Severe Fire Seasons Research Articles

Florida wildfire activity and atmospheric teleconnections

Since 1991, the Florida Division of Forestry has been making seasonal fire severity forecasts based on a relationship between area burned in Florida and El Niño–Southern Oscillation (ENSO). The present study extends the original analysis on which these forecasts are based and attempts to augment it with the addition of other patterns of climate variability. Two atmospheric teleconnection patterns, the North Atlantic Oscillation and Pacific–North American pattern, are examined as potential indicators of seasonal and monthly area burned in Florida. Although ENSO was the only climate index to show a significant correlation to area burned in Florida, the Pacific–North American pattern (PNA) is shown to be a factor influencing fire season severity although the relationship is not monotonic and therefore not revealed by correlation analysis.

Ozone-CO Correlations in Siberian Wildfire Plumes Observed at Rishiri Island

We used ozone (O3) and carbon monoxide (CO) measurements conducted at Rishiri Island, a remote surface site located in northern Japan to characterize impacts of boreal forest fires in Siberia on photochemical O3 formation. Hourly O3 observations during severe fire seasons in 1998, 2002, and 2003 were examined based on large enhancement in the CO mixing ratios and backward trajectories. In total, we identified sixteen episodes impacted by Siberian biomass burning. Correlations of O3 to CO in individual plumes were significant in eight wildfire plumes. The relative enhancement of O3 to CO quantified in these fire plumes ranged from slightly negative to up to ∼0.4, depending on episodes. Two episodes in 2002 and 2003 suggested that O3 formation in wildfire-polluted plumes was comparable to the magnitude typically observed in industrially-polluted air masses from the Asian continent. Possible physical, chemical, and biogeochemical factors leading to different O3 to CO ratios were presented.

Statistical Model for Forecasting Monthly Large Wildfire Events in Western United States

Abstract The ability to forecast the number and location of large wildfire events (with specified confidence bounds) is important to fire managers attempting to allocate and distribute suppression efforts during severe fire seasons. This paper describes the development of a statistical model for assessing the forecasting skills of fire-danger predictors and producing 1-month-ahead wildfire-danger probabilities in the western United States. The method is based on logistic regression techniques with spline functions to accommodate nonlinear relationships between fire-danger predictors and probability of large fire events. Estimates were based on 25 yr of historic fire occurrence data (1980–2004). The model using the predictors monthly average temperature, and lagged Palmer drought severity index demonstrated significant improvement in forecasting skill over historic frequencies (persistence forecasts) of large fire events. The statistical models were particularly amenable to model evaluation and production of probability-based fire-danger maps with prespecified precisions. For example, during the 25 yr of the study for the month of July, an area greater than 400 ha burned in 3% of locations where the model forecast was low; 11% of locations where the forecast was moderate; and 76% of locations where the forecast was extreme. The statistical techniques may be used to assess the skill of forecast fire-danger indices developed at other temporal or spatial scales.

A simulation model of the growth and suppression of large forest fires in Ontario

Most of the area burned by forest fires in Canada is due to the few fires that escape initial attack and become large. We developed a discrete event simulation model of the growth and suppression of large fires in the province of Ontario. Based on fire, weather and suppression data from the Ontario Ministry of Natural Resources, our model includes a logistic regression component to predict the probability that a fire will escape initial attack and burn more than 100 ha, a component that simulates the growth of large fires based on weather and forest vegetation, and a component that simulates fire suppression by firefighters and aircraft. We used our model to predict area burned under mild and severe weather with varying levels of fire suppression resources. We found that, although severe weather limits fire suppression effectiveness, suppression has a significant effect on area burned even during severe fire seasons.

Forest fires in cork oak (Quercus suber L.) stands in Portugal

Fire and cork can be considered both the most serious problem and the most valuable resource of Portuguese forests. The existence of important areas of burned cork oak stands resulting from severe fire seasons in recent years is an environmental problem which deserves special attention. This paper makes a multidisciplinary survey of the problem of burned cork oak stands focusing on: the dimensions of the problem in Portugal, the remarkable resistance of cork oak to fire, the post‐fire management of cork oak stands, and the economic and ecological effects of fire in cork oak stands. Particular emphasis is given to knowledge gaps in this context.

Climate and Wildfire in the Western United States

Abstract A 21-yr gridded monthly fire-starts and acres-burned dataset from U.S. Forest Service, Bureau of Land Management, National Park Service, and Bureau of Indian Affairs fire reports recreates the seasonality and interannual variability of wildfire in the western United States. Despite pervasive human influence in western fire regimes, it is striking how strongly these data reveal a fire season responding to variations in climate. Correlating anomalous wildfire frequency and extent with the Palmer Drought Severity Index illustrates the importance of prior and accumulated precipitation anomalies for future wildfire season severity. This link to antecedent seasons' moisture conditions varies widely with differences in predominant fuel type. Furthermore, these data demonstrate that the relationship between wildfire season severity and observed moisture anomalies from antecedent seasons is strong enough to forecast fire season severity at lead times of one season to a year in advance.

