Science.gov

Sample records for regional wildfire plumes

  1. Evolution of brown carbon in wildfire plumes

    NASA Astrophysics Data System (ADS)

    Forrister, Haviland; Liu, Jiumeng; Scheuer, Eric; Dibb, Jack; Ziemba, Luke; Thornhill, Kenneth L.; Anderson, Bruce; Diskin, Glenn; Perring, Anne E.; Schwarz, Joshua P.; Campuzano-Jost, Pedro; Day, Douglas A.; Palm, Brett B.; Jimenez, Jose L.; Nenes, Athanasios; Weber, Rodney J.

    2015-06-01

    Particulate brown carbon (BrC) in the atmosphere absorbs light at subvisible wavelengths and has poorly constrained but potentially large climate forcing impacts. BrC from biomass burning has virtually unknown lifecycle and atmospheric stability. Here, BrC emitted from intense wildfires was measured in plumes transported over 2 days from two main fires, during the 2013 NASA SEAC4RS mission. Concurrent measurements of organic aerosol (OA) and black carbon (BC) mass concentration, BC coating thickness, absorption Ångström exponent, and OA oxidation state reveal that the initial BrC emitted from the fires was largely unstable. Using back trajectories to estimate the transport time indicates that BrC aerosol light absorption decayed in the plumes with a half-life of 9 to 15 h, measured over day and night. Although most BrC was lost within a day, possibly through chemical loss and/or evaporation, the remaining persistent fraction likely determines the background BrC levels most relevant for climate forcing.

  2. Doppler lidar observations of plume dynamics from large wildfires

    NASA Astrophysics Data System (ADS)

    Lareau, N.; Clements, C. B.

    2014-12-01

    Novel Doppler lidar observations of smoke plumes from large wildfires are made from a mobile atmospheric profiling system. Few quantitative observations exist that resolve the plume dynamics of active wildfires. Our observations elucidate three important and poorly understood aspects of convective columns: (1) column rotation, (2) penetrative convection, and (3) deep pyrocumulus clouds. Our first observational case examines vigorus anti-cyclonic rotation that occurred in a rapidly developing wildfire. The convective column was first purely convergent, then as the fire intensified, the column acquired strong (+/- 15 m s-1) anticyclonic rotation. The Doppler lidar recorded the vortex structure, strength, and evolution, including the merger of smaller vorticies into a single long-lived vortex. The second case examines the interaction of the convective plumes with shear layers and capping stable layers. These data show explosive convective growth as fire-induced buoyancy penetrated into the free troposphere. Observations of entrainment into the plumes is expecitly resolved in the lidar scans. The final case examines rarely observed deep pyrocumulus clouds associated with an intense forest fire. The lidar data reveal plume structure, including t the height of the lifted condensation level and the full height of the plume top which was in excess of 8 km AGL.

  3. Polarimetric and Multi-Doppler Radar Observations of Electrified and Unelectrified Wildfire Smoke Plumes

    NASA Technical Reports Server (NTRS)

    Lang, Timothy J.; Rutledge, Steven A.; Dolan, Brenda; Krehbiel, Paul; Rison, William; Lindsey, Daniel T.

    2013-01-01

    Pyrocumulus clouds above three Colorado wildfires (Hewlett Gulch, High Park, and Waldo Canyon; all occurred during summer 2012) electrified and produced small intracloud discharges whenever the smoke plumes grew to high altitudes (over 10 km above mean sea level, or MSL). This occurred during periods of rapid wildfire growth, as indicated by the shortwave infrared channel on a geostationary satellite, as well as by incident reports. In the Hewlett Gulch case, the fire growth led to increased updrafts within the plume, as inferred by multiple- Doppler radar syntheses, which led to the vertical development and subsequent electrification - a life cycle as short as 30 minutes. The lightning, detected by a threedimensional lightning mapping network, was favored in high-altitude regions (10 km MSL) containing modest reflectivities (25 dBZ and lower), 0 dB differential reflectivity, and reduced correlation coefficient (0.6-0.7). This indicated the likely presence of ice particles (crystals and aggregates, possibly rimed) mixed with ash. Though neither multiple-Doppler nor polarimetric observations were available during the electrification of the High Park and Waldo Canyon plumes, their NEXRAD observations showed reflectivity structures consistent with Hewlett Gulch. In addition, polarimetric and multiple-Doppler scanning of unelectrified High Park plumes indicated only irregularly shaped ash, and not ice, was present (i.e., reflectivities < 25 dBZ, differential reflectivity > 5 dB, correlation < 0.4), and there was no broaching of the 10 km altitude. Based on these results, the electrification likely was caused by ice-based processes that did not involve significant amounts of graupel. The results demonstrate the scientific value of multiple-Doppler and polarimetric radar observations of wildfire smoke plumes - including the ability to distinguish between regions of pure hydrometeors, regions of pure ash, and mixtures of both - and also suggest a possible new application

  4. A review of approaches to estimate wildfire plume injection height within large-scale atmospheric chemical transport models

    NASA Astrophysics Data System (ADS)

    Paugam, R.; Wooster, M.; Freitas, S.; Martin, M. Val

    2016-01-01

    Landscape fires produce smoke containing a very wide variety of chemical species, both gases and aerosols. For larger, more intense fires that produce the greatest amounts of emissions per unit time, the smoke tends initially to be transported vertically or semi-vertically close by the source region, driven by the intense heat and convective energy released by the burning vegetation. The column of hot smoke rapidly entrains cooler ambient air, forming a rising plume within which the fire emissions are transported. The characteristics of this plume, and in particular the height to which it rises before releasing the majority of the smoke burden into the wider atmosphere, are important in terms of how the fire emissions are ultimately transported, since for example winds at different altitudes may be quite different. This difference in atmospheric transport then may also affect the longevity, chemical conversion, and fate of the plumes chemical constituents, with for example very high plume injection heights being associated with extreme long-range atmospheric transport. Here we review how such landscape-scale fire smoke plume injection heights are represented in larger-scale atmospheric transport models aiming to represent the impacts of wildfire emissions on component of the Earth system. In particular we detail (i) satellite Earth observation data sets capable of being used to remotely assess wildfire plume height distributions and (ii) the driving characteristics of the causal fires. We also discuss both the physical mechanisms and dynamics taking place in fire plumes and investigate the efficiency and limitations of currently available injection height parameterizations. Finally, we conclude by suggesting some future parameterization developments and ideas on Earth observation data selection that may be relevant to the instigation of enhanced methodologies aimed at injection height representation.

  5. A study of algorithm to detect wildfire with edge of smoke plumes

    NASA Astrophysics Data System (ADS)

    Mototani, I.; Kimura, K.; Honma, T.

    2008-12-01

    Recent years, huge wildfires occur in many part of the world. And some researches have proceeded to improve wildfire detection with satellite imagery. Dozier (1981) developed the method that detects hotspot pixel by comparing the pixel with adjacent pixels. After that, Threshold method based on Dozier's approach and Contextual Method using relationship among neighbor pixels were appeared. But each of these algorithms needs more improvement in accuracy. In this study, we formulate a new algorithm with the edges of smoke plumes based on the rule of fire pixels match the origin of smoke plumes, and validate with the truth data. In this algorithm, MODIS band 1 (visible red) is extracted and smoke plumes are accented by histogram stretching. The edges of smoke plumes are extracted. Edge pixels that consist of fire smoke plumes are approximated by least squares method. Finally, the origins of the smoke plumes are determined and fire pixels are detected by the threshold approach. Our method, however, contain a problem that hotspot area shapes often a rectangle under the condition of not so high threshold temperature. In the results of this algorithm applied, it is found that it is easy to detect fire when clouds are not so thick and when smoke shape is visible clearly. On the other hand, false alarms along are detected along coast line and at the high refraction areas on a glacier, cirrocumulus clouds and so on. In addition, excessive detections increase in the low latitude because brightness temperature is raised by sunlight reflection. The wildfires in Alaska were detected well with our method. To validate this result, it is compared with the observational data and the common detection method. The Alaska Fire History Data (AFHD) is observed by Alaska Fire Service frequently, and the AFHD is offered as GIS data. On the other hand, MOD14 is one of the most famous and common methods to detect wildfire. It is calculated easily by MODIS data. Its accuracy rate to detect fire

  6. Development of a region-specific wildfire scheme in the Community Land Model of the CESM

    NASA Astrophysics Data System (ADS)

    Zou, Y.; Ke, Z.; Song, Y.; Wang, Y.

    2014-12-01

    Wildfire is a key perturbation in the earth system to modulate climate variability by changing emissions and energy budget. Fire activities show broad spatial and temporal variability with distinct regional and seasonal characteristics. To improve modeling capability for fire activities, we newly developed a region-specific fire model with emission estimation and plume rise module in the latest Community Land Model (CLM) of the Community Earth System Model (CESM). Using the observations in the past decade, we improve the fire model by applying natural and socioeconomic constraints for fire occurrence and spread separately for 14 regions and as a function of major Plant Functional Type (PFT) categories. We then add an emission module into the fire model that accounts for the interactions between fire activities and climate variability. Plume rise processes are also incorporated into this emission module for better vertical allocation of aerosol emissions from fires, which are important for simulating long-range transport of fire aerosols and their climate effects. Observation-based evaluation of simulation results using the new fire model demonstrates enhanced modeling performance for both global intensity and regional variability of wildfires, which lay the foundation for investigating wildfire feedback to regional and global climate. The impacts on improving the modeling capability of assessing the radiative forcing of fire aerosols are assessed.

  7. Regional Influence of Aerosol Emissions from Wildfires Driven by Combustion Efficiency: Insights from the BBOP Campaign.

    PubMed

    Collier, Sonya; Zhou, Shan; Onasch, Timothy B; Jaffe, Daniel A; Kleinman, Lawrence; Sedlacek, Arthur J; Briggs, Nicole L; Hee, Jonathan; Fortner, Edward; Shilling, John E; Worsnop, Douglas; Yokelson, Robert J; Parworth, Caroline; Ge, Xinlei; Xu, Jianzhong; Butterfield, Zachary; Chand, Duli; Dubey, Manvendra K; Pekour, Mikhail S; Springston, Stephen; Zhang, Qi

    2016-08-16

    Wildfires are important contributors to atmospheric aerosols and a large source of emissions that impact regional air quality and global climate. In this study, the regional and nearfield influences of wildfire emissions on ambient aerosol concentration and chemical properties in the Pacific Northwest region of the United States were studied using real-time measurements from a fixed ground site located in Central Oregon at the Mt. Bachelor Observatory (∼2700 m a.s.l.) as well as near their sources using an aircraft. The regional characteristics of biomass burning aerosols were found to depend strongly on the modified combustion efficiency (MCE), an index of the combustion processes of a fire. Organic aerosol emissions had negative correlations with MCE, whereas the oxidation state of organic aerosol increased with MCE and plume aging. The relationships between the aerosol properties and MCE were consistent between fresh emissions (∼1 h old) and emissions sampled after atmospheric transport (6-45 h), suggesting that biomass burning organic aerosol concentration and chemical properties were strongly influenced by combustion processes at the source and conserved to a significant extent during regional transport. These results suggest that MCE can be a useful metric for describing aerosol properties of wildfire emissions and their impacts on regional air quality and global climate. PMID:27398804

  8. Development and optimization of a wildfire plume rise model based on remote sensing data inputs - Part 2

    NASA Astrophysics Data System (ADS)

    Paugam, R.; Wooster, M.; Atherton, J.; Freitas, S. R.; Schultz, M. G.; Kaiser, J. W.

    2015-03-01

    Biomass burning is one of a relatively few natural processes that can inject globally significant quantities of gases and aerosols into the atmosphere at altitudes well above the planetary boundary layer, in some cases at heights in excess of 10 km. The "injection height" of biomass burning emissions is therefore an important parameter to understand when considering the characteristics of the smoke plumes emanating from landscape scale fires, and in particular when attempting to model their atmospheric transport. Here we further extend the formulations used within a popular 1D plume rise model, widely used for the estimation of landscape scale fire smoke plume injection height, and develop and optimise the model both so that it can run with an increased set of remotely sensed observations. The model is well suited for application in atmospheric Chemistry Transport Models (CTMs) aimed at understanding smoke plume downstream impacts, and whilst a number of wildfire emission inventories are available for use in such CTMs, few include information on plume injection height. Since CTM resolutions are typically too spatially coarse to capture the vertical transport induced by the heat released from landscape scale fires, approaches to estimate the emissions injection height are typically based on parametrizations. Our extensions of the existing 1D plume rise model takes into account the impact of atmospheric stability and latent heat on the plume up-draft, driving it with new information on active fire area and fire radiative power (FRP) retrieved from MODIS satellite Earth Observation (EO) data, alongside ECMWF atmospheric profile information. We extend the model by adding an equation for mass conservation and a new entrainment scheme, and optimise the values of the newly added parameters based on comparison to injection heights derived from smoke plume height retrievals made using the MISR EO sensor. Our parameter optimisation procedure is based on a twofold approach

  9. Signatures of Biomass Burning Aerosols in the Plume of a Saltmarsh Wildfire in South Texas.

    PubMed

    Myers-Pigg, Allison N; Griffin, Robert J; Louchouarn, Patrick; Norwood, Matthew J; Sterne, Amanda; Cevik, Basak Karakurt

    2016-09-01

    The most conventional and abundant tracers of biomass combustion in aerosol particles include potassium and biomarkers derived from thermally altered cellulose/hemicellulose (anhydrosugars) and lignin (methoxyphenols). However, little is known of the role biomass combustion plays as a particulate source of major plant polymers to the atmosphere. Here, concentrations of solvent-extractable anhydrosugars and methoxyphenols are compared to the yields of polymeric lignin oxidation products (LOPs) during a smoke plume event in Houston, Texas. Downwind aerosol samples (PM2.5) were collected surrounding a two-day wildfire in the McFaddin National Wildlife Refuge, 125 km southeast of Houston, which was 12-16 h directly downwind during the peak of the burn. Concentrations of all organic markers, potassium, and calcium increased by a factor of 2-13 within 1-2 days of the start of the fire and dropped to prefire levels 3 days after the peak event. Source signatures of anhydrosugars and methoxyphenols during the peak of the plume were identical to those of grass charcoals collected from the site, confirming the use of charcoals as end-members for source input reconstruction during atmospheric transport. An enrichment factor of 20 in the anhydrosugar to methoxyphenol ratio of aerosols versus charcoals can be explained partially by differences in degradation rate constants between the biomarker groups. LOPs comprised 73-91% of all lignin material in the aerosols, pointing to fires as major sources of primary biogenic aerosol particles in which lignin phenols occur predominantly in polymeric form. PMID:27462728

  10. Impacts of regional climate variability and change on U.S. wildfire

    NASA Astrophysics Data System (ADS)

    Liu, Y.

    2008-05-01

    Atmospheric condition is one of the factors affecting wildfire. Anomalous weather events such as droughts are a major contributor to intense wildfires. Climate change due to the greenhouse effect is expected to lead to significant wildfire disturbances. This study investigates the impacts of regional climate variability and change on wildfires in the contiguous United States. A severe drought and intense wildfire case is first simulated with the NCAR regional climate model. For comparison, simulation is also conducted for a flood event. Wildfire danger indices are estimated using model outputs. The results indicate that soil water content is close to its wilting point during the drought period. The fire danger indices point out a high risk of wildfire. This agrees with the reported wildfire activity that shows much more intense wildfires during the drought than flood period. A statistical analysis is then made. Singular value decomposition is applied to historical wildfire and antecedent sea surface temperature (SST). It is found that warming in the North Pacific is a major feature in the SST spatial pattern related to intense wildfires in the northwestern U.S. The warming signals were observed in all the major wildfire events during the past two decades. The SST anomaly therefore can be used as a predictor for wildfires in this region. Finally, future disturbances in wildfires are predicted based on the projected climate change with climate models under various IPCC SRES scenarios. The burned areas by wildfire in the western U.S. are expected to increase dramatically by the end of this century.

  11. Signatures of Biomass Burning Aerosols during a Smoke Plume Event from a Saltmarsh Wildfire in South Texas

    NASA Astrophysics Data System (ADS)

    Louchouarn, P.; Griffin, R. J.; Norwood, M. J.; Sterne, A. M. E.; Karakurt Cevik, B.

    2014-12-01

    The most conventional and abundant tracers of biomass combustion in aerosol particles include potassium and biomarkers derived from thermally altered cellulose/hemicellulose (anhydrosugars) and lignin (methoxyphenols). However, little is known of the role of biomass combustion as a particulate source of major plant polymers to the atmosphere. Here, concentrations of "free" (solvent-extractable) anhydrosugars and methoxyphenols are compared to the yields of polymeric lignin oxidation products (LOPs) during a smoke plume event in Houston, Texas. Downwind aerosol samples (PM2.5) were collected prior to, during, and following a two-day wildfire event that burned ~5,000 acres of a spartina saltmarsh ecosystem in the McFaddin National Wildlife Refuge, 125 km southeast of Houston. In addition, charcoals of the burned plants were collected within a week of the fire at the wildfire site. HYSPLIT modeling shows that Houston was directly downwind of this wildfire during the peak of the burn, with an approximate travel time from source to aerosol sampling site of 12-16 hrs. Concentrations of all organic markers, K+, and Ca2+ jumped by a factor of 2-13 within 1-2 days of the start of the fire and dropped to pre-fire levels three days after the peak event. Source signatures of anhydrosugars and free methoxyphenols during the peak of the plume were identical to those of grass charcoals collected from the site, confirming the potential use of charcoals as endmembers for source input reconstruction during atmospheric transport. An enrichment factor of 20 in the anhydrosugar to methoxyphenol ratio of aerosols vs. charcoals can partially be explained by differences in degradation rate constants between the two biomarker groups. Polymeric LOP comprised 73-91% of all lignin material in the aerosols, pointing to fires as major sources of primary biogenic aerosol particles and confirming an earlier study that lignin phenols in atmospheric particles occur predominantly in polymeric form.

  12. Regional modeling of large wildfires under current and potential future climates in Colorado and Wyoming, USA

    USGS Publications Warehouse

    West, Amanda; Kumar, Sunil; Jarnevich, Catherine S.

    2016-01-01

    Regional analysis of large wildfire potential given climate change scenarios is crucial to understanding areas most at risk in the future, yet wildfire models are not often developed and tested at this spatial scale. We fit three historical climate suitability models for large wildfires (i.e. ≥ 400 ha) in Colorado andWyoming using topography and decadal climate averages corresponding to wildfire occurrence at the same temporal scale. The historical models classified points of known large wildfire occurrence with high accuracies. Using a novel approach in wildfire modeling, we applied the historical models to independent climate and wildfire datasets, and the resulting sensitivities were 0.75, 0.81, and 0.83 for Maxent, Generalized Linear, and Multivariate Adaptive Regression Splines, respectively. We projected the historic models into future climate space using data from 15 global circulation models and two representative concentration pathway scenarios. Maps from these geospatial analyses can be used to evaluate the changing spatial distribution of climate suitability of large wildfires in these states. April relative humidity was the most important covariate in all models, providing insight to the climate space of large wildfires in this region. These methods incorporate monthly and seasonal climate averages at a spatial resolution relevant to land management (i.e. 1 km2) and provide a tool that can be modified for other regions of North America, or adapted for other parts of the world.

  13. Spatial Surface PM2.5 Concentration Estimates for Wildfire Smoke Plumes in the Western U.S. Using Satellite Retrievals and Data Assimilation Techniques

    NASA Astrophysics Data System (ADS)

    Loria Salazar, S. M.; Holmes, H.

    2015-12-01

    Health effects studies of aerosol pollution have been extended spatially using data assimilation techniques that combine surface PM2.5 concentrations and Aerosol Optical Depth (AOD) from satellite retrievals. While most of these models were developed for the dark-vegetated eastern U.S. they are being used in the semi-arid western U.S. to remotely sense atmospheric aerosol concentrations. These models are helpful to understand the spatial variability of surface PM2.5concentrations in the western U.S. because of the sparse network of surface monitoring stations. However, the models developed for the eastern U.S. are not robust in the western U.S. due to different aerosol formation mechanisms, transport phenomena, and optical properties. This region is a challenge because of complex terrain, anthropogenic and biogenic emissions, secondary organic aerosol formation, smoke from wildfires, and low background aerosol concentrations. This research concentrates on the use and evaluation of satellite remote sensing to estimate surface PM2.5 concentrations from AOD satellite retrievals over California and Nevada during the summer months of 2012 and 2013. The aim of this investigation is to incorporate a spatial statistical model that uses AOD from AERONET as well as MODIS, surface PM2.5 concentrations, and land-use regression to characterize spatial surface PM2.5 concentrations. The land use regression model uses traditional inputs (e.g. meteorology, population density, terrain) and non-traditional variables (e.g. FIre Inventory from NCAR (FINN) emissions and MODIS albedo product) to account for variability related to smoke plume trajectories and land use. The results will be used in a spatially resolved health study to determine the association between wildfire smoke exposure and cardiorespiratory health endpoints. This relationship can be used with future projections of wildfire emissions related to climate change and droughts to quantify the expected health impact.

  14. Ozone enhancement in Western U.S. wildfire plumes at the Mt. Bachelor Observatory: The Role of NOx

    NASA Astrophysics Data System (ADS)

    Baylon, Leo Miguel Paolo M.

    We looked at 19 wildfire events that were observed in the summers of 2012 (July 22 -- September 20) and 2013 (July 12 -- August 30) at the Mt. Bachelor Observatory (MBO, 2.7 km a.s.l.), a mountaintop site located in central Oregon. Fire events were identified based on the following criteria: 5-minute ambient aerosol scattering ≥ 20 Mm-1 for at least two hours; 5-minute CO ≥ 150 ppbv for at least two hours; strong correlation (R2 ≥ 0.70) between aerosol scattering and CO; and backward trajectories consistently indicating transport over fire spots. We identified wildfire plumes using enhancement ratios (DeltaY/DeltaX), which we calculated for each plume by taking the Reduced Major Axis linear regression slope of various species. We reported the calculated enhancement ratios and explored their variation with source distance. We measured NOx at MBO during Summer 2012 and 2013 using a two-channel chemiluminescence instrument manufactured by Air Quality Design, Inc. The instrument has been used at MBO previously. During 2012, average summertime NO sensitivities in the NO and NOx channels were 2.7 and 2.2 counts per second (cps)/pptv, respectively. Average summertime NO2 sensitivity in the NOx channel was 0.7 cps/pptv. These values correspond to NO and NO 2 detection limits of 15 pptv and 35 pptv, respectively. During 2013, a different ozone generator was used. Average summertime NO sensitivities in the NO and NOx channels were 4.0 and 3.5 cps/pptv, respectively. Average NO2 sensitivity in the NOx channel was 0.9 cps/pptv. These correspond to detection limits of 7 pptv for NO and 30 pptv for NO2. We observed a negative correlation between DeltaO3/DeltaCO and DeltaNOx/DeltaNOy (r = -0.72). This showed that the degree of NOx oxidation is a key predictor of ozone production. The highest DeltaNOx/DeltaNOy (0.57 pptv/pptv) was associated with ozone loss (ozone titration). Low DeltaNOx/DeltaNOy values (ranging from 0.049 to 0.15 pptv/pptv) are generally associated with

  15. Viejas Wildfire

    NASA Technical Reports Server (NTRS)

    2002-01-01

    More than 2,000 firefighters continue to battle the 'Viejas Wildfire' which has consumed more than 11,000 acres in the dry, mountainous region just east of San Diego, California. Authorities there believe the blaze may have been started on Wednesday, January 3, by a cigarette thrown from a car on Interstate 8. Shifty winds with gusts of up to 65 miles per hour helped fan and quickly spread the flames. Late Wednesday, eyewitnesses reported seeing thick smoke and dime-sized bits of ash blowing toward downtown San Diego, prompting health officials there to warn residents with respiratory conditions to take necessary precautions. Parts of other communities, such as Alpine, have been evacuated to avoid the rapidly spreading flames. Firefighters estimate that the Viejas Fire, named after a nearby Native American reservation, will be contained by late Saturday, January 6. This image of the wildfire was acquired on January 4, 2001, by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra spacecraft. The scene shows the wildfire and smoke plume from the Alpine region, east of San Diego. This false-color image was generated using a combination of MODIS' thermal infrared data, at 1-kilometer resolution, along with two of the sensor's 500-meter resolution visible channels. These data were acquired via direct broadcast by the SeaSpace TeraScan SX-EOS receiving station at SeaSpace Corporation in Poway, California. The image was processed, Earth-located and enhanced using TeraScan software. Image courtesy Dave Brooks, SeaSpace Corporation

  16. Elemental abundances variations in plume and interplume regions

    NASA Astrophysics Data System (ADS)

    Guennou, Chloé; Savin, Daniel; Hahn, Michael

    2016-07-01

    Plumes are relatively bright, narrow structures in coronal holes that extend along open magnetic field lines far out into the corona. Extensive coronal measurements show abundances anomalies in the solar corona, in which elements with a low first ionization potential (FIP) < 10 eV are enhanced relative to the high FIP elements. Remote sensing spectroscopic measurements show that interplume regions have a photospheric composition. In contrast, the elemental composition of plume material is still unclear, previous spectroscopic measurements have reached contradictory results as to whether the elemental abundances in plumes are the same as or different from interplume regions. In this work, we measured the FIP bias, i.e. the ratio of coronal to photospheric abundances, in both interplumes and plumes using Hinode/Extreme Ultraviolet Imaging Spectrometer (EIS) data. Using spectral line intensities and Differential Emission Measure analysis, we assess the chemical composition of plumes and interplumes over an ~24 hour period in March, 2007. We find that some plumes do show different elemental abundances relative to interplumes. Moreover, the abundance anomaly in plumes is time dependent. If previous studies observed plumes at different stages in their evolution, this time dependence may explain the lack of consistency among previous results. Our work on plume and interplume elemental composition may also enable in situ measurements to answer the longstanding question of whether plumes contribute to the fast solar wind, which originates from coronal holes.

  17. Global and regional analysis of climate and human drivers of wildfire.

    PubMed

    Aldersley, Andrew; Murray, Steven J; Cornell, Sarah E

    2011-08-15

    Identifying and quantifying the statistical relationships between climate and anthropogenic drivers of fire is important for global biophysical modelling of wildfire and other Earth system processes. This study used regression tree and random forest analysis on global data for various climatic and human variables to establish their relative importance. The main interactions found at the global scale also apply regionally: greatest wildfire burned area is associated with high temperature (> 28 °C), intermediate annual rainfall (350-1100 mm), and prolonged dry periods (which varies by region). However, the regions of highest fire incidence do not show clear and systematic behaviour. Thresholds seen in the regression tree split conditions vary, as do the interplay between climatic and anthropogenic variables, so challenges remain in developing robust predictive insight for the most wildfire-threatened regions. Anthropogenic activities alter the spatial extent of wildfires. Gross domestic product (GDP) density is the most important human predictor variable at the regional scale, and burned area is always greater when GDP density is minimised. South America is identified as a region of concern, as anthropogenic factors (notably land conversions) outweigh climatic drivers of wildfire burned area. PMID:21689843

  18. Measurement of Black Carbon Particles and their Mixing State in Wildfire Plumes from New Mexico: Aged Whitewater Baldy Complex in 2012 and Fresh Las Conchas in 2011

    NASA Astrophysics Data System (ADS)

    Aiken, A. C.; Dubey, M. K.; Gorkowski, K.; Mazzoleni, C.; China, S.

    2012-12-01

    Approximately 50% of black carbon (BC) aerosols come from wildfires and are estimated to contribute up to ~0.6 W/m2 warming of the atmosphere globally. Organic carbon (OC) from fires condenses and/or mixes with BC resulting in an overall lower forcing of 0.03 ± 0.12 Wm-2 from biomass burning. However, this reduction depends strongly on the composition of the carbonaceous aerosols and on the mixing state of OC and BC. Detailed model treatments and laboratory measurements indicate that a BC core coated with a non-absorbing OC layer enhances absorption with a positive climate forcing. However, the real-time identification of the coating on this internally mixed BC in the field has only recently become detectable with the analysis of lag times between the scattering and incandescence signals in measurements from the single particle soot photometer (SP2). While fully coated BC has a positive lag time (cBC) in the SP2 data, BC that is located near the surface (nsBC) is associated with a negative lag time (Sedlacek et al. 2012). We investigate BC mixing states in concentrated wildfire plumes from the two largest wildfires in New Mexico's history with different ages. Plumes from the Las Conchas (LC) Fire, a wildfire that occurred in July-August of 2011 and burned ~157K acres, were sampled in the near-field after only a few hours of aging. Older plumes from the Whitewater Baldy (WB) Fire (May-June, 2012) that burned ~300K acres were sampled from further afield with an aging period of 7-9 hours. We find up to 23% of the internally mixed BC to be nsBC in the older WB plume. The nsBC fraction is smaller for the relatively fresh LC plume. Figure 1 shows %nsBC versus plume age as a conceptual framework of increasing %nsBC with age for the wildfire data shown here. SP2 results are corroborated by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) of single particles collected on nuclepore membranes that clearly show the shifts in morphology. Furthermore

  19. PLUME DEFINITION IN REGIONS OF STRONG BENDING

    EPA Science Inventory

    In recent years most of the emphasis in plume modeling has been directed at improving the entrainment equations while the non-entrainment equations (momentum, energy, state, etc.) have been thought to be firmly established. t is shown that serious deficiencies remain in the non-e...

  20. Hydrothermal plumes in the NE Lau basin: A regional perspective

    NASA Astrophysics Data System (ADS)

    Walker, S. L.; Baker, E. T.

    2013-12-01

    Exploration for mineral resources and the presence of an extensive plume of excess 3He centered at 1750 m water depth in the Samoa-Tonga-Fiji region (Lupton, 2004) have motivated exploration for active hydrothermal vent sites in the NE Lau basin during the past decade. The region is tectonically complex with back-arc spreading centers, rift zones, and volcanic centers, all of which potentially host active venting and/or active volcanism. To date, 400 km of the three back-arc spreading centers in the NE Lau basin (FRSC, Fonualei Rift and Spreading Center; MTJ, Mangatolu Triple Junction; and NELSC, Northeastern Lau Spreading Center) plus several volcanic centers have been systematically surveyed for hydrothermal plumes using towed CTD or MAPR arrays that include both optical backscatter and oxidation-reduction potential (ORP) sensors. The FRSC, where spreading rates range from 47 mm/a in the south to 85 mm/a in the north, has 5 active sites (plume depths ranging from 1300-2200 m) distributed one every ~40 km over its 200 km length. There is evidence for 4 active sites (plume depths range from 1950-2380 m) along the 150 km combined length of the MTJ segments, however plumes were optically weak (dNTU < 0.02) and except for one location along the northeastern limb, no ORP anomalies were detected. Plumes were observed off-axis to the MTJ at a bathymetric high adjacent to the northeastern limb (1700 m) as well as over the summit of a cratered volcanic edifice east of the central junction (1200-1300 m). The southern segment of the NELSC was the site of an active eruption in 2008 which injected event plumes throughout the water column (900-1600 m depth range) in addition to the chronic plume from the Maka massive sulfide vent site (1500 m). There is evidence for at least two additional active areas along the northern segments of the NELSC (1800-1900 m). Several volcanoes in the region are hydrothermally active ranging from the northernmost volcano on the Tonga arc (Niua

  1. Can increased biomass offset carbon release from permafrost region soils, streams, and wildfire: an expert elicitation?

    NASA Astrophysics Data System (ADS)

    Abbott, B. W.; Jones, J.; Schuur, E. A.; Bowden, W. B.; Chapin, F. S., III; Epstein, H. E.; Flannigan, M.; Harms, T.; Hollingsworth, T. N.; Mack, M. C.; Natali, S.; Rocha, A. V.; Tank, S. E.; Turetsky, M. R.; Vonk, J.; Wickland, K.

    2013-12-01

    As the permafrost region warms, up to 288 Pg carbon (CO2 equivalent) may be released from soil by the end of the century, and up to 616 Pg by 2300. This soil carbon can be released to the atmosphere directly via mineralization or wildfire, or enter aquatic ecosystems as dissolved or particulate organic or inorganic carbon. Some models predict an increase in Arctic and boreal living biomass in response to extended growing season, enhanced nutrient cycling, and CO2 fertilization, but we have a poor understanding of how the production of new biomass will compare with loss of carbon from permafrost thaw. We administered surveys to permafrost region experts to assess current understanding of the magnitude and timing of biomass accumulation, hydrologic carbon flux, and wildfire carbon losses. Surveys addressed three time periods (present to 2040, 2100, and 2300) and four warming scenarios based on IPCC representative concentration pathways. Estimates of change in biomass and fire losses were provided individually for the boreal forest and arctic tundra. Experts estimated changes in carbon delivery to freshwater ecosystems as well as delivery to the ocean, including carbon release due to coastal erosion, fluxes infrequently captured in high-latitude models. Initial expert estimates indicated that while tundra biomass would increase substantially, total permafrost region biomass would decrease by the end of the century due to boreal forest drying and browning, followed by a modest increase by 2300 due to vegetation community shifts. Changes in aquatic systems could release an additional 2.7 Pg carbon by 2100 and 7.3 Pg by 2300. Modified wildfire regime could cause the release of an additional 13.6 Pg carbon by 2100 and 51.7 Pg by 2300. Current expert understanding therefore suggests that carbon gains in high-latitude biomass will be orders of magnitude smaller than carbon loss from permafrost soils and that hydrologic and wildfire pathways of carbon loss will likely

  2. Quantification of Asian Dust Plume Seasonal Dynamics and Regional Features

    NASA Technical Reports Server (NTRS)

    Goetz, Michael

    2011-01-01

    Dust is but one of many aerosols that are analyzed at the Jet Propulsion Laboratory in Pasadena. The purpose of this paper is to describe the process in analyzing and digitizing dust within a source region to better explain the work achieved by my internship. This paper will go over how to view collected data by Multi-angle Imaging SpectroRadiometer (MISR) [1] and the procedure of downloading data to be analyzed. With this data, one can digitize dust plumes using two methods called plume lines and plume polygons with the help of the software MISR INteractive eXplorer (MINX)[3]; thus, the theory of MINX's[3] algorithm and these methods are discussed in detail. Research was gathered from these techniques and emphasis is also focused on the obtained data and results.

  3. Size of wildfires in the Euro-Mediterranean region: observations and theoretical analysis

    NASA Astrophysics Data System (ADS)

    Hernandez, C.; Drobinski, P.; Turquety, S.; Dupuy, J.-L.

