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The Potential Use and Misuse of ENSO Information in North America
Michael H. Glantz
Introduction
El Niño and Society
There is considerable and growing interest in the progress that has been made since the earliest decades of this century with regard to research and understanding of El Niño-Southern Oscillation events, popularly referred to as El Niño. Research in this area began at the turn of the twentieth century with Sir Gilbert Walker's research on the Southern Oscillation, a seesaw of pressure systems across the equatorial Pacific Ocean, centered on Darwin (Australia) and Tahiti. He also identified, through a variety of statistical measures, linkages over relatively large distances, called teleconnections, between seemingly unrelated climate anomalies.
Along the coast of western South America, people had been aware of sea surface temperature changes that disrupted ecological processes, such as fish and guano-bird population dynamics. That awareness stems at least back to the early 1800s.
Jacob Bjerknes in the mid-1960s identified the physical mechanisms that linked these two phenomena --- El Niño and the Southern Oscillation. Before then, these physical processes had been treated separately. Since the mid-1960s, the research community involved in long-range forecasting has shown a constantly, if not exponentially, increasing interest in ENSO events and their teleconnections.
In 1986, a research team within the forecast community went public with an El Niño forecast in 1986, much to the chagrin of fellow researchers. Fellow researchers opposed making research forecasts public because of the uncertainties in their scientific knowledge about the phenomenon. Yet, the initial public forecast proved to be a correct one and received a great deal of attention from science reporters. By the end of the 1980s, several groups had followed suit by issuing their forecasts of ENSO. As various groups, using a variety of modeling, observational and statistical techniques, would become aware of the possibility of the onset of a warm event, they would issue forecasts; a climate applications group in NOAA's National Weather Service issues a forecast in the form of an ENSO advisory.
Considerable insight into air-sea interactions in the equatorial and extratropical regions has been gained. First of all, the ENSO events of the 1980s and early 1990s have been the most intensively observed and assessed to date. And, secondly, through the efforts of researchers involved in an international, decade-long (1985 to 1994) research and field program called TOGA (Tropical Ocean-Global Atmosphere), our understanding of ENSO has greatly improved. The end of the TOGA program is likely to be followed by another decadal-scale related research effort on interannual variability in the mid-latitude region, called GOALS (Global-Ocean-Atmosphere-Land System).
In light of recent gains in scientific knowledge of air-sea interaction in the Pacific Ocean (eg, ENSO), it is clearly time for the social science research community to become more deeply engaged in efforts to enhance the utility of existing scientific information about ENSO events by focusing not only on the physical processes of ENSO but on identifying those groups in societies in North America that can use ENSO-related information to enrich their decisionmaking capabilities with respect to their climate-sensitive activities.
Several scientific researchers have identified possible linkages between weather anomalies in North America and the occurrence of ENSO events in the central and eastern equatorial Pacific. While they do not necessarily agree with the linkages (called teleconnections) proposed by other researchers, there is an identifiable set of anomalies in North America that can provide useful information to the user community.
By user community, we are referring to both actual users of ENSO and teleconnection information (including forecasts) and potential users. The former are those who are already aware of either El Nino, the Southern Oscillation or ENSO and its possible impacts on their activities in North America or elsewhere (e.g., farming, fishing, manufacturing, transporting, human health). The latter group --- potential users --- are those whose activities could benefit from the use of such scientific information, if they were to be shown how ENSO events can affect their activities and how to use ENSO-related information in their decisionmaking processes. Awareness of and belief in the potential value of ENSO information are important first steps toward converting potential users into actual ones.
Those who write about ENSO research findings, such as science writers and reporters (among other media specialists), need to be convinced that ENSO forecasts have value for their geographic or functional regions, either directly or indirectly. The media are not only consumers of information about ENSO, but they are the potential educators of the public, including policymakers. In essence they are the creators of actual users, converting their potential into reality. But the media that reports on scientific research activities are faced with numerous constraints not the least of which is a focus on regional and local weather-relatedissues. Aside from providing general interest stories with the generic information on ENSO, they await more certainty in ENSO teleconnections research and they want it to be focused on the communities that they serve. For example, Californians want to know what an ENSO means for them, drought or floods; New Englanders want to know what it means for their region, more hurricanes or less; the Gulf states are also concerned with the possibility of increased flooding from Texas to Florida; the Pacific Northwest states are concerned about wintertime precipitation shortfalls; the Canadian Prairie farmers want to know about ENSO, for agricultural production purposes; and so forth. Each of these regional interests is not necessarily captured in the interests of other regions. This is a variation of NIMBY (Not In My Back Yard): I am not interested in writing stories about climate-related phenomena that are not directly affecting my back yard.
