Extended Abstract (80K)8.7
The Analysis of the Haines Index Climatology for the Eastern United States, Alaska, Hawaii, and Puerto Rico
Paul J. Croft, Jackson State University, Jackson, MS; and M. Watts, B. E. Potter, and A. Reed
Abstract
Since the Haines Index (HI) was introduced in 1988, it has been used as a tool to aid fire managers with their decision-making in assessing fire risk. The HI is a lower atmospheric severity index for wildfire severity (growth potential) based upon environmental lapse rates and moisture. The index values range from 2 to 6 depending on weather conditions. The lower value represents conditions that are generally not favorable for fire growth while the higher value represents conditions more conducive to fire growth. Low atmospheric stability and lack of moisture can promote the spread and intensity of fires by increasing the height and strength of the smoke columns, chance of causing spotting, fire whirls and dust devils, and other convective, or uplifting winds at the surface that affect fire behavior. The HI is a quick and easy way to combine two important variables into one simple value as a measure of atmospheric stability and dry air. However, the HI has little value for nighttime operations because the reports are only valid around the time of the weather balloon soundings, 00Z and 12Z. It does not take into account fuel moisture and is not a component of the National Fire Rating System or the Fire Behavior Prediction System. The Haines Index Climatology for the Western United States has been examined/refined by Werth and Werth. It established a more detailed high-elevation HI based upon upper air data. In the present study, The Analysis of the Haines Index Climatology for the Eastern United States, Alaska, Hawaii, and Puerto Rico has been examined at low, mid, and high elevations. HI parameters, averages, and relevant statistics were obtained using C++ and spreadsheet analysis. HI files for 00Z and 12Z and mixing depth will be summarized using spreadsheet analysis and histograms, bar graphs, etc. The climatology will include the frequency of occurrence of HI values (2 to 6) and address the typical patterns displayed by the HI. The frequency distribution for the components (lapse rate and moisture) will be examined for spatial variations. The observations will also help determine if the 1200Z values can provide more advance notice of pending fire risk than the 0000Z values. The index will help provide aid to fire managers in their decision-making in assessing wildland fires.
Session 8, Fire Danger Indexes: Continued
Thursday, 15 November 2001, 3:20 PM-5:00 PM
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