    2015-06-01

    MODIS (Moderate Resolution Imaging Spectroradiometer) satellite observations of fire size and ERA-Interim meteorological reanalysis are used to derive a relationship between burnt area and wind speed over the Mediterranean region and Eastern Europe. The largest wildfire size does not show a strong response with respect to wind speed in Eastern Europe. In the Mediterranean, as intuitively expected, the burnt area associated with the largest wildfires is an increasing function of wind speed for moderate temperature anomalies. In situations of severe heatwaves, the relationship between burnt area and wind speed displays a bimodal shape. Burnt areas are large for low 10 m wind speed (lower than 2 m s-1), decrease for moderate wind speed values (lower than 5 m s-1 and larger than 2 m s-1) and increase again for high wind speed (higher than 5 m s-1). To explain such behavior we use a stochastic model of fire propagation, known as a probabilistic cellular automata. This model uses a probabilistic local rule to derive the total burnt area. The observed relationship between burnt area and wind speed can be interpreted in terms of percolation threshold above which the propagation in the model is infinite, which mainly depends on local terrain slope and vegetation state (type, density, fuel moisture). In Eastern Europe, the percolation threshold is never exceeded for observed wind speeds. In the Mediterranean Basin we see two behaviors. During moderately hot weather, the percolation threshold is passed when the wind grows strong. On the other hand, in situations of severe Mediterranean heatwaves, moderate wind speed values impair the propagation of the wildfire against the wind and do not sufficiently accelerate the forward propagation to allow a growth of wildfire size.

  4. Modeling the Complex Photochemistry of Biomass Burning Plumes in Plume-Scale, Regional, and Global Air Quality Models

    NASA Astrophysics Data System (ADS)

    Alvarado, M. J.; Lonsdale, C. R.; Yokelson, R. J.; Travis, K.; Fischer, E. V.; Lin, J. C.

    2014-12-01

    Forecasting the impacts of biomass burning (BB) plumes on air quality is difficult due to the complex photochemistry that takes place in the concentrated young BB plumes. The spatial grid of global and regional scale Eulerian models is generally too large to resolve BB photochemistry, which can lead to errors in predicting the formation of secondary organic aerosol (SOA) and O3, as well as the partitioning of NOyspecies. AER's Aerosol Simulation Program (ASP v2.1) can be used within plume-scale Lagrangian models to simulate this complex photochemistry. We will present results of validation studies of the ASP model against aircraft observations of young BB smoke plumes. We will also present initial results from the coupling of ASP v2.1 into the Lagrangian particle dispersion model STILT-Chem in order to better examine the interactions between BB plume chemistry and dispersion. In addition, we have used ASP to develop a sub-grid scale parameterization of the near-source chemistry of BB plumes for use in regional and global air quality models. The parameterization takes inputs from the host model, such as solar zenith angle, temperature, and fire fuel type, and calculates enhancement ratios of O3, NOx, PAN, aerosol nitrate, and other NOy species, as well as organic aerosol (OA). We will present results from the ASP-based BB parameterization as well as its implementation into the global atmospheric composition model GEOS-Chem for the SEAC4RS campaign.

  5. Application of wildfire spread and behavior models to assess fire probability and severity in the Mediterranean region

    NASA Astrophysics Data System (ADS)

    Salis, Michele; Arca, Bachisio; Bacciu, Valentina; Spano, Donatella; Duce, Pierpaolo; Santoni, Paul; Ager, Alan; Finney, Mark

    2010-05-01

    Characterizing the spatial pattern of large fire occurrence and severity is an important feature of the fire management planning in the Mediterranean region. The spatial characterization of fire probabilities, fire behavior distributions and value changes are key components for quantitative risk assessment and for prioritizing fire suppression resources, fuel treatments and law enforcement. Because of the growing wildfire severity and frequency in recent years (e.g.: Portugal, 2003 and 2005; Italy and Greece, 2007 and 2009), there is an increasing demand for models and tools that can aid in wildfire prediction and prevention. Newer wildfire simulation systems offer promise in this regard, and allow for fine scale modeling of wildfire severity and probability. Several new applications has resulted from the development of a minimum travel time (MTT) fire spread algorithm (Finney, 2002), that models the fire growth searching for the minimum time for fire to travel among nodes in a 2D network. The MTT approach makes computationally feasible to simulate thousands of fires and generate burn probability and fire severity maps over large areas. The MTT algorithm is imbedded in a number of research and fire modeling applications. High performance computers are typically used for MTT simulations, although the algorithm is also implemented in the FlamMap program (www.fire.org). In this work, we described the application of the MTT algorithm to estimate spatial patterns of burn probability and to analyze wildfire severity in three fire prone areas of the Mediterranean Basin, specifically Sardinia (Italy), Sicily (Italy) and Corsica (France) islands. We assembled fuels and topographic data for the simulations in 500 x 500 m grids for the study areas. The simulations were run using 100,000 ignitions under weather conditions that replicated severe and moderate weather conditions (97th and 70th percentile, July and August weather, 1995-2007). We used both random ignition locations

  6. Measurement of trace gases and organic compounds in the smoke plume from a wildfire in Penedono (central Portugal)

    NASA Astrophysics Data System (ADS)

    Vicente, Ana; Alves, Célia; Monteiro, Cristina; Nunes, Teresa; Mirante, Fátima; Evtyugina, Margarita; Cerqueira, Mário; Pio, Casimiro

    2011-09-01

    Gas and particulate fractions were measured simultaneously from a wildfire in Penedono, central Portugal, which occurred in summer 2009. The total volatile hydrocarbons (THC) and carbon oxides (CO 2 and CO) collected in Tedlar bags were measured using automatic analysers with flame ionisation and non-dispersive infrared detectors, respectively. Carbonyls (formaldehyde and acetaldehyde) were sampled from the Tedlar bags in DNHP cartridges and analysed by high-performance liquid chromatography. Fine (PM 2.5) and coarse (PM 2.5-10) smoke particles were collected sequentially, on pre-fired quartz fibre filters, with a portable high-volume sampler. The detailed speciation of organic compounds in smoke samples was carried out by gas chromatography-mass spectrometry. The organic and elemental carbon content of particulate matter was analysed by a thermal-optical transmission technique. Average emission factors of 1.86 ± 0.80 and 0.063 ± 0.066 g kg -1 (dry basis) were obtained for acetaldehyde and formaldehyde, respectively. The THC, CO, CO 2, PM 2.5, PM 10, OC and EC emission factors (g kg -1 fuel burned, dry basis) were 260 ± 88, 268 ± 92, 1200 ± 172, 37 ± 12.2, 40 ± 12.6, 21 ± 6.7 and 0.44 ± 0.21, respectively. The chromatographically resolved organics included n-alkanes, n-alkenes, n-alkanoic acids, n-di-acids, unsaturated fatty acids, phenolic compounds, ketones, steroids, di- and triterpenoids, PAHs, with retene as the major compound, oxygenated PAH and anhydrosugars.

  7. Spatiotemporal impacts of wildfire and climate warming on permafrost across a subarctic region, Canada

    NASA Astrophysics Data System (ADS)

    Zhang, Yu; Wolfe, Stephen A.; Morse, Peter D.; Olthof, Ian; Fraser, Robert H.

    2015-11-01

    Field observations show significant impacts of wildfires on active layer thickness and ground temperatures. However, the importance of fires to permafrost conditions at regional scales remains unclear, especially with climate warming. This study evaluated the regional impacts of fire on permafrost with climate change from 1942 to 2100 using a process-based model in a large subarctic region in the Northwest Territories, Canada. Climate warming is shown to be the dominant factor for permafrost reduction. The warming trend of climate reduces permafrost extent in this region from 67% at present to 2% by 2100. For burned areas, fire increases the reduction of permafrost extent by up to 9% on average, with up to 16% for forest, 10% for tundra and bogs, and 4% for fens. Fire accelerates permafrost disappearance by 5 years on average. The effects of fire on active layer thickness and permafrost extent are much larger in forest areas than in tundra, bogs, and fens. Since active layer is thicker after a fire and cannot recover in most of the areas, the fire effects on active layer are widespread. On average, fires thickens active layer by about 0.5 m. The fire effects on active layer increased significantly after 1990 due to climate warming.

  8. Ozone from Wildfires: Peering through the Smog

    NASA Astrophysics Data System (ADS)

    Jaffe, D. A.; Baylon, P.; Wigder, N. L.; Collier, S.; Zhou, S.; Zhang, Q.; Alvarado, M. J.

    2014-12-01

    In the western US, many areas are near the current air quality standard for O3. Yet there is substantial inter-annual variability (IAV) in the number of days that exceed the O3 air quality threshold (currently 75 ppbv for an 8-hour average). We propose that wildfires are the dominant cause for this IAV. However there are large uncertainties around O3 production from wildfires due to numerous complicating factors. Ozone formation in wildfire plumes differs substantially from urban O3 production in several ways: substantial variations in the emissions, much larger aerosol loadings, a much greater variety of reactive and oxygenated VOCs, rapid and substantial formation of PAN and very different sources of HOx in the plume. These factors make it challenging to model wildfire impacts on photochemistry in the usual way. In this presentation we will show examples of three common situations based on data from the Mt. Bachelor Observatory: Rapid O3 formation (within one day) in a wildfire plume. Slow, but substantial, O3 formation (over days to a week) in a wildfire plume. No detectable O3 formation in a wildfire plume. We will interpret these results with respect to the observed NOy mixing ratios, the photochemical environment, the combustion efficiency, the plume transport and other factors and suggest some key experiments and modeling studies that can help further our understanding of wildfire O3 production.

  9. Forest surveys and wildfire assessment in the Los Alamos Region; 1998-1999

    SciTech Connect

    Randy G. Balice; Jay D. Miller; Brian P. Oswald; Carl Edminster; Stephen R. Yool

    2000-06-01

    To better understand the structural characteristics of vegetation in the Los Alamos region, the authors conducted two years of field surveys and associated analyses. This report introduces field methods, lists the summarized field data, and discusses the results of preliminary spatial analyses. During 1998 and 1999, seventy-six terrestrial plant communities were sampled for topographic characteristics, soil surface features, and vegetational conditions. A nested, randomized design was used to select the plot locations and to guide the sampling of the plot. The samples included a variety of fuel types, including surface fuels and ground fuels, shrubby and small tree fuels, and overstory fuels. Species composition data were also collected. The fuels data were summarized by vegetation type and evaluated for the topographic and spatial relationships of major field categories. The results of these analyses indicate that many of the fuels categories depend on topographic factors in a linear and curvilinear fashion. In particular, middle elevations within the Los Alamos region tend to support more surface fuels and ground fuels, whereas large-diameter trees are most dense at higher elevations and are specific to community types at these elevations. Small-diameter trees occur in more dense stands at lower and middle elevations and on specific soil and topographic conditions. Areas that burned in 1954 were found to be relatively free of fuels. The implications are that the western portions of the Los Alamos region are at risk from wildfire during dry, summer periods.

  10. Profile distribution of polycyclic aromatic hydrocarbons in soils of drained peatlands after wildfires (Moscow region, Russia)

    NASA Astrophysics Data System (ADS)

    Tsibart, Anna; Gennadiev, Alexander; Koshovskii, Timur; Kovach, Roman

    2014-05-01

    Polycyclic aromatic compounds (PAHs) are formed in different natural and anthropogenic processes and could be found in many landscape components. These compounds are carcinogenic and belong to the group of persistent organic pollutants. The anthropogenic sources of PAHs are well-studied, but insufficient data are available on the hightemperature production of PAHs in natural processes. For example, natural fires are frequently related to the PAHs sources in landscapes, but very little factual data are on this topic. The soils of drained peatlands affected by catastrophic wildfires of 2010 and 2002 were studied in the Eastern part of Moscow Region (Russia). A total of 14 profiles of histosols and histic podsols were investigated. These series included soils of plots subjected to fires of different intensities and age, as well as soils of the background plots. Soil samples were taken from genetic horizons and from every 10 cm. The samples were analyzed for the contents of 14 prevailing individual compounds: fluorene, naphthalene, phenanthrene, chrysene, pyrene, anthracene, tetraphene, benz[a]pyrene, benzo[ghi]perylene, benzo[e]pyrene, coronene, dibenztiophene, triphenilene, benz(k)fluorantene. Morfological properties of soils after wildfires on drained peatlands were changed dramatically, the horizons of ash and char instead of organic layers were formed. These new horizons differ in the capability of PAHs accumulation. The char horizons have the highest concentrations of PAHs - up to 300 ng/g because of incomplete burning of organic matter in this sites, and the ash horizons, where the complete burning occured, contain only 10 ng/g PAHs. The highest concentrations of PAHs in soil profiles were detected after recent fires, and in cases of thick peat layers. After the combustion of peat chrysene, benz[a]pyrene, benz[e]pyrene, benzo[ghi]perylene, benz(k)fluorantene and tetraphene accumulated in soils. This is mainly the group of 4-6-nuclear compounds. The formation of

  11. Plasma Conditions in Polar Plumes and Interplume Regions in Polar Coronal Holes

    NASA Astrophysics Data System (ADS)

    Cranmer, S. R.; Kohl, J. L.; Miralles, M.; Panasyuk, A. V.

    2001-05-01

    During times of low solar activity, large polar coronal holes are observed to contain bright raylike polar plumes that appear to follow open magnetic field lines. Plumes are believed to be flux tubes that are heated impulsively at their base, which leads to a higher density, a lower outflow speed, and a lower overall temperature in the extended corona, compared to the surrounding interplume regions. Despite years of white light and spectroscopic observations, though, the differences in mass, momentum, and energy flux in plumes and between plumes are not known precisely. This poster presents an updated survey of data from the Ultraviolet Coronagraph Spectrometer (UVCS), aboard SOHO, that attempts to sort out the local plume and interplume conditions. These results will be compared with previous analyses that characterized the ``mean'' plume/interplume coronal hole, averaged over many lines of sight through varying concentrations of plumes. Limits on the relative contributions of plumes and interplume regions to the high-speed solar wind will be determined, with emphasis on the proton outflow speed in the corona and at 1 AU. Implications for theoretical models of coronal heating and solar wind acceleration will be discussed. This work is supported by the National Aeronautics and Space Administration under grant NAG5-10093 to the Smithsonian Astrophysical Observatory, by Agenzia Spaziale Italiana, and by the Swiss contribution to the ESA PRODEX program.

  12. Airborne In-Situ Trace Gas Measurements of Multiple Wildfires in California (2013-2014)

    NASA Astrophysics Data System (ADS)

    Iraci, L. T.; Yates, E. L.; Tanaka, T.; Roby, M.; Gore, W.; Clements, C. B.; Lareau, N.; Ambrosia, V. G.; Quayle, B.; Schroeder, W.

    2014-12-01

    Biomass burning emissions are an important source of a wide range of trace gases and particles that can impact local, regional and global air quality, climate forcing, biogeochemical cycles and human health. In the western US, wildfires dominate over prescribed fires, contributing to atmospheric trace gas budgets and regional and local air pollution. Limited sampling of emissions from wildfires means western US emission estimates rely largely on data from prescribed fires, which may not be a suitable proxy for wildfire emissions. We report here in-situ measurements of carbon dioxide, methane, ozone and water vapor from the plumes of a variety of wildfires sampled in California in the fire seasons of 2013 and 2014. Included in the analysis are the Rim Fire (August - October 2013, near Yosemite National Park), the Morgan Fire (September 2013, near Clayton, CA), and the El Portal Fire (July - August 2014, in Yosemite National Park), among others. When possible, fires were sampled on multiple days. Emission ratios and estimated emission factors will be presented and discussed in the context of fuel composition, plume structure, and fire phase. Correlations of plume chemical composition to MODIS/VIIRS Fire Radiative Power (FRP) and other remote sensing information will be explored. Furthermore, the role of plumes in delivery of enhanced ozone concentrations to downwind municipalities will be discussed.

  13. Observations of the frontal region of a buoyant river plume using an autonomous underwater vehicle

    NASA Astrophysics Data System (ADS)

    Rogowski, Peter; Terrill, Eric; Chen, Jialin

    2014-11-01

    To characterize the transitional region from the near-field to far-field of a river plume entering coastal waters, we conducted four surveys using an autonomous underwater vehicle (AUV) to target the outflow of the New River Inlet, North Carolina, during maximum ebb tide. The utilization of a mobile sensor to synoptically observe current velocity data in tandem with natural river plume tracers (e.g., colored dissolved organic matter, salinity) was essential in understanding the mechanisms driving the observed circulation and mixing patterns within these waters. We find that this region is regularly impacted by two primary processes: (1) the interaction of an old dredged channel plume with the main discharge and (2) the recirculation of the discharge plume by an eddy that persistently forms between the old channel and main discharge location. Wind-driven processes in the nearshore can enhance the interaction of these two plumes resulting in unstable regions where mixing of the merged plume with the receiving waters is accelerated. We also conduct comparisons between AUV velocity observations from two surveys and their corresponding velocity outputs from a parallelized quasi-3-D model. We conclude that the ability to observe the estuarine outflow transitional region at near-synoptic temporal scales and resolutions discussed in this paper is key in providing the mechanisms driving local circulation which is essential for proper parameterization of high-resolution numerical coastal models.

  14. Wildfire Awareness.

    ERIC Educational Resources Information Center

    Wallace, Glenda

    2002-01-01

    Provides information about the Firewise Program whose goal is to assist people to become more fire-aware and better prepared for the effects of wildfire on property. Discusses why there are so many wildfires and what can be done. Includes the Wildland Fire Risk and Hazard Severity Assessment Form. (KHR)

  15. The direct radiative effect of wildfire smoke on a severe thunderstorm event in the Baltic Sea region

    NASA Astrophysics Data System (ADS)

    Toll, V.; Männik, A.

    2015-03-01

    On August 8, 2010, a severe derecho type thunderstorm in the Baltic Sea region coincided with smoke from wildfires in Russia. Remarkable smoke aerosol concentrations, with a maximum aerosol optical depth of more than 2 at 550 nm, were observed near the thunderstorm. The impact of the wildfire smoke on the thunderstorm through direct radiative effects was investigated using the Hirlam Aladin Research for Mesoscale Operational Numerical Weather Prediction in Euromed (HARMONIE) model. HARMONIE was successfully able to resolve the dynamics of the thunderstorm, and simulations that considered the influence of the smoke-related aerosols were compared to simulation without aerosols. As simulated by the HARMONIE model, the smoke reduced the shortwave radiation flux at the surface by as much as 300 W/m2 and decreased the near-surface temperature by as much as 3 °C in the vicinity of the thunderstorm and respectively 100 W/m2 and 1 °C in the thunderstorm region. Atmospheric instability decreased through the direct radiative effect of aerosols, and several dynamic features of the simulated thunderstorm appeared slightly weaker.

  16. How wild is your model fire? Constraining WRF-Chem wildfire smoke simulations with satellite observations

    NASA Astrophysics Data System (ADS)

    Fischer, E. V.; Ford, B.; Lassman, W.; Pierce, J. R.; Pfister, G.; Volckens, J.; Magzamen, S.; Gan, R.

    2015-12-01

    Exposure to high concentrations of particulate matter (PM) present during acute pollution events is associated with adverse health effects. While many anthropogenic pollution sources are regulated in the United States, emissions from wildfires are difficult to characterize and control. With wildfire frequency and intensity in the western U.S. projected to increase, it is important to more precisely determine the effect that wildfire emissions have on human health, and whether improved forecasts of these air pollution events can mitigate the health risks associated with wildfires. One of the challenges associated with determining health risks associated with wildfire emissions is that the low spatial resolution of surface monitors means that surface measurements may not be representative of a population's exposure, due to steep concentration gradients. To obtain better estimates of ambient exposure levels for health studies, a chemical transport model (CTM) can be used to simulate the evolution of a wildfire plume as it travels over populated regions downwind. Improving the performance of a CTM would allow the development of a new forecasting framework that could better help decision makers estimate and potentially mitigate future health impacts. We use the Weather Research and Forecasting model with online chemistry (WRF-Chem) to simulate wildfire plume evolution. By varying the model resolution, meteorology reanalysis initial conditions, and biomass burning inventories, we are able to explore the sensitivity of model simulations to these various parameters. Satellite observations are used first to evaluate model skill, and then to constrain the model results. These data are then used to estimate population-level exposure, with the aim of better characterizing the effects that wildfire emissions have on human health.

  17. Characterisation of plumes from the Johannesburg-Pretoria megacity within the regional South African context

    NASA Astrophysics Data System (ADS)

    Beukes, J. P.; Vakkari, V.; Van Zyl, P. G.; Venter, A. D.; Josipovic, M.; Tiitta, P.; Jaars, K.; Pienaar, J. J.; Kulmala, M.; Worsnop, D.; Laakso, L.

    2012-04-01

    Introduction The Johannesburg-Pretoria conurbation in South Africa is inhabited by more than 10 million people, making it one of the 40 largest metropolitan areas in the world. Conurbations of this magnitude have been defined as megacities (Molina and Molina, 2004). However, similar to many developing world megacities, relatively little has been published on the Johannesburg-Pretoria conurbation. Megacities are not only important from a local air quality (health) perspective, but also since they have a global atmospheric impact (Butler and Lawrence, 2009). Approach In this paper, the Johannesburg-Pretoria megacity source region, as well as other source regions in the interior of South Africa was defined, as observed from a relatively new super site for atmospheric measurements (www.welgegund.org) that is located at Welgegund (26°34'10"S, 26° 56'21"E, 1480 m.asl). This site is approximately 70km west of the Johannesburg-Pretoria megacity source region. Plumes from the megacity source region arriving at Welgegund were identified via obtaining and overlaying back trajectories for a two year period. The back trajectory arrival times were correlated to in situ measurement to chemically and physically characterize the plumes. The characteristics of the megacity plumes were also compared to plumes from other defined source regions, as well as the regional background. Results Results indicated that the plumes arriving at Welgegund after passing over the Johannesburg-Pretoria megacity source region had much higher concentrations of gaseous pollutant species which include NO, NO2, O3, SO2, CO and anthropogenic VOC's, as well as aerosol total organic content, SO42-, NO3- and NH4+, if compared to the regional background. PM1 aerosol absorption (black carbon), scattering and number concentrations indicated similar trends. Comparison of the Johannesburg-Pretoria megacity source region with other defined source regions indicated that plumes from the megacity was as polluted as

  18. Regional-residual separation of bathymetry and revised estimates of Hawaii plume flux

    NASA Astrophysics Data System (ADS)

    Wessel, Paul

    2016-02-01

    Observations of the temporal variations in the volume flux of a plume can provide useful constraints on geodynamic models of plumes and plume-plate interactions. Furthermore, they can be compared with observations at other plumes and may be analysed further to understand the nature and cause of the variations. The volume plume flux is typically derived from a sum of edifice and compensation root volumes. The former can be obtained via the application of regional-residual separation procedures that split the observed relief into regional (swell) and residual (edifice) components, while the latter is generally inferred from the former using local (Airy) or regional (flexural) compensation models. Most regional-residual techniques used in past studies give non-unique results and provide no estimates of the uncertainty in the separation, which impacts the significance of the results. Here, the optimal robust separator (ORS) method achieves a unique separation for the swell and edifice components of the Hawaiian Ridge and furthermore obtain confidence bounds on the total volume flux. A fast spectral method for plate flexure with different edifice and infill densities is used to determine compensation volumes. Although my flux estimates have assigned confidence bounds, these are much smaller than the flux estimates themselves. A comparison of my new results to published volume flux curves shows that my revised flux estimates are lower by a factor of 2-3. Reproducing the prior higher results demonstrates that these discrepancies appear to be related to shortcomings in the implementation of the methodology used in the separation. The variability in the Hawaiian plume flux occurs at two different time scales: A short (1-2 Myr) periodicity related to the spacing of islands and seamounts, which ultimately is related to plume-plate flexural interactions, and a much longer (10-15 Myr) periodicity that may be related to plate kinematic changes. Superimposed on these trends may

  19. Formation of secondary organic aerosol in the Paris pollution plume and its impact on surrounding regions

    NASA Astrophysics Data System (ADS)

    Zhang, Q. J.; Beekmann, M.; Freney, E.; Sellegri, K.; Pichon, J. M.; Schwarzenboeck, A.; Colomb, A.; Bourrianne, T.; Michoud, V.; Borbon, A.

    2015-03-01

    Secondary pollutants such as ozone, secondary inorganic aerosol, and secondary organic aerosol formed in the plume of megacities can affect regional air quality. In the framework of the FP7/EU MEGAPOLI project, an intensive campaign was launched in the Greater Paris Region in July 2009. The major objective was to quantify different sources of organic aerosol (OA) within a megacity and in its plume. In this study, we use airborne measurements aboard the French ATR-42 aircraft to evaluate the regional chemistry-transport model CHIMERE within and downwind the Paris region. Slopes of the plume OA levels vs. Ox (= O3 + NO2) show secondary OA (SOA) formation normalized with respect to photochemical activity and are used for specific evaluation of the OA scheme in the model. Simulated and observed slopes are in good agreement, when the most realistic "high-NOx" yields are used in the Volatility-Basis-Set scheme implemented into the model. In addition, these slopes are relatively stable from one day to another, which suggest that they are characteristic for the given megacity plume environment. Since OA within the plume is mainly formed from anthropogenic precursors (VOC and primary OA, POA), this work allows a specific evaluation of anthropogenic SOA and SOA formed from primary semi-volatile and intermediate volatile VOCs (SI-SOA) formation scheme in a model. For specific plumes, this anthropogenic OA build-up can reach about 10 μg m-3. For the average of the month of July 2009, maximum increases occur close to the agglomeration for primary OA are noticed at several tens (for POA) to hundred (for SI-SOA) kilometers of distance from the Paris agglomeration.

  20. UAS Developments Supporting Wildfire Observations

    NASA Astrophysics Data System (ADS)

    Ambrosia, V. G.; Dahlgren, R. P.; Watts, A.; Reynolds, K. W.; Ball, T.

    2014-12-01

    Wildfires are regularly occurring emergency events that threaten life, property, and natural resources in every U.S. State and many countries around the world. Despite projections that $1.8 billion will be spent by U.S. Federal agencies alone on wildfires in 2014, the decades-long trend of increasing fire size, severity, and cost is expected to continue. Furthermore, the enormous potential for UAS (and concomitant sensor systems) to serve as geospatial intelligence tools to improve the safety and effectiveness of fire management, and our ability to forecast fire and smoke movements, remains barely tapped. Although orbital sensor assets are can provide the geospatial extent of wildfires, generally those resources are limited in use due to their spatial and temporal resolution limitations. These two critical elements make orbital assets of limited utility for tactical, real-time wildfire management, or for continuous scientific analysis of the temporal dynamics related to fire energy release rates and plume concentrations that vary significantly thru a fire's progression. Large UAS platforms and sensors can and have been used to monitor wildfire events at improved temporal, spatial and radiometric scales, but more focus is being placed on the use of small UAS (sUAS) and sensors to support wildfire observation strategies. The use of sUAS is therefore more critical for TACTICAL management purposes, rather than strategic observations, where small-scale fire developments are critical to understand. This paper will highlight the historical development and use of UAS for fire observations, as well as the current shift in focus to smaller, more affordable UAS for more rapid integration into operational use on wildfire events to support tactical observation strategies, and support wildfire science measurement inprovements.

  1. Diurnal variations of wildfire emissions in Europe: analysis of the MODIS and SEVIRI measurements in the framework of the regional scale air pollution modelling

    NASA Astrophysics Data System (ADS)

    Konovalov, Igor B.; Beekmann, Matthias; Kaiser, Johannes W.; Shudyaev, Anton A.; Yurova, Alla; Kuznetsova, Irina N.

    2013-04-01

    Wildfires episodically provide a major contribution to air pollution in many regions of the world. For example, the extreme air pollution level and strongly reduced visibility were observed in the Central European region of Russia during the intensive wildfire events in summer of 2010. Such episodes provide a strong impetus for further developments in air pollution modeling, aimed at improving the ability of chemistry transport models to simulate and predict evolution of atmospheric composition affected by wildfires. The main goals of our study are (1) to investigate the diurnal cycles of air pollutant emissions from wildfires in several European regions, taking into account the fire radiative power (FRP) satellite measurements for different vegetation land cover types and (2) to examine the possibilities of improving air pollution simulations by assimilating the diurnal variability of the FRP measurements performed by the polar orbiting (MODIS) and geostationary (SEVIRI) satellite instruments into a chemistry transport model. These goals are addressed for the case of wildfires occurred in summer 2010. The analysis of both the MODIS and SEVIRI data indicate that air pollutant emissions from wildfires in Europe in summer 2010 were typically much larger during daytime than during nighttime. The important exception is intensive fires around Moscow, featuring an almost "flat" diurnal cycle. These findings confirm the similar results reported earlier [1] but also extend them by attributing the flat diurnal cycle only to forest fires and by examining a hypothetical association of the "abnormal" diurnal cycle of FRP with peat fires. The derived diurnal variations of wildfire emissions have been used in the framework of the modeling system employed in our previous studies of the atmospheric effects of the 2010 Russian wildfires [2, 3]. The numerical experiments reveal that while the character of the diurnal variation of wildfire emissions has a rather small impact on the

  2. The effects of magnetic field in plume region on the performance of multi-cusped field thruster

    SciTech Connect

    Hu, Peng Liu, Hui Yu, Daren; Gao, Yuanyuan; Mao, Wei

    2015-10-15

    The performance characteristics of a Multi-cusped Field Thruster depending on the magnetic field in the plume region were investigated. Five magnetic field shielding rings were separately mounted near the exit of discharge channel to decrease the strength of magnetic field in the plume region in different levels, while the magnetic field in the upstream was well maintained. The test results show that the electron current increases with the decrease of magnetic field strength in the plume region, which gives rise to higher propellant utilization and lower current utilization. On the other hand, the stronger magnetic field in the plume region improves the performance at low voltages (high current mode) while lower magnetic field improves the performance at high voltages (low current mode). This work can provide some optimal design ideas of the magnetic strength in the plume region to improve the performance of thruster.

  3. Deforestation as a result of wildfire incidence in the Worobong Forest Reserve in the Eastern Region of Ghana

    NASA Astrophysics Data System (ADS)

    Danquah, S.

    2009-04-01

    This submission captures report on the perennial occurrence of wildfires and their accompanying effects on the inhabitants and the fringe forest communities in the Worobong Forest Reserve within the Eastern part of Ghana. Wildfire continues to be the single serious threat to the sustainable development and management of forest and wildlife resources in Ghana, thus depriving indigenous fringe forest communities of enormous socio-economic benefit of the forest. Locally, fire is used in the preparation of farm lands, tapping of palm-wine, charcoal production, honey harvesting, etc. This paper identifies some of the effects of wildfires on the indigenous communities and various interventions made to address the wildfire menace in the area of study over the years. Keywords: Wildfire, Fringe Forest Communities, Sustainable Development Resources, Socio-Economic Benefits

  4. Wildfire Plumes in the Lower Free Troposphere Over the North Atlantic: the Impact of Plume Travel Height and Age on Enhancement Ratios of Ozone, Nitrogen Oxides and Black Carbon

    NASA Astrophysics Data System (ADS)

    Lapina, K.; Honrath, R. E.; Owen, R. C.; Val Martin, M.; Hyer, E. J.; Fialho, P.; Barata, F.

    2006-12-01

    Fire plumes from Siberia, Alaska, and Canada were sampled during the fire seasons of 2003, 2004 and 2005 at the PICO-NARE station (2225 m asl) in the Azores Islands, a location more than 6 days downwind from the emission sources. Enhancement ratios (excess concentration normalized by the increase in CO) of ozone, total reactive nitrogen oxides (NOy) and equivalent black carbon within these air masses were highly variable. Here, we determine to what extent the travel height and duration of transport of fire emissions to the station can explain this variability. To determine travel height and age of the studied plumes, we use the Lagrangian particle dispersion model FLEXPART. Plume travel height is derived from the FLEXPART retroplume product in conjunction with forward simulations as described by Owen et al. [2006]. To determine plume age we analyze the FLEXPART age spectrum, which provides the distribution of ages since CO tracer emission. Daily biomass-burning emissions of CO and NOx (NO and NO2 were generated with the Boreal Wildland-Fire Emissions Model to provide an input to FLEXPART. The NOx inventory used improved NOx emission factors based on a review of available literature. Emissions were divided into flaming and smoldering, with different release heights. We evaluate the CO simulations by comparing them with CO observed at the station. The consistency of NOx tracer simulations with measured NOy is also assessed. CO and NOx tracer transport and impacts calculated as part of this study may be useful for interpretation of measurements at other locations as well. Owen R. C. et al. 2006. A new method for transport analysis: Lagrangian tracking of pollution plumes using combined forward and backward model simulations. Eos Trans. AGU, this issue. Fall Meet. Suppl.

  5. Vegetation fires in the himalayan region - Aerosol load, black carbon emissions and smoke plume heights

    NASA Astrophysics Data System (ADS)

    Vadrevu, Krishna Prasad; Ellicott, Evan; Giglio, Louis; Badarinath, K. V. S.; Vermote, Eric; Justice, Chris; Lau, William K. M.

    2012-02-01

    In this study, we investigate the potential of multi-satellite datasets for quantifying the biomass burning emissions from the Himalayan region. A variety of satellite products were used for characterizing fire events including active fire counts, burnt areas, aerosol optical depth (AOD) variations, aerosol index and smoke plume heights. Results from the MODerate-resolution Imaging Spectroradiometer (MODIS) fire product suggest March-June as the major fire season with the peak during the April. An average of 3908 fire counts per year were recorded with sixty four percent of the fires occurring in the low elevation areas in the Himalayan Region. We estimate average burnt areas of 1129 sq. km, with the black carbon emissions of 431 Mg, per year. The mean AOD (2005-2010) was 0.287 ± 0.105 (one sigma) with peak values in May. Correlation analysis between the fire counts and AOD resulted in a Pearson correlation coefficient of 0.553; the correlation between the FRP and AOD is relatively weaker ( r = 0.499). Planetary boundary layer height retrieved from the Modern Era Retrospective-Analysis For Research And Applications (MERRA) product suggests typical PBL height of 1000-1200 m during the April-May peak biomass burning season. Cloud-Aerosol Lidar Orthogonal Polarisation (CALIOP) retrievals show the extent of smoke plume heights beyond the planetary boundary layer during the peak biomass burning month of April. However, comparison of fires in the Himalayan region with other regions and comparisons to aerosol index data from the Ozone Monitoring Instrument (OMI) suggest smoke plumes reaching less than 3 km. Our results on fires and smoke plume height relationships provide valuable information for addressing aerosol transport in the region.

