Research Database
Displaying 41 - 60 of 106
Smoke-weather interaction affects extreme wildfires in diverse coastal regions
Year: 2023
Extreme wildfires threaten human lives, air quality, and ecosystems. Meteorology plays a vital role in wildfire behaviors, and the links between wildfires and climate have been widely studied. However, it is not fully clear how fire-weather feedback affects short-term wildfire variability, which undermines our ability to mitigate fire disasters. Here, we show the primacy of synoptic- scale feedback in driving extreme fires in Mediterranean and monsoon climate regimes in the West Coast of the United States and Southeastern Asia. We found that radiative effects of smoke aerosols can modify near…
Publication Type: Journal Article
Examining the influence of mid-tropospheric conditions and surface wind changes on extremely large fires and fire growth days
Year: 2023
Background: Previous work by the author and others has examined weather associated with growth of exceptionally large fires (‘Fires of Unusual Size’, or FOUS), looking at three of four factors associated with critical fire weather patterns: antecedent drying, high wind and low humidity. However, the authors did not examine atmospheric stability, the fourth factor. Aims: This study examined the relationships of mid-tropospheric stability and dryness used in the Haines Index, and changes in surface wind speed or direction, to growth of FOUS. Methods. Weather measures were paired with daily…
Publication Type: Journal Article
Lightning-Ignited Wildfires in the Western United States: Ignition Precipitation and Associated Environmental Conditions
Year: 2023
Cloud-to-ground lightning with minimal rainfall (“dry” lightning) is a major wildfire ignition source in the western United States (WUS). Although dry lightning is commonly defined as occurring with <2.5 mm of daily-accumulated precipitation, a rigorous quantification of precipitation amounts concurrent with lightning-ignited wildfires (LIWs) is lacking. We combine wildfire, lightning and precipitation data sets to quantify these ignition precipitation amounts across ecoprovinces of the WUS. The median precipitation for all LIWs is 2.8 mm but varies with vegetation and fire characteristics…
Publication Type: Journal Article
Hydrological and Meteorological Controls on Large Wildfire Ignition and Burned Area in Northern California during 2017–2020
Year: 2023
This study examined the hydrological/meteorological controls on large wildfires > 10,000 acres (40.5 km2) during 2017–2020 in Northern California at spatial and temporal scales of the target wildfires’ occurrence or growth. This study used the following simple indices for analysis: Moisture Deficit Index (MDI) computed by dividing vapor pressure deficit by soil moisture, MDIWIND computed by multiplying MDI by horizontal wind speed, and MDIGUST computed by multiplying MDI by wind gust speed. The ignition location MDIWIND and MDIGUST showed larger values on the ignition date in fire-years…
Publication Type: Journal Article
Disaster preparedness and community helping behaviour in the wake of the 2020 Oregon wildfires
Year: 2023
Extreme weather events are increasing in frequency and severity owing to climate change. Individual-level behavioural responses—notably, disaster preparedness and community helping actions (such as donating and volunteering)—supplement government efforts to respond to such phenomena, but rarely have they been explored together. Using data from a survey administered soon after the 2020 Oregon wildfires, this paper compares a range of socio-demographic, experiential, attitudinal, and communication-related factors associated with these two individual-level behavioural responses. Findings…
Publication Type: Journal Article
Landscape‑scale fuel treatment effectiveness: lessons learned from wildland fire case studies in forests of the western United States and Great Lakes region
Year: 2023
Background Maximizing the effectiveness of fuel treatments at landscape scales is a key research and management need given the inability to treat all areas at risk from wildfire. We synthesized information from case studies that documented the influence of fuel treatments on wildfire events. We used a systematic review to identify relevant case studies and extracted information through a series of targeted questions to summarize experiential knowledge of landscape fuel treatment effectiveness. Within a larger literature search, we identified 18 case study reports that included (1) manager…
Publication Type: Journal Article
Summer and Fall Extreme Fire Weather Projected to Occur More Often and Affect a Growing Portion of California throughout the 21st Century
Year: 2022