Wildfire: A Reader

Review: Wildfire: A Reader By Alianor True (Ed.) Reviewed by Mary Sue Rose Sheldon Jackson College, Alaska, USA Alianor True (Ed.). Wildfire: A Reader. Washington, DC: Island Press, 2001. 248 pp. ISBN 1-55963-907-5 (paperback) US$17.95. Recycled, acid-free paper. The questions rage on. Set fires? Fight fires? Let fires burn without intervention? Scientists and environmentalists have been arguing for years about wildfire management. Editor Alianor True, nature writer and firefighter, has gathered an informative and extremely readable collection of essays and book segments on wildfire. Drawing from 24 sources, True brings together thinking on wildfire, beginning with fire tales from the voices of Native Americans up to modern voices experiencing the severe fire season of 2000 in the United States. Thinking about wildfire management continues to evolve and this book captures the evolution. It is organized around shifts in thinking on wildfire management. Because both ancient and modern fires play a defining role in history, writers throughout the ages have attempted to convey the power, beauty, terror, and changes wrought by fire. All of these aspects are captured by the selections. Part I: Big Country, Big Fires includes, in addition to Native American tales, excerpts by Meriwether Lewis, Washington Irving, Henry David Thoreau, John Muir, Mark Twain, and Stephen J. Pyne. Part II: Of Fire and Landscape covers the time period from the mid-1920s through the mid-1980s when the way Americans related to the environment changed radically. The wilderness was no longer considered untamable. Dams, pesticides, and widespread fire suppression were the norm. Economic values prevailed. Writings included in this middle section of the book are by Aldo Leopold, Norman Maclean, Margaret Millar, Roger Caras, Edward Abbey, and Ed Engle. Illustrative of the power captured by True is an excerpt chosen from Panther by Roger Caras. The fire, only minutes old, had already consumed millions of lives, billions upon billions, really if the insects were included. Small pools had been sucked dry in seconds as the fire passed overhead. With a sizzling, snapping sound, water vanished and the mud curled and cracked and turned ash-gray. Birds rising late from grassy hides were snatched up by the heat and smashed to the ground, where they kicked convulsively for a second or

Climate change and forest fires

This paper addresses the impacts of climate change on forest fires and describes how this, in turn, will impact on the forests of the United States. In addition to reviewing existing studies on climate change and forest fires we have used two transient general circulation models (GCMs), namely the Hadley Centre and the Canadian GCMs, to estimate fire season severity in the middle of the next century. Ratios of 2×CO 2 seasonal severity rating (SSR) over present day SSR were calculated for the means and maximums for North America. The results suggest that the SSR will increase by 10–50% over most of North America; although, there are regions of little change or where the SSR may decrease by the middle of the next century. Increased SSRs should translate into increased forest fire activity. Thus, forest fires could be viewed as an agent of change for US forests as the fire regime will respond rapidly to climate warming. This change in the fire regime has the potential to overshadow the direct effects of climate change on species distribution and migration.

Contextual algorithm adapted for NOAA-AVHRR fire detection in Indonesia

A widely cited contextual algorithm for fire pixel detection was applied to NOAA-AVHRR data of Indonesia acquired during the severe fire season of 1997. The contextual algorithm tended to underestimate the number of fire pixels. Many fire pixels which could be identified visually in AVHRR band 3 imagery were missing in the output of the contextual algorithm. Through experimentation with the data. the authors were able to developed two alterations to the original algorithm to enhance the accuracy of fire detection in the Indonesian context. The enhanced algorithm was made capable of detecting fire pixels that the original algorithm failed to identify.

Bushfire Disasters in Australia, 1945–1975

SUMMARY Conflagrations occur whenever there is a favourable combination of fuel, weather and ignition source and may be disastrous when human resources are affected; the role of these factors in past conflagrations is discussed. Some of the most severe fire seasons and the major fires between 1945 and 1975 are discussed briefly with reference to the areas burnt and the losses of life and property. While past disaster fires have been quite variable a common characteristic is that the period when the fire exhibits violent behaviour and when most damage occurs is relatively short (generally less than 8 hours) although these periods can recur in close succession. The frequency of large fires has been used to delineate fire-hazardous areas; the frequency ranges from once every 3 years in coastal districts of New South Wales and eastern Victoria to less than once every 30 years in central Australia. Likely changes in the patterns of large fire frequency and in the nature and intensity of disaster fires are discussed. Forest fires are likely to decrease in frequency and intensity but rural fires may become more destructive in the future.

Hours of Sunshine and Fire Season Severity over the Vancouver Forest District

The accumulated hours of bright sunshine provide a simple index of fire season severity for the southern coastal area of British Columbia. This index, based on the period May 1 to August 31, is highly correlated with the annual acreage burned over the Vancouver Forest District.By removing that part of the year-by-year deviation in area burned which can be attributed to variations in this weather index, it is possible to see more clearly the effects of other controls on the annual fire load.The existence of appreciable fluctuations of summer sunshine over periods of the order of decades would suggest that 10-year averages of fire statistics are not long enough to be independent of the effects of weather.