  6. Montana Wildfires

    Atmospheric Science Data Center

    2014-05-15

    ... the heights of smoke plumes and wind speeds near the plume sources. Smoke from the Horse Creek fire extends to the southeast over 44 miles ... NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Science Mission Directorate, Washington, D.C. The Terra spacecraft is managed ...

  7. Identification of an ancient mantle reservoir and young recycled materials in the source region of a young mantle plume: Implications for potential linkages between plume and plate tectonics

    NASA Astrophysics Data System (ADS)

    Wang, Xuan-Ce; Li, Zheng-Xiang; Li, Xian-Hua; Li, Jie; Xu, Yi-Gang; Li, Xiang-Hui

    2013-09-01

    Whether or not mantle plumes and plate subduction are genetically linked is a fundamental geoscience question that impinges on our understanding of how the Earth works. Late Cenozoic basalts in Southeast Asia are globally unique in relation to this question because they occur above a seismically detected thermal plume adjacent to deep subducted slabs. In this study, we present new Pb, Sr, Nd, and Os isotope data for the Hainan flood basalts. Together with a compilation of published results, our work shows that less contaminated basaltic samples from the synchronous basaltic eruptions in Hainan-Leizhou peninsula, the Indochina peninsula and the South China Sea seamounts share the same isotopic and geochemical characteristics. They have FOZO-like Sr, Nd, and Pb isotopic compositions (the dominant lower mantle component). These basalts have primitive Pb isotopic compositions that lie on, or very close to, 4.5- to 4.4-Ga geochrons on 207Pb/204Pb versus 206Pb/204Pb diagram, suggesting a mantle source developed early in Earth's history (4.5-4.4 Ga). Furthermore, our detailed geochemical and Sr, Nd, Pb and Os isotopic analyses suggest the presence of 0.5-0.2 Ga recycled components in the late Cenozoic Hainan plume basalts. This implies a mantle circulation rate of >1 cm/yr, which is similar to that of previous estimates for the Hawaiian mantle plume. The identification of the ancient mantle reservoir and young recycled materials in the source region of these synchronous basalts is consistent with the seismically detected lower mantle-rooted Hainan plume that is adjacent to deep subducted slab-like seismic structures just above the core-mantle boundary. We speculate that the continued deep subduction and the presence of a dense segregated basaltic layer may have triggered the plume to rise from the thermal-chemical pile. This work therefore suggests a dynamic linkage between deep subduction and mantle plume generation.

  8. An extended velocity projection method for estimating the subsurface current and density structure for coastal plume regions: An application to the Chesapeake Bay outflow plume

    NASA Astrophysics Data System (ADS)

    Gangopadhyay, Avijit; Shen, Colin Y.; Marmorino, George O.; Mied, Richard P.; Lindemann, Gloria J.

    2005-07-01

    We describe a method for estimating subsurface current and density structure in a coastal region dominated by a plume from a set of surface observations of velocity and density. A detailed application of the method is shown via a case study of the Chesapeake Bay in November 1997. The proposed technique relies on developing a 'plume feature model' from theoretical models and past synoptic observational data sets, and incorporating the feature model into the previously developed velocity projection method [J. Geophys. Res. 106 (2001) 6973] to obtain subsurface current structure within the Ekman layer depth. The primary feature model parameters include the location and extent of the frontal boundary, a simplified gravity current structure, and the spatial gradient of salinity across the frontal head of the plume, which are inferred from remote sensing or minimal strategic in situ observations. For the Chesapeake Bay case study, we show how the proposed method, referred to as 'extended velocity projection', can produce estimates of plume current structure consistent with available ADCP profiles. We assess the sensitivity of the results to feature model parameters, and identify the resolution of spatial salinity gradient as being particularly important. The difference between the density-stratified estimate and the ADCP data can be used to calibrate and improve the zero-order dynamic feature model parameters. This synergistic approach with the extended velocity projection method should be applicable to other coastal plumes and possibly other shallow water features.

  9. Assessing coastal plumes in a region of multiple discharges: the U.S.-Mexico border.

    PubMed

    Kim, Sung Yong; Terrill, Eric J; Cornuelle, Bruce D

    2009-10-01

    The San Diego/Tijuana border region has several environmental challenges with regard to assessing water quality impacts resulting from local coastal ocean discharges for which transport is not hindered by political boundaries. While an understanding of the fate and transport of these discharged plumes has a broad audience, the spatial and temporal scales of the physical processes present numerous challenges in conducting assessment with any fidelity. To address these needs, a data-driven model of the transport of both shoreline and offshore discharges is developed and operated in a hindcast mode for a four-year period to analyze regional connectivity between the discharges and the receiving of waters and the coastline. The plume exposure hindcast model is driven by surface current data generated by a network of high-frequency radars. Observations provided by both boat-based CTD measurements and fixed oceanographic moorings are used with the Roberts-Snyder-Baumgartner model to predict the plume rise height. The surface transport model outputs are compared with shoreline samples of fecal indicator bacteria (FIB), and the skill of the model to assess low water quality is evaluated using receiver operating characteristic (ROC) analysis. PMID:19848160

  10. Formation of secondary organic aerosol in the Paris pollution plume and its impact on surrounding regions

    NASA Astrophysics Data System (ADS)

    Zhang, Q. J.; Beekmann, M.; Freney, E.; Sellegri, K.; Pichon, J. M.; Schwarzenboeck, A.; Colomb, A.; Bourrianne, T.; Michoud, V.; Borbon, A.

    2015-12-01

    Secondary pollutants such as ozone, secondary inorganic aerosol, and secondary organic aerosol formed in the plumes of megacities can affect regional air quality. In the framework of the FP7/EU MEGAPOLI (Megacities: Emissions, urban, regional and Global Atmospheric POLlution and climate effects, and Integrated tools for assessment and mitigation) project, an intensive campaign was launched in the greater Paris region in July 2009. The major objective was to quantify different sources of organic aerosol (OA) within a megacity and in its plume. In this study, we use airborne measurements aboard the French ATR-42 aircraft to evaluate the regional chemistry-transport model CHIMERE within and downwind of the Paris region. Two mechanisms of secondary OA (SOA) formation are used, both including SOA formation from oxidation and chemical aging of primary semivolatile and intermediate volatility organic compounds (SI-SOA) in the volatility basis set (VBS) framework. As for SOA formed from traditional VOC (volatile organic compound) precursors (traditional SOA), one applies chemical aging in the VBS framework adopting different SOA yields for high- and low-NOx environments, while another applies a single-step oxidation scheme without chemical aging. Two emission inventories are used for discussion of emission uncertainties. The slopes of the airborne OA levels versus Ox (i.e., O3 + NO2) show SOA formation normalized with respect to photochemical activity and are used for specific evaluation of the OA scheme in the model. The simulated slopes were overestimated slightly by factors of 1.1, 1.7 and 1.3 with respect to those observed for the three airborne measurements, when the most realistic "high-NOx" yields for traditional SOA formation in the VBS scheme are used in the model. In addition, these slopes are relatively stable from one day to another, which suggests that they are characteristic for the given megacity plume environment. The configuration with increased primary

  11. Vegetation fires, absorbing aerosols and smoke plume characteristics in diverse biomass burning regions of Asia

    NASA Astrophysics Data System (ADS)

    Prasad Vadrevu, Krishna; Lasko, Kristofer; Giglio, Louis; Justice, Chris

    2015-10-01

    In this study, we explored the relationships between the satellite-retrieved fire counts (FC), fire radiative power (FRP) and aerosol indices using multi-satellite datasets at a daily time-step covering ten different biomass burning regions in Asia. We first assessed the variations in MODIS-retrieved aerosol optical depths (AOD’s) in agriculture, forests, plantation and peat land burning regions and then used MODIS FC and FRP (hereafter FC/FRP) to explain the variations in AOD characteristics. Results suggest that tropical broadleaf forests in Laos burn more intensively than the other vegetation fires. FC/FRP-AOD correlations in different agricultural residue burning regions did not exceed 20% whereas in forest regions they reached 40%. To specifically account for absorbing aerosols, we used Ozone Monitoring Instrument-derived aerosol absorption optical depth (AAOD) and UV aerosol index (UVAI). Results suggest relatively high AAOD and UVAI values in forest fires compared with peat and agriculture fires. Further, FC/FRP could explain a maximum of 29% and 53% of AAOD variations, whereas FC/FRP could explain at most 33% and 51% of the variation in agricultural and forest biomass burning regions, respectively. Relatively, UVAI was found to be a better indicator than AOD and AAOD in both agriculture and forest biomass burning plumes. Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations data showed vertically elevated aerosol profiles greater than 3.2-5.3 km altitude in the forest fire plumes compared to 2.2-3.9 km and less than 1 km in agriculture and peat-land fires, respectively. We infer the need to assimilate smoke plume height information for effective characterization of pollutants from different sources.

  12. Plume radiation

    NASA Astrophysics Data System (ADS)

    Dirscherl, R.

    1993-06-01

    The electromagnetic radiation originating from the exhaust plume of tactical missile motors is of outstanding importance for military system designers. Both missile- and countermeasure engineer rely on the knowledge of plume radiation properties, be it for guidance/interference control or for passive detection of adversary missiles. To allow access to plume radiation properties, they are characterized with respect to the radiation producing mechanisms like afterburning, its chemical constituents, and reactions as well as particle radiation. A classification of plume spectral emissivity regions is given due to the constraints imposed by available sensor technology and atmospheric propagation windows. Additionally assessment methods are presented that allow a common and general grouping of rocket motor properties into various categories. These methods describe state of the art experimental evaluation techniques as well as calculation codes that are most commonly used by developers of NATO countries. Dominant aspects influencing plume radiation are discussed and a standardized test technique is proposed for the assessment of plume radiation properties that include prediction procedures. These recommendations on terminology and assessment methods should be common to all employers of plume radiation. Special emphasis is put on the omnipresent need for self-protection by the passive detection of plume radiation in the ultraviolet (UV) and infrared (IR) spectral band.

  13. Evaluation of regionally-collected sideoats grama and big galleta grass for wildfire revegetation in the Eastern Upper Mojave Desert

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increased wildfires in the western U.S. are due to the cyclic accumulation and burning of invasive annual plants such as cheatgrass (Bromus tectorum) and red brome (B. rubens), which reduces native rangeland species and results in servere economic losses and land degradation. Fire was not prevalent...

  14. Evaluation of regionally-collected sideoats grams and big galleta grass for wildfire revegetation in the Eastern Upper Mojave Desert

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increased wildfires in the western U.S. are due to the cyclic accumulation and burning of invasive annual plants such as cheatgrass (Bromus tectorum) and red brome (B. rubens), which reduces native rangeland species and results in severe economic losses and land degradation. Fire was not prevalent ...

  15. Prolonged Effect of Severe Wildfires on Mercury and Other Volatiles in Forest Soils of the Lake Superior Region, USA

    NASA Astrophysics Data System (ADS)

    Cannon, W. F.; Woodruff, L. G.

    2003-12-01

    Soils in Isle Royale National Park, Michigan and Voyageurs National Park, Minnesota show spatial patterns of depletion of total Hg, organic C, Se, total S, P, and Pb within areas of severe, stand-replacing wildfires that burned in 1936, approximately 65 years prior to our current study. The fires burned during a regional drought, were of high severity, and likely consumed a high percentage of organic forest-floor material (O-horizon). A "fire factor" is defined by positive correlations among Hg, C, Se, S, P, and Pb. A factor score for this six-element grouping derived from factor analysis was assigned to each sample. The scores show a high spatial correlation with the footprint of the 1936 fires in both parks, particularly for A-horizon soils. Because many of these elements are volatile, and are highly correlated with soil organic matter, observed depletions likely represent instantaneous atmospheric release during combustion of O-horizon soils coupled with decades-long reduction of organic matter on the forest floor and near-surface soils. Nearly complete combustion of the modern O-horizon would release roughly 1 mg Hg/m2 from the forest floor. Decades-long disturbance resulting from destruction of mature forests and gradual regrowth following fire also play an important role in Hg cycling. Destruction of a mature forest results in decreased deposition of Hg from litterfall as well as throughfall, which contributes Hg by wash-off of dry deposited Hg from foliar surfaces. Hg in forest soils may follow a fire-dependent cycle in which sudden Hg loss during fire is followed by a period of continued Hg loss as evasion exceeds sequestration in the early stand-replacement stage, finally to resume gradual buildup in later stages of forest regrowth. In the Lake Superior region this cycle exceeds 65 years in duration and is of the same magnitude as the fire return interval for this region. Forests that are controlled by fire-induced cycles of stand replacement may also be

  16. Ozone production from wildfires: A critical review

    NASA Astrophysics Data System (ADS)

    Jaffe, Daniel A.; Wigder, Nicole L.

    2012-05-01

    Tropospheric ozone (O3) negatively impacts human health and ecosystems, and is a greenhouse gas. Wildfires are a source of tropospheric O3, and studies show that wildfires are increasing in North America. In this study, we present a critical review of O3 production from wildfires focusing on three key topics: the influence of wildfire emissions on O3 production; the influence of photochemistry on wildfire O3 production; and regulatory issues associated with wildfire O3 production in the United States. Observations of ΔO3/ΔCO range from approximately -0.1 to 0.9, and are caused by the interplay of numerous factors including fire emissions, efficiency of combustion, chemical and photochemical reactions, aerosol effects on chemistry and radiation, and local and downwind meteorological patterns. Using average ΔO3/ΔCO ratios for major biomes, we estimate global wildfires produce approximately 170 Tg of O3 per year, which is 3.5% of all global tropospheric O3 production. Areas of uncertainty in wildfire O3 production include the net effect of aerosols on chemical and photochemical reactions within a fire plume, the impact of oxygenated volatile organic compounds and nitrous acid on O3 production, and the interplay of variables that lead to extreme ΔO3/ΔCO values. Because wildfire frequencies are likely increasing and have been shown to contribute to elevated O3 at air quality monitoring sites, it is important to better understand the emissions, photochemistry and impacts of these fires.

  17. Seeing through the Smoke: A collaborative, multidisciplinary effort to address the interplay between wildfire, climate, air quality, and health

    NASA Astrophysics Data System (ADS)

    Brey, S. J.; Fischer, E. V.; Pierce, J. R.; Ford, B.; Lassman, W.; Pfister, G.; Volckens, J.; Gan, R.; Magzamen, S.; Barnes, E. A.

    2015-12-01

    Exposure to wildfire smoke plumes represents an episodic, uncertain, and potentially growing threat to public health in the western United States. The area burned by wildfires in this region has increased over recent decades, and the future of fires within this region is largely unknown. Future fire emissions are intimately linked to future meteorological conditions, which are uncertain due to the variability of climate model outputs and differences between representative concentration pathways (RCP) scenarios. We know that exposure to wildfire smoke is harmful, particularly for vulnerable populations. However the literature on the heath effects of wildfire smoke exposure is thin, particularly when compared to the depth of information we have on the effects of exposure to smoke of anthropogenic origin. We are exploring the relationships between climate, fires, air quality and public health through multiple interdisciplinary collaborations. We will present several examples from these projects including 1) an analysis of the influence of fire on ozone abundances over the United States, and 2) efforts to use a high-resolution weather forecasting model to nail down exposure within specific smoke plumes. We will also highlight how our team works together. This discussion will include examples of the university structure that facilitates our current collaborations, and the lessons we have learned by seeking stakeholder input to make our science more useful.

  18. Can SHEEP prevent wildfires?

    NASA Astrophysics Data System (ADS)

    yoder, M. R.; Turcotte, D. L.; Rundle, J. B.

    2011-12-01

    Wildfires have been shown to exhibit power law frequency-magnitude statistics with non-cumulative slope, or scaling exponent, b between approximately 1.3 < b < 2.0. Land management practice appear to have increased the rate of large fires (shallower slopes, smaller b values) in some regions. Ironically, aggressive wildfire suppression may be one of the most pernicious culprits. In order to study this problem, we present an agent based variation to the venerable Drossel-Schwabl forest-fire model. In addition to conventional fires, we introduce a number of simulated herbivorous endemic and environmental process (SHEEP) agents to the lattice. SHEEP fracture and trim large clusters to produce steeper frequency-size distributions of fuel clusters and model fires. We discuss the role of cluster shape, or fractal dimension, in the model, and we propose several interpretations of the SHEEP agent. Of particular interest, we discuss the effects of fire suppression as well as wildlife and livestock populations with respect to wildfire hazard.

  19. Molecular flux measurements in the back flow region of a nozzle plume

    NASA Technical Reports Server (NTRS)

    Chirivella, J. E.

    1973-01-01

    A series of tests were conducted to measure the mass flux in the far field of a nozzle plume in a high vacuum with emphasis on the back flow region. The measurements presented provided fairly accurate data for off-axis angles as large as 140 deg (i.e., in the back flow region). This region, since it is well behind the exit plane, is of paticular interest to those concerned with instrument contamination. Usually sensitive spacecraft surfaces are located in the region affected by the back flow. Parameters such as expansion ratio, throat diameter, nozzle lip shape, and plenum (chamber) pressure were varied, carbon dioxide and nitrogen gases were flowed and mass flux measurements were taken using quartz crystal microbalances in as many as nine different locations relative to the tests nozzle. Several conclusions with respect to the effect of nozzle and gas parameters on the amount of back flow mass flux are offered, and it was demonstrated that gaseous mass fluxes, which are not predictable by present theories, are encountered in the region behind the nozzle exit plane. This knowledge is significant if materials incompatible with the gaseous exhaust products are used in this region.

  20. Understanding ozone formation and the radical budget during oil sands plume transport in the Athabasca region of Alberta

    NASA Astrophysics Data System (ADS)

    Moussa, S. G.; Leithead, A.; Li, S. M.; Wang, D. K.; O'brien, J.; Mittermeier, R. L.; Gordon, M.; Staebler, R. M.; Liu, P.; Liggio, J.

    2015-12-01

    The sources of ozone and hydroxyl radicals (OH) in the Alberta oil sands (OS) region have not previously been well characterized. In the summer of 2013, airborne measurements of various volatile organic compounds (VOCs), nitrogen oxides (NOx = NO2+NO) and ozone were made in the Athabasca OS region between August 13 and September 7, 2013. Proton Transfer Reaction-Time of Flight-Mass Spectrometry (PTR-ToF-MS) and whole air samples were used to measure VOCs. A box model incorporating the Master Chemical Mechanism (MCM v3.3), was constrained by measured chemical species and meteorological parameters and used to simulate the evolution of an OS plume. In doing so, an improved understanding of the chemical factors controlling the radical budget and the evolution of ozone in oil sands plumes is achieved. Our results indicate that approximately 20% of the in-plume generated OH radicals are derived from primary sources (HCHO, O3 and HONO photolysis). The remaining OH is derived from the recycling of hydroperoxyl radical (HO2). The HO2 and alkyl peroxyl radical (RO2) chemistry leads to 35% of the ozone formation in the plume, while the main sink for ozone in the plume was via reactions with alkenes (anthropogenic and biogenic). The results of this work will help to characterize ozone formation and the factors influencing its atmospheric fate in the oil sands region.

  1. Ammonia and methane dairy emission plumes in the San Joaquin Valley of California from individual feedlot to regional scales

    NASA Astrophysics Data System (ADS)

    Miller, David J.; Sun, Kang; Tao, Lei; Pan, Da; Zondlo, Mark A.; Nowak, John B.; Liu, Zhen; Diskin, Glenn; Sachse, Glen; Beyersdorf, Andreas; Ferrare, Richard; Scarino, Amy Jo

    2015-09-01

    Agricultural ammonia (NH3) emissions are highly uncertain, with high spatiotemporal variability and a lack of widespread in situ measurements. Regional NH3 emission estimates using mass balance or emission ratio approaches are uncertain due to variable NH3 sources and sinks as well as unknown plume correlations with other dairy source tracers. We characterize the spatial distributions of NH3 and methane (CH4) dairy plumes using in situ surface and airborne measurements in the Tulare dairy feedlot region of the San Joaquin Valley, California, during the NASA Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality 2013 field campaign. Surface NH3 and CH4 mixing ratios exhibit large variability with maxima localized downwind of individual dairy feedlots. The geometric mean NH3:CH4 enhancement ratio derived from surface measurements is 0.15 ± 0.03 ppmv ppmv-1. Individual dairy feedlots with spatially distinct NH3 and CH4 source pathways led to statistically significant correlations between NH3 and CH4 in 68% of the 69 downwind plumes sampled. At longer sampling distances, the NH3:CH4 enhancement ratio decreases 20-30%, suggesting the potential for NH3 deposition as a loss term for plumes within a few kilometers downwind of feedlots. Aircraft boundary layer transect measurements directly above surface mobile measurements in the dairy region show comparable gradients and geometric mean enhancement ratios within measurement uncertainties, even when including NH3 partitioning to submicron particles. Individual NH3 and CH4 plumes sampled at close proximity where losses are minimal are not necessarily correlated due to lack of mixing and distinct source pathways. Our analyses have important implications for constraining NH3 sink and plume variability influences on regional NH3 emission estimates and for improving NH3 emission inventory spatial allocations.

  2. Ammonia and Methane Dairy Emission Plumes in the San Joaquin Valley of California from Individual Feedlot to Regional Scales

    NASA Technical Reports Server (NTRS)

    Miller, David J.; Sun, Kang; Pan, Da; Zondlo, Mark A.; Nowak, John B.; Liu, Zhen; Diskin, Glenn; Sachse, Glen; Beyersdorf, Andreas; Ferrare, Richard; Scarino, Amy J.

    2015-01-01

    Agricultural ammonia (NH3) emissions are highly uncertain, with high spatiotemporal variability and a lack of widespread in situ measurements. Regional NH3 emission estimates using mass balance or emission ratio approaches are uncertain due to variable NH3 sources and sinks as well as unknown plume correlations with other dairy source tracers. We characterize the spatial distributions of NH3 and methane (CH4) dairy plumes using in situ surface and airborne measurements in the Tulare dairy feedlot region of the San Joaquin Valley, California, during the NASA Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality 2013 field campaign. Surface NH3 and CH4 mixing ratios exhibit large variability with maxima localized downwind of individual dairy feedlots. The geometric mean NH3:CH4 enhancement ratio derived from surface measurements is 0.15 +/- 0.03 ppmv ppmv-1. Individual dairy feedlots with spatially distinct NH3 and CH4 source pathways led to statistically significant correlations between NH3 and CH4 in 68% of the 69 downwind plumes sampled. At longer sampling distances, the NH3:CH4 enhancement ratio decreases 20-30%, suggesting the potential for NH3 deposition as a loss term for plumes within a few kilometers downwind of feedlots. Aircraft boundary layer transect measurements directly above surface mobile measurements in the dairy region show comparable gradients and geometric mean enhancement ratios within measurement uncertainties, even when including NH3 partitioning to submicron particles. Individual NH3 and CH4 plumes sampled at close proximity where losses are minimal are not necessarily correlated due to lack of mixing and distinct source pathways. Our analyses have important implications for constraining NH3 sink and plume variability influences on regional NH3 emission estimates and for improving NH3 emission inventory spatial allocations.

  3. Learning to coexist with wildfire.

    PubMed

    Moritz, Max A; Batllori, Enric; Bradstock, Ross A; Gill, A Malcolm; Handmer, John; Hessburg, Paul F; Leonard, Justin; McCaffrey, Sarah; Odion, Dennis C; Schoennagel, Tania; Syphard, Alexandra D

    2014-11-01

    The impacts of escalating wildfire in many regions - the lives and homes lost, the expense of suppression and the damage to ecosystem services - necessitate a more sustainable coexistence with wildfire. Climate change and continued development on fire-prone landscapes will only compound current problems. Emerging strategies for managing ecosystems and mitigating risks to human communities provide some hope, although greater recognition of their inherent variation and links is crucial. Without a more integrated framework, fire will never operate as a natural ecosystem process, and the impact on society will continue to grow. A more coordinated approach to risk management and land-use planning in these coupled systems is needed. PMID:25373675

  4. Mapping erosion-sensitive areas after wildfires using fieldwork, remote sensing, and geographic information systems techniques on a regional scale

    NASA Astrophysics Data System (ADS)

    PéRez-Cabello, F.; de La Riva FernáNdez, J.; Montorio LloveríA, R.; GarcíA-MartíN, A.

    2006-12-01

    Alterations in the hydrological cycle following wildfire due to the loss of ground cover vegetation and changes in soil properties have been documented in many studies. Nevertheless, the rapid process of vegetation recovery reduces such negative effects. Vegetation cover before fire, fire severity, and geophysical properties are important factors that control spatial discontinuities involved in the vegetation-covering process. The objective of this study was to estimate the probability of high erosion in order to map erosion-sensitive areas after fire. The analysis was carried out in different plant communities burnt by summer wildfires in the pre-Pyrenean area (Spain). Three-year Landsat Thematic Mapper (TM) images have been used for mapping wildfire areas and severity levels. Conversion to spectral reflectance has been applied for radiometric correction by normalizing topographic and atmospheric effects. Likewise, other physical variables have also been incorporated into the geographic information system (GIS): vegetation types, parent material, illumination, slope, aspect, and precipitation. The dependent variable has been characterized by means of fieldwork and a photointerpretation process based on high-resolution digital aerial orthophotographs taken 11-12 years after the fire. Different logistic regression models have been used for mapping the probability of erosion. Results indicate that prefire normalized difference vegetation index values and aspect are the most important variables for estimating erosion-sensitive areas after fire (Nagelkerke r2 = 0.66; Kappa values = 0.65). Finally, the use of nonparametric models with environmental digital information based on GIS can facilitate the management of burnt areas.

  5. Alfvenicity of Fluctuations Associated with Kelvin-Helmholtz Instability in Plume-Interplume Region

    NASA Astrophysics Data System (ADS)

    Parhi, S.; Suess, S.; Sulkanen, M.

    1999-05-01

    We study the velocity shear between plumes and the interplume flow in coronal holes. We model these plumes as jets (or, strictly speaking, wakes). Weak and strong magnetic fields are considered both inside and outside the jet for a shear Mach number 6. The shear can be unstable and evolve into a new less sheared pattern. As the instability sets in, the jet first develops a cocoon of intermediate speed flow and slowly a bridge develops between upstream and downstream flows. This marks the onset of jet disruption via what appears to be mass entrainment and fluid instability. This could also be induced by the jet's passage through the accompanying fast shock formation. The jet bends upon crossing the oblique shocks because all streamlines bend away from the shock normal. In a short time the downstream flow just ahead of the bending suffers a change in speed but still maintains or reestablishes supersonic conditions somehow. The transverse velocity here is very low because the instability generated in the disturbed region reduces the shear ahead. The shear ultimately must dissipate. The generation of this instability depends both temporally and spatially on the amount of shear and the time needed for nonlinear growth. To analyse the fluctuations quantitatively we perform a time series analysis at various points inside and adjacent to the jet. Specifically we consider points either in the center of the jet or just outside the transition layer- the initial location of the shear layer. We find the fully developed nonlinear fluctuations are more Alfvenic than magnetosonic in the high beta case than in low beta case.

  6. Wildfires in eastern Texas in August and September 2000: Emissions, aircraft measurements, and impact on photochemistry

    NASA Astrophysics Data System (ADS)

    Junquera, Victoria; Russell, Matthew M.; Vizuete, William; Kimura, Yosuke; Allen, David

    The accuracy of wildfire air pollutant emission estimates was assessed by comparing observations of carbon monoxide (CO) and particulate matter (PM) concentrations in wildfire plumes to predictions of CO and PM concentrations, based on emission estimates and air quality models. The comparisons were done for observations made in southeast Texas in August and September of 2000. The fire emissions were estimated from acreage burned, fuel loading information, and fuel emission factor models. A total of 389 km 2 (96,100 acres) burned in wildfires in the domain encompassing the Houston/Galveston-Beaumont/Port Arthur (HGBPA) area during August and September 2000. On the days of highest wildfire activity, the fires resulted in an estimated 3700 tons of CO emissions, 250 tons of volatile organic carbon (VOC) emissions, 340 tons of PM 2.5, and 50 tons of NO x emissions; estimated CO and VOC emissions from the fires exceeded light duty gasoline vehicle emissions in the Houston area on those days. When the appropriate aircraft data were available, aloft measurements of CO in the fire plumes were compared to concentrations of CO predicted using the emission estimates. Concentrations estimated based on emission predictions and air quality models were within a factor of 2 of the observed values. The estimated emissions from fires were used, together with a gridded photochemical model, to characterize the extent of dispersion of the fire emissions and the photochemistry associated with the fire emissions. Although the dispersion and photochemical impacts varied from fire to fire, for wildfires less than 10,000 acres, the greatest enhancements of CO and ozone concentrations due to the fire emissions were generally confined to regions within 10-100 km of the fire. Within 10 km of these fires, CO concentrations can exceed 2 ppm and ozone concentrations can be enhanced by 60 ppb. The extent of photo-oxidant formation in the plumes was limited by NO x availability and isoprene

  7. Assessing ecosystem response to phosphorus and nitrogen limitation in the Pearl River plume using the Regional Ocean Modeling System (ROMS)

    NASA Astrophysics Data System (ADS)

    Gan, Jianping; Lu, Zhongming; Cheung, Anson; Dai, Minhan; Liang, Linlin; Harrison, Paul J.; Zhao, Xiaozheng

    2014-12-01

    The effect of phosphorus limitation on the Pearl River plume ecosystem, where large gradients in both nitrogen (N) and phosphorus (P) concentrations exist, is investigated in this process-oriented study by coupling the Regional Ocean Modeling System (ROMS) model with a new nitrogen, phosphorus, phytoplankton, zooplankton, and detritus (NPPZD) ecosystem model. The results of the N-based only model of Gan et al. (2010) were compared with those of the new NP-based model for the plume. The inclusion of P-limitation noticeably reduces the total phytoplankton production in the plume in the P-limited near and midfield regions of the plume. However, the nitrate in the plume extends farther downstream and forms a broad area of phytoplankton bloom in the N-limited far field. Moreover, it changes the photosynthetically active radiation and strengthens the subsurface chlorophyll maximum in the near and midfields, but weakens it in the far field. A high N:P ratio of ˜120 in the near field decreases quickly to a low N:P ratio of <13.3 in the far field due to a higher N:P consumption ratio and mixing with ambient waters with a lower N:P ratio. Mortality and coagulation acts as major sinks for phytoplankton production in the near and midfield during the developmental stage of the bloom, but grazing gradually becomes the most important sink for phytoplankton production in the entire plume during the mature stage. It was shown that the magnitudes of the difference between the NP-based and N-based cases decrease sequentially for nutrients, phytoplankton, and zooplankton.

  8. Regional occurrence characteristics of ESF backscatter plumes observed with the VHF radar in Southeast Asia

    NASA Astrophysics Data System (ADS)

    Ning, Baiqi; Li, Guozhu

    The development of the equatorial spread-F (ESF) plumes can be well recorded by steerable backscatter radars operated at and off the magnetic equator due to the fact that the vertically extended plume structures are tracers of magnetically north-south aligned larger scale structures. In this study, the temporal and spatial evolutions of ESF plasma plumes and their smaller scale longitudinal differences in Southeast Asia are investigated using the beam steering capability of the two radars, the Equatorial Atmosphere Radar (EAR) (0.2ºS, 100.3ºE; dip lat 10.4ºS) and the Sanya VHF radar (18.4ºN, 109.6ºE; dip lat 12.8ºN) separated in longitude by ~1000 km. In the beam steering mode of operation, the scanned area at a height of 300 km covers approximately 360 km and 280 km in east-west direction for the EAR and the Sanya radar, respectively. Thus the beam steering measurements by the two radars provide a good spatial coverage, and can be used to study the occurrence and dynamics of equatorial plasma plumes in Southeast Asia and possible short longitude scale differences in their characteristics. We present observations of periodic backscatter plume structures with the EAR and Sanya radar during geomagnetic quiet days and examine the mechanism responsible for the generation of these structures. A tracing analysis on the onset locations of plasma plumes reveals spatially well-separated backscatter plumes, with a maximum east-west wavelength of about 1000 km, periodically generated in longitudes of Southeast Asia. The post-sunset backscatter plumes seen by the Sanya VHF radar are found to be due to the passage of sunset plumes initiated around the longitude of EAR. On the other hand, the EAR measurements show multiple plume structures that developed successively in the radar scanned area with east-west separation of ~50 km, with however, no sunset plasma plume over Sanya at times. This could indicate that the small scale waves, unlike the large scale wave structure

  9. Relative and Absolute Plate Motions, Mantle Plumes and Volcanism in the Arctic region

    NASA Astrophysics Data System (ADS)

    Gaina, C.; Torsvik, T. H.

    2012-04-01

    Seafloor spreading in the North Atlantic ocean from Mesozoic until present day involved relative motion between three major tectonic plates: North America, Greenland and Eurasia and a number of microplates. Relative motions between these tectonic plates and movement of northern Pacific terranes since the Jurassic led to the development of the Arctic region as we know it today. Studying the connection between the two realms involve good knowledge of the development of the North Atlantic and Arctic margins and oceanic basins and ideally, model uncertainties. Here we review the kinematics of North Atlantic and asses the implications of different models for locating the plate boundaries in the Arctic. One set of models implies extension before opening of the Eurasia basin and we postulate that this was accommodated in the proximity of Alpha- Mendeleev Ridge. The origin of (mainly) Cretaceous large igneous activity in the central Arctic (the Alpha Mendeleev Ridge) and in the proximity of rifted margins, the so-called HALIP, is still debated. New models of global plate circuits and the connection with deep mantle are used to re-evaluate a possible link between the Arctic volcanism and mantle plumes.

  10. Physicochemical characterization of aged biomass burning aerosol after long-range transport to Greece from large scale wildfires in Russia and surrounding regions, Summer 2010

    NASA Astrophysics Data System (ADS)

    Diapouli, E.; Popovicheva, O.; Kistler, M.; Vratolis, S.; Persiantseva, N.; Timofeev, M.; Kasper-Giebl, A.; Eleftheriadis, K.