Annual burned area has increased in California over the past three decades as a result of rising temperatures and a greater atmospheric demand for moisture, a trend that is projected to continue throughout the 21st century as a result of climate change. Here, we implement a bias-correction and statistical downscaling technique to obtain high resolution, daily meteorological conditions for input into two fire weather indices: vapor pressure deficit (VPD) and the Canadian Fire Weather Index System (FWI). We focus our analysis on 10 ecoregions that together account for the diverse range of…
Publication Type: Journal Article
Extreme Winds Alter Influence of Fuels and Topography on Megafire Burn Severity in Seasonal Temperate Rainforests under Record Fuel Aridity
Year: 2022
Nearly 0.8 million hectares of land were burned in the North American Pacific Northwest (PNW) over two weeks under record-breaking fuel aridity and winds during the extraordinary 2020 fire season, representing a rare example of megafires in forests west of the Cascade Mountains. We quantified the relative influence of weather, vegetation, and topography on patterns of high burn severity (>75% tree mortality) among five synchronous megafires in the western Cascade Mountains. Despite the conventional wisdom in climate-limited fire regimes that regional drivers (e.g., extreme aridity, and…
Publication Type: Journal Article
Community Engagement With Proactive Wildfire Management in British Columbia, Canada: Perceptions, Preferences, and Barriers to Action
Year: 2022
Wildfires in the wildland-urban interface (WUI) are increasingly threatening lives and livelihoods. These growing impacts have prompted a paradigm shift toward proactive wildfire management that prioritizes prevention and preparedness instead of response. Despite this shift, many communities remain unprepared for wildfires in the WUI due to diverse individual and social-political factors influencing engagement with proactive management approaches. The catastrophic fire seasons of 2017, 2018, and 2021 in British Columbia (BC), Canada, highlighted just how vulnerable communities continue to be…
Publication Type: Journal Article
Engagement in local and collaborative wildfire risk mitigation planning across the western U.S.—Evaluating participation and diversity in Community Wildfire Protection Plans
Year: 2022
Since their introduction two decades ago, Community Wildfire Protection Plans (CWPPs) have become a common planning tool for improving community preparedness and risk mitigation in fire-prone regions, and for strengthening coordination among federal and state land management agencies, local government, and residents. While CWPPs have been the focus of case studies, there are limited large-scale studies to understand the extent of, and factors responsible for, variation in stakeholder participation—a core element of the CWPP model. This article describes the scale and scope of participation in…
Publication Type: Journal Article
Contrasting the role of human- and lightning-caused wildfires on future fire regimes on a Central Oregon landscape
Year: 2021
Climate change is expected to increase fire activity in many regions of the globe, but the relative role of human vs. lightning-caused ignitions on future fire regimes is unclear. We developed statistical models that account for the spatiotemporal ignition patterns by cause in the eastern slopes of the Cascades in Oregon, USA. Projected changes in energy release component from a suite of climate models were used with our model to quantify changes in frequency and extent of human and lightning-caused fires and record-breaking events based on sizes of individual fires between contemporary (2006…
Publication Type: Journal Article
Episodic occurrence of favourable weather constrains recovery of a cold desert shrubland after fire
Year: 2021
1. Key to the long-term resilience of dryland ecosystems is the recovery of foundation plant species following disturbance. In ecosystems with high interannual weather variability, understanding the influence of short-term environmental conditions on establishment of foundation species is essential for identifying vulnerable landscapes and developing restoration strategies. We asked how annual environmental conditions affect post-fire establishment of Artemisia tridentata, a shrub species that dominates landscapes across much of the western United States, and evaluated the influence of…
Publication Type: Journal Article
The "strings attached" to community difference and potential pathways to fire adaptiveness in the wildland urban interface
Year: 2021
This article identifies specific social characteristics in two wildland urban interface communities that may have significant impacts on the ability of those communities to adapt to wildfire. Researchers used a mixed-methods approach to triangulate results to identify potential views and motives surrounding three important behaviors and values related to crafting potential strategies to mitigate wildfire risk. The analysis of quantitative data in the form of responses to Likert-type questions and qualitative data in the form of responses to questions asked during focus group sessions yielded…