Users' Perceptions
The following chart was devised, based on information provided by the potential users of ENSO information in their discussion papers. The chart depicts the overriding concern about climate-related information of his or her company or agency, specific concerns, and the potential value to that specific segment of the user community of improved ENSO-related information. The information on the chart should also be treated as anecdotal information. Similar information for a variety of potential users of ENSO information and forecasts could be, however, gathered in a systematic way, providing greater insights to the ENSO research community about users' perceptions of their needs. Such information would also serve as a good starting point for meaningful dialogue between producers of ENSO-related information and the potential users of that information.
Chart of Users' ENSO-Related Concerns
Users' Needs
Various segments of the user community clearly have ideas of what they believe they need from ENSO researchers in general and forecasters, specifically. Some of these stated needs were identified in the discussion papers presented at the workshop and are listed below. Like the information on the preceding chart, the following list of needs should be treated as anecdotal information. It does not represent an attempt to identify a comprehensive list of needs of the user community.
Forecasters' Needs from Users
Users' Needs from Forecasters
Users' Needs from Users
Forecasters' Needs from Forecasters
The North American ENSO Applications Workshop
The Workshop on Usable Science II: The Use and Misuse of ENSO Information in North America was held in Boulder, Colorado, 31 October to 3 November 1994. It was designed to bring together climate impacts researchers, weather-sensitive industry representatives, physical scientists concerned with ENSO (El Niño/Southern Oscillation), media specialists and policymakers. The overriding goal of the workshop was to foster interaction between the producers of ENSO-related scientific information and the potential users of that information.
In addition to fostering discussion among these groups of interest, workshop organizers asked participants to prepare in advance of the meeting discussion papers that raised their concerns about ENSO forecasts or about what kinds of information that they needed for their activities from the ENSO research and forecast communities. These papers served as starting points for discussion and not for presentation.
In order to focus discussion on specific issues, some of the participants were asked to make presentations in order to stimulate discussion. The Workshop Agenda which follows identifies the issues that were discussed. A record of all of the discussion sessions throughout the meeting were put together into one section. Several recurrent themes were identified, and almost all of the points made in the discussion sessions were clustered under one of those themes. These are presented in the Summary Section. It is very important to note at the outset of this report that the workshop discussion sessions were designed to focus, not on the successes in the forecast system, but on identifying problems from the perspective of potential and actual users related to forecasting ENSO events and using ENSO forecasts. It is important to keep this in mind when reading the Summary of Workshop Discussions.
It became clear at the workshop that there were different, sometimes opposing, perceptions on the reliability of El Niño forecasts for local and regional level decisionmaking. While there are several views in the scientific and popular literature about how El Niño events in the equatorial Pacific affect weather patterns in various parts of North America, for most of them there is little consensus for a variety of reasons. One is that not all researchers use the same "objective" criteria for determining the onset of El Niño. Some favor monitoring the Southern Oscillation, while others favor monitoring sea surface temperatures, and so forth. There are also some differences of opinion within the scientific community about what constitutes the onset of an El Niño.
It became clear at the workshop that interest in the ENSO phenomenon has sharply increased since the onset of an event in 1991, an event that had been correctly forecast some months in advance by a few groups. Federal emergency managers, tropical fruit producers, insurance companies, humanitarian assistance agencies, water resources planners, and agricultural commodities interests have developed a healthy respect for and interest in El Niño.
Important concerns were raised for discussion, such as the following: To what extent is the increasing level of public interest in the use of El Niño forecasts appropriate to our present-day level of scientific understanding about the phemenon? Who has the responsibility to help the attentive public in determining the use such information? Who specifically are the potential users of El Niño information, including forecasts, to whom we constantly hear references?
While there are several locations around the globe where El Niño's impacts can be clearly shown to occur (i.e., Peru, Australia, Indonesia, India, Vietnam, Brazil), the strength and reliability of teleconnections to North American weather patterns remain less clear. Nevertheless, it is not difficult to show how information about ENSO events and their proposed North American teleconnections does provide decisionmakers in various sectors of society with enough information to "hedge their bets."
In 1966, when he was on the verge of identifying linkages between sea surface temperature changes and sea level pressure changes in the equatorial Pacific Ocean, Bjerknes made the following projection:
Although this primary triggering may remain obscure, a close watch of the temperature anomalies arising over the eastern tropical Pacific is likely to play an important part in future seasonal forecasting of climate anomalies over North America, and even over Europe.(1)
1.J. Bjerknes, 1966: A possible response of the atmospheric Hadley calculations to equatorial anomalies of ocean temperatures. Tellus, 18(4), 820-829.
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