    2014-10-01

    Smoke aerosol emitted by large scale wildfires in the European part of Russia and Ukraine, was transported to Athens, Greece during August 2010 and detected at an urban background site. Measurements were conducted for physico-chemical characterization of the aged aerosol and included on-line monitoring of PM10 and carbonaceous particles mass concentrations, as well as number size distributions and aerosol optical properties. In addition TSP filter samples were analyzed for major inorganic ions, while morphology and composition of particles was studied by individual particle analysis. Results supported the long-range transport of smoke plumes from Ukraine and Russia burning areas indicated by back trajectory analysis. An increase of 50% and 40% on average in organic (OC) and elemental carbon (EC) concentrations respectively, and more than 95% in carbonate carbon (CC) levels was observed for the biomass burning (BB) transport period of August with respect to the previous month of July. Mean 24-h OC/EC ratio was found in the range 3.2-8.5. Single scattering albedo (SSA) was also increased, indicating abundance of light scattering constituents and/or shift of size distributions towards larger particles. Increase in particle size was further supported by a decreasing trend in absorption Angström exponent (AAE). Ion analysis showed major contribution of secondary species (ammonium sulfate and nitrate) and soil components (Ca2+, Mg2+). Non-sea salt K+ exhibited very good correlation with secondary species, indicating the long-range transport of BB smoke as a possible common source. Individual particle analysis of the samples collected during BB-transport event in Athens revealed elevated number of soot externally mixed with fly ash Ca-rich particles. This result is in agreement with the increased OC and CC levels measured, thus pointing towards the main components comprising the aged BB aerosol microstructure.

  11. Processing of analogues of plume fallout in cold regions of Enceladus by energetic electrons

    NASA Astrophysics Data System (ADS)

    Bergantini, A.; Pilling, S.; Nair, B. G.; Mason, N. J.; Fraser, H. J.

    2014-10-01

    Context. Enceladus, a small icy moon of Saturn, is one of the most remarkable bodies in the solar system. This moon is a geologically active object, and despite the lower temperatures on most of its surface, the geothermally heated south polar region presents geysers that spouts a plume made of water (~90%), carbon dioxide, methane, ammonia, and methanol, among other molecules. Most of the upward-moving particles do not have the velocity to escape from the gravitational influence of the moon and fall back to the surface. The molecules in the ice are continuously exposed to ionizing radiation, such as UV and X-rays photons, cosmic rays, and electrons. Over time, the ionizing radiation promotes molecular bond rupture, destroying and also forming molecules, radicals, and fragments. Aims: We analyse the processing of an ice mixture analogue to the Enceladus fallout ice in cold resurfaced areas (north pole) by 1 keV electrons. The main goal is to search for complex species that have not yet been detected in this moon, and to determine relevant physico-chemical parameters, such as destruction and formation cross-sections and the half-life of the studied molecules in the ice. Methods: The experiment consisted of the electron irradiation of an Enceladus-like ice mixture (H2O:CO2:CH4:NH3:CH3OH) in an ultra-high vacuum chamber at 20 K. The analysis was made by infrared spectrometry in the mid-infrared region (4000-800 cm-1 or 2.5-12.5 μm). Results: The absolute dissociation cross-sections of the parent molecules, the formation cross-section of daughter species, and the half-life of the parental species in a simulated Enceladus irradiation scenario were determined. Among the produced species, CO (carbon monoxide), OCN- (cyanate anion), HCONH2 (formamide), and H2CO (formaldehyde) were tentatively detected.

  12. Wildfires Rage in Southern California

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Large plumes of smoke rising from devastating wildfires burning near Los Angeles and San Diego on Sunday, October 26, 2003, are highlighted in this set of images from the Multi-angle Imaging SpectroRadiometer (MISR). These images include a natural color view from MISR's nadir camera (left) and an automated stereo height retrieval (right). The tops of the smoke plumes range in altitude from 500 - 3000 meters, and the stereo retrieval clearly differentiates the smoke from patches of high-altitude cirrus. Plumes are apparent from fires burning near the California-Mexico border, San Diego, Camp Pendleton, the foothills of the San Bernardino Mountains, and in and around Simi Valley. The majority of the smoke is coming from the fires near San Diego and the San Bernardino Mountains.

    The Multiangle Imaging Spectro Radiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82o north and 82o south latitude. These data products were generated from a portion of the imagery acquired during Terra orbit 20510. The panels cover an area of 329 kilometers x 543 kilometers, and utilize data from blocks 62 to 66 within World Reference System-2 path 40.

    MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

  13. Surface Properties Associated With Dust Storm Plume's Point-Source Locations In The Border Region Of The US And Mexico

    NASA Astrophysics Data System (ADS)

    Bleiweiss, M. P.; DuBois, D. W.; Flores, M. I.

    2013-12-01

    Dust storms in the border region of the Southwest US and Northern Mexico are a serious problem for air quality (PM10 exceedances), health (Valley Fever is pandemic in the region) and transportation (road closures and deadly traffic accidents). In order to better understand the phenomena, we are attempting to identify critical characteristics of dust storm sources so that, possibly, one can perform more accurate predictions of events and, thus, mitigate some of the deleterious effects. Besides the emission mechanisms for dust storm production that are tied to atmospheric dynamics, one must know those locations whose source characteristics can be tied to dust production and, therefore, identify locations where a dust storm is eminent under favorable atmospheric dynamics. During the past 13 years, we have observed, on satellite imagery, more than 500 dust events in the region and are in the process of identifying the source regions for the dust plumes that make up an event. Where satellite imagery exists with high spatial resolution (less than or equal to 250m), dust 'plumes' appear to be made up of individual and merged plumes that are emitted from a 'point source' (smaller than the resolution of the imagery). In particular, we have observed events from the ASTER sensor whose spatial resolution is 15m as well as Landsat whose spatial resolution is 30m. Tying these source locations to surface properties such as NDVI, albedo, and soil properties (percent sand, silt, clay, and gravel; soil moisture; etc.) will identify regions with enhanced capability to produce a dust storm. This, along with atmospheric dynamics, will allow the forecast of dust events. The analysis of 10 events from the period 2004-2013, for which we have identified 1124 individual plumes, will be presented.

  14. Landowner response to wildfire risk: Adaptation, mitigation or doing nothing.

    PubMed

    Gan, Jianbang; Jarrett, Adam; Johnson Gaither, Cassandra

    2015-08-15

    Wildfire has brought about ecological, economic, and social consequences that engender human responses in many parts of the world. How to respond to wildfire risk is a common challenge across the globe particularly in areas where lands are controlled by many small private owners because effective wildfire prevention and protection require coordinated efforts of neighboring stakeholders. We explore (i) wildfire response strategies adopted by family forestland owners in the southern United States, one of the most important and productive forest regions in the world, through a landowner survey; and (ii) linkages between the responses of these landowners and their characteristics via multinomial logistic regression. We find that landowners used diverse strategies to respond to wildfire risk, with the most popular responses being "doing nothing" and combined adaptation and mitigation, followed by adaptation or mitigation alone. Landowners who had lost properties to wildfire, lived on their forestlands, had a forest management plan, and were better educated were more likely to proactively respond to wildfire risk. Our results indicate the possibility to enhance the effectiveness of collective action of wildfire risk response by private forestland owners and to coordinate wildfire response with forest conservation and certification efforts. These findings shed new light on engaging private landowners in wildfire management in the study region and beyond. PMID:26074470

  15. Distribution and Fate of Black Carbon Nanoparticles from Regional Urban Pollution and Wildfire at a Large Subalpine Lake in the Western United States

    NASA Astrophysics Data System (ADS)

    Bisiaux, M. M.; Heyvaert, A. C.; Edwards, R.

    2012-04-01

    Emitted to the atmosphere through fire and fossil fuel combustion, refractory black carbon nanoparticles (rBC) impact human health, climate, atmospheric chemistry, and the carbon cycle. Eventually these particles enter aquatic environments, where their distribution, fate and association with other pollutants are still poorly characterized. This study presents results from an evaluation of rBC in the waters of oligotrophic Lake Tahoe and its watershed in the western United States. The study period included a large wildfire within the Tahoe basin, seasonal snowmelt, and a number of storm events that resulted in pulsed urban runoff into the lake with rBC concentrations up to four orders of magnitude higher than mid-lake concentrations. The results show that elevated rBC concentrations from wildfire and urban runoff were rapidly attenuated in the lake, suggesting unexpected aggregation or degradation of the particles that prevent rBC concentrations from building up in the water of this lake, renowned for its clarity. The rBC concentrations were also measured in sediment cores from Lake Tahoe to evaluate the sediment archive as a potential combustion record. The evidence suggests that rBC is efficiently transferred to these sediments, which preserve a local-to-regional scale history of rBC emissions, as revealed by comparison with other pollutant records in the sediment. Rapid removal of rBC soon after entry into the lake has implications for transport of rBC in the global aquatic environment and flux of rBC from continents to the global ocean.

  16. Australian 2009 Black Saturday Bushfire smoke plume in the UTLS region: transport, evolution, and effects

    NASA Astrophysics Data System (ADS)

    Siddaway, Jason; Petelina, Svetlana

    We analyze vertical and horizontal transport and evolution of the Victorian Black Saturday bushfire smoke plume in the stratosphere during the 11 February -30 April 2009 period. Limb-scattered solar radiation measured by the Optical Spectrograph and InfraRed Imager System on the Odin satellite are used for this purpose. For higher aerosol/Rayleigh scattering ratio, the near infrared measurements around 800 nm are considered. According to OSIRIS observations, the smoke plume travelled westward and circled the globe in about 7 weeks from the event, remaining in the tropical channel mainly between 5° and 35° S. It gradually advected upwards from 19 km in mid-February to 23 km in April and its vertical extent varied from 2 to 6 km. During the February-April period, the net plume peak radiance, which is governed by the number, size, and chemical composition of smoke particles, decreased by half in about 19 days. The entire OSIRIS spectrum between 280 and 810 nm is analyzed in order to identify species that cause certain absorption features detected inside the smoke plume at its earlier stages. We also investigate an increase in the lower stratosphere background aerosol levels in 2009-2010, particularly in the southern hemisphere, due to the dispersion of the Black Saturday smoke plume material.

  17. Photochemical processing of organic aerosol at nearby continental sites: contrast between urban plumes and regional aerosol

    NASA Astrophysics Data System (ADS)

    Slowik, J. G.; Brook, J.; Chang, R. Y.-W.; Evans, G. J.; Hayden, K.; Jeong, C.-H.; Li, S.-M.; Liggio, J.; Liu, P. S. K.; McGuire, M.; Mihele, C.; Sjostedt, S.; Vlasenko, A.; Abbatt, J. P. D.

    2011-03-01

    As part of the BAQS-Met 2007 field campaign, Aerodyne time-of-flight aerosol mass spectrometers (ToF-AMS) were deployed at two sites in southwestern Ontario from 17 June to 11 July 2007. One instrument was located at Harrow, ON, a rural, agriculture-dominated area approximately 40 km southeast of the Detroit/Windsor/Windsor urban area and 5 km north of Lake Erie. The second instrument was located at Bear Creek, ON, a rural site approximately 70 km northeast of the Harrow site and 50 km east of Detroit/Windsor. Positive matrix factorization analysis of the combined organic mass spectral dataset yields factors related to secondary organic aerosol (SOA), direct emissions, and a factor tentatively attributed to the reactive uptake of isoprene and/or condensation of its early generation reaction products. This is the first application of PMF to simultaneous AMS measurements at different sites, an approach which allows for self-consistent, direct comparison of the datasets. Case studies are utilized to investigate processing of SOA from (1) fresh emissions from Detroit/Windsor and (2) regional aerosol during periods of inter-site flow. A strong correlation is observed between SOA/excess CO and photochemical age as represented by the NOx/NOy ratio for Detroit/Windsor outflow. Although this correlation is not evident for more aged air, measurements at the two sites during inter-site transport nevertheless show evidence of continued atmospheric processing by SOA production. However, the rate of SOA production decreases with airmass age from an initial value of ~10.1 μg m-3 ppmvCO-1 h-1 for the first ~10 h of plume processing to near-zero in an aged airmass (i.e. after several days). The initial SOA production rate is comparable to the observed rate in Mexico City over similar timescales.

  18. Epidemic cholera spreads like wildfire

    PubMed Central

    Roy, Manojit; Zinck, Richard D.; Bouma, Menno J.; Pascual, Mercedes

    2014-01-01

    Cholera is on the rise globally, especially epidemic cholera which is characterized by intermittent and unpredictable outbreaks that punctuate periods of regional disease fade-out. These epidemic dynamics remain however poorly understood. Here we examine records for epidemic cholera over both contemporary and historical timelines, from Africa (1990–2006) and former British India (1882–1939). We find that the frequency distribution of outbreak size is fat-tailed, scaling approximately as a power-law. This pattern which shows strong parallels with wildfires is incompatible with existing cholera models developed for endemic regions, as it implies a fundamental role for stochastic transmission and local depletion of susceptible hosts. Application of a recently developed forest-fire model indicates that epidemic cholera dynamics are located above a critical phase transition and propagate in similar ways to aggressive wildfires. These findings have implications for the effectiveness of control measures and the mechanisms that ultimately limit the size of outbreaks. PMID:24424273

  19. Wildfires in a warmer climate: Emission fluxes, emission heights, and black carbon concentrations in 2090-2099

    NASA Astrophysics Data System (ADS)

    Veira, A.; Lasslop, G.; Kloster, S.

    2016-04-01

    Global warming is expected to considerably impact wildfire activity and aerosol emission release in the future. Due to their complexity, the future interactions between climate change, wildfire activity, emission release, and atmospheric aerosol processes are still uncertain. Here we use the process-based fire model SPITFIRE within the global vegetation model JSBACH to simulate wildfire activity for present-day climate conditions and future Representative Concentration Pathways (RCPs). The modeled fire emission fluxes and fire radiative power serve as input for the aerosol-climate model ECHAM6-HAM2, which has been extended by a semiempirical plume height parametrization. Our results indicate a general increase in extratropical and a decrease in tropical wildfire activity at the end of the 21st century. Changes in emission fluxes are most pronounced for the strongest warming scenario RCP8.5 (+49% in the extratropics, -37% in the tropics). Tropospheric black carbon (BC) concentrations are similarly affected by changes in emission fluxes and changes in climate conditions with regional variations of up to -50% to +100%. In the Northern Hemispheric extratropics, we attribute a mean increase in aerosol optical thickness of +0.031±0.002 to changes in wildfire emissions. Due to the compensating effects of fire intensification and more stable atmospheric conditions, global mean emission heights change by at most 0.3 km with only minor influence on BC long-range transport. The changes in wildfire emission fluxes for the RCP8.5 scenario, however, may largely compensate the projected reduction in anthropogenic BC emissions by the end of the 21st century.

  20. Wildfire and the future of water supply.

    PubMed

    Bladon, Kevin D; Emelko, Monica B; Silins, Uldis; Stone, Micheal

    2014-08-19

    In many parts of the world, forests provide high quality water for domestic, agricultural, industrial, and ecological needs, with water supplies in those regions inextricably linked to forest health. Wildfires have the potential to have devastating effects on aquatic ecosystems and community drinking water supply through impacts on water quantity and quality. In recent decades, a combination of fuel load accumulation, climate change, extensive droughts, and increased human presence in forests have resulted in increases in area burned and wildfire severity-a trend predicted to continue. Thus, the implications of wildfire for many downstream water uses are increasingly concerning, particularly the provision of safe drinking water, which may require additional treatment infrastructure and increased operations and maintenance costs in communities downstream of impacted landscapes. A better understanding of the effects of wildfire on water is needed to develop effective adaptation and mitigation strategies to protect globally critical water supplies originating in forested environments. PMID:25007310

  1. Thermal analysis of wildfires and effects on global ecosystem cycling

    NASA Technical Reports Server (NTRS)

    Ambrosia, Vincent G.; Brass, James A.

    1988-01-01

    Biomass combustion plays an important role in the earth's biogeochemical cycling. The monitoring of wildfires and their associated variables at global scales is feasible and can lead to predictions of the influence of combustion on biogeochemical cycling and tropospheric chemistry. Remote sensing data collected during the 1985 California wildfire season indicate that the information content of key thermal and infrared/thermal wave band channels centered at 11.5 microns, 3.8 microns, and 2.25 microns are invaluable for discriminating and calculating fire related variables. These variables include fire intensity, rate-of-spread, soil cooling recovery behind the fire front, and plume structure. Coinciding Advanced Very High Resolution Radiometer (AVHRR) data provided information regarding temperature estimations and the movement of the smoke plume from one wildfire into the Los Angeles basin.

  2. Green Science: Wildfires

    ERIC Educational Resources Information Center

    Palliser, Janna

    2012-01-01

    Every summer, fires rage in different areas of the western United States. They are often massive, out of control, and extremely destructive. How do these fires begin and how are they controlled? What are the overall impacts of a wildfire? Are there any benefits of a wildfire? These questions will be addressed in this article. (Contains 3 online…

  3. Improving the Representation of Near Source and Downwind Smoke Plume Chemistry in Regional and Global Air Quality Models

    NASA Astrophysics Data System (ADS)

    Alvarado, M. J.; Lonsdale, C. R.; Yokelson, R. J.; Travis, K.; Lin, J. C.; McNeill, V. F.; Blake, D. R.; Griffith, D. W. T.; Johnson, T. J.; Kreidenweis, S. M.; Lee, T.; May, A.; McMeeking, G. R.; Meinardi, S.; Simpson, I. J.; Sullivan, A.; Urbanski, S. P.; Weise, D.

    2015-12-01

    The complex photochemistry within a biomass burning smoke plume can cause large changes in the concentration, size distribution, composition, and optical properties of the fine particles (PM2.5) emitted by the fires, as well as significant formation of ozone (O3) and organic nitrate species like peroxyacetyl nitrate (PAN). The Aerosol Simulation Program (ASP) is designed to simulate this chemical evolution of biomass burning plumes under a wide variety of conditions, and can be used to parameterize this chemistry in regional and global air quality models. Here we present ASP simulations of the evolution of biomass burning aerosol from South Carolina prescribed fires in October and November of 2011. This data set contains more detailed measurements of the non-methane organic compounds (NMOCs) in the smoke than the data sets previously used to develop and test ASP, allowing for a more detailed evaluation of the model's gas- and particle-phase chemistry. We also assess the potential impact of secondary organic aerosol (SOA) from glyoxal and isoprene epoxydiols (IEPOX) on the growth of biomass burning aerosols by incorporating the simpleGAMMA (Gas-Aerosol Model for Mechanism Analysis) model into ASP. Finally, we will discuss our efforts to use the ASP model to build a sub-grid scale parameterization of the near-source chemistry of biomass burning plumes for use in regional and global air quality models, using examples from the global chemical transport model GEOS-Chem and the stochastic Lagrangian air quality model STILT-Chem.

  4. Airborne measurements and emission estimates of greenhouse gases and other trace constituents from the 2013 California Yosemite Rim wildfire

    NASA Astrophysics Data System (ADS)

    Yates, E. L.; Iraci, L. T.; Singh, H. B.; Tanaka, T.; Roby, M. C.; Hamill, P.; Clements, C. B.; Lareau, N.; Contezac, J.; Blake, D. R.; Simpson, I. J.; Wisthaler, A.; Mikoviny, T.; Diskin, G. S.; Beyersdorf, A. J.; Choi, Y.; Ryerson, T. B.; Jimenez, J. L.; Campuzano-Jost, P.; Loewenstein, M.; Gore, W.

    2016-02-01

    This paper presents airborne measurements of multiple atmospheric trace constituents including greenhouse gases (such as CO2, CH4, O3) and biomass burning tracers (such as CO, CH3CN) downwind of an exceptionally large wildfire. In summer 2013, the Rim wildfire, ignited just west of the Yosemite National Park, California, and burned over 250,000 acres of the forest during the 2-month period (17 August to 24 October) before it was extinguished. The Rim wildfire plume was intercepted by flights carried out by the NASA Ames Alpha Jet Atmospheric eXperiment (AJAX) on 29 August and the NASA DC-8, as part of SEAC4RS (Studies of Emissions, Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys), on 26 and 27 August during its intense, primary burning period. AJAX revisited the wildfire on 10 September when the conditions were increasingly smoldering, with slower growth. The more extensive payload of the DC-8 helped to bridge key measurements that were not available as part of AJAX (e. g. CO). Data analyses are presented in terms of emission ratios (ER), emission factors (EF) and combustion efficiency and are compared with previous wildfire studies. ERs were 8.0 ppb CH4 (ppm CO2)-1 on 26 August, 6.5 ppb CH4 (ppm CO2)-1 on 29 August and 18.3 ppb CH4 (ppm CO2)-1 on 10 September 2013. The increase in CH4 ER from 6.5 to 8.0 ppb CH4 (ppm CO2)-1 during the primary burning period to 18.3 ppb CH4 (ppm CO2)-1 during the fire's slower growth period likely indicates enhanced CH4 emissions from increased smoldering combustion relative to flaming combustion. Given the magnitude of the Rim wildfire, the impacts it had on regional air quality and the limited sampling of wildfire emissions in the western United States to date, this study provides a valuable dataset to support forestry and regional air quality management, including observations of ERs of a wide number of species from the Rim wildfire.

  5. Modeling Wildfire Incident Complexity Dynamics

    PubMed Central

    Thompson, Matthew P.

    2013-01-01

    Wildfire management in the United States and elsewhere is challenged by substantial uncertainty regarding the location and timing of fire events, the socioeconomic and ecological consequences of these events, and the costs of suppression. Escalating U.S. Forest Service suppression expenditures is of particular concern at a time of fiscal austerity as swelling fire management budgets lead to decreases for non-fire programs, and as the likelihood of disruptive within-season borrowing potentially increases. Thus there is a strong interest in better understanding factors influencing suppression decisions and in turn their influence on suppression costs. As a step in that direction, this paper presents a probabilistic analysis of geographic and temporal variation in incident management team response to wildfires. The specific focus is incident complexity dynamics through time for fires managed by the U.S. Forest Service. The modeling framework is based on the recognition that large wildfire management entails recurrent decisions across time in response to changing conditions, which can be represented as a stochastic dynamic system. Daily incident complexity dynamics are modeled according to a first-order Markov chain, with containment represented as an absorbing state. A statistically significant difference in complexity dynamics between Forest Service Regions is demonstrated. Incident complexity probability transition matrices and expected times until containment are presented at national and regional levels. Results of this analysis can help improve understanding of geographic variation in incident management and associated cost structures, and can be incorporated into future analyses examining the economic efficiency of wildfire management. PMID:23691014

  6. Quantifying wildfires exposure for investigating health-related effects

    NASA Astrophysics Data System (ADS)

    Youssouf, H.; Liousse, C.; Roblou, L.; Assamoi, E. M.; Salonen, R. O.; Maesano, C.; Banerjee, S.; Annesi-Maesano, I.

    2014-11-01

    A wildfire is an uncontrolled fire in an area of combustible vegetation that occurs in the countryside or a wilderness area. The United Nation International Strategy for Disaster Reduction estimates that between 3 and 4 million km2 are affected by wildfire annually, with 18 000 km2 occurring in Europe. The Mediterranean region is one of the most affected regions by wildfires in Europe. Nearly 500 000 ha, on average, are burned annually by 50 000 wildfires in the countries of southern Europe bordering the Mediterranean Sea. Wildfires or biomass burning seriously damage ecosystems and affect public health. A major difficulty related to the assessment of health impact of wildfire emissions derives from the complexity of wildfire exposure assessments. Based on the literature, several methods, including satellite data, chemical transport models and, less often, personal exposure monitoring are available. However, few investigations have used methods allowing separating wildfires emissions from air pollutants emissions from urban sources having the same components. An inventory of wildfires occurred in Europe between 2006 and 2010 was obtained in terms of burnt areas, duration and related emissions of major air pollutants (black carbon, particulate matter), as obtained using a hybrid model that allows excluding anthropic sources of air pollution.

  7. Health Impacts of Wildfires

    PubMed Central

    Finlay, Sarah Elise; Moffat, Andrew; Gazzard, Rob; Baker, David; Murray, Virginia

    2012-01-01

    Introduction Wildfires are common globally. Although there has been considerable work done on the health effects of wildfires in countries such as the USA where they occur frequently there has been relatively little work to investigate health effects in the United Kingdom. Climate change may increase the risk of increasing wildfire frequency, therefore there is an urgent need to further understand the health effects and public awareness of wildfires. This study was designed to review current evidence about the health effects of wildfires from the UK standpoint. Methods A comprehensive literature review of international evidence regarding wildfire related health effects was conducted in January 2012. Further information was gathered from authors’ focus groups. Results A review of the published evidence shows that human health can be severely affected by wildfires. Certain populations are particularly vulnerable. Wood smoke has high levels of particulate matter and toxins. Respiratory morbidity predominates, but cardiovascular, ophthalmic and psychiatric problems can also result. In addition severe burns resulting from direct contact with the fire require care in special units and carry a risk of multi – organ complications. The wider health implications from spreading air, water and land pollution are of concern. Access to affected areas and communication with populations living within them is crucial in mitigating risk. Conclusion This study has identified factors that may reduce public health risk from wildfires. However more research is needed to evaluate longer term health effects from wildfires. An understanding of such factors is vital to ensure preparedness within health care services for such events. PMID:23145351

  8. Case study: Wildfire visualization

    SciTech Connect

    Ahrens, J.; McCormick, P.; Bossert, J.; Reisner, J.; Winterkamp, J.

    1997-11-01

    The ability to forecast the progress of crisis events would significantly reduce human suffering and loss of life, the destruction of property, and expenditures for assessment and recovery. Los Alamos National Laboratory has established a scientific thrust in crisis forecasting to address this national challenge. In the initial phase of this project, scientists at Los Alamos are developing computer models to predict the spread of a wildfire. Visualization of the results of the wildfire simulation will be used by scientists to assess the quality of the simulation and eventually by fire personnel as a visual forecast of the wildfire`s evolution. The fire personnel and scientists want the visualization to look as realistic as possible without compromising scientific accuracy. This paper describes how the visualization was created, analyzes the tools and approach that was used, and suggests directions for future work and research.

  9. Modeling the effect of climatological drought on European wildfire extent

    NASA Astrophysics Data System (ADS)

    Stagge, James H.; Dias, Susana; Rego, Francisco; Tallaksen, Lena M.

    2014-05-01

    Wildfires are a natural hazard most commonly associated with the Mediterranean region in Europe, but which can affect all regions and cause significant impact and damage. Because vegetation dryness is a primary factor in both the ignition and spread of wildfires, it is assumed that there is a link between climatological drought and wildfire extent in Europe. The objective of this study is therefore to test this link between wildfire extent, defined by area burned, and several climatological drought indices across all geoclimatic regions of Europe, eventually determining the relative effect and most relevant combination of these indices on fire extent. Using the European Fire Database, compiled by the EU Joint Research Centre, these analyses are performed at the national and sub-national (NUTS 1,2,3) scale for 22 countries. Drought indices used as predictor variables include the Standardized Precipitation Index (SPI) and the Standardized Precipitation-Evapotranspiration Index (SPEI), which calculate anomalies in precipitation and climatic water balance, respectively, accumulated over several periods (1, 2, 3, 6, 9, 12, and 24 months). Climate data is based on the gridded Watch Forcing Dataset ERA-Interim (WFDEI), which spans the duration of the wildfire series (1985-2010). Two methods of analysis are used in this study. First, the annual maximum wildfire extent for each country or region is modeled using multiple linear regression for all possible linear combinations of the drought indices. Second, wildfire extent is modeled individually for each month to determine how the relevant drought indices change throughout the wildfire season. Preliminary results show that, for the majority of European countries, wildfire extent is most strongly related to short-term (2-3 month) SPEI anomalies, which represent a combined lack of precipitation and increased evapotranspiration associated with high temperatures. Longer accumulated dryness (6-9 months) was also related to

  10. The contribution of sub-grid, plume-scale nucleation to global and regional aerosol and CCN concentrations

    NASA Astrophysics Data System (ADS)

    Stevens, R.; Pierce, J. R.

    2013-12-01

    New-particle formation in the plumes of coal-fired power plants and other anthropogenic sulphur sources may be an important source of particles in the atmosphere. It has been unclear, however, how best to reproduce this formation in global and regional aerosol models with grid-box lengths that are 10s of kilometres and larger. The predictive power of these models is thus limited by the resultant uncertainties in aerosol size distributions. Based on the results of the System for Atmospheric Modelling (SAM), a Large-Eddy Simulation/Cloud-Resolving Model (LES/CRM) with online TwO Moment Aerosol Sectional (TOMAS) microphysics, we develop the Predicting Particles Produced in Power-Plant Plumes (P6) parameterization: a computationally-efficient, but physically-based, parameterization that predicts the characteristics of aerosol formed within sulphur-rich plumes based on parameters commonly available in global- and regional-scale models. Given large-scale mean meteorological parameters, emissions from the source, the desired distance from the source, and the mean background SO2, NOx, and condensation sink, the parameterization will predict the fraction of the emitted SO2 that is oxidized to H2SO4, the fraction of that H2SO4 that forms new particles instead of condensing onto preexisting particles, the median diameter of the newly-formed particles, and the number of newly-formed particles per kilogram SO2 emitted. We implement the P6 parameterization in the GEOS-Chem global chemical-transport model in order to evaluate the contributions of coal-fired power plants globally to particle number and CCN concentrations.

  11. Wildfire Danger Potential in California

    NASA Astrophysics Data System (ADS)

    Kafatos, M.; Myoung, B.; Kim, S. H.; Fujioka, F. M.; Kim, J.

    2015-12-01

    Wildfires are an important concern in California (CA) which is characterized by the semi-arid to arid climate and vegetation types. Highly variable winter precipitation and extended hot and dry warm season in the region challenge an effective strategic fire management. Climatologically, the fire season which is based on live fuel moisture (LFM) of generally below 80% in Los Angeles County spans 4 months from mid-July to mid-November, but it has lasted over 7 months in the past several years. This behavior is primarily due to the ongoing drought in CA during the last decade, which is responsible for frequent outbreaks of severe wildfires in the region. Despite their importance, scientific advances for the recent changes in wildfire risk and effective assessments of wildfire risk are lacking. In the present study, we show impacts of large-scale atmospheric circulations on an early start and then extended length of fire seasons. For example, the strong relationships of North Atlantic Oscillation (NAO) with springtime temperature and precipitation in the SWUS that was recently revealed by our team members have led to an examination of the possible impact of NAO on wildfire danger in the spring. Our results show that the abnormally warm and dry spring conditions associated with positive NAO phases can cause an early start of a fire season and high fire risks throughout the summer and fall. For an effective fire danger assessment, we have tested the capability of satellite vegetation indices (VIs) in replicating in situ LFM of Southern CA chaparral ecosystems by 1) comparing seasonal/interannual characteristics of in-situ LFM with VIs and 2) developing an empirical model function of LFM. Unlike previous studies attempting a point-to-point comparison, we attempt to examine the LFM relationship with VIs averaged over different areal coverage with chamise-dominant grids (i.e., 0.5 km to 25 km radius circles). Lastly, we discuss implications of the results for fire danger

  12. Impact of wildfires on size-resolved aerosol composition at a coastal California site

    NASA Astrophysics Data System (ADS)

    Maudlin, L. C.; Wang, Z.; Jonsson, H. H.; Sorooshian, A.

    2015-10-01

    Size-resolved aerosol composition measurements were conducted at a coastal site in central California during the Nucleation in California Experiment (NiCE) between July and August of 2013. The site is just east of ship and marine emission sources and is also influenced by continental pollution and wildfires, such as those near the California-Oregon border which occurred near the end of NiCE. Two micro-orifice uniform deposit impactors (MOUDIs) were used, and water-soluble and elemental compositions were measured. The five most abundant water-soluble species (in decreasing order) were chloride, sodium, non-sea salt (nss) sulfate, ammonium, and nitrate. During wildfire periods, nss K mass concentrations were not enhanced as strongly as other species in the sub-micrometer stages and even decreased in the super-micrometer stages; species other than nss K are more reliable tracers for biomass burning in this region. Chloride levels were reduced in the fire sets likely due to chloride depletion by inorganic and organic acids that exhibited elevated levels in transported plumes. During wildfire periods, the mass size distribution of most dicarboxylic acids changed from unimodal to bimodal with peaks in the 0.32 μm and 1.0-1.8 μm stages. Furthermore, sulfate's peak concentration shifted from the 0.32 μm to 0.56 μm stage, and nitrate also shifted to larger sizes (1.0 μm to 1.8-3.2 μm stages). Mass concentrations of numerous soil tracer species (e.g., Si, Fe) were strongly enhanced in samples influenced by wildfires, especially in the sub-micrometer range. Airborne cloud water data confirm that soil species were associated with fire plumes transported south along the coast. In the absence of biomass burning, cloud condensation nuclei (CCN) composition is dominated by nss sulfate and ammonium, and the water-soluble organic fraction is dominated by methanesulfonate, whereas for the samples influenced by wildfires, ammonium becomes the dominant overall species, and

  13. Ignition of global wildfires at the Cretaceous/Tertiary boundary

    NASA Technical Reports Server (NTRS)

    Melosh, H. J.; Schneider, N. M.; Zahnle, K. J.; Latham, D.

    1990-01-01

    The recent discovery of an apparently global soot layer at the Cretaceous/Tertiary boundary indicates that global wildfires were somehow ignited by the impact of a comet or asteroid. It is shown here that the thermal radiation produced by the ballistic reentry of ejecta condensed from the vapor plume of the impact could have increased the global radiation flux by factors of 50 to 150 times the solar input for periods ranging from one to several hours. This great increase in thermal radiation may have been responsible for the ignition of global wildfires, as well as having deleterious effects on unprotected animal life.

  14. Midcontinent rift volcanism in the Lake Superior region: Sr, Nd, and Pb isotopic evidence for a mantle plume origin

    USGS Publications Warehouse

    Nicholson, S.W.; Shirey, S.B.

    1990-01-01

    Between 1091 and 1098 Ma, most of a 15- to 20-km thickness of dominantly tholeiitic basalt erupted in the Midcontinent Rift System of the Lake Superior region, North America. The Portage Lake Volcanics in Michigan, which are the younget MRS flood basalts, fall into distinctly high- and low-TiO2 types having different liquid lines of descent. Incompatible trace elements in both types of tholeiites are enriched compared to depleted or primitive mantle and both basalt types are isotopically indistinguishable. The isotopic enrichment of the MRS source compared to depleted mantle is striking and must have occurred at least 700 m.y. before 1100 Ma. There are two likely sources for such magmatism: subcontinental lithospheric mantle enriched during the early Proterozoic or enriched mantle derived from an upwelling plume. Decompression melting of an upwelling enriched mantle plume in a region of lithosphere thinned by extension could have successfully generated the enormous volume (850 ?? 103 km3) of relatively homogeneous magma in a restricted time interval. -from Authors

  15. Highly buoyant bent-over plumes in a boundary layer

    NASA Astrophysics Data System (ADS)

    Tohidi, Ali; Kaye, Nigel B.

