which such change occurs anthropogenically (i.e., by the actions of human beings).

 Figure 1. The Arctic Oscillation (AO) Index, as reproduced from Thompson et al. [2000]. The thin black line is the JFM seasonal mean, while the thick black line is a 5 year running mean. It has been suggested that the trend displayed in the 1980's and 1990's is evidence of climatic change.

After much research and careful data analysis, most of the scientific community now accepts that the global climate (as measurable in aspects such as air temperature patterns, sea-surface temperature and pressure patterns, atmospheric composition, etc.) has been changing significantly over the past hundred years. (It should be noted that, as with all scientific and other questions, there are a few scientists who strongly disagree.)

The changes have apparently been increasing in magnitude during recent decades. One such change has been evident in the past twenty years' values of the so-called "Arctic Oscillation (AO) Index" (see Thompson et al., 2000 for a detailed explanation). The effect is shown graphically in Figure 1. Related research has also suggested potential global change signatures in the Earth's middle and upper atmosphere. Studies involving data obtained from ice core samples, tree rings, and even jellyfish populations reveal similar climatic trends.

However, there is inherent difficulty in doing climate research. This is due to many factors, including the variance that is induced by daily weather activity and that related to local climatological variability. There is continued need for further analysis on temporally long data sets obtained by suitable instrumentation. The instrument we describe here -- Phil -- appears to offer significant advantages over the better-known alternatives.

Instrumentation and Observations

The observations made on Groundhog Day of most every year for over a century have recorded whether Punxsutawney Phil (Marmota monax, also known as the groundhog, woodchuck, or whistle-pig; see Figure 2) "sees" or "does not see" his shadow. Thus, the data represents a series of binary events.

Phil's observations are ideal for global change studies, for a number of reasons:

* There is a temporally long baseline of measurements, extending back to approximately 1888.
* The instrument (Phil) is relatively cheap to maintain (though at times a bit hazardous to an untrained operator).
* The instrument does not require the unnecessary expense of being satellite or rocket borne (nor the further expense that would entail in complying with other standards (PETA, OSHA, etc.).
* The instrument operates at middle latitudes, where upkeep and maintenance are considerably cheaper than at equatorial or high latitudes.
* No (extensive) additional funding is required to maintain the instrument. Public donations and support are nearly sufficient to fund the entire operation (especially with the recent added support due to Phil's Hollywood movie career, which consisted of a starring role alongside Bill Murry and Andie McDowell in the film Groundhog Day).
* The instrument is robust, light (less than 20 lbs.), small (< 3 cubic ft.), and relatively attractive.

 Figure 3. Phil's observations over the past approximately 100 years. Note the dramatic change (i.e., relatively consistent to highly oscillating) in "observation pattern" in recent years. This change is what we refer to as the Groundhog Oscillation (GO). (Image credit: Nerch via Wikipedia)

Data Analysis

Phil's observations are depicted graphically in Figure 3. Note that in many of the years prior to 1975, Phil saw his shadow. In those years Phil retreated into his burrow, where he rode out a minimum of six subsequent additional weeks of winter (i.e., there were long winters throughout most of the early and mid 1900's).

In the early 1980s the reported values began varying greatly from year to year. During this period there was roughly an equal chance of Phil seeing his shadow or not seeing his shadow. This new high variability is strikingly different than the relatively consistent values observed in earlier decades. We have given a name to this new, strong, persistent oscillation: the Groundhog Oscillation (or GO, after the AO above).

Discussion and Conclusions

The Groundhog Oscillation is convincing evidence of climate change. This finding is consistent with those of other recent studies. Compare Figure 3 with Figure 1 to see one instance of this.
This raises a number of intriguing questions. Perhaps the most puzzling is this: How is this phenomenon -- the GO - related to sea-surface changes? Phil is normally landlocked in west-central Pennsylvania, so the connection must be complex, and therefore fascinating.

To make further progress in understanding global climate change, we must initiate additional, widespread groundhog observation programs (each calibrated by Phil, of course). In the interest of science, we must place groundhogs at each weather observing station worldwide. Only thus can we obtain and analyze the complete set of data we need to understand global climate change.

It has not escaped our attention that, in Phil, we have discovered a key for easing tensions over politically touchy scientific questions. All the world loves a furry, cute scientific instrument.

(Image credit: Flickr user Jimmy Emerson)


The authors thank CG, Punxsutawney Phil, and the Inner Circle for their contributions to this research endeavor. Information on Phil, including his observations, can be obtained at the Punxsutawney Groundhog Club.


"Annular Modes in the Extratropical Circulation, Part II: Trends" D. W. Thompson, J., J. M. Wallace, and G. C. Hegerl, Journal of Climate, vol. 13, 2000, pp. 1018-1036.


This article is republished with permission from the Jan-Feb 2001 issue of the Annals of Improbable Research. You can download or purchase back issues of the magazine, or subscribe to receive future issues. Or get a subscription for someone as a gift! Visit their website for more research that makes people LAUGH and then THINK.

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