Simulation of the 2009 Harmanli fire (Bulgaria)

We use a coupled atmosphere-fire model to simulate a fire that occurred on August 14--17, 2009, in the Harmanli region, Bulgaria. Data was obtained from GIS and satellites imagery, and from standard atmospheric data sources. Fuel data was classified in the 13 Anderson categories. For correct fire behavior, the spatial resolution of the models needed to be fine enough to resolve the essential micrometeorological effects. The simulation results are compared to available incident data. The code runs faster than real time on a cluster. The model is available from openwfm.org and it extends WRF-Fire from WRF 3.3 release.Comment: 8 pages, 2 tables, 5 figures. 8th International Conference on Large-Scale Scientific Computations, June 6-10, 2011, Sozopol, Bulgari

Assimilation of Perimeter Data and Coupling with Fuel Moisture in a Wildland Fire - Atmosphere DDDAS

We present a methodology to change the state of the Weather Research Forecasting (WRF) model coupled with the fire spread code SFIRE, based on Rothermel's formula and the level set method, and with a fuel moisture model. The fire perimeter in the model changes in response to data while the model is running. However, the atmosphere state takes time to develop in response to the forcing by the heat flux from the fire. Therefore, an artificial fire history is created from an earlier fire perimeter to the new perimeter, and replayed with the proper heat fluxes to allow the atmosphere state to adjust. The method is an extension of an earlier method to start the coupled fire model from a developed fire perimeter rather than an ignition point. The level set method is also used to identify parameters of the simulation, such as the spread rate and the fuel moisture. The coupled model is available from openwfm.org, and it extends the WRF-Fire code in WRF release.Comment: ICCS 2012, 10 pages; corrected some DOI typesetting in the reference

Identifying the Geographic Origins for the Introduction of \u3cem\u3eTaeniatherum caput-medusae\u3c/em\u3e subsp. \u3cem\u3easperum\u3c/em\u3e (Medusahead) in the Western United States

The use of molecular markers can provide insights into the demographic and evolutionary processes that have shaped the genetic diversity of native populations and can be used to identify an invasive species’ geographic origins. Taeniatherum caput-medusae subsp. asperum (medusahead) is a cleistogamous, diploid, annual grass native toEurasia that is now invasive in the western United States (U.S.). Enzyme electrophoresis methods (allozymes) have previously been used to analyze both native and invasive populations of medusahead. Results from these studies suggest that the invasion of medusahead in the westernU.S. stems from multiple introduction events. In addition, 10 of 34 populations from across the native range of the species possessed multilocus genotypes that match some of those detected in invasive populations, with six of these putative source populations located inGreece andNorthwestern Turkey. The overall objective of the current study is to better circumscribe the geographic origins for this invasion through allozyme analysis of 48 native populations of medusahead from Southeastern Europe (Albania, Bulgaria, Greece, Macedonia, Romania, Serbia, Northwestern Turkey, and Ukraine) and South-central Turkey. Among the 48 native populations I analyzed, a total of 35 multilocus genotypes were detected, with four of these genotypes matching those previously reported among invasive populations. Forty of the 48 (83.3%) native populations contained at least one individual with a multilocus genotype matching a genotype reported among invasive populations. The 48 populations from Southeastern Europe andSouth-central Turkey exhibit less genetic structure and display lower levels of genetic diversity compared with the 34 native populations previously analyzed. Also, the genetic diversity of these 48 populations is not geographically structured; it does not conform to an isolation-by-distance pattern. Taken together, results from this study suggest that the geographic origins of this invasion occur broadly across the study region. In addition, the genetic diversity of these 48 native populations appears to be influenced by stochastic demographic processes in which an individual or individuals with various genotypes randomly colonizes disturbed sites and establishes a population. This process has led to an intermixing of genotypes within and among populations across the study area. Because allozymes typical underestimate the genetic diversity of populations, the findings of this study should be assessed using a molecular marker with greater resolving power (i.e., amplified fragment length analysis)

Data management and analysis with WRF and SFIRE

pre-printWe introduce several useful utilities in development for the creation and analysis of real wildland fire simulations using WRF and SFIRE. These utilities exist as standalone programs and scripts as well as extensions to other well known software. Python web scrapers automate the process of downloading and preprocessing atmospheric and surface data from common sources. Other scripts simplify the domain setup by creating parameter files automatically. Integration with Google Earth allows users to explore the simulation in a 3D environment along with real surface imagery. Postprocessing scripts provide the user with a number of output data formats compatible with many commonly used visualization suites allowing for the creation of high quality 3D renderings. As a whole, these improvements build toward a unified web application that brings a sophisticated wildland fire modeling environment to scientists and users alike