    2016-04-01

    Highly buoyant plumes, such as wildfire plumes, in low to moderate wind speeds have initial trajectories that are steeper than many industrial waste plumes. They will rise further into the atmosphere before bending significantly. In such cases the plume's trajectory will be influenced by the vertical variation in horizontal velocity of the atmospheric boundary layer. This paper examined the behavior of a plume in an unstratified environment with a power-law ambient velocity profile. Examination of previously published experimental measurements of plume trajectory show that inclusion of the boundary layer velocity profile in the plume model often provides better predictions of the plume trajectory compared to algebraic expressions developed for uniform flow plumes. However, there are many cases in which uniform velocity profile algebraic expressions are as good as boundary layer models. It is shown that it is only important to model the role of the atmospheric boundary layer velocity profile in cases where either the momentum length (square root of source momentum flux divided by the reference wind speed) or buoyancy length (buoyancy flux divided by the reference wind speed cubed) is significantly greater than the plume release height within the boundary layer. This criteria is rarely met with industrial waste plumes, but it is important in modeling wildfire plumes.

  16. Wildfire Perception and Community Change

    ERIC Educational Resources Information Center

    Gordon, Jason S.; Matarrita-Cascante, David; Stedman, Richard C.; Luloff, A. E.

    2010-01-01

    Given increasing political and financial commitments to wildfire preparedness, risk policy demands that risk identification, assessment, and mitigation activities are balanced among diverse resident groups. Essential for this is the understanding of residents' perceptions of wildfire risks. This study compares wildfire-risk perceptions of…

  17. Post-wildfire recovery of water yield in the Sydney Basin water supply catchments: An assessment of the 2001/2002 wildfires

    NASA Astrophysics Data System (ADS)

    Heath, J. T.; Chafer, C. J.; van Ogtrop, F. F.; Bishop, T. F. A.

    2014-11-01

    Wildfire is a recurring event which has been acknowledged by the literature to impact the hydrological cycle of a catchment. Hence, wildfire may have a significant impact on water yield levels within a catchment. In Australia, studies of the effect of fire on water yield have been limited to obligate seeder vegetation communities. These communities regenerate from seed banks in the ground or within woody fruits and are generally activated by fire. In contrast, the Sydney Basin is dominated by obligate resprouter communities. These communities regenerate from fire resistant buds found on the plant and are generally found in regions where wildfire is a regular occurrence. The 2001/2002 wildfires in the Sydney Basin provided an opportunity to investigate the impacts of wildfire on water yield in a number of catchments dominated by obligate resprouting communities. The overall aim of this study was to investigate whether there was a difference in water yield post-wildfire. Four burnt subcatchments and 3 control subcatchments were assessed. A general additive model was calibrated using pre-wildfire data and then used to predict post-wildfire water yield using post-wildfire data. The model errors were analysed and it was found that the errors for all subcatchments showed similar trends for the post-wildfire period. This finding demonstrates that wildfires within the Sydney Basin have no significant medium-term impact on water yield.

  18. Wildfires and Schools

    ERIC Educational Resources Information Center

    National Clearinghouse for Educational Facilities, 2009

    2009-01-01

    This publication discusses conditions that feed wildfires, how a building catches fire, determining the school's risk, creating a survivable space for the school, the importance of maintenance, the fire-resistant school, meeting code requirements, and related flood and mudslide risks. Much of this publication has been adapted for schools from the…

  19. Wildfire Prevention Strategies.

    ERIC Educational Resources Information Center

    National Wildlife Coordinating Group, Boise, ID.

    This document provides information and guidance on wildfire prevention strategies. Chapters include: (1) "Introduction"; (2) "How to Use this Guide"; (3) "Fire Cause Classification"; (4) "Relative Effectiveness"; (5) "Degree of Difficulty"; (6) "Intervention Techniques"; (7) "Prevention Activities"; (8) "Sample Prevention Strategies"; and (9)…

  20. Automated Wildfire Detection Through Artificial Neural Networks

    NASA Technical Reports Server (NTRS)

    Miller, Jerry; Borne, Kirk; Thomas, Brian; Huang, Zhenping; Chi, Yuechen

    2005-01-01

    We have tested and deployed Artificial Neural Network (ANN) data mining techniques to analyze remotely sensed multi-channel imaging data from MODIS, GOES, and AVHRR. The goal is to train the ANN to learn the signatures of wildfires in remotely sensed data in order to automate the detection process. We train the ANN using the set of human-detected wildfires in the U.S., which are provided by the Hazard Mapping System (HMS) wildfire detection group at NOAA/NESDIS. The ANN is trained to mimic the behavior of fire detection algorithms and the subjective decision- making by N O M HMS Fire Analysts. We use a local extremum search in order to isolate fire pixels, and then we extract a 7x7 pixel array around that location in 3 spectral channels. The corresponding 147 pixel values are used to populate a 147-dimensional input vector that is fed into the ANN. The ANN accuracy is tested and overfitting is avoided by using a subset of the training data that is set aside as a test data set. We have achieved an automated fire detection accuracy of 80-92%, depending on a variety of ANN parameters and for different instrument channels among the 3 satellites. We believe that this system can be deployed worldwide or for any region to detect wildfires automatically in satellite imagery of those regions. These detections can ultimately be used to provide thermal inputs to climate models.

  1. Wildfire Impacts Upon US Air Quality for Current and Future Climate Conditions

    NASA Astrophysics Data System (ADS)

    Gonzalez Abraham, R.; Chung, S. H.; Lamb, B. K.; Tao, I.; Avise, J. C.; Stavros, E. N.; Strand, T. T.; McKenzie, D.; Guenther, A. B.; Wiedinmyer, C.; Duhl, T.; Salathe, E. P.; Zhang, Y.

    2011-12-01

    Wildfires can have an important impact on regional air quality as they are large and intermittent sources of primary particulates, secondary aerosols, and ozone precursors. As part of an ongoing analysis on the effects of global change upon US air quality, we report results for current and future decade simulations of the inter-relationship among climate change, wildfires and air quality. The results are reported for the Northwest, Southwest, and Central Rockies regions of the US. Meteorological fields from the ECHAM5 global climate model for the IPCC A1B scenario were downscaled using the Weather Research Forecast (WRF) model to drive the MEGAN biogenic emissions model, a stochastic fire occurrence model, Fire Simulation Builder (FSB), and the CMAQ chemical transport model to predict ozone and aerosol concentrations. Simulations were completed for two nested domains covering most of the northern hemisphere from eastern Asia to North America at 220 km horizontal resolution (hemispheric domain) and covering the continental US at 36 km resolution (CONUS). Sensitivity studies were conducted for representative summer periods with fire occurrence generated from FSB within the current (1995-2004) and future decade (2045-2054) and using current decade historical fire data obtained from the Bureau of Land Management Database. Results are reported in terms of the effects of global change upon fire occurrence, fire plume transport and PM and ozone pollutant levels.

  2. Modeling Study of the Contribution of Wildfires to Ambient Black Carbon Concentrations

    NASA Astrophysics Data System (ADS)

    Chung, S. H.; Gonzalez-Abraham, R.; Lamb, B. K.; Larkin, N. K.; Strand, T.; O'Neill, S.

    2013-12-01

    Wildland fires are a major source of particulate emissions, including black carbon (BC). In combination with other emissions, these BC and particulate emissions can directly lead to air quality degradation, both locally and more regionally. BC and other particulate matter (PM) can also affect climate in various ways, including by scattering and absorbing radiation, modifying cloud formation and properties, and changing snow albedo. BC emissions reduction is a potential strategy for mitigating global warming because it is emitted in large quantities and has a relatively short lifetime in the atmosphere in comparison to long-live greenhouse gases. Due to the highly variable nature of wildland fires, both in terms of fire occurrences on the landscape and the high spatial and temporal variability of fuels, consumption, and emissions, the impact of wildfire emissions varies significantly over the period of the wildfire season as well as inter-annually. In the U.S., while anthropogenic emissions are projected to decrease, as the climate warms wildfire activity is predicted to increase along with the contribution of fire emissions. Thus, a robust analysis of the effects of BC from fire emissions on air quality and climate necessitates a comprehensive, multi-scale study of all fire-related pollutants and other emission sources spanning multiple years of fire data and weather conditions. In this study we apply the WRF-BlueSky-SMOKE-CMAQ regional air-quality modeling system for multi-year (1997-2005) summertime simulations to evaluate the contribution of fire emissions to atmospheric BC and total PM2.5 concentrations. Historical fire records from the Bureau of Land Management are used by the BlueSky framework to calculate fire emissions. Plume rise is calculated by the SMOKE emission processor, taking into account meteorology from the WRF model. These emissions are combined with anthropogenic emissions from the NEI 2002 and biogenic emissions from the MEGAN model. CMAQ is

  3. Development of On-line Wildfire Emissions for the Operational Canadian Air Quality Forecast System

    NASA Astrophysics Data System (ADS)

    Pavlovic, R.; Menard, S.; Chen, J.; Anselmo, D.; Paul-Andre, B.; Gravel, S.; Moran, M. D.; Davignon, D.

    2013-12-01

    An emissions processing system has been developed to incorporate near-real-time emissions from wildfires and large prescribed burns into Environment Canada's real-time GEM-MACH air quality (AQ) forecast system. Since the GEM-MACH forecast domain covers Canada and most of the USA, including Alaska, fire location information is needed for both of these large countries. Near-real-time satellite data are obtained and processed separately for the two countries for organizational reasons. Fire location and fuel consumption data for Canada are provided by the Canadian Forest Service's Canadian Wild Fire Information System (CWFIS) while fire location and emissions data for the U.S. are provided by the SMARTFIRE (Satellite Mapping Automated Reanalysis Tool for Fire Incident Reconciliation) system via the on-line BlueSky Gateway. During AQ model runs, emissions from individual fire sources are injected into elevated model layers based on plume-rise calculations and then transport and chemistry calculations are performed. This 'on the fly' approach to the insertion of emissions provides greater flexibility since on-line meteorology is used and reduces computational overhead in emission pre-processing. An experimental wildfire version of GEM-MACH was run in real-time mode for the summers of 2012 and 2013. 48-hour forecasts were generated every 12 hours (at 00 and 12 UTC). Noticeable improvements in the AQ forecasts for PM2.5 were seen in numerous regions where fire activity was high. Case studies evaluating model performance for specific regions, computed objective scores, and subjective evaluations by AQ forecasters will be included in this presentation. Using the lessons learned from the last two summers, Environment Canada will continue to work towards the goal of incorporating near-real-time intermittent wildfire emissions within the operational air quality forecast system.

  4. An analysis of wildfire prevention

    NASA Technical Reports Server (NTRS)

    Heineke, J. M.; Weissenberger, S.

    1974-01-01

    A model of the production of wildfire ignitions and damages is developed and used to determine wildland activity-regulation decisions, which minimize total expected cost-plus-loss due to wildfires. In this context, the implications of various policy decisions are considered. The resulting decision rules take a form that makes it possible for existing wildfire management agencies to readily adopt them upon collection of the required data.

  5. Linking local wildfire dynamics to pyroCb development

    NASA Astrophysics Data System (ADS)

    McRae, R. H. D.; Sharples, J. J.; Fromm, M.

    2014-12-01

    Extreme wildfires are global phenomena that consistently result in loss of life and property, and further impact the cultural, economic and political stability of communities. In their most extreme form they cause widespread devastation of environmental assets and are capable of impacting the upper troposphere-lower stratosphere through the formation of a thunderstorm within the plume. Such fires are now often observed by a range of remote sensing technologies, which together allow a greater understanding of a fire's complex dynamics. This paper considers one such fire that burnt in the Blue Mountains region of Australia in late-November 2006, that is known to have generated significant pyrocumulonimbus clouds in a series of blow-up events. Observations of this fire are analysed in detail to investigate the localised processes contributing to extreme fire development. In particular, it has been possible to demonstrate for the first time that the most severe instances of pyroconvection were driven by, and not just associated with, extreme local fire dynamics, especially the fire channelling phenomenon, which arises due to an interaction between an active fire, local terrain attributes and critical fire weather, and causes the fire to rapidly transition from a frontal to an areal burning pattern. The impacts of local variations in fire weather and of the atmospheric profile are also discussed, and the ability to predict extreme fire development with state-of-the-art tools is explored.

  6. Linking local wildfire dynamics to pyroCb development

    NASA Astrophysics Data System (ADS)

    McRae, R. H. D.; Sharples, J. J.; Fromm, M.

    2015-03-01

    Extreme wildfires are global phenomena that consistently result in loss of life and property and further impact the cultural, economic and political stability of communities. In their most severe form they cause widespread devastation of environmental assets and are capable of impacting the upper troposphere/lower stratosphere through the formation of a thunderstorm within the plume. Such fires are now often observed by a range of remote-sensing technologies, which together allow a greater understanding of a fire's complex dynamics. This paper considers one such fire that burnt in the Blue Mountains region of Australia in late November 2006, which is known to have generated significant pyrocumulonimbus clouds in a series of blow-up events. Observations of this fire are analysed in detail to investigate the localised processes contributing to extreme fire development. In particular, it has been possible to demonstrate for the first time that the most violent instances of pyroconvection were driven by, and not just associated with, atypical local fire dynamics, especially the fire channelling phenomenon, which arises due to an interaction between an active fire, local terrain attributes and critical fire weather and causes the fire to rapidly transition from a frontal to an areal burning pattern. The impacts of local variations in fire weather and of the atmospheric profile are also discussed, and the ability to predict extreme fire development with state-of-the-art tools is explored.

  7. Wildfire Decision Making Under Uncertainty

    NASA Astrophysics Data System (ADS)

    Thompson, M.

    2013-12-01

    Decisions relating to wildfire management are subject to multiple sources of uncertainty, and are made by a broad range of individuals, across a multitude of environmental and socioeconomic contexts. In this presentation I will review progress towards identification and characterization of uncertainties and how this information can support wildfire decision-making. First, I will review a typology of uncertainties common to wildfire management, highlighting some of the more salient sources of uncertainty and how they present challenges to assessing wildfire risk. This discussion will cover the expanding role of burn probability modeling, approaches for characterizing fire effects, and the role of multi-criteria decision analysis, and will provide illustrative examples of integrated wildfire risk assessment across a variety of planning scales. Second, I will describe a related uncertainty typology that focuses on the human dimensions of wildfire management, specifically addressing how social, psychological, and institutional factors may impair cost-effective risk mitigation. This discussion will encompass decision processes before, during, and after fire events, with a specific focus on active management of complex wildfire incidents. An improved ability to characterize uncertainties faced in wildfire management could lead to improved delivery of decision support, targeted communication strategies, and ultimately to improved wildfire management outcomes.

  8. Why is particulate matter produced by wildfires toxic to lung macrophages?

    SciTech Connect

    Franzi, Lisa M.; Bratt, Jennifer M.; Williams, Keisha M.; Last, Jerold A.

    2011-12-15

    The mechanistic basis of the high toxicity to lung macrophages of coarse PM from the California wildfires of 2008 was examined in cell culture experiments with mouse macrophages. Wildfire PM directly killed macrophages very rapidly in cell culture at relatively low doses. The wildfire coarse PM is about four times more toxic to macrophages on an equal weight basis than the same sized PM collected from normal ambient air (no wildfires) from the same region and season. There was a good correlation between the extent of cytotoxicity and the amount of oxidative stress observed at a given dose of wildfire PM in vitro. Our data implicate NF-{kappa}B signaling in the response of macrophages to wildfire PM, and suggest that most, if not all, of the cytotoxicity of wildfire PM to lung macrophages is the result of oxidative stress. The relative ratio of toxicity and of expression of biomarkers of oxidant stress between wildfire PM and 'normal' PM collected from ambient air is consistent with our previous results in mice in vivo, also suggesting that most, if not all, of the cytotoxicity of wildfire PM to lung macrophages is the result of oxidative stress. Our findings from this and earlier studies suggest that the active components of coarse PM from the wildfire are heat-labile organic compounds. While we cannot rule out a minor role for endotoxin in coarse PM preparations from the collected wildfire PM in our observed results both in vitro and in vivo, based on experiments using the inhibitor Polymyxin B most of the oxidant stress and pro-inflammatory activity observed was not due to endotoxin. -- Highlights: Black-Right-Pointing-Pointer Wildfire coarse PM kills macrophages at lower doses than coarse. Black-Right-Pointing-Pointer Wildfire coarse PM activates the NF-kB pathway at lower doses than ambient. Black-Right-Pointing-Pointer Wildfire coarse PM in vitro and in vivo kill macrophages by oxidative stress.

  9. Analysis of the burning region and plume of a large fire. Technical report, 26 November 1984-26 February 1986

    SciTech Connect

    Small, R.D.; Larson, D.A.; Remetch, D.; Brode, H.L.

    1986-09-30

    The strongly buoyant flow generated in and around a large area fire is analyzed. Jump conditions applicable at the fire periphery are used to affect model-problem closure, thus permitting calculation of induced fire winds independent of a far-field analysis. Combustion processes are modeled by a volume heat addition. The induced flow is compressible, with arbitrary changes in temperature and density allowed. In one parameter limit, a closed-form solution is developed that concisely describes the basic interchanges of energy and momentum as well as the role of pressure gradients in fire-wind generation. The full analysis is applied in simulation of the hydrothermodynamics of a multiple-fuel-bed Flambeau fire. Computed results duplicate observed flow patterns. A parametric analysis explores the influence of combustion-zone dimensions, heating rate, radiation, and turbulent diffusion on the solution for even larger fires. Next, hydrocode solutions are presented for fires of city size with radii of several kilometers and flame heights of 100 m. The atmospheric response as a function of time is illustrated. Vortex motions generated by the fire influence both the inflow and plume structure. A fairly persistent circulatory flow develops below the tropopause. Periodically, however, the tropopause is penetrated, and an upper-level counter-rotating flow develops that may contain some combustion products from the central fire region. Results suggest the formation of distinct smoke strata in the lower atmosphere, with some particulate and aerosol mass entering the stratosphere.

  10. The Human and Physical Determinants of Wildfires and Burnt Areas in Israel.

    PubMed

    Levin, Noam; Tessler, Naama; Smith, Andrew; McAlpine, Clive

    2016-09-01

    Wildfires are expected to increase in Mediterranean landscapes as a result of climate change and changes in land-use practices. In order to advance our understanding of human and physical factors shaping spatial patterns of wildfires in the region, we compared two independently generated datasets of wildfires for Israel that cover approximately the same study period. We generated a site-based dataset containing the location of 10,879 wildfires (1991-2011), and compared it to a dataset of burnt areas derived from MODIS imagery (2000-2011). We hypothesized that the physical and human factors explaining the spatial distribution of burnt areas derived from remote sensing (mostly large fires, >100 ha) will differ from those explaining site-based wildfires recorded by national agencies (mostly small fires, <10 ha). Small wildfires recorded by forestry agencies were concentrated within planted forests and near built-up areas, whereas the largest wildfires were located in more remote regions, often associated with military training areas and herbaceous vegetation. We conclude that to better understand wildfire dynamics, consolidation of wildfire databases should be achieved, combining field reports and remote sensing. As nearly all wildfires in Mediterranean landscapes are caused by human activities, improving the management of forest areas and raising public awareness to fire risk are key considerations in reducing fire danger. PMID:27246121

  11. The Human and Physical Determinants of Wildfires and Burnt Areas in Israel

    NASA Astrophysics Data System (ADS)

    Levin, Noam; Tessler, Naama; Smith, Andrew; McAlpine, Clive

    2016-09-01

    Wildfires are expected to increase in Mediterranean landscapes as a result of climate change and changes in land-use practices. In order to advance our understanding of human and physical factors shaping spatial patterns of wildfires in the region, we compared two independently generated datasets of wildfires for Israel that cover approximately the same study period. We generated a site-based dataset containing the location of 10,879 wildfires (1991-2011), and compared it to a dataset of burnt areas derived from MODIS imagery (2000-2011). We hypothesized that the physical and human factors explaining the spatial distribution of burnt areas derived from remote sensing (mostly large fires, >100 ha) will differ from those explaining site-based wildfires recorded by national agencies (mostly small fires, <10 ha). Small wildfires recorded by forestry agencies were concentrated within planted forests and near built-up areas, whereas the largest wildfires were located in more remote regions, often associated with military training areas and herbaceous vegetation. We conclude that to better understand wildfire dynamics, consolidation of wildfire databases should be achieved, combining field reports and remote sensing. As nearly all wildfires in Mediterranean landscapes are caused by human activities, improving the management of forest areas and raising public awareness to fire risk are key considerations in reducing fire danger.

  12. Effect of photochemical self-action of carbon-containing aerosol: Wildfires

    NASA Astrophysics Data System (ADS)

    Konovalov, I. B.; Berezin, E. V.; Beekmann, M.

    2016-05-01

    It has been shown by numerical simulation that the rate of formation of secondary organic aerosols (SOAs) in smoke plumes caused by vegetation and peat fires under real conditions can significantly depend on the aerosol optical thickness (AOT). The AOT determines the photodissociation rate and hydroxyl radical concentration, which in turn determines the rate of SOA generation as a result of oxidation of semivolatile organic compounds. Quantitative analysis has been carried out for the situation that took place in European Russia during the 2010 Russian wildfires. The state-of-the-art 3D chemical transport model is used in this study; the simulations are optimized and validated using the data of monitoring of the particulate matter in the Moscow region and Finland. The findings indicate that it is important to allow for this effect in studies focused on the analysis and prediction of air pollution due to wildfires, as well as climate and weather studies, whose results may depend on the assumptions about the content and properties of atmospheric carbon-containing aerosol.

  13. Geochemical Characterization of Hydrothermal Plume Fluids From Peridotite- and Basalt- Dominated Regions of the Ultra-Slow Spreading Gakkel Ridge

    NASA Astrophysics Data System (ADS)

    Upchurch, L.; Edmonds, H. N.; Resing, J.; Nakamura, K.; Buck, N.; Liljebladh, B.; Stranne, C.; Tupper, G.; Winsor, P.

    2007-12-01

    Geochemical characterization of hydrothermal plumes initially located during the 2001 AMORE cruise to the Gakkel Ridge was undertaken as part of the 2007 Arctic Gakkel Vents Expedition (AGAVE). One peridotite- and one basalt-dominated area were targeted for this exploration to constrain the range of venting environments found on the Gakkel Ridge, the ultra-slow spreading endmember of the global mid-ocean ridge. CTD hydrocasts at the 7 E peridotite-hosted site relocated the plumes found initially on the AMORE cruise. The target plume was located between 2800 and 2950 meters and exhibited a localized signal in temperature and light scattering. While shipboard analysis of dissolved gases was unavailable at the 7 E site, samples were preserved for manganese and helium measurements. No Eh signal was found at the 7 E site. The 85 E basalt-hosted site has experienced recent volcanic activity and was more extensively studied relative to the 7 E site during the AGAVE cruise. CTD casts detected numerous temperature, light scattering, and Eh plumes at 85 E indicative of multiple hydrothermal sources. Three of the plumes sampled exhibited methane concentrations ranging from 20 nM to greater than 250 nM and hydrogen concentrations ranging from 10nM to 100nM. In situ Eh measurements recorded negative excursions of at least 25 mV in each plume. Associated manganese and particle chemistry samples collected at both sites will be analyzed in time for this meeting.

  14. Suppressing downy brome following wildfires

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Downy brome (Bromus tectorum), more widely known as cheatgrass, has invaded millions of hectares of rangelands throughout the Intermountain West. Downy brome provides an early maturing, fine-textured fuel that has increased the chance, rate, season and spread of wildfires. In July 2006, a wildfire b...

  15. Protect Your Home from Wildfire!

    ERIC Educational Resources Information Center

    PTA Today, 1994

    1994-01-01

    Homes in wooded areas or in the wildland/urban interface are at special risk for wildfire. The article provides a checklist of what to keep on hand to make homes safer from wildfire, focusing on vegetation around the home and maintenance of the yard and home. (SM)

  16. Atlas of climatic controls of wildfire in the western United States

    USGS Publications Warehouse

    Hostetler, S.W.; Bartlein, P.J.; Holman, J.O.

    2006-01-01

    Wildfire behavior depends on several factors including ecologic characteristics, near-term and antecedent climatic conditions,fuel availability and moisture level, weather, and sources of ignition (lightning or human). The variability and interplay of these factors over many spatial and temporal scales present an ongoing challenge to our ability to forecast a given wildfire season. Here we focus on one aspect of wildfire in the western US through a retrospective analysis of wildfire (starts and area burned) and climate over monthly time scales. We consider prefire conditions up to a year preceding fire outbreaks. For our analysis, we used daily and monthly wildfire records and a combination of observed and model-simulated atmospheric and surface climate data. The focus of this report is on monthly wildfire and climate for the period 1980-2000. Although a longer fire record is desirable, the 21-year record is the longest currently available and it is sufficient for the purpose of a first-order regional analysis. We present the main results in the form of a wildfire-climate atlas for 8 subregions of the West that can be used by resource managers to assess current wildfire conditions relative to high, normal, and low fire years in the historical record. Our results clearly demonstrate the link between wildfire conditions and a small set of climatic variables, and our methodology is a framework for providing near-real-time assessments of current wildfire conditions in the West.

  17. Flooding could follow wildfires

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    Summertime wildfires that have already burned about 2.7 million hectares in the United States may cause a double-whammy for property owners by greatly increasing the risk of flooding, according to the Federal Emergency Management Agency or FEMA.FEMA director Joe Allbaugh said, “The loss of trees, ground cover, and other vegetation has greatly increased the possibility of flash floods and mudflows.” Allbaugh said that land scorched and barren from the loss of natural forest barriers can take decades to recover and result in erosion and devastating floods.

  18. Wildfire contribution to world-wide desertification.

    NASA Astrophysics Data System (ADS)

    Neary, D.; Wittenberg, L.; Bautista, S.; Ffolliott, P.

    2009-04-01

    a three-year period (2003 - 2005). In 2005, 338,262 ha of forest land burned. This was a 77% increase over the 10-year burn average of 189,500 ha. Desertification is about the loss of the land's proper hydrologic function, biological productivity, and other ecosystem services as a result of human activities and climate change. It affects one third of the earth's surface and over a billion people. In the past, desertification was considered a problem of only arid, semi-arid, and dry sub-humid areas. However, humid zones can undergo desertification with the wrong combination of human impacts. The Amazon region is an example of where forest harvesting, shifting cut and burn agriculture, and large-scale grazing are producing desertification of a tropical rain forest on a large scale. Some of the environmental consequences of wildfires are vegetation destruction, plant species and type shifts, exotic plant invasions, wildlife habitat destruction, soil erosion, floods, watershed function decline, water supply disruption, and air pollution. All of these are immediate impacts. Some impacts will persist beyond the careers and lifetimes of individuals. Small, isolated areas do not produce noticeable desertification. But, the cumulative effect of multiple, large area, and adjacent fires can be landscape-level desertification. This paper examines wildfire contributions to desertification in regions of the world that are prone to wildfire and climate change.

  19. Atmospheric numerical simulation of the aerosol microphysics and radiative effects in a regional biomass burning smoke plume in South America

    NASA Astrophysics Data System (ADS)

    Longo, K.; Freitas, S.; Silva Dias, M.; Silva Dias, P.; Chatfield, R.

    2003-04-01

    A study about the atmospheric transport of biomass burning emissions in the Amazon and the central of Brazil including its radiative effects is presented. The sources are spatially and temporally distributed and daily assimilated, according to the biomass burning spots defined by GOES-8 ABBA fire products. A fire smoke particles source parameterization, including aerosol particle concentration and optical properties, was used to build the initial smoke plumes associated with biomass burning in tropical forest and savanna. This study is carried out through a numerical simulation of the atmospheric motions using the atmospheric model RAMS "Regional Atmospheric Modeling System" and the coupled microphysics aerosol model CARMA "Community Aerosol &Radiation Model for Atmospheres". In this method the mass conservation equation and aerosol particle process, like nucleation, coagulation, condensation and dry deposition, are resolved for the biomass burning aerosol particles. The advection, in a resolved scale, and turbulent transport, in a sub-grid scale, are resolved using RAMS model parameterizations. A transport sub-grid parameterization, associated to deep and shallow cumulus convection, not explicitly resolved by the model due its low spatial resolution, is introduced. Also, a wet deposition term, coupled to the cumulus parameterization, is taken into account. The methodology is applied to a case study on August 2002 and the responses of the model to the presence of the aerosol particles in the atmosphere are explored. Also the comparison of the simulated smoke haze layer with MODIS products pointed out the usefulness of the sources emissions parameterization and the suitability of the aerosol process description presented here.

  20. Examining Atmospheric and Ecological Drivers of Wildfires, Modeling Wildfire Occurrence in the Southwest United States, and Using Atmospheric Sounding Observations to Verify National Weather Service Spot Forecasts

    NASA Astrophysics Data System (ADS)

    Nauslar, Nicholas J.

    This dissertation is comprised of three different papers that all pertain to wildland fire applications. The first paper performs a verification analysis on mixing height, transport winds, and Haines Index from National Weather Service spot forecasts across the United States. The final two papers, which are closely related, examine atmospheric and ecological drivers of wildfire for the Southwest Area (SWA) (Arizona, New Mexico, west Texas, and Oklahoma panhandle) to better equip operational fire meteorologists and managers to make informed decisions on wildfire potential in this region. The verification analysis here utilizes NWS spot forecasts of mixing height, transport winds and Haines Index from 2009-2013 issued for a location within 50 km of an upper sounding location and valid for the day of the fire event. Mixing height was calculated from the 0000 UTC sounding via the Stull, Holzworth, and Richardson methods. Transport wind speeds were determined by averaging the wind speed through the boundary layer as determined by the three mixing height methods from the 0000 UTC sounding. Haines Index was calculated at low, mid, and high elevation based on the elevation of the sounding and spot forecast locations. Mixing height forecasts exhibited large mean absolute errors and biased towards over forecasting. Forecasts of transport wind speeds and Haines Index outperformed mixing height forecasts with smaller errors relative to their respective means. The rainfall and lightning associated with the North American Monsoon (NAM) can vary greatly intra- and inter-annually and has a large impact on wildfire activity across the SWA by igniting or suppressing wildfires. NAM onset thresholds and subsequent dates are determined for the SWA and each Predictive Service Area (PSA), which are sub-regions used by operational fire meteorologists to predict wildfire potential within the SWA, April through September from 1995-2013. Various wildfire activity thresholds using the number

  1. Smoke Plume Over Eastern Canada

    NASA Technical Reports Server (NTRS)

    2007-01-01

    In late May, a massive smoke plume hundreds of kilometers across blew eastward over New Brunswick toward the Atlantic Ocean. On May 26, 2007, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite captured this image at 11:40 a.m. local time. By the time MODIS took this picture, the smoke appeared to have completely detached itself from the source, a large fire burning in southwestern Quebec, beyond the western edge of this image. In this image, the smoke appears as a gray-beige opaque mass with fuzzy, translucent edges. The plume is thickest in the southwest and diminishes toward the northeast. Just southwest of the plume is a red outline indicating a hotspot an area where MODIS detected anomalously warm surface temperatures, such as those resulting from fires. This hotspot, however, is not the source for this smoke plume. According to a bulletin from the National Oceanic and Atmospheric Administration, the southwestern Quebec fire was the source. According to reports from the Canadian Interagency Forest Fire Centre on May 29, that fire was estimated at 63,211 hectares (156,197 acres), and it was classified as 'being held.' At the same time, more than 20 wildfires burned in Quebec, news sources reported, and firefighters from other Canadian provinces and the United States had been brought in to provide reinforcements for the area's firefighters.

  2. Superfund record of decision (EPA Region 4): Paducah Gaseous Diffusion Plant, Northwest Plume, Paducah, KY, July 1993

    SciTech Connect

    Not Available

    1993-07-01

    This decision document presents the selected remedial action for the Northwest Plume at the Paducah Gaseous Diffusion Plant (PGDP) in Paducah, Kentucky. The primary objective of this interim remedial action is to initiate a first phase remedial action, as an interim action to initiate control of the source and mitigate the spread of contamination in the Northwest plume. This operable unit addresses a portion of the contaminated ground water. Additional interim actions associated with this integrator operable unit are being considered, as well as for other areas of contaminated ground water.

  3. Is the Central Europe more inclinable to wildfires?

    NASA Astrophysics Data System (ADS)

    Mozny, M.; Virag, M.; Bares, D.; Trnka, M.; Zalud, Z.; Hlavinka, P.

    2009-09-01

    Many studies indicate a gradual increase in danger of wildfire in Central Europe. The risk of wildfire differs greatly among individual areas (whether regions or districts), and this difference remains, irrespective of the methods used to describe the danger of wildfires. For this study was used the calculation of the FDI (Fire Danger Index) for 200 stations on the territory of Czech Republic in the period 1961-2008. The FDI model is being developed in the Doksany observatory based on evaluation of weather conditions. FDI model describes danger of wildfire for vegetation covered countryside. There are five levels of danger: 1 - very low risk, 2 - low risk, 3 - moderate risk, 4 - high risk, 5 - very high risk. During processing the model compute upper soil profile moisture, surface moistening and the speed of spread of wildfire. Between years 1991-2008 there was an increase in the average monthly FDI indices in comparison to the period 1961-1990. During this period, a statistically significant trend toward higher indices was found (0.02 FDI index/year). The trend of danger of wildfires growth was evident in all months.

  4. Quantifying the multiscale environmental controls on wildfire from species distribution models

    NASA Astrophysics Data System (ADS)

    Parisien, M.; Moritz, M.

    2007-05-01

    Despite its widespread occurrence globally, wildfire preferentially occupies an environmental middle-ground and is significantly less prevalent in biomes characterized by environmental extremes (e.g., tundra, rainforests, deserts). We evaluated the biophysical "environmental space" of wildfire from regional to continental extents, using methods developed for modeling species distributions ("niche models"). This approach is particularly suitable for the biogeographical study of wildfire, because it simultaneously considers patterns in multiple factors controlling wildfire suitability over large areas. We used the Maxent algorithm to asses relationships between wildfire and environmental predictors for three levels of complexity in variable inclusion at three spatial scales, the conterminous United States, the state of California, and five wildfire-prone ecoregions of California. The resulting models were projected geographically to obtain spatial predictions of wildfire suitability and also projected to other regions to assess their generality and spatial "transferability." The models identified several important variables that were previously unsuspected in the large-scale control of wildfires and successfully predicted the potential range of wildfire among study areas. Models projected to different areas were useful only when they overlapped appreciably with the target area's environmental space, which has implications for creating future models. Application of this approach should allow us to explore the global range of wildfire in a changing climate, the potential for wildfire restoration where it has been "extirpated," and, conversely, the "invasiveness" of wildfire following changes in plant species composition. To our knowledge, it is also the first application of niche models to characterize environmental controls on a process.