Publication Type: Journal Article
Existing Improvements in Simulation of Fire–Wind Interaction and Its Effects on Structures
Year: 2021
This work provides a detailed overview of existing investigations into the fire–wind interaction phenomena. Specifically, it considers: the fanning effect of wind, wind direction and slope angle, and the impact of wind on fire modelling, and the relevant analysis (numerical and experimental) techniques are evaluated. Recently, the impact of fire on buildings has been widely analysed. Most studies paid attention to fire damage evaluation of structures as well as structure fire safety engineering, while the disturbance interactions that influence structures have been neglected in prior studies…
Publication Type: Journal Article
Recovering & rebuilding from Oregon's 2020 wildfires
Year: 2021
The recovery requires an “all-hands-on-deck” approach to meet people where they are, assess their needs, and work collaboratively for the best solutions in each community. In addition, it will be critical to listen to individuals in communities to gain a deep understanding of barriers and needs.
Publication Type: Government Report
Put Fire to Work
Year: 2020
Put Fire to Work is a prescribed fire outreach toolkit for partners and practitionersin Washington and the Pacific Northwest. We invite you to explore, engage and collaborate, and play an active role in bringing good fire back home. This has been put together by the Washington Prescribed Fire Council in collaboration with numerous partners. It has several tools and resources for communication with public and partners about prescribed fire.
Publication Type: Website
The hot-dry-windy index: A new tool for forecasting fire weather
Year: 2020
Accurate predictions of how weather may affect a wildfire’s behavior are needed to protect crews on the line and efficiently allocate firefighting resources. Since 1988, fire meteorologists have used a tool called the Haines Index to predict days when the weather will exacerbate a wildfire. Although the Haines Index is widely believed to have value, it never received rigorous testing on the line. Even Don Haines, the U.S. Forest Service meteorologist who developed the index, has said the Haines Index needs further refinement. Recognizing that a new fire weather prediction tool was needed, a…
Publication Type: Report
Weather, Risk, and Resource Orders on Large Wildland Fires in the Western US
Year: 2020
Our results suggest that weather is a primary driver of resource orders over the course of extended attack efforts on large fires. Incident Management Teams (IMTs) synthesize information about weather, fuels, and order resources based on expected fire growth rather than simply reacting to observed fire growth. Background and Objectives: Weather conditions are a well-known determinant of fire behavior and are likely to become more erratic under climate change. Yet, there is little empirical evidence demonstrating how IMTs respond to observed or expected weather conditions. An understanding of…
Publication Type: Journal Article
Severe Fire Danger Index: A Forecastable Metric to Inform Firefighter and Community Wildfire Risk Management
Year: 2019
Despite major advances in numerical weather prediction, few resources exist to forecast wildland fire danger conditions to support operational fire management decisions and community early-warning systems. Here we present the development and evaluation of a spatial fire danger index that can be used to assess historical events, forecast extreme fire danger, and communicate those conditions to both firefighters and the public. It uses two United States National Fire Danger Rating System indices that are related to fire intensity and spread potential. These indices are normalized, combined, and…
Publication Type: Journal Article
Exploring the influence of local social context on strategies for achieving Fire Adapted Communities
Year: 2019
There is a growing recognition that the social diversity of communities at risk from wildland fire may necessitate divergent combinations of policies, programs and incentives that allow diverse populations to promote fire adapted communities (FACs). However, there have been few coordinated research efforts to explore the perceived utility and effectiveness of various options for FACs among residents, professionals, and local officials in disparate communities with different social contexts. The research presented here attempts to systematically explore the combination of local social factors…
Publication Type: Journal Article