  5. Coupling the Biophysical and Social Dimensions of Wildfire Risk to Improve Wildfire Mitigation Planning.

    PubMed

    Ager, Alan A; Kline, Jeffrey D; Fischer, A Paige

    2015-08-01

    We describe recent advances in biophysical and social aspects of risk and their potential combined contribution to improve mitigation planning on fire-prone landscapes. The methods and tools provide an improved method for defining the spatial extent of wildfire risk to communities compared to current planning processes. They also propose an expanded role for social science to improve understanding of community-wide risk perceptions and to predict property owners' capacities and willingness to mitigate risk by treating hazardous fuels and reducing the susceptibility of dwellings. In particular, we identify spatial scale mismatches in wildfire mitigation planning and their potential adverse impact on risk mitigation goals. Studies in other fire-prone regions suggest that these scale mismatches are widespread and contribute to continued wildfire dwelling losses. We discuss how risk perceptions and behavior contribute to scale mismatches and how they can be minimized through integrated analyses of landscape wildfire transmission and social factors that describe the potential for collaboration among landowners and land management agencies. These concepts are then used to outline an integrated socioecological planning framework to identify optimal strategies for local community risk mitigation and improve landscape-scale prioritization of fuel management investments by government entities. PMID:25968881

  6. Characteristics of Borneo and Sumatra fire plume heights and smoke clouds and their impact on regional El Niño-induced drought

    NASA Astrophysics Data System (ADS)

    Tosca, Michael; Randerson, James; Zender, Cs; Flanner, Mg; Nelson, Dl; Diner, Dj; Rasch, Pj; Logan, Ja

    2010-05-01

    During the dry season, anthropogenic fires in tropical forests and peatlands in equatorial Asia produce regionally expansive smoke clouds. We estimated the altitude of smoke clouds from these fires, characterized the sensitivity of these clouds to regional drought and El Niño variability, and investigated their effect on climate. We used the MISR satellite product and MISR INteractive eXplorer (MINX) software to estimate the heights of 382 smoke plumes (smoke with a visible surface source and transport direction) on Borneo and 143 plumes on Sumatra for 2001—2009. In addition, we estimated the altitudes of 10 smoke clouds (opaque regions of smoke with no detectable surface source or transport direction) on Borneo during 2006. Most smoke plumes (84%) were observed during El Niño events (2002, 2004, 2006, and 2009); this is consistent with higher numbers of active fire detections and larger aerosol optical depths observed during El Niño years. Annually averaged plume heights on Borneo were positively correlated to the Oceanic Niño Index (ONI), an indicator of El Niño (r2 = 0.53), and the mean plume height for all El Niño years was 772.5 ± 15.9m, compared to 711.4 ± 28.7m for non-El Niño years. The median altitude of the 10 smoke clouds observed on Borneo during 2006 was 1313m, considerably higher than the median of nearby smoke plumes (787m). The difference in height between individual plumes and regional smoke clouds may be related to deeper planetary boundary layers and injection heights later in the afternoon (after the 10:30am MISR overpass) or other atmospheric mixing processes that occur on synoptic timescales. We investigated the climate response to these expansive smoke clouds using the Community Atmosphere Model (CAM). Climate responses to smoke from two 30 year simulations were compared: one simulation was forced with fire emissions typical of a dry (El Niño) burning year, while the other was forced with emissions typical of a low (La Ni

  7. MISR Images Wildfires in Northwestern US

    NASA Technical Reports Server (NTRS)

    2000-01-01

    MISR image of smoke plumes from devastating wildfires in the northwestern US. This view of the Clearwater and Salmon River Mountains in Idaho was acquired on August 5, 2000 (Terra orbit 3370). The body of water to the left of image center is the Cascade Reservoir, located about 100 km north of Boise and 80 km east of the Snake River. North is at the top, and the image is approximately 380 km across.

    In addition to the huge plumes traversing the mountains in the northern part of the image, smoke accumulating in the lower elevation canyons and plains is visible. This image was generated using data from the MISR camera that looks forward at a steep angle (70.5 degrees). The smoke is far more visible when viewed at this highly oblique angle than it would be in a conventional, straight-downward view. In creating this color composite, data from the blue and green MISR bands, acquired at 1.1-km spatial resolution, were digitally 'sharpened' using 275-m resolution data acquired in the red band.

    MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

    For more information: http://www-misr.jpl.nasa.gov

  8. Large Enhancements of Nitrogen Oxides Over the Central North Atlantic Lower Free Troposphere Resulting From Boreal Wildfires: Observations at the PICO-NARE Station During Summer 2004

    NASA Astrophysics Data System (ADS)

    Val Martin, M.; Honrath, R. E.; Owen, R. C.; Kleissl, J.; Fialho, P.; Pfister, G.; Lapina, K.

    2005-12-01

    Extensive wildfires burned in Alaska and western Canada during the summer of 2004. Boreal wildfires are a large source of trace gases and aerosols in the atmosphere. However, little is known about the impact of their emissions on the nitrogen oxides and O3 levels over the Northern Hemisphere. During the summer of 2004, measurements of NO_x and NO_y were made at the PICO-NARE station (Azores Islands, Portugal, 2225 m asl), a location 5--15 days downwind from the fires. Measurements in 10 fire plumes between July and September were analyzed in combination with CO and aerosol black carbon observations, backward trajectories, satellite images, and MOZART simulations, in order to study the effect of boreal fire emissions on nitrogen oxides levels over the central North Atlantic lower free troposphere, and their further potential for O3 formation over this region. During the fire-impacted periods, NO_x, NO_y, and CO levels were extremely high for such a remote region, with enhancements up to 110 pptv, 1000 pptv, 150 ppbv above background, respectively. NO_y was significantly correlated to CO, with an average enhancement ratio of approximately 6 pptv/ppbv. The magnitude of the NO_y/CO enhancement ratio is a significant fraction (~20%) of the estimated NO_x/CO emission ratio from boreal forest fires and is only moderately smaller than previous measurements closer to fires, indicating limited NO_y removal during transport to the site. In addition to NO_y, NO_x was typically correlated to CO, with an average enhancement ratio of approximately 1 pptv/ppbv. Since the major component of NO_y in boreal fires plumes is believed to be PAN, this suggests that decomposition of PAN to NO_x is a significant source of NO_x in the fire plumes arriving to this region. These observations indicate that nitrogen oxides emissions from wildfires can be efficiently transported to the lower free troposphere over the central North Atlantic region. Furthermore, high levels of NO_x and NO_y in

  9. Assessment of Superflux relative to fisheries research and monitoring. [airborne remote sensing of the Chesapeake bay plume and shelf regions

    NASA Technical Reports Server (NTRS)

    Thomas, J. P.

    1981-01-01

    Some of the findings of the Superflux program relative to fishery research and monitoring are reviewed. The actual and potential influences of the plume on the shelf ecosystem contiguous to the mouth of Chesapeake Bay are described and insights derived from the combined use of in situ and remotely sensed data are presented.

  10. Characteristics of Borneo and Sumatra fire plume heights and smoke clouds and their impact on regional El Niño-induced drought

    NASA Astrophysics Data System (ADS)

    Tosca, Michael; Randerson, James; Zender, Charles; Flanner, Mark; Nelson, David; Diner, David; Rasch, Phil; Logan, Jennifer

    2010-05-01

    During the dry season, anthropogenic fires burn the tropical forests and peatlands of equatorial Asia and produce regionally expansive smoke clouds. We estimated the altitude of smoke from these fires, characterized the sensitivity of this smoke to regional drought and El Niño variability, and investigated its effect on climate. We used the MISR satellite product and MISR INteractive eXplorer (MINX) software to estimate the heights of 382 smoke plumes (smoke with a visible surface source and transport direction) on Borneo and 121 plumes on Sumatra for 2001-2009. In addition, we estimated the altitudes of 10 smoke clouds (opaque regions of smoke with no detectable surface source or transport direction) on Borneo for 2006. Most smoke plumes (80%) were observed during El Niño events (2002, 2004, 2006, 2009); this is consistent with higher aerosol optical depths observed during El Niño-induced drought. Annually averaged plume heights on Borneo were positively correlated to the Oceanic Niño Index (ONI), an indicator of El Niño (r2 = 0.53). The mean plume height for all El Niño years was 765.8 ± 19.7m, compared to 711.4 ± 28.7 for non-El Niño years. The median altitude of all 10 smoke clouds observed on Borneo during 2006 was 1313m, compared to a median 787m for smoke plume grid cells. The area covered by all smoke plumes from 2006 corresponded to approximately three individual smoke clouds. We investigated the climate response to these expansive smoke clouds using the Community Atmosphere Model (CAM). Climate variables from two 30 year simulations were compared: one simulation was forced with fire emissions typical of a dry (El Niño) burning year, while the other was forced with emissions typical of a low (La Niña) burning year. Fire aerosols reduced net shortwave radiation at the surface during August-October by an average of 10% in the region encompassing most of Sumatra and Borneo (90°E-120°E, 5°S-5°N). The reductions in net radiation cooled both ocean

  11. Io Pele plume

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Voyager 1 took this narrow-angle camera image on 5 March 1979 from a distance of 450,000 kilometers. At this geometry, the camera looks straight down through a volcanic plume at one of Io's most active volcanos, Pele. The large heart-shaped feature is the region where Pele's plume falls to the surface. At the center of the 'heart' is the small dark fissure that is the source of the eruption. The Voyager Project is managed by the Jet Propulsion Laboratory for NASA's Office of Space Science.

  12. Seismic Imaging of Mantle Plumes

    NASA Astrophysics Data System (ADS)

    Nataf, Henri-Claude

    The mantle plume hypothesis was proposed thirty years ago by Jason Morgan to explain hotspot volcanoes such as Hawaii. A thermal diapir (or plume) rises from the thermal boundary layer at the base of the mantle and produces a chain of volcanoes as a plate moves on top of it. The idea is very attractive, but direct evidence for actual plumes is weak, and many questions remain unanswered. With the great improvement of seismic imagery in the past ten years, new prospects have arisen. Mantle plumes are expected to be rather narrow, and their detection by seismic techniques requires specific developments as well as dedicated field experiments. Regional travel-time tomography has provided good evidence for plumes in the upper mantle beneath a few hotspots (Yellowstone, Massif Central, Iceland). Beneath Hawaii and Iceland, the plume can be detected in the transition zone because it deflects the seismic discontinuities at 410 and 660 km depths. In the lower mantle, plumes are very difficult to detect, so specific methods have been worked out for this purpose. There are hints of a plume beneath the weak Bowie hotspot, as well as intriguing observations for Hawaii. Beneath Iceland, high-resolution tomography has just revealed a wide and meandering plume-like structure extending from the core-mantle boundary up to the surface. Among the many phenomena that seem to take place in the lowermost mantle (or D''), there are also signs there of the presence of plumes. In this article I review the main results obtained so far from these studies and discuss their implications for plume dynamics. Seismic imaging of mantle plumes is still in its infancy but should soon become a turbulent teenager.

  13. Assessment of Superflux relative to marine science and oceanography. [airborne remote sensing of the Chesapeake Bay plume and shelf regions

    NASA Technical Reports Server (NTRS)

    Esaias, W. E.

    1981-01-01

    A general assessment of the Superflux project is made in relation to marine science and oceanography. It is commented that the program clearly demonstrated the effectiveness of state-of-the-art technology required to study highly dynamic estuarine plumes, and the necessity of a broadly interdisciplinary, interactive remote sensing and shipboard program required to significantly advance the understanding of transport processes and impacts of estuarine outflows.

  14. Assessing the Impact of Active Land Management in Mitigating Wildfire Threat to Source Water Supply Quality

    NASA Astrophysics Data System (ADS)

    Bladon, K. D.; Silins, U.; Emelko, M. B.; Flannigan, M.; Dupont, D.; Robinne, F.; Wang, X.; Parisien, M. A.; Stone, M.; Thompson, D. K.; Tymstra, C.; Schroeder, D.; Kienzle, S. W.; Anderson, A.

    2014-12-01

    The vast majority of surface water supplies in Alberta originates in forested regions of the province, and supports approximately 94 municipal utilities, 208 communities, and 67% of the provincial population. These surface water supplies are highly vulnerable to contamination inputs and changing water conditions associated with wildfires. A provincial scale risk analysis framework is being used to investigate the magnitude and likelihood of wildfire occurrence in source water regions to evaluate the potential for altered water quality and quantity. The initial analysis identified which forested regions and which municipal drinking water treatment facilities are most at risk from wildfire. The efficacy of several current and potential landscape treatments to mitigate wildfire threats, along with the likely outcome of these treatments on mitigation of potential impacts of wildfire to drinking water treatment, are being modeled. A Monte Carlo modeling approach incorporating wildfire regime characteristics is used to simulate the ignition and growth of wildfires and generate outcome distributions for the different mitigation strategies. Cumulative changes in water quality at large river basin scales are being modeled and linked to water treatment impacts with the Soil and Water Assessment Tool (SWAT). A critical foundation of this approach is the close interaction of a large, trans-disciplinary team of researchers capable of integrating highly diverse issues of landscape wildfire dynamics, cross-scale water supply issues, and their linkage to downstream risks to drinking water treatment engineering.

  15. Satellite Observation Highlights of the 2010 Russian Wildfires

    NASA Technical Reports Server (NTRS)

    Witte, Jacquelyn C.; Douglass, Anne R.; Duncan, Bryan N.; daSilva, Arlindo; Torres, Omar

    2010-01-01

    From late-July through mid-August 2010, wildfires raged in western Russia. The resulting thick smoke and biomass burning products were transported over the highly populated Moscow city and surrounding regions, seriously impairing visibility and affecting human health. We demonstrate the uniqueness of the 2010 Russian wildfires by using satellite observations from NASA's Earth Observing System (EOS) platforms. Over Moscow and the region of major fire activity to the southeast, we calculate unprecedented increases in the MODIS fire count record of 178 %, an order of magnitude increase in the MODIS fire radiative power (308%) and OMI absorbing aerosols (255%), and a 58% increase in AIRS total carbon monoxide (CO). The exceptionally high levels of CO are shown to be of comparable strength to the 2006 El Nino wildfires over Indonesia. Both events record CO values exceeding 30x10(exp 7) molec/ square cm.

  16. Impact of wildfire emissions on trace gas and aerosol concentration measured at the Zotino Tall Tower Observatory (ZOTTO) in Central Siberia

    NASA Astrophysics Data System (ADS)

    Panov, A.; Chi, X.; Winderlich, J.; Birmili, W.; Lavrič, J. V.; Andreae, M. O.

    2012-04-01

    Boreal wildfires are large sources of reactive trace gases and aerosols to the atmosphere, accounting for 20% of carbon emissions from global biomass burning. Siberian wildfires are a major extratropical source of carbon monoxide (CO), as well as a significant source of black carbon, smoke aerosols, and other climate-relevant atmospheric gas/particle species. Smoke particles released by Siberian wildfires could be tracked thousands of kilometers downwind in the entire Northern Hemisphere, perturbing regional to global radiation budgets by influencing light scattering and cloud microphysical processes. The boreal regions of the Northern Hemisphere are expected to experience the largest temperature increases, which will likely increase the severity and frequency of fires. Consequently, long-term continuous trace gas and aerosol measurements in central Siberia are vital for assessing the atmospheric impact of Siberian boreal fires on regional to global air quality and climate. Since 2006, the Zotino Tall Tower Facility (ZOTTO; www.zottoproject.org), a unique international research platform for large-scale climatic observations, is operational about 20 km west of the Yenisei river (60.8°N; 89.35°E). A 300 m-tall tower allows regular probing of the mixed part of the boundary layer, which is only moderately influenced by diurnal variations of local surface fluxes and thus, in comparison with surface layer, representative for a larger region. Our investigation of the wildfires' impact on surface air composition in Central Siberia is based on four years of CO/CO2/CH4 and aerosol particle mass data measured at 300 m a.g.l.. Episodes of atmospheric transport from wildfires upwind of the measurements site are identified based on ensembles of HYSPLIT backward trajectories and MODIS active fire products. The emission factors are calculated using the Carbon Mass Balance method. In an effort to simplify combustion to its most fundamental principles, the combustion efficiency

  17. Dynamics of laser ablated colliding plumes

    SciTech Connect

    Gupta, Shyam L.; Pandey, Pramod K.; Thareja, Raj K.

    2013-01-15

    We report the dynamics of single and two collinearly colliding laser ablated plumes of ZnO studied using fast imaging and the spectroscopic measurements. Two dimensional imaging of expanding plume and temporal evolution of various species in interacting zones of plumes are used to calculate plume front velocity, electron temperature, and density of plasma. The two expanding plumes interact with each other at early stage of expansion ({approx}20 ns) resulting in an interaction zone that propagates further leading to the formation of stagnation layer at later times (>150 ns) at the lateral collision front of two plumes. Colliding plumes have larger concentration of higher ionic species, higher temperature, and increased electron density in the stagnation region. A one-to-one correlation between the imaging and optical emission spectroscopic observations in interaction zone of the colliding plumes is reported.

  18. Exhaust Nozzle Plume and Shock Wave Interaction

    NASA Technical Reports Server (NTRS)

    Castner, Raymond S.; Elmiligui, Alaa; Cliff, Susan

    2013-01-01

    Fundamental research for sonic boom reduction is needed to quantify the interaction of shock waves generated from the aircraft wing or tail surfaces with the exhaust plume. Both the nozzle exhaust plume shape and the tail shock shape may be affected by an interaction that may alter the vehicle sonic boom signature. The plume and shock interaction was studied using Computational Fluid Dynamics simulation on two types of convergent-divergent nozzles and a simple wedge shock generator. The nozzle plume effects on the lower wedge compression region are evaluated for two- and three-dimensional nozzle plumes. Results show that the compression from the wedge deflects the nozzle plume and shocks form on the deflected lower plume boundary. The sonic boom pressure signature of the wedge is modified by the presence of the plume, and the computational predictions show significant (8 to 15 percent) changes in shock amplitude.

  19. The mantle transition zone beneath the Afar Depression and adjacent regions: Implications for mantle plumes and hydration

    NASA Astrophysics Data System (ADS)

    Reed, C. A.; Gao, S. S.; Liu, K. H.; Yu, Y.

    2016-03-01

    The Afar Depression and its adjacent areas are underlain by an upper mantle marked by some of the world's largest negative velocity anomalies, which are frequently attributed to the thermal influences of a lower-mantle plume. In spite of numerous studies, however, the existence of a plume beneath the area remains enigmatic, partially due to inadequate quantities of broadband seismic data and the limited vertical resolution at the mantle transition zone (MTZ) depth of the techniques employed by previous investigations. In this study, we use an unprecedented quantity (over 14,500) of P-to-S receiver functions (RFs) recorded by 139 stations from 12 networks to image the 410 and 660 km discontinuities and map the spatial variation of the thickness of the MTZ. Non-linear stacking of the RFs under a 1-D velocity model shows robust P-to-S conversions from both discontinuities, and their apparent depths indicate the presence of an upper mantle low-velocity zone (LVZ) beneath the entire study area. The Afar Depression and the northern Main Ethiopian Rift are characterized by an apparent 40-60 km depression of both MTZ discontinuities and a normal MTZ thickness. The simplest and most probable interpretation of these observations is that the apparent depressions are solely caused by velocity perturbations in the upper mantle and not by temperature or hydration anomalies within the MTZ. Thickening of the MTZ on the order of 15 km beneath the southern Arabian Plate, southern Red Sea and western Gulf of Aden, which comprise the southward extension of the Afro-Arabian Dome, could reflect long-term hydration of the MTZ. A 20 km thinning of the MTZ beneath the western Ethiopian Plateau is observed and is interpreted as evidence for a possible mantle plume stem originating from the lower mantle.

  20. The mantle transition zone beneath the Afar Depression and adjacent regions: implications for mantle plumes and hydration

    NASA Astrophysics Data System (ADS)

    Reed, C. A.; Gao, S. S.; Liu, K. H.; Yu, Y.

    2016-06-01

    The Afar Depression and its adjacent areas are underlain by an upper mantle marked by some of the world's largest negative velocity anomalies, which are frequently attributed to the thermal influences of a lower-mantle plume. In spite of numerous studies, however, the existence of a plume beneath the area remains enigmatic, partially due to inadequate quantities of broad-band seismic data and the limited vertical resolution at the mantle transition zone (MTZ) depth of the techniques employed by previous investigations. In this study, we use an unprecedented quantity (over 14 500) of P-to-S receiver functions (RFs) recorded by 139 stations from 12 networks to image the 410 and 660 km discontinuities and map the spatial variation of the thickness of the MTZ. Non-linear stacking of the RFs under a 1-D velocity model shows robust P-to-S conversions from both discontinuities, and their apparent depths indicate the presence of an upper-mantle low-velocity zone beneath the entire study area. The Afar Depression and the northern Main Ethiopian Rift are characterized by an apparent 40-60 km depression of both MTZ discontinuities and a normal MTZ thickness. The simplest and most probable interpretation of these observations is that the apparent depressions are solely caused by velocity perturbations in the upper mantle and not by deeper processes causing temperature or hydration anomalies within the MTZ. Thickening of the MTZ on the order of 15 km beneath the southern Arabian Plate, southern Red Sea and western Gulf of Aden, which comprise the southward extension of the Afro-Arabian Dome, could reflect long-term hydration of the MTZ. A 20 km thinning of the MTZ beneath the western Ethiopian Plateau is observed and interpreted as evidence for a possible mantle plume stem originating from the lower mantle.

  1. Mapping Wildfires In Nearly Real Time

    NASA Technical Reports Server (NTRS)

    Nichols, Joseph D.; Parks, Gary S.; Denning, Richard F.; Ibbott, Anthony C.; Scott, Kenneth C.; Sleigh, William J.; Voss, Jeffrey M.

    1993-01-01

    Airborne infrared-sensing system flies over wildfire as infrared detector in system and navigation subsystem generate data transmitted to firefighters' camp. There, data plotted in form of map of fire, including approximate variations of temperature. System, called Firefly, reveals position of fires and approximate thermal intensities of regions within fires. Firefighters use information to manage and suppress fires. Used for other purposes with minor modifications, such as to spot losses of heat in urban areas and to map disease and pest infestation in vegetation.

  2. Unifying wildfire models from ecology and statistical physics.

    PubMed

    Zinck, Richard D; Grimm, Volker

    2009-11-01

    Understanding the dynamics of wildfire regimes is crucial for both regional forest management and predicting global interactions between fire regimes and climate. Accordingly, spatially explicit modeling of forest fire ecosystems is a very active field of research, including both generic and highly specific models. There is, however, a second field in which wildfire has served as a metaphor for more than 20 years: statistical physics. So far, there has been only limited interaction between these two fields of wildfire modeling. Here we show that two typical generic wildfire models from ecology are structurally equivalent to the most commonly used model from statistical physics. All three models can be unified to a single model in which they appear as special cases of regrowth-dependent flammability. This local "ecological memory" of former fire events is key to self-organization in wildfire ecosystems. The unified model is able to reproduce three different patterns observed in real boreal forests: fire size distributions, fire shapes, and a hump-shaped relationship between disturbance intensity (average annual area burned) and diversity of succession stages. The unification enables us to bring together insights from both disciplines in a novel way and to identify limitations that provide starting points for further research. PMID:19799499

  3. Why is Particulate Matter Produced by Wildfires Toxic To Lung Macrophages?

    PubMed Central

    Franzi, Lisa M.; Bratt, Jennifer M.; Williams, Keisha M.; Last, Jerold A.

    2011-01-01

    The mechanistic basis of the high toxicity to lung macrophages of coarse PM from the California wildfires of 2008 was examined in cell culture experiments with mouse macrophages. Wildfire PM directly killed macrophages very rapidly in cell culture at relatively low doses. The wildfire coarse PM are about four times more toxic to macrophages on an equal weight basis than the same sized PM collected from normal ambient air (no wildfires) from the same region and season. There was a good correlation between the extent of cytotoxicity and the amount of oxidative stress observed at a given dose of wildfire PM in vitro. Our data implicate NF-kB signaling in the response of macrophages to wildfire PM, and suggest that most, if not all, of the cytotoxicity of wildfire PM to lung macrophages is the result of oxidative stress. The relative ratio of toxicity and of expression of biomarkers of oxidant stress between wildfire PM and “normal” PM collected from ambient air is consistent with our previous results in mice in vivo, also suggesting that most, if not all, of the cytotoxicity of wildfire PM to lung macrophages is the result of oxidative stress. Our findings from this and earlier studies suggest that the active components of coarse PM from the wildfire are heat-labile organic compounds. While we can not rule out a minor role for endotoxin in coarse PM preparations from the collected wildfire PM in our observed results both in vitro and in vivo, based on experiments using the inhibitor Polymyxin B most of the oxidant stress and pro-inflammatory activity observed was not due to endotoxin. PMID:21945489

  4. Why is particulate matter produced by wildfires toxic to lung macrophages?

    PubMed

    Franzi, Lisa M; Bratt, Jennifer M; Williams, Keisha M; Last, Jerold A

    2011-12-01

    The mechanistic basis of the high toxicity to lung macrophages of coarse PM from the California wildfires of 2008 was examined in cell culture experiments with mouse macrophages. Wildfire PM directly killed macrophages very rapidly in cell culture at relatively low doses. The wildfire coarse PM is about four times more toxic to macrophages on an equal weight basis than the same sized PM collected from normal ambient air (no wildfires) from the same region and season. There was a good correlation between the extent of cytotoxicity and the amount of oxidative stress observed at a given dose of wildfire PM in vitro. Our data implicate NF-κB signaling in the response of macrophages to wildfire PM, and suggest that most, if not all, of the cytotoxicity of wildfire PM to lung macrophages is the result of oxidative stress. The relative ratio of toxicity and of expression of biomarkers of oxidant stress between wildfire PM and "normal" PM collected from ambient air is consistent with our previous results in mice in vivo, also suggesting that most, if not all, of the cytotoxicity of wildfire PM to lung macrophages is the result of oxidative stress. Our findings from this and earlier studies suggest that the active components of coarse PM from the wildfire are heat-labile organic compounds. While we cannot rule out a minor role for endotoxin in coarse PM preparations from the collected wildfire PM in our observed results both in vitro and in vivo, based on experiments using the inhibitor Polymyxin B most of the oxidant stress and pro-inflammatory activity observed was not due to endotoxin. PMID:21945489

  5. Impact of drought on wildfires in Iberia

    NASA Astrophysics Data System (ADS)

    Russo, Ana; Gouveia, Célia M.; DaCamara, Carlos; Sousa, Pedro; Trigo, Ricardo M.

    2015-04-01

    Southern European countries, and the Iberian Peninsula (IP) in particular, have been vastly affected by summer wildfires (Trigo et al., 2013). This condition is hampered by the frequent warm and dry meteorological conditions found in summer which play a significant role in the triggering and spreading of wildfires. These meteorological conditions are also particularly important for the onset and end of drought periods, a phenomenon that has recurrently affected the IP (Gouveia et al., 2012). Moreover, the IP corresponds to one of the most sensitive areas to current and future climate change, and recent and future trends towards a dryer and warmer Mediterranean climate (Sousa et al., 2014) will tend to exacerbate these problems. The main scope of this study was to investigate the impact of drought on wildfires' burned areas in the IP. The objective was to examine the correlation between drought, as expressed by both the Standardized Precipitation Index (SPI) and the Standardized Precipitation Evapotranspiration Index (SPEI) (Vicente-Serrano et al., 2010), and wildfire burned areas. The SPI and SPEI were both calculated for 4 large regions (Northwestern, Northern, Southwestern and Eastern) whose spatial patterns and seasonal fire regimes were shown to be related with constraining factors such as topography, vegetation cover and climate conditions (Trigo et al., 2013). In this study, the drought indices were determined for the time scales of 3 and 6 months for August and for 12 months in September, thus representing the summer and annual drought. The correlation between drought and burned areas during July and August was particularly significant for the 3 months SPEI and SPI relatively to the 6 and 12 time scales, which indicates that drought and fires relation is a small-size scale process. Moreover, the correlation between drought and burned areas during July and August was particularly significant for the Northern and Southwestern regions both for SPEI for 3 and 6

  6. Relationship between the Fluorescence Lifetime of Chlorophyll 'a' and Primary Productivity within the Mississippi River Plume and Adjacent Shelf Region

    NASA Technical Reports Server (NTRS)

    Hall, Callie; Miller, Richard L.; Fernandez, Salvador M.; McKee, Brent A.

    2000-01-01

    In situ measurements of chlorophyll fluorescence intensity have been widely used to estimate phytoplankton biomass. However, because the fluorescence quantum yield of chlorophyll a in vivo can be highly variable, measurements of chlorophyll fluorescence intensity cannot be directly correlated with phytoplankton biomass and do not provide information on the physiological state of the phytoplankton under study. Conversely, lifetime-based measurements of chlorophyll fluorescence provide a framework in which photosynthetic rates of phytoplankton can be analyzed according to phytoplankton physiology. Along with the measurement of primary production and ambient nutrient concentrations within the Mississippi River plume in the northern Gulf of Mexico, phytoplankton fluorescence lifetimes were measured using a Fluorescence Lifetime Phytoplankton Analyzer (developed under a NASA Small Business Innovative Research contract to Ciencia, Inc.). Variability of fluorescence lifetimes within the plume can be used as a background from which to interpret variations in the maximum quantum yield of photochemistry. The extent to which nutrient and effluent loading in this dynamic coastal area affect the photosynthetic performance of phytoplankton will be presented as a function of phytoplankton fluorescence lifetimes.

  7. Smoke from Colorado Wildfires

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Hayman fire, situated about 65 kilometers southwest of Denver, Colorado, is the largest fire ever recorded in that state. The amount and distribution of smoke from the Hayman fire and from the Ponil Complex fires south of the New Mexico-Colorado border are portrayed in these views from the Multi-angle Imaging SpectroRadiometer (MISR). The images were captured on June 9, 2002, on the second day of the Hayman fire, when only about 13 percent of the total 137,000 acres eventually consumed had been scorched.

    The image at top-left was acquired by MISR's most oblique (70-degree) forward-viewing camera, and the view at bottom-left was captured by MISR's 26-degree forward-viewing camera. Both left-hand panels are 'false color' views, utilizing near-infrared, red, and blue spectral bands displayed as red, green and blue respectively. With this spectral combination, highly vegetated areas appear red. At top right is a map of aerosol optical depth. This map utilizes the capability of the oblique view angles to measure the abundance of particles in the atmosphere. Haze distributed across the eastern part of the state is indicated by a large number of green pixels, and areas where no retrieval occurred are shown in dark grey. The more oblique perspective utilized within the top panels enhances the appearance of smoke and reveals the haze. In the lower left-hand panel the view is closer to nadir (downward-looking). Here the smoke plumes appear more compact and the haze across eastern Colorado is not detected. The lower right-hand panel is a stereoscopically derived height field that echoes the compact shape of the smoke plumes in the near-nadir image. Results indicate that the smoke plumes reached altitudes of a few kilometers above the surface terrain, or about the same height as the small clouds that appear orange along the bottom edge to the left of center.

    Data used in these visualizations were generated as part of operational processing at the Atmospheric

  8. The worldwide "wildfire" problem.

    PubMed

    Gill, A Malcolm; Stephens, Scott L; Cary, Geoffrey J

    2013-03-01

    The worldwide "wildfire" problem is headlined by the loss of human lives and homes, but it applies generally to any adverse effects of unplanned fires, as events or regimes, on a wide range of environmental, social, and economic assets. The problem is complex and contingent, requiring continual attention to the changing circumstances of stakeholders, landscapes, and ecosystems; it occurs at a variety of temporal and spatial scales. Minimizing adverse outcomes involves controlling fires and fire regimes, increasing the resistance of assets to fires, locating or relocating assets away from the path of fires, and, as a probability of adverse impacts often remains, assisting recovery in the short-term while promoting the adaptation of societies in the long-term. There are short- and long-term aspects to each aspect of minimization. Controlling fires and fire regimes may involve fire suppression and fuel treatments such as prescribed burning or non-fire treatments but also addresses issues associated with unwanted fire starts like arson. Increasing the resistance of assets can mean addressing the design and construction materials of a house or the use of personal protective equipment. Locating or relocating assets can mean leaving an area about to be impacted by fire or choosing a suitable place to live; it can also mean the planning of land use. Assisting recovery and promoting adaptation can involve insuring assets and sharing responsibility for preparedness for an event. There is no single, simple, solution. Perverse outcomes can occur. The number of minimizing techniques used, and the breadth and depth of their application, depends on the geographic mix of asset types. Premises for policy consideration are presented. PMID:23634593

  9. Drainage networks after wildfire

    USGS Publications Warehouse

    Kinner, D.A.; Moody, J.A.

    2005-01-01

    Predicting runoff and erosion from watersheds burned by wildfires requires an understanding of the three-dimensional structure of both hillslope and channel drainage networks. We investigate the small-and large-scale structures of drainage networks using field studies and computer analysis of 30-m digital elevation model. Topologic variables were derived from a composite 30-m DEM, which included 14 order 6 watersheds within the Pikes Peak batholith. Both topologic and hydraulic variables were measured in the field in two smaller burned watersheds (3.7 and 7.0 hectares) located within one of the order 6 watersheds burned by the 1996 Buffalo Creek Fire in Central Colorado. Horton ratios of topologic variables (stream number, drainage area, stream length, and stream slope) for small-scale and large-scale watersheds are shown to scale geometrically with stream order (i.e., to be scale invariant). However, the ratios derived for the large-scale drainage networks could not be used to predict the rill and gully drainage network structure. Hydraulic variables (width, depth, cross-sectional area, and bed roughness) for small-scale drainage networks were found to be scale invariant across 3 to 4 stream orders. The relation between hydraulic radius and cross-sectional area is similar for rills and gullies, suggesting that their geometry can be treated similarly in hydraulic modeling. Additionally, the rills and gullies have relatively small width-to-depth ratios, implying sidewall friction may be important to the erosion and evolutionary process relative to main stem channels.

  10. Wildfire exposure analysis on the national forests in the Pacific Northwest, USA.

    PubMed

    Ager, Alan A; Buonopane, Michelle; Reger, Allison; Finney, Mark A

    2013-06-01

    We analyzed wildfire exposure for key social and ecological features on the national forests in Oregon and Washington. The forests contain numerous urban interfaces, old growth forests, recreational sites, and habitat for rare and endangered species. Many of these resources are threatened by wildfire, especially in the east Cascade Mountains fire-prone forests. The study illustrates the application of wildfire simulation for risk assessment where the major threat is from large and rare naturally ignited fires, versus many previous studies that have focused on risk driven by frequent and small fires from anthropogenic ignitions. Wildfire simulation modeling was used to characterize potential wildfire behavior in terms of annual burn probability and flame length. Spatial data on selected social and ecological features were obtained from Forest Service GIS databases and elsewhere. The potential wildfire behavior was then summarized for each spatial location of each resource. The analysis suggested strong spatial variation in both burn probability and conditional flame length for many of the features examined, including biodiversity, urban interfaces, and infrastructure. We propose that the spatial patterns in modeled wildfire behavior could be used to improve existing prioritization of fuel management and wildfire preparedness activities within the Pacific Northwest region. PMID:23078351

  11. Monitoring the Impacts of Wildfires on Forest Ecosystems and Public Health in the Exo-Urban Environment Using High-Resolution Satellite Aerosol Products from the Visible Infrared Imaging Radiometer Suite (VIIRS)

    PubMed Central

    Huff, Amy K; Kondragunta, Shobha; Zhang, Hai; Hoff, Raymond M

    2015-01-01

    display tailored combinations of AOD and RGB imagery, as well as overlay the VIIRS smoke mask and fire hotspots at pixel resolution (~750-m × 750-m), and zoom into the county level. Two case studies of recent wildfires in the Western US are presented to show how operational users can access and display VIIRS aerosol products to monitor the transport of smoke plumes and evolution of fires in the exo-urban environment on the regional and county scales. The new National Oceanic and Atmospheric Administration (NOAA) Western Region Fire and Smoke Initiative is also discussed, which will enhance IDEA to allow visualization of VIIRS aerosol products down to the neighborhood scale. The new high-resolution VIIRS aerosol products can be used for NRT monitoring of human exposure to smoke, and they can be used to gauge the spread of fires and, thus, provide advanced warning for evacuations and fire suppression efforts, thereby reducing risks to human populations and forest ecosystems in the exo-urban environment. PMID:26078588

  12. Monitoring the Impacts of Wildfires on Forest Ecosystems and Public Health in the Exo-Urban Environment Using High-Resolution Satellite Aerosol Products from the Visible Infrared Imaging Radiometer Suite (VIIRS).

    PubMed

    Huff, Amy K; Kondragunta, Shobha; Zhang, Hai; Hoff, Raymond M

    2015-01-01

    display tailored combinations of AOD and RGB imagery, as well as overlay the VIIRS smoke mask and fire hotspots at pixel resolution (~750-m × 750-m), and zoom into the county level. Two case studies of recent wildfires in the Western US are presented to show how operational users can access and display VIIRS aerosol products to monitor the transport of smoke plumes and evolution of fires in the exo-urban environment on the regional and county scales. The new National Oceanic and Atmospheric Administration (NOAA) Western Region Fire and Smoke Initiative is also discussed, which will enhance IDEA to allow visualization of VIIRS aerosol products down to the neighborhood scale. The new high-resolution VIIRS aerosol products can be used for NRT monitoring of human exposure to smoke, and they can be used to gauge the spread of fires and, thus, provide advanced warning for evacuations and fire suppression efforts, thereby reducing risks to human populations and forest ecosystems in the exo-urban environment. PMID:26078588

  13. Downwelling wind, tides, and estuarine plume dynamics

    NASA Astrophysics Data System (ADS)

    Lai, Zhigang; Ma, Ronghua; Huang, Mingfen; Chen, Changsheng; Chen, Yong; Xie, Congbin; Beardsley, Robert C.

    2016-06-01

    The estuarine plume dynamics under a downwelling-favorable wind condition were examined in the windy dry season of the Pearl River Estuary (PRE) using the PRE primitive-equation Finite-Volume Community Ocean Model (FVCOM). The wind and tide-driven estuarine circulation had a significant influence on the plume dynamics on both local and remote scales. Specifically, the local effect of downwelling-favorable winds on the plume was similar to the theoretical descriptions of coastal plumes, narrowing the plume width, and setting up a vertically uniform downstream current at the plume edge. Tides tended to reduce these plume responses through local turbulent mixing and advection from upstream regions, resulting in an adjustment of the isohalines in the plume and a weakening of the vertically uniform downstream current. The remote effect of downwelling-favorable winds on the plume was due to the wind-induced estuarine sea surface height (SSH), which strengthened the estuarine circulation and enhanced the plume transport accordingly. Associated with these processes, tide-induced mixing tended to weaken the SSH gradient and thus the estuarine circulation over a remote influence scale. Overall, the typical features of downwelling-favorable wind-driven estuarine plumes revealed in this study enhanced our understanding of the estuarine plume dynamics under downwelling-favorable wind conditions.

  14. Wildfire dynamics: Understanding some behavior trends

    NASA Astrophysics Data System (ADS)

    Canfield, Jesse M.

    This dissertation explores wildfire dynamics. Chapters 2 and 3 are peer reviewed journal articles that present an understanding of three-dimensionality in grass fires and how it affects forward rate of spread (ROS) of the fire. In Chapter 2 the numerical model HIGRAD/FIRETEC was used to give arguments supporting that modeling wildfire in a two-dimensional vertical and stream-wise plane does not represent all of the physics that are required to determine a meaningful forward ROS. Chapter 2 inspired the work that makes up chapter 3. In chapter 3, HIGRAD/FIRETEC was again used, to determine the effect that ignition line length has on forward ROS. In both chapters, finger shaped structures were present in the combusting fuels, upstream of the fire front. The fingers correlated with counter-rotating vortex pairs in the gas-phase above them. It was also shown that increasing ignition line length does indeed increase forward ROS, an expected result supported by previous investigations. Results were presented that suggest physical reasons why a spreading grass fire develops flanks that move forward slower than the front of the fire. Chapter 4 describes the gas phase in the planetary boundary layer (PBL), where fires and other phenomena occur. A muti-component gas phase model was derived that represents individual ideal gas species. The mass dependent nature of this model allows the individual species to have dynamic effects on the flow field. The multi-component model was then coupled to HIGRAD to explore three PBL scenarios. The purpose of the first case was to numerically spin-up a moist unstable PBL. The second case used the mixture model to look at a hypothetical scenario representative of the Las Conchas wildfire. In the second case, an idealized column of a gaseous mixture containing heat, dry air, water vapor, and fullerene was initialized over the topography where the Las Conchas fire occurred. The gas column represented an idealized fire plume. As predicted, the

  15. An investigation of methods for injecting emissions from boreal wildfires using WRF-Chem during ARCTAS

    NASA Astrophysics Data System (ADS)

    Sessions, W. R.; Fuelberg, H. E.; Kahn, R. A.; Winker, D. M.

    2010-11-01

    The Weather Research and Forecasting Model (WRF) is considered a "next generation" mesoscale meteorology model. The inclusion of a chemistry module (WRF-Chem) allows transport simulations of chemical and aerosol species such as those observed during NASA's Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) in 2008. The ARCTAS summer deployment phase during June and July coincided with large boreal wildfires in Saskatchewan and Eastern Russia. One of the most important aspects of simulating wildfire plume transport is the height at which emissions are injected. WRF-Chem contains an integrated one-dimensional plume rise model to determine the appropriate injection layer. The plume rise model accounts for thermal buoyancy associated with fires and the local atmospheric stability. This study compares results from the plume model against those of two more traditional injection methods: Injecting within the planetary boundary layer, and in a layer 3-5 km above ground level. Fire locations are satellite derived from the GOES Wildfire Automated Biomass Burning Algorithm (WF_ABBA) and the MODIS thermal hotspot detection. Two methods for preprocessing these fire data are compared: The prep_chem_sources method included with WRF-Chem, and the Naval Research Laboratory's Fire Locating and Monitoring of Burning Emissions (FLAMBE). Results from the simulations are compared with satellite-derived products from the AIRS, MISR and CALIOP sensors. Results show that the FLAMBE pre-processor produces more realistic injection heights than does prep_chem_sources. The plume rise model using FLAMBE provides the best agreement with satellite-observed injection heights. Conversely, when the planetary boundary layer or the 3-5 km AGL layer were filled with emissions, the resulting injection heights exhibit less agreement with observed plume heights. Results indicate that differences in injection heights produce different transport pathways. These

  16. Eucalypt smoke and wildfires

    NASA Astrophysics Data System (ADS)

    Maleknia, Simin D.; Bell, Tina L.; Adams, Mark A.

    2009-01-01

    Eucalypt contributions to biogenic sources of volatile organic compounds (VOCs) in Australia are estimated at teragram (Tg = 1012 g) amounts each year. Biogenic VOCs include plant-specific isoprenoids (isoprene and a range of terpenes) and other reactive organic compounds (i.e., acids, aldehydes and ketones). Atmospheric reactions of VOCs are numerous and many have significant environmental impact. Wildfires increase both the amounts of VOCs released and the complexity of their reactions. Proton-transfer reaction mass spectrometry (PTR-MS), gas chromatography mass spectrometry (GCMS) and direct analysis in real time (DART) mass spectrometry were applied to analyze release of VOCs as a function of temperatures ranging from ambient to combustion. PTR-MS enabled trace level analysis of VOCs from a complex forest atmosphere and revealed the release of terpenes associated with leaf damage during a storm. Temperature profile studies revealed ion abundances (i.e., emissions of VOCs) could be correlated with boiling points and vapor pressures of specific compounds. PTR-MS analysis of VOCs resulting from heating fresh leaf (E. grandis) material suggested that emissions of protonated methanol (m/z 33) and protonated acetaldehyde (m/z 45) were greatest at ~60 °C while m/z 137 and 153 (associated with a series of terpenes) showed monotonic increases in ion abundance over a wide temperature range from ambient to 200 °C. GCMS analysis of fresh and senescent leaves of E. grandis showed that a series of VOCs (ethylvinylketone, diethylketone, 2-ethylfuran, hexanal and hexenals) are present only in fresh leaves while several terpenes ([alpha] and [beta] pinenes, [alpha]-phellandrene, eucalyptol, [gamma]-terpinene) were common in both. DART analysis of fresh leaf and stem of E. sideroxylon identified tissue-specific VOCs (e.g., methanol and ethanol were more abundant in stems). PTR-MS combustion studies of senescent leaves (E. grandis) identified two distinct, temperature

  17. Wildfire: A Family Activity Book.

    ERIC Educational Resources Information Center

    WGBH-TV, Boston, MA.

    This family activity book provides information for discovering and demonstrating the science of fire--how firefighters decide which fires to let burn and which to put out, how fires start and spread, and what to do when they flare up. Chapters include: (1) "A Game about Wildfire"; (2) "Create a Fire Safety Commercial"; (3) "Make a Fire Escape…

  18. Wildfire on Karst: an Overview

    NASA Astrophysics Data System (ADS)

    Coleborn, K.; Lupingna, A.; Flemons, I.; Nagra, G.; Treble, P. C.; Andersen, M. S.; Baker, A.; Tozer, M.; Fairchild, I. J.; Baker, A.; Meehan, S.

    2015-12-01

    Wildfires dramatically change the surface environment by removing vegetation and soil microbial communities and altering soil structure and geochemistry. Karst subsurface processes such as dissolution, cave formation and speleothem deposition are sensitive to environmental change, which is precisely why speleothems have been widely used as recorders of surface and climate change at an annual to millennial temporal scale. The effect of fire on karst processes is poorly understood. We hypothesise that a wildfire induced change at the surface will impact karst dissolution and precipitation processes. Firstly, sterilisation of the soil by heating causes a reduction in soil CO2 concentration which is a key component in dissolution processes. Secondly, removal of vegetation alters surface albedo and soil water storage properties. This could change the hydrology and isotopic signature of speleothem-forming drip water. We also hypothesise that a wildfire will produce a unique biogeochemical signature due to a change in the organic and inorganic properties of soil, which can be transported into speleothem forming drip water. Fire changes the organic matter character which is an important component in the mobilisation and transport of trace metals. Combustion of vegetation results in addition of ash derived minerals to the soil. Quantifying the biogeochemical signature from a burnt landscape will enable us to determine whether this wildfire signature is preserved in speleothems. This would provide the opportunity to use speleothems as recorders of fire history for the first time. Determining the impact of fire on karst processes would inform fire management and karst conservation policies.

  19. Simulation for the expansion of the wildfire with numerical weather simulation MM5

    NASA Astrophysics Data System (ADS)

    Kimura, K.; Honma, T.

    2008-12-01

    1. Background Frequent occurrence of wildfires all over the world is considered as one of major resources of greenhouse gases. For example, a lot of wildfires in Alaska occur in summer. Now, the satellites of NOAA and Terra/Aqua are watching the earth and the wildfire are detected. Of course, to detection wildfire is very important, but the influence on inhabitants is more important. Our purpose is to make the numerical simulation of the wildfire spread in the small area with numerical weather simulation MM5. We think this will be useful to help fire fighting and global environment such as the replace of CO2. 2. Numerical Wildfire Spread Simulation There are many type of the numerical simulation of wildfire spread. In our simulation, the wildfire velocity is based on the Rhothermel equation and other parts are made of the cell automata. The area of the wildfire is the uniform vegetation consisted of the boreal forest (Picea mariana). The main factor of the expansion speed is wind velocity and speed. The continuous change of the weather is simulated with regional meteorological simulation MM5. The real spread of the Boundary Fire are observed by Alaska Fire Service. In this study, we validate the simulation result with the AFS data. 3. The Simulation Results We are constructing the simulation with Boundary Fire in 2004 in central Alaska. MM5 is very useful to reconstruct or forecast the distribution of local weather. We show the examples of the results in the poster. 4. Conclusion We constructed the numerical simulation model of wildfire spread with numerical weather simulation MM5. The result of simulation is being verified by the observed data by AFS .

  20. Downwind O3 and PM2.5 speciation during the wildfires in 2002 and 2010

    NASA Astrophysics Data System (ADS)

    Kang, Choong-Min; Gold, Diane; Koutrakis, Petros

    2014-10-01

    A series of wildfires in northern Quebec, early July 2002, and in southern Quebec, late May 2010, resulted in severe air pollution downwind. Downwind exposures were investigated to estimate the impact on outdoor and indoor environments. The plumes derived from the wildfires resulted in an increase of over 10 ppbv ozone (O3) concentrations in both major cities and rural areas, while O3 enhancement was not observed at locations adjacent to wildfire burning areas. Temporal trend in PM2.5 concentration showed a peak of 105.5 μg/m3 on July 7, 2002, while on May 31, 2010 the peak was 151.1 μg/m3 in Boston downwind. PM2.5 speciation showed similar trends between the episodes, along with spikes in the PM2.5/PM10 ratio, and in the concentrations of Black Carbon, ΔC (i.e., UV absorbing compounds minus Black Carbon), Organic Carbon (OC), potassium, and chlorine. OC was the most dominant constituent of the PM2.5 mass in the wildfires. The dominant specific carbon fractions include OC fraction 3, pyrolysis carbon, and EC fraction 1, likely due to pyrolysis of structural components of wood. Indoor PM2.5 peaks at two houses corresponded well with the ambient PM2.5 peak, along with the elemental composition, which could indicate an impact of wildfires on indoor air pollution exposure.

  1. A systematic review of the physical health impacts from non-occupational exposure to wildfire smoke

    PubMed Central

    Liu, Jia C.; Pereira, Gavin; Uhl, Sarah A.; Bravo, Mercedes A.; Bell, Michelle L.

    2014-01-01

    Background Climate change is likely to increase threat of wildfires, and little is known about how wildfires affect health in exposed communities. A better understanding of the impacts of the resulting air pollution has important public health implications for the present day and the future. Method We performed a systematic search to identify peer-reviewed scientific studies published since 1986 regarding impacts of wildfire smoke on health in exposed communities. We reviewed and synthesized the state of science of this issue including methods to estimate exposure, and identified limitations in current research. Results We identified 61 epidemiological studies linking wildfire and human health in communities. The U.S. and Australia were the most frequently studied countries (18 studies on the U.S., 15 on Australia). Geographic scales ranged from a single small city (population about 55,000) to the entire globe. Most studies focused on areas close to fire events. Exposure was most commonly assessed with stationary air pollutant monitors (35 of 61 studies). Other methods included using satellite remote sensing and measurements from air samples collected during fires. Most studies compared risk of health outcomes between 1) periods with no fire events and periods during or after fire events, or 2) regions affected by wildfire smoke and unaffected regions. Daily pollution levels during or after wildfire in most studies exceeded U.S. EPA regulations. Levels of PM10, the most frequently studied pollutant, were 1.2 to 10 times higher due to wildfire smoke compared to non-fire periods and/or locations. Respiratory disease was the most frequently studied health condition, and had the most consistent results. Over 90% of these 45 studies reported that wildfire smoke was significantly associated with risk of respiratory morbidity. Conclusion Exposure measurement is a key challenge in current literature on wildfire and human health. A limitation is the difficulty of estimating

  2. Stormwater contaminant loading following southern California wildfires.

    PubMed

    Stein, Eric D; Brown, Jeffrey S; Hogue, Terri S; Burke, Megan P; Kinoshita, Alicia

    2012-11-01

    Contaminant loading associated with stormwater runoff from recently burned areas is poorly understood, despite the fact that it has the potential to affect downstream water quality. The goal of the present study is to assess regional patterns of runoff and contaminant loading from wildfires in urban fringe areas of southern California. Postfire stormwater runoff was sampled from five wildfires that each burned between 115 and 658 km(2) of natural open space between 2003 and 2009. Between two and five storm events were sampled per site over the first one to two years following the fires for basic constituents, metals, nutrients, total suspended solids, and polycyclic aromatic hydrocarbons (PAHs). Results were compared to data from 16 unburned natural areas and six developed sites. Mean copper, lead, and zinc flux (kg/km(2)) were between 112- and 736-fold higher from burned catchments and total phosphorus was up to 921-fold higher compared to unburned natural areas. Polycyclic aromatic hydrocarbon flux was four times greater from burned areas than from adjacent urban areas. Ash fallout on nearby unburned watersheds also resulted in a threefold increase in metals and PAHs. Attenuation of elevated concentration and flux values appears to be driven mainly by rainfall magnitude. Contaminant loading from burned landscapes has the potential to be a substantial contribution to the total annual load to downstream areas in the first several years following fires. PMID:22927117

  3. Modeling ozone plumes observed downwind of New York City over the North Atlantic Ocean during the ICARTT field campaign

    NASA Astrophysics Data System (ADS)

    Lee, S.-H.; Kim, S.-W.; Trainer, M.; Frost, G. J.; McKeen, S. A.; Cooper, O. R.; Flocke, F.; Holloway, J. S.; Neuman, J. A.; Ryerson, T.; Senff, C. J.; Swanson, A. L.; Thompson, A. M.

    2011-07-01

    Transport and chemical transformation of well-defined New York City (NYC) urban plumes over the North Atlantic Ocean were studied using aircraft measurements collected on 20-21 July 2004 during the ICARTT (International Consortium for Atmospheric Research on Transport and Transformation) field campaign and WRF-Chem (Weather Research and Forecasting-Chemistry) model simulations. The strong NYC urban plumes were characterized by carbon monoxide (CO) mixing ratios of 350-400 parts per billion by volume (ppbv) and ozone (O3) levels of about 100 ppbv near New York City on 20 July in the WP-3D in-situ and DC-3 lidar aircraft measurements. On 21 July, the two aircraft captured strong urban plumes with about 350 ppbv CO and over 150 ppbv O3 (~160 ppbv maximum) about 600 km downwind of NYC over the North Atlantic Ocean. The measured urban plumes extended vertically up to about 2 km near New York City, but shrank to 1-1.5 km over the stable marine boundary layer (MBL) over the North Atlantic Ocean. The WRF-Chem model reproduced ozone formation processes, chemical characteristics, and meteorology of the measured urban plumes near New York City (20 July) and in the far downwind region over the North Atlantic Ocean (21 July). The quasi-Lagrangian analysis of transport and chemical transformation of the simulated NYC urban plumes using WRF-Chem results showed that the pollutants can be efficiently transported in (isentropic) layers in the lower atmosphere (<2-3 km) over the North Atlantic Ocean while maintaining a dynamic vertical decoupling by cessation of turbulence in the stable MBL. The O3 mixing ratio in the NYC urban plumes remained at 80-90 ppbv during nocturnal transport over the stable MBL, then grew to over 100 ppbv by daytime oxidation of nitrogen oxides (NOx = NO + NO2) with mixing ratios on the order of 1 ppbv. Efficient transport of reactive nitrogen species (NOy), specifically nitric acid (HNO3), was confirmed through the comparison of the CO/NOy ratio in

  4. Modeling ozone plumes observed downwind of New York City over the North Atlantic Ocean during the ICARTT field campaign

    NASA Astrophysics Data System (ADS)

    Lee, S.-H.; Kim, S.-W.; Trainer, M.; Frost, G. J.; McKeen, S. A.; Cooper, O. R.; Flocke, F.; Holloway, J. S.; Neuman, J. A.; Ryerson, T.; Senff, C. J.; Swanson, A. L.; Thompson, A. M.

    2011-05-01

    Transport and chemical transformation of well-defined New York City (NYC) urban plumes over the North Atlantic Ocean were studied using aircraft measurements collected on 20-21 July 2004 during the ICARTT (International Consortium for Atmospheric Research on Transport and Transformation) field campaign and WRF-Chem (Weather Research and Forecasting-Chemistry) model simulations. The strong NYC urban plumes were characterized by carbon monoxide (CO) mixing ratios of 350-400 parts per billion by volume (ppbv) and ozone (O3) levels of about 100 ppbv near New York City on 20 July in the WP-3D in-situ and DC-3 lidar aircraft measurements. On 21 July, the two aircraft captured strong urban plumes with about 350 ppbv CO and over 150 ppbv O3 (~160 ppbv maximum) about 600 km downwind of NYC over the North Atlantic Ocean. The measured urban plumes extended vertically up to about 2 km near New York City, but shrank to 1-1.5 km over the stable marine boundary layer (MBL) over the North Atlantic Ocean. The WRF-Chem model reproduced ozone formation processes, chemical characteristics, and meteorology of the measured urban plumes near New York City (20 July) and in the far downwind region over the North Atlantic Ocean (21 July). The quasi-Lagrangian analysis of transport and chemical transformation of the simulated NYC urban plumes using WRF-Chem results showed that the pollutants can be efficiently transported in (isentropic) layers in the lower atmosphere (<2-3 km) over the North Atlantic Ocean while maintaining a dynamic vertical decoupling by cessation of turbulence in the stable MBL. The O3 mixing ratio in the NYC urban plumes remained at 80-90 ppbv during nocturnal transport over the stable MBL, then grew to over 100 ppbv by daytime oxidation of nitrogen oxides (NOx = NO + NO2) with mixing ratios on the order of 1 ppbv. Efficient transport of reactive nitrogen species (NOy), specifically nitric acid (HNO3), was confirmed through the comparison of the CO/NOy ratio in

  5. Quantifying wildfire impacts on air quality during the ARCTAS-CARB campaign: Contribution of fire emissions to NAAQS exceedances

    NASA Astrophysics Data System (ADS)

    Hu, Y.; Odman, M. T.; Russell, A.; Zhang, X.; Kondragunta, S.; Yu, H.; Bian, H.; Munchak, L. A.; Mattoo, S.; Remer, L. A.

    2012-12-01

    Increasingly frequent wildfires in the US have led to imposed adverse impacts on rural and urban air quality. During severe wildfire episodes, exceedances of NAAQS for ozone and PM2.5 have occurred. The US EPA allows these "exceptional events" to be exempted from being used in the designation of an area exceeding NAAQS. However, how much the wildfires contribute to elevated ozone and PM2.5 observations are poorly understood and not readily quantified. For example, the northern California wildfires of summer 2008 are suspected of causing severe air pollution in the urban areas in California. Here we employed a state of art air quality model - CMAQ equipped with the sensitivity analysis tool DDM-3D - to quantify the wildfire emissions' contribution to the exceedances of NAAQS during the 2008 summer northern California wildfires period. We simulated the air quality impacts of the 2008 northern California wildfires using CMAQ, equipped with a new SOA module including the multi-generational oxidation process. The simulation covers the period of June 15 through July 14, 2008. Three nesting grids are used with the 36-km grid covering the CONUS, the 12-km grid covering California and the 4-km grid covering most metro areas in California. All the three grids have 34 vertical layers extending to ~16km above the ground with the first layer ~18m thick. We evaluate model performance by examining ozone and PM2.5 as well as other gaseous and PM components against observations from multiple platforms: surface, airborne and space. The June-July 2008 ARCTAS-CARB campaign, which was conducted in the same period, has additional airborne data collected in flights chasing the wildfire plumes, along with the regular surface network measurements and satellite observations, providing an extensive database to evaluate model deficiencies and improve model performance in capturing the wildfire impacts on air quality. Further, having these various data allows inter-comparison of the relative

  6. Wildfire policy and management in England: an evolving response from Fire and Rescue Services, forestry and cross-sector groups.

    PubMed

    Gazzard, Rob; McMorrow, Julia; Aylen, Jonathan

    2016-06-01

    Severe wildfires are an intermittent problem in England. The paper presents the first analysis of wildfire policy, showing its halting evolution over two decades. First efforts to coordinate wildfire management came from local fire operation groups, where stakeholders such as fire services, land owners and amenity groups shared knowledge and equipment to tackle the problem. A variety of structures and informal management solutions emerged in response to local needs. Knowledge of wildfire accumulated within regional and national wildfire forums and academic networks. Only later did the need for central emergency planning and the response to climate change produce a national policy response. Fire statistics have allowed wildfires to be spatially evidenced on a national scale only since 2009. National awareness of wildfire was spurred by the 2011 fire season, and the high-impact Swinley Forest fire, which threatened critical infrastructure and communities within 50 miles of London. Severe wildfire was included in the National Risk Register for the first time in 2013. Cross-sector approaches to wildfire proved difficult as government responsibility is fragmented along the hazard chain. Stakeholders such as the Forestry Commission pioneered good practice in adaptive land management to build fire resilience into UK forests. The grass-roots evolution of participatory solutions has also been a key enabling process. A coordinated policy is now needed to identify best practice and to promote understanding of the role of fire in the ecosystem.This article is part of a themed issue 'The interaction of fire and mankind'. PMID:27216511

  7. Wildfire policy and management in England: an evolving response from Fire and Rescue Services, forestry and cross-sector groups

    PubMed Central

    McMorrow, Julia; Aylen, Jonathan

    2016-01-01

    Severe wildfires are an intermittent problem in England. The paper presents the first analysis of wildfire policy, showing its halting evolution over two decades. First efforts to coordinate wildfire management came from local fire operation groups, where stakeholders such as fire services, land owners and amenity groups shared knowledge and equipment to tackle the problem. A variety of structures and informal management solutions emerged in response to local needs. Knowledge of wildfire accumulated within regional and national wildfire forums and academic networks. Only later did the need for central emergency planning and the response to climate change produce a national policy response. Fire statistics have allowed wildfires to be spatially evidenced on a national scale only since 2009. National awareness of wildfire was spurred by the 2011 fire season, and the high-impact Swinley Forest fire, which threatened critical infrastructure and communities within 50 miles of London. Severe wildfire was included in the National Risk Register for the first time in 2013. Cross-sector approaches to wildfire proved difficult as government responsibility is fragmented along the hazard chain. Stakeholders such as the Forestry Commission pioneered good practice in adaptive land management to build fire resilience into UK forests. The grass-roots evolution of participatory solutions has also been a key enabling process. A coordinated policy is now needed to identify best practice and to promote understanding of the role of fire in the ecosystem. This article is part of a themed issue ‘The interaction of fire and mankind’. PMID:27216511

  8. Unsaturated Zone Flow Changes After Wildfire: A Virtual Experiment Perspective

    NASA Astrophysics Data System (ADS)

    Ebel, B. A.

    2013-12-01

    Wildfire is a frequent disturbance event in the Western U.S. and other regions worldwide. It is well known that wildfire impacts the hydrologic cycle, yet the accompanying changes in unsaturated zone flow are poorly understood. This effort uses unsaturated zone flow simulation for well characterized experimental plots covering north- and south-facing slope aspects for plots both affected and unaffected by wildfire to improve understanding. Comparisons to observed soil-water content and matric potential data establish 'foundation simulations' that lay the groundwork for virtual experiments testing hypotheses developed from interpretation of field and laboratory data. The virtual experiments with the numerical model then extend understanding beyond what could be gleaned from data alone. Unsaturated zone flow is simulated with Hydrus-1D and the field site for this work is within the area affected by the 2010 Fourmile Canyon Fire near Boulder, CO USA. Preliminary work shows that loss of transpiration because of vegetation combustion/mortality caused soils to be wetter at depths greater than 5 cm on both north- and south-facing slopes. Loss of interception by the tree canopy also contributes to wetter subsurface conditions on north-facing slopes. On south-facing slopes, at depths less than 3 cm, the soil was drier after wildfire because of decreases in soil-water retention, confirming hypotheses from field and laboratory measurements.

  9. Air quality simulations of wildfires in the Pacific Northwest evaluated with surface and satellite observations during the summers of 2007 and 2008

    NASA Astrophysics Data System (ADS)

    Herron-Thorpe, F. L.; Mount, G. H.; Emmons, L. K.; Lamb, B. K.; Jaffe, D. A.; Wigder, N. L.; Chung, S. H.; Zhang, R.; Woelfle, M. D.; Vaughan, J. K.

    2014-11-01

    Evaluation of a regional air quality forecasting system for the Pacific Northwest was carried out using a suite of surface and satellite observations. Wildfire events for the 2007 and 2008 fire seasons were simulated using the Air Information Report for Public Access and Community Tracking v.3 (AIRPACT-3) framework utilizing the Community Multi-scale Air Quality (CMAQ) model. Fire emissions were simulated using the BlueSky framework with fire locations determined by the Satellite Mapping Automated Reanalysis Tool for Fire Incident Reconciliation (SMARTFIRE). Plume rise was simulated using two different methods: the Fire Emission Production Simulator (FEPS) and the Sparse Matrix Operator Kernel Emissions (SMOKE) model. Predicted plume top heights were compared to the Cloud-Aerosol LIDAR with Orthogonal Polarization (CALIOP) instrument aboard the Cloud Aerosol LIDAR and Infrared Pathfinder Satellite Observation (CALIPSO) satellite. Carbon monoxide predictions were compared to the Atmospheric InfraRed Sounder (AIRS) instrument aboard the Aqua satellite. Horizontal distributions of column aerosol optical depth (AOD) were compared to retrievals by the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard the Aqua satellite. Model tropospheric nitrogen dioxide distributions were compared to retrievals from the Ozone Monitoring Instrument (OMI) aboard the Aura satellite. Surface ozone and PM2.5 predictions were compared to surface observations. The AIRPACT-3 model captured the location and transport direction of fire events well, but sometimes missed the timing of fire events and overall underestimated the PM2.5 impact of wildfire events at surface monitor locations. During the 2007 (2008) fire period, the fractional biases (FBs) of AIRPACT-3 for various pollutant observations included: average 24 h PM2.5 FB = -33% (-27%); maximum daily average 8 h ozone FB = -8% (+1%); AOD FB = -61% (-53%); total column CO FB = -10% (-5%); and tropospheric column NO2 FB

  10. Pastoral wildfires in the Mediterranean: understanding their linkages to land cover patterns in managed landscapes.

    PubMed

    Ruiz-Mirazo, Jabier; Martínez-Fernández, Jesús; Vega-García, Cristina

    2012-05-15

    The pastoral use of fire to regenerate rangelands is a major cause of wildfires in many Mediterranean countries. Despite producing important environmental impacts, this phenomenon has hardly ever been studied separately from other wildfire ignition causes. As extensive livestock breeding relies on the available pasture resources, we hypothesised that a higher rate of pastoral wildfire ignitions could be associated with land cover patterns, as these reflect the spatial arrangement of human activities in managed landscapes. To investigate these patterns, we studied landscape structure and the pastoral wildfires recorded between 1988 and 2000 in 24 Nature Park landscapes in Andalusia (Spain). The CORINE Land Cover map was reclassified according to five levels of grazing use and landscape metrics were calculated. Neural networks were developed to model the relationship between landscape metrics and pastoral wildfires, obtaining a set of significant variables which are discussed in the frame of land and livestock management in the region. We conclude that pastoral wildfire ignitions are more likely in landscapes where the pattern of being dominated by a matrix composed of several large patches of low to moderate grazing use, and having abundant small and elongated patches of higher grazing use, is more extreme. This pattern could be reflecting the persistence of numerous small livestock farms within an increasingly abandoned agrarian landscape. To prevent pastoral wildfires, land management could attempt to enlarge and merge those small patches of higher grazing use, reducing the amount of interface and their intermixture with the surrounding poorer pasture resources. PMID:22245863

  11. Application of Unstructured Grid Finite Volume Coastal Ocean Model to Louisiana Coast: Simulation of River Water Plumes into the Hypoxia Region

    NASA Astrophysics Data System (ADS)

    Li, C.; Rabalais, N. N.; Chen, C.; Twilley, R. R.; Lin, H.; Turner, E. R.

    2008-12-01

    We have applied the unstructured grid finite volume coastal ocean model (FVCOM), developed at the University of Massachusetts, to the entire Gulf of Mexico, with a particular focus on the northern Gulf of Mexico including the Regions of Freshwater Influence. This area covers one of the largest hypoxia zones in coastal oceans where freshwater and nutrient inputs are significant from land drainage. Among the rivers included in the model are the Mississippi River and the Atchafalaya River that run into the continental shelf along the Louisiana coast. The complexity of the LA coastline and bays, low-lying marsh areas are among the challenges for an accurate simulation of transport of water and associated dynamics. The FVCOM is selected to address this complexity. The model is implemented by using irregular triangles with the smallest ones having scales of ~50 m. This allows accurate representation of fluxes through the multiple inlets connecting the shelf and a series of semi-enclosed bays. A total of more than 263,000 triangles are used to cover the domain, with more than 90% concentrated over the Louisiana shelf and coast areas. The astronomical tides, river discharges, and wind are provided as the forcing for the model. The preliminary simulations yielded detailed flow structure including the river plumes that mimics the high resolution images observed from satellites. These plumes respond to wind forcing and river discharges as well as the numerical model parameters related to turbulence and bottom friction. The accuracy of coastlines and bathymetry also has influence to the results. The model results show multiple eddies in the bays, at the inlets, near the river mouth and deltas, and on the shelf. This preliminary study provides a new tool to study the dynamics of hypoxia in the northern Gulf of Mexico.

  12. Dust Plumes off Libya

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Two-toned dust plumes blew northward off the coast of Libya on October 26, 2007, as the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite took this picture. While plumes in the west are beige, reminiscent of the Sahara's sands, the plumes in the east are distinctly darker. The differences in color can be traced to the plumes's varied origins.

  13. Fire risk, atmospheric chemistry and radiative forcing assessment of wildfires in eastern Mediterranean

    NASA Astrophysics Data System (ADS)

    Athanasopoulou, E.; Rieger, D.; Walter, C.; Vogel, H.; Karali, A.; Hatzaki, M.; Gerasopoulos, E.; Vogel, B.; Giannakopoulos, C.; Gratsea, M.; Roussos, A.

    2014-10-01

    The current research study aims at investigating the atmospheric implications of a major fire event in the Mediterranean area. For this purpose, a regional aerosol model coupled online with meteorology (COSMO-ART) is applied over Greece during late summer 2007. Fire risk model results proved to be adequate in reproducing the highly destructive event, which supports further applications for national meteorological forecasts and early warning systems for fire prevention. Columnar aerosol loading field predictions are consistent with satellite maps, which further allows for the correlation of this wildfire event to the atmospheric chemistry and the radiative forcing. Gaseous chemistry resembles that in urban environments and led to nitrogen dioxide and ozone exceedances in several cities in proximity to and downwind the fire spots, respectively. Influence in Athens is found significant from the Euboean plume (45% of total surface PM10) and small (5%) from the fires in Peloponnese. Fire events are indicated by sharp increases in organic to elemental carbon (6), together with sharp decreases in secondary to total organic components (0.1), in comparison to their values during the pre- and post-fire period over Athens (1 and 0.6, respectively). The change in the radiative budget induced by the fire plume is found negative (3-day-average value up to -10 W m-2). Direct heat input is found negligible, thus the net temperature effect is also negative over land (-0.5 K). Nevertheless, positive temperature changes are found overseas (hourly value up to +2 K), due to the amplified radiation absorption by aged soot, coupled to the intense stabilization of the atmosphere above the sea surface.

  14. Igniting the Secret Wildfires of the Past: Searching for Wildfire Records in Caves to Unravel Hidden Paleo-fire Records

    NASA Astrophysics Data System (ADS)

    Nagra, G.; Treble, P. C.; Andersen, M. S.; Fairchild, I. J.; Coleborn, K.; Baker, A.

    2015-12-01

    Cave environments are sensitive to environmental changes that can affect both the δ18O composition and solute concentrations of infiltrating cave dripwater and subsequently speleothem composition. The effect of wildfire on karst processes remains poorly understood. We provide a unique analysis of the effects of an intense wildfire on δ18O composition and solute concentrations of dripwater in a shallow cave, at a forested site in southwest Australia. By determining the local controls on dripwater chemistry, i.e. vegetation cover, evapotranspiration and carbonate mineral reactions, we determine a cave dripwater signature for wildfires in semi-arid regions. The dripwater response to the wildfire is clearest in the combined δ18O and Cl signature due to increased evaporation, and decreased transpiration in the case of Cl. Other solutes such as Mg, Sr and Ca strengthen this argument when coupled with δ18O over this time period. In fact our fire response from 18O shows an approx. 2‰ increase equivalent to some of the greatest changes seen in the Quaternary record. This highlights the significance of multi-year signatures that could be mistakenly interpreted as climate variability especially when combined with other proxies that would also be affected by fire, such as speleothem growth rate. Furthermore, the potential preservation of δ18O and Ca (as a growth rate determinant) in speleothems, combined with trace elements (Mg, Sr, Cl to a lesser extent), opens a new avenue for paleo-fire records.

  15. Rapid increases and time-lagged declines in amphibian occupancy after wildfire.

    PubMed

    Hossack, Blake R; Lowe, Winsor H; Corn, Paul Stephen

    2013-02-01

    Climate change is expected to increase the frequency and severity of drought and wildfire. Aquatic and moisture-sensitive species, such as amphibians, may be particularly vulnerable to these modified disturbance regimes because large wildfires often occur during extended droughts and thus may compound environmental threats. However, understanding of the effects of wildfires on amphibians in forests with long fire-return intervals is limited. Numerous stand-replacing wildfires have occurred since 1988 in Glacier National Park (Montana, U.S.A.), where we have conducted long-term monitoring of amphibians. We measured responses of 3 amphibian species to fires of different sizes, severity, and age in a small geographic area with uniform management. We used data from wetlands associated with 6 wildfires that burned between 1988 and 2003 to evaluate whether burn extent and severity and interactions between wildfire and wetland isolation affected the distribution of breeding populations. We measured responses with models that accounted for imperfect detection to estimate occupancy during prefire (0-4 years) and different postfire recovery periods. For the long-toed salamander (Ambystoma macrodactylum) and Columbia spotted frog (Rana luteiventris), occupancy was not affected for 6 years after wildfire. But 7-21 years after wildfire, occupancy for both species decreased ≥ 25% in areas where >50% of the forest within 500 m of wetlands burned. In contrast, occupancy of the boreal toad (Anaxyrus boreas) tripled in the 3 years after low-elevation forests burned. This increase in occupancy was followed by a gradual decline. Our results show that accounting for magnitude of change and time lags is critical to understanding population dynamics of amphibians after large disturbances. Our results also inform understanding of the potential threat of increases in wildfire frequency or severity to amphibians in the region. PMID:22978248

  16. Amphibian responses to wildfire in the western united states: Emerging patterns from short-term studies

    USGS Publications Warehouse

    Hossack, B.R.; Pilliod, D.S.

    2011-01-01

    The increased frequency and severity of large wildfires in the western United States is an important ecological and management issue with direct relevance to amphibian conservation. Although the knowledge of fire effects on amphibians in the region is still limited relative to most other vertebrate species, we reviewed the current literature to determine if there are evident patterns that might be informative for conservation or management strategies. Of the seven studies that compared pre- and post-wildfire data on a variety of metrics, ranging from amphibian occupancy to body condition, two reported positive responses and five detected negative responses by at least one species. Another seven studies used a retrospective approach to compare effects of wildfire on populations: two studies reported positive effects, three reported negative effects from wildfire, and two reported no effects. All four studies that included plethodontid salamanders reported negative effects on populations or individuals; these effects were greater in forests where fire had been suppressed and in areas that burned with high severity. Species that breed in streams are also vulnerable to post-wildfire changes in habitat, especially in the Southwest. Wildfire is also important for maintaining suitable habitat for diverse amphibian communities, although those results may not be evident immediately after an area burns. We expect that wildfire will extirpate few healthy amphibian populations, but it is still unclear how populations will respond to wildfire in the context of land management (including pre- and post-fire timber harvest) and fragmentation. Wildfire may also increase the risk of decline or extirpation for small, isolated, or stressed (e.g., from drought or disease) populations. Improved understanding of how these effects vary according to changes in fire frequency and severity are critical to form more effective conservation strategies for amphibians in the western United States.

  17. Superfund record of decision (EPA Region 4): USDOE Paducah Gas Diffusion Plant, Northeast Plume Operable Unit, Paducah, KY, June 15, 1995

    SciTech Connect

    1995-06-01

    The decision document presents the selected interim remedial action for the Northeast Plume at the Paducah Gaseous Diffusion Plant (PGDP) near Paducah, Kentucky. The primary objective of the interim remedial action is to implement a first-phase remedial action as an interim action to initiate hydraulic control of the high concentration area within the Northeast Plume that extends outside the plant security fence.

  18. Constraining the source of mantle plumes

    NASA Astrophysics Data System (ADS)

    Cagney, N.; Crameri, F.; Newsome, W. H.; Lithgow-Bertelloni, C.; Cotel, A.; Hart, S. R.; Whitehead, J. A.

    2016-02-01

    In order to link the geochemical signature of hot spot basalts to Earth's deep interior, it is first necessary to understand how plumes sample different regions of the mantle. Here, we investigate the relative amounts of deep and shallow mantle material that are entrained by an ascending plume and constrain its source region. The plumes are generated in a viscous syrup using an isolated heater for a range of Rayleigh numbers. The velocity fields are measured using stereoscopic Particle-Image Velocimetry, and the concept of the 'vortex ring bubble' is used to provide an objective definition of the plume geometry. Using this plume geometry, the plume composition can be analysed in terms of the proportion of material that has been entrained from different depths. We show that the plume composition can be well described using a simple empirical relationship, which depends only on a single parameter, the sampling coefficient, sc. High-sc plumes are composed of material which originated from very deep in the fluid domain, while low-sc plumes contain material entrained from a range of depths. The analysis is also used to show that the geometry of the plume can be described using a similarity solution, in agreement with previous studies. Finally, numerical simulations are used to vary both the Rayleigh number and viscosity contrast independently. The simulations allow us to predict the value of the sampling coefficient for mantle plumes; we find that as a plume reaches the lithosphere, 90% of its composition has been derived from the lowermost 260-750 km in the mantle, and negligible amounts are derived from the shallow half of the lower mantle. This result implies that isotope geochemistry cannot provide direct information about this unsampled region, and that the various known geochemical reservoirs must lie in the deepest few hundred kilometres of the mantle.

  19. THE STRUCTURE AND ORIGIN OF SOLAR PLUMES: NETWORK PLUMES

    SciTech Connect

    Gabriel, A.; Tison, E.; Bely-Dubau, F.; Wilhelm, K.

    2009-07-20

    This study is based upon plumes seen close to the solar limb within coronal holes in the emission from ions formed in the temperature region of 1 MK, in particular, the band of Fe IX 171 A from EIT on the Solar and Heliospheric Observatory. It is shown, using geometric arguments, that two distinct classes of structure contribute to apparently similar plume observations. Quasi-cylindrical structures are anchored in discrete regions of the solar surface (beam plumes), and faint extended structures require integration along the line of sight (LOS) in order to reproduce the observed brightness. This second category, sometimes called 'curtains', are ubiquitous within the polar holes and are usually more abundant than the beam plumes, which depend more on the enhanced magnetic structures detected at their footpoints. It is here proposed that both phenomena are based on plasma structures in which emerging magnetic loops interact with ambient monopolar fields, involving reconnection. The important difference is in terms of physical scale. It is proposed that curtains are composed of a large number of microplumes, distributed along the LOS. The supergranule network provides the required spatial structure. It is shown by modeling that the observations can be reproduced if microplumes are concentrated within some 5 Mm of the cell boundaries. For this reason, we propose to call this second population 'network plumes'. The processes involved could represent a major contribution to the heating mechanism of the solar corona.

  20. The potential of satellite data to study individual wildfire events

    NASA Astrophysics Data System (ADS)

    Benali, Akli; López-Saldana, Gerardo; Russo, Ana; Sá, Ana C. L.; Pinto, Renata M. S.; Nikos, Koutsias; Owen, Price; Pereira, Jose M. C.

    2014-05-01

    Large wildfires have important social, economic and environmental impacts. In order to minimize their impacts, understand their main drivers and study their dynamics, different approaches have been used. The reconstruction of individual wildfire events is usually done by collection of field data, interviews and by implementing fire spread simulations. All these methods have clear limitations in terms of spatial and temporal coverage, accuracy, subjectivity of the collected information and lack of objective independent validation information. In this sense, remote sensing is a promising tool with the potential to provide relevant information for stakeholders and the research community, by complementing or filling gaps in existing information and providing independent accurate quantitative information. In this work we show the potential of satellite data to provide relevant information regarding the dynamics of individual large wildfire events, filling an important gap in wildfire research. We show how MODIS active-fire data, acquired up to four times per day, and satellite-derived burnt perimeters can be combined to extract relevant information wildfire events by describing the methods involved and presenting results for four regions of the world: Portugal, Greece, SE Australia and California. The information that can be retrieved encompasses the start and end date of a wildfire event and its ignition area. We perform an evaluation of the information retrieved by comparing the satellite-derived parameters with national databases, highlighting the strengths and weaknesses of both and showing how the former can complement the latter leading to more complete and accurate datasets. We also show how the spatio-temporal distribution of wildfire spread dynamics can be reconstructed using satellite-derived active-fires and how relevant descriptors can be extracted. Applying graph theory to satellite active-fire data, we define the major fire spread paths that yield

  1. Vertical cloud structure of Jupiter's equatorial plumes

    NASA Technical Reports Server (NTRS)

    Stoker, C. R.; Hord, C.

    1985-01-01

    Multiple-scattering radiative transfer calculations were used to deduce the vertical cloud structure (VCS) of Jupiter's equatorial region. The VCS model of the equatorial plumes is obtained through an analysis of Voyager images of the 6190-A methane band and the 6000-A continuum, and ground-based 8900-A methane band images. The VCS of the equatorial plumes is found to be consistent with the hypothesis that the plumes are caused by upwelling at the ammonia condensation level produced by buoyancy due to latent heat release from the condensation of water clouds nearly three scale heights below the plumes.

  2. Bifurcation of volcanic plumes in a crosswind

    NASA Astrophysics Data System (ADS)

    Ernst, Gerald G. J.; Davis, John P.; Sparks, R. Stephen J.

    1994-08-01

    Bent-over buoyant jets distorted by a crosscurrent develop a vortex pair structure and can bifurcate to produce two distinct lobes which diverge from one another downwind. The region downwind of the source between the lobes has relatively low proportions of discharged fluid. Factors invoked by previous workers to cause or enhance bifurcation include buoyancy, release of latent heat at the plume edge by evaporating water droplets, geometry and orientation of the source, and the encounter with a density interface on the rising path of the plume. We suggest that the pressure distribution around the vortex pair of a rising plume may initially trigger bifurcation. We also report new experimental observations confirming that bifurcation becomes stronger for stronger bent-over plumes, identifying that bifurcation can also occur for straight-edged plumes but gradually disappears for stronger plumes which form a gravity current at their final level and spread for a significant distance against the current. Observations from satellites and the ground are reviewed and confirm that volcanic plumes can show bifurcation and a large range of bifurcation angles. Many of the bifurcating plumes spread out at the tropopause level and suggest the tropopause may act on the plumes as a density interface enhancing bifurcation. Even for quite moderate bifurcation angles, the two plume lobes become rapidly separated downwind by distances of tens of kilometers. Such bifurcating plumes drifting apart can only result in bilobate tephra fall deposits. The tephra fall deposit from the 16 km elevation, SE spreading, bifurcating volcanic plume erupted on 15 May 1981 from Mt Pagan was sampled by previous workers and clearly displayed bilobate characteristics. Examples of bilobate tephra fall deposits are reviewed and their origin briefly discussed. Bilobate deposits are common and may result from many causes. Plume bifurcation should be considered one of the possible mechanisms which can account

  3. The Influence of Wildfire on Hillslope Geometry

    NASA Astrophysics Data System (ADS)

    Rengers, F. K.; Inbar, A.; Sheridan, G. J.; Nyman, P.

    2014-12-01

    In southeastern Australia wildfire occurs regularly, resulting in increased hillslope erosion. However, post-wildfire erosion processes differ depending on hillslope aspect. Equatorial (north)-facing slopes are drier than polar (south)-facing slopes and experience overland flow erosion after wildfire. By contrast, overland flow is not an active process on polar-facing slopes, even after high-intensity wildfires. These differences in post-wildfire erosion processes are accompanied by observations that slope angle and curvature also differ by hillslope aspect. An airborne LiDAR dataset flown over our study area in the Kinglake National Park, Victoria shows that the mean slope angle of polar-facing slopes is nearly 5 degrees steeper than equatorial-facing slopes. We have sought to test the hypothesis that aspect differences in post-wildfire erosion processes are sufficient to create differences in hillslope geometry. In order to test this hypothesis, we use a simple 1D model that simulates hillslope evolution over thousands of years. We limit our model to low-drainage area hillslopes where debris-flows are unlikely to occur. Erosion is modeled as nonlinear diffusion regardless of aspect during non-wildfire model years. Wildfire is modeled by changing the erosional processes on each slope aspect to reflect the effects of post-wildfire erosion according to a wildfire recurrence interval. For two years following a model wildfire we allow overland flow erosion to erode equatorial-facing slopes, whereas polar-facing slopes erode according to nonlinear diffusion for only one year following a wildfire. The erosion parameters on the polar-facing slopes are changed during this period to reflect higher post-wildfire erosion. In addition to erosional processes, we use an exponential soil production law to simulate new soil formation every model year. Our preliminary results suggest that changes in erosional magnitude associated with the different wildfire erosional processes are

  4. MISR Interactive Explorer (MINX) : Production Digitizing to Retrieve Smoke Plume Heights and Validating Heights Against Lidar Data

    NASA Technical Reports Server (NTRS)

    Dunst, Ben

    2011-01-01

    The height at which smoke from a wildfire is injected into the atmosphere is an important parameter for climatology, because it determines how far the smoke can be transported. Using the MINX program to analyze MISR (Multi-angle Imaging Spectro-Radiometer) data, I digitized wildfire smoke plumes to add to an existing database of these heights for use by scientists studying smoke transport and plume dynamics. In addition to using MINX to do production digitizing of heights, I assisted in gathering lidar data for an ongoing validation of MINX and helped evaluate those data.

  5. A non-plume model for the Permian protracted (266-286 Ma) basaltic magmatism in the Beishan-Tianshan region, Xinjiang, Western China

    NASA Astrophysics Data System (ADS)

    Xue, Sheng-Chao; Li, Chusi; Qin, Ke-Zhang; Tang, Dong-Mei

    2016-07-01

    The convenient mantle plume model for the Permian protracted mafic-ultramafic intrusions and mafic dykes (266-286 Ma) in the Beishan-Tianshan region, northern Xinjiang, western China can be rejected, because their temporal-spatial distribution does not show a hotspot track predicted by such model. New zircon U-Pb ages reveal that two small mafic dyke clusters (Podong, 280.5 ± 2 Ma; Luodong, 266.2 ± 3.2 Ma) that are separated by only ~ 20 km in the Pobei area, the southernmost part of the Beishan-Tianshan region, have a large age difference of ~ 18 Ma. The older mafic dykes are characterized by nearly flat mantle-normalized rare-earth-element patterns, pronounced negative Nb-Ta anomalies and positive εNd(t) values from 5.5 to 7.5, similar to the majority of the Permian mafic-ultramafic intrusions in the region. The younger mafic dykes are characterized by significant light rare-earth-element enrichments as well as pronounced negative Nb-Ta anomalies, plus lower εNd(t) (- 1.2 to 2.6) values and higher initial 87Sr/86Sr ratios than the older mafic dykes. The observed compositional variations can be explained by source mantle heterogeneity plus different degrees of crustal contamination. Overall, the Permian mafic-ultramafic rocks in the Beishan-Tianshan region are geochemically consistent with the products of basaltic magmatism induced by lithospheric delamination and asthenosphere upwelling in a convergent tectonic zone.

  6. Wildfire susceptibility mapping: comparing deterministic and stochastic approaches

    NASA Astrophysics Data System (ADS)

    Pereira, Mário; Leuenberger, Michael; Parente, Joana; Tonini, Marj

    2016-04-01

    Estimating the probability of wildfire-occurrence in a certain area under particular environmental conditions represents a modern tool to support forest protection plans and to reduce fires consequences. This can be performed by the implementation of wildfire susceptibility mapping, normally achieved employing more or less sophisticated models which combine the predisposing variables (as raster datasets) into a geographic information systems (GIS). The selection of the appropriate variables includes the evaluation of success and the implementation of prediction curves, as well as independent probabilistic validations for different scenarios. These methods allow to define the spatial pattern of wildfire-occurrences, characterize the susceptibility of the territory, namely for specific fire causes/types, and can also account for other factors such as human behavior and social aspects. We selected Portugal as the study region which, due to its favorable climatic, topographic and vegetation conditions, is by far the European country most affected by wildfires. In addition, Verde and Zêzere (2010) performed a first assessment and validation of wildfire susceptibility and hazard in Portugal which can be used as benchmarking. The objectives of the present study comprise: (1) assessing the structural forest fire risk in Portugal using updated datasets, namely, with higher spatial resolution (80 m to 25 m), most recent vegetation cover (Corine Land Cover), longer fire history (1975-2013); and, (2) comparing linear vs non-linear approaches for wildfire susceptibility mapping. The data we used includes: (i) a DEM derived from the Shuttle Radar Topographic Mission in a resolution of 1 arc-seconds (DEM-SRTM 25 m) to assess elevation and slope; (ii) the Corine Land Cover inventory provided by the European Environment Agency (http://www.eea.europa.eu/pt) to produce the land use land cover map; (iii) the National Mapping Burnt Areas (NMBA) provided by the Institute for the

  7. Effects of flow regime on stream turbidity and suspended solids after wildfire, Colorado Front Range

    USGS Publications Warehouse

    Murphy, Sheila F.; McCleskey, R. Blaine; Writer, Jeffrey H.

    2012-01-01

    Wildfires occur frequently in the Colorado Front Range and can alter the hydrological response of watersheds, yet little information exists on the impact of flow regime and storm events on post-wildfire water quality. The flow regime in the region is characterized by base-flow conditions during much of the year and increased runoff during spring snowmelt and summer convective storms. The impact of snowmelt and storm events on stream discharge and water quality was evaluated for about a year after a wildfire near Boulder, Colorado, USA. During spring snowmelt and low-intensity storms, differences in discharge and turbidity at sites upstream and downstream from the burned areas were minimal. However, high-intensity convective storms resulted in dramatic increases in discharge and turbidity at sites downstream from the burned area. This study highlights the importance of using high-frequency sampling to assess accurately wildfire impacts on water quality downstream.

  8. Big Sagebrush Seed Bank Densities Following Wildfires

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Big sagebrush (Artemisia sp.) is a critical shrub to such sagebrush obligate species as sage grouse, (Centocercus urophasianus), mule deer (Odocoileus hemionus), and pygmy rabbit (Brachylagus idahoensis). Big sagebrush do not sprout after wildfires wildfires and big sagebrush seed is generally sho...

  9. Current research issues related to post-wildfire runoff and erosion processes

    USGS Publications Warehouse

    Moody, John A.; Shakesby, Richard A.; Robichaud, Peter R.; Cannon, Susan H.; Martin, Deborah A.

    2013-01-01

    Research into post-wildfire effects began in the United States more than 70 years ago and only later extended to other parts of the world. Post-wildfire responses are typically transient, episodic, variable in space and time, dependent on thresholds, and involve multiple processes measured by different methods. These characteristics tend to hinder research progress, but the large empirical knowledge base amassed in different regions of the world suggests that it should now be possible to synthesize the data and make a substantial improvement in the understanding of post-wildfire runoff and erosion response. Thus, it is important to identify and prioritize the research issues related to post-wildfire runoff and erosion. Priority research issues are the need to: (1) organize and synthesize similarities and differences in post-wildfire responses between different fire-prone regions of the world in order to determine common patterns and generalities that can explain cause and effect relations; (2) identify and quantify functional relations between metrics of fire effects and soil hydraulic properties that will better represent the dynamic and transient conditions after a wildfire; (3) determine the interaction between burned landscapes and temporally and spatially variable meso-scale precipitation, which is often the primary driver of post-wildfire runoff and erosion responses; (4) determine functional relations between precipitation, basin morphology, runoff connectivity, contributing area, surface roughness, depression storage, and soil characteristics required to predict the timing, magnitudes, and duration of floods and debris flows from ungaged burned basins; and (5) develop standard measurement methods that will ensure the collection of uniform and comparable runoff and erosion data. Resolution of these issues will help to improve conceptual and computer models of post-wildfire runoff and erosion processes.

  10. Combustion efficiency and emission factors for US wildfires

    NASA Astrophysics Data System (ADS)

    Urbanski, S. P.

    2013-01-01

    In the US wildfires and prescribed burning present significant challenges to air regulatory agencies attempting to achieve and maintain compliance with National Ambient Air Quality Standards (NAAQS) and Regional Haze Regulations. Wildland fire emission inventories (EI) provide critical inputs for atmospheric chemical transport models used by air regulatory agencies to understand and to predict the impact of fires on air quality. Fire emission factors (EF), which quantify the amount of pollutants released per mass of biomass burned, are essential input for the emission models used to develop EI. Over the past decade substantial progress has been realized in characterizing the composition of fresh biomass burning (BB) smoke and in quantifying BB EF. However, most BB studies of temperate ecosystems have focused on emissions from prescribed burning. Little information is available on EF for wildfires in the temperate forests of the conterminous US. Current emission estimates for US wildfires rely largely on EF measurements from prescribed burns and it is unknown if these fires are a reasonable proxy for wildfires. Over 8 days in August of 2011 we deployed airborne chemistry instruments and sampled emissions from 3 wildfires and a prescribed fire that occurred in mixed conifer forests of the northern Rocky Mountains. We measured the combustion efficiency, quantified as the modified combustion efficiency (MCE), and EF for CO2, CO, and CH4. Our study average values for MCE, EFCO2, EFCO, and EFCH4 were 0.883, 1596 g kg-1, 135 g kg-1, 7.30 g kg-1, respectively. Compared with previous field studies of prescribed fires in similar forest types, the fires sampled in our study had significantly lower MCE and EFCO2 and significantly higher EFCO and EFCH4. An examination of our study and 47 temperate forest prescribed fires from previously published studies shows a clear trend in MCE across US region/fire type: southeast (MCE = 0.933) > southwest (MCE = 0.922) > northwest (MCE = 0

  11. Downwind Measurements of Wildfires with Varying Burn Conditions: Flaming vs. Smoldering Emissions

    NASA Astrophysics Data System (ADS)

    Collier, S.; Zhou, S.; Onasch, T. B.; Wigder, N. L.; Hee, J.; Jaffe, D. A.; Shilling, J. E.; Fortner, E.; Worsnop, D. R.; Kleinman, L. I.; Sedlacek, A. J., III; Zhang, Q.

    2014-12-01

    During July and August of 2013 two sampling platforms were utilized to probe the physical and chemical properties of wildfire emissions in the Pacific Northwest area of the U.S. during the Department of Energy (DOE) sponsored Biomass Burning Observation Project (BBOP). Continuous ground measurements were taken at the Mt. Bachelor Observatory (MBO) including non-refractory (NR) PM1 size-resolved chemical composition using a High Resolution Time-of-Flight Aerosol Mass Spectrometer (AMS), aerosol light scattering using a Nephelometer, and gas-phase CO, CO2, O3, NOx, and NOy measurements. A similarly equipped sampling platform was launched aboard the Gulfstream-1 (G-1) aircraft which flew near wildfires to probe near-source emissions. Sixteen well-defined fire plumes observed at MBO were selected for detailed analysis and calculation of the modified combustion efficiency (MCE), a quantitative measure of burning conditions. The analyses include calculation of enhancement ratios relative to CO and CO2, elemental ratios of organic aerosols, and back-trajectory analysis for approximate plume age and fire source location. Strong trends were observed when comparing dilution corrected aerosol parameters vs MCE for all plumes identified. Organic PM, scattering and particle-phase inorganic nitrate enhancements displayed a negative correlation with increasing MCE. Various plumes from the G1 data set were analyzed using the same criteria and consistencies were found. We will explore the potential role that burning conditions have on wildfire emissions and how these may be used for better modeling and more accurate emissions inventories.

  12. Linking the Earth's surface with the deep-mantle plume beneath a region from Iceland to the city of Perm

    NASA Astrophysics Data System (ADS)

    Glišović, Petar; Forte, Alessandro; Simmons, Nathan; Grand, Stephen

    2014-05-01

    Current tomography models consistently reveal three large-scale regions of strongly reduced seismic velocity in the lowermost mantle under the Pacific, Africa and a region that extends from below Iceland to the city of Perm (the Perm Anomaly). We have carried out mantle dynamic simulations (Glišović et al., GJI 2012; Glišović & Forte, EPSL 2014) of the evolution of these large-scale structures that directly incorporate: 1) robust constraints provided by joint seismic-geodynamic inversions of mantle density structure with constraints provided by mineral physics data (Simmons et al., GJI 2009); and 2) constraints on mantle viscosity inferred by inversion of a suite of convection-related and glacial isostatic adjustment data sets (Mitrovica & Forte, EPSL 2004) characterised by Earth-like Rayleigh numbers. The convection simulations provide a detailed insight into the very-long-time evolution of the buoyancy of these lower-mantle anomalies. We find, in particular, that the buoyancy associated with the Perm Anomaly generates a very long-lived superplume that is connected to the paleomagnetic location of the Siberian Traps at the time of their eruption (Smirnov & Tarduno, EPSL 2010) and also to location of North Atlantic Igneous Provinces (i.e., the opening of North Atlantic Ocean).

  13. Transport Simulations of Carbon Monoxide and Aerosols from Boreal Wildfires during ARCTAS using WRF-Chem

    NASA Astrophysics Data System (ADS)

    Sessions, W.; Fuelberg, H. E.; Winker, D. M.; Chu, A. D.; Kahn, R. A.

    2009-12-01

    The Weather Research and Forecasting Model (WRF) was developed by the National Center for Atmospheric Research as the next generation of mesoscale meteorology model. The inclusion of a chemistry module (WRF-Chem) allows transport simulations of chemical and aerosol species such as those observed during NASA’s Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) during 2008. The ARCTAS summer deployment phase during June and July coincided with large boreal wildfires in Saskatchewan and Eastern Russia. We identified fires using the GOES Wildfire Automated Biomass Burning Algorithm (WF_ABBA) and thermal hotspot detections from MODIS sensors onboard the Aqua and Terra satellites. The fires on both continents produced plumes large enough to affect the atmospheric chemical composition of downwind population centers as well as the Arctic. Atmospheric steering currents vary greatly with altitude, making plume injection height one of the most important aspects of accurately modeling the transport of burning emissions. WRF-Chem integrates a one-dimensional plume model at grid cells containing fires to explicitly resolve the upper and lower limits of injection height. The early July fires provide multiple cases to satellite remotely sense the horizontal and vertical evolution of carbon monoxide (AIRS/MISR) and aerosols (CALIPSO) downwind of the fires. Lidar and in situ measurements from the NASA DC-8 and B-200 aircraft permit further validation of results from WRF-Chem. Using these various data sources, this paper will evaluate the ability of WRF-Chem to properly model the biomass injection heights and the downwind transport of fire plumes. Model-derived plume characteristics also will be compared with those observed by the satellites and in situ data. Finally, forecast sensitivities to varying WRF-Chem grid resolutions and plume rise mechanics will be presented.

  14. Midcontinent rift volcanism in the Lake Superior region: Sr, Nd, and Pb isotopic evidence for a mantle plume origin

    SciTech Connect

    Nicholson, S.W. Univ. of Minnesota, MN ); Shirey, S.B. )

    1990-07-10

    Between 1091 and 1098 Ma, most of a 15- to 20-km thickness of dominantly tholeiitic basalt erupted in the Midcontinent Rift System of the Lake Superior region, North American. The Portage Lake Volcanics in Michigan, which are the youngest MRS flood basalts, fall into distinctly high- and low-TiO{sub 2} types having different liquid lines of descent. Incompatible trace elements in both types of tholeiites are enriched compared to depleted or primitive mantle (La/Yb = 4.3-5.3; Th/Ta = 2.12-2.16; Zr/Y = 4.3-4.4), and both basalt types are isotopically indistinguishable. Sr, Nd, and Pb isotopic compositions of the Portage Lake tholeiites have {sup 87}Sr/{sup 86}Sr{sub i} {approx}0.7038, {epsilon}{sub Nd(1095 Ma)} {approx}0 {plus minus} 2, and {mu}{sub 1} {approx}8.2. Model ages with respect to a depleted mantle source (T{sub DM}) average about 1950-2100 Ma. Portage Lake rhyolits fall into two groups. Type I rhyolites have Nd and Pb isotopic characteristics ({epsilon}{sub Nd(1095 Ma)} {approx}0 to {minus}4.7; {mu}{sub 1} {approx}8.2-7.8) consistent with contamination of tholeiitic rocks by 5-10% Archean crust. The one type II rhyolite analyzed has Nd and Pb isotopic compositions ({epsilon}{sub Nd(1095 Ma)} {approx}{minus}13 to {minus}16; {mu}{sub 1} {approx}7.6-7.7) which are consistent with partial melting of Archean crust. Early Proterozoic crust was not a major contaminant of MRS rocks in the Lake Superior region. Most reported Nd and Pb isotopic compositions of MRS tholeiites from the main stage of volcanism in the Lake Superior region and of the Duluth Complex are comparable to the Nd and Pb isotopic data for Portage lake tholeiites. The isotopic enrichment of the MRS source compared to depleted mantle is striking and must have occurred at least 700 m.y. before 1100 Ma.

  15. Spatiotemporal prediction of fine particulate matter during the 2008 northern California wildfires using machine learning.

    PubMed

    Reid, Colleen E; Jerrett, Michael; Petersen, Maya L; Pfister, Gabriele G; Morefield, Philip E; Tager, Ira B; Raffuse, Sean M; Balmes, John R

    2015-03-17

    Estimating population exposure to particulate matter during wildfires can be difficult because of insufficient monitoring data to capture the spatiotemporal variability of smoke plumes. Chemical transport models (CTMs) and satellite retrievals provide spatiotemporal data that may be useful in predicting PM2.5 during wildfires. We estimated PM2.5 concentrations during the 2008 northern California wildfires using 10-fold cross-validation (CV) to select an optimal prediction model from a set of 11 statistical algorithms and 29 predictor variables. The variables included CTM output, three measures of satellite aerosol optical depth, distance to the nearest fires, meteorological data, and land use, traffic, spatial location, and temporal characteristics. The generalized boosting model (GBM) with 29 predictor variables had the lowest CV root mean squared error and a CV-R2 of 0.803. The most important predictor variable was the Geostationary Operational Environmental Satellite Aerosol/Smoke Product (GASP) Aerosol Optical Depth (AOD), followed by the CTM output and distance to the nearest fire cluster. Parsimonious models with various combinations of fewer variables also predicted PM2.5 well. Using machine learning algorithms to combine spatiotemporal data from satellites and CTMs can reliably predict PM2.5 concentrations during a major wildfire event. PMID:25648639

  16. Inclusion of biomass burning in WRF-Chem: Impact of wildfires on weather forecasts

    SciTech Connect

    Grell, G. A.; Freitas, Saulo; Stuefer, Martin; Fast, Jerome D.

    2011-06-06

    A plume rise algorithm for wildfires was included in WRF-Chem, and applied to look at the impact of intense wildfires during the 2004 Alaska wildfire season on weather forecasts using model resolutions of 10km and 2km. Biomass burning emissions were estimated using a biomass burning emissions model. In addition, a 1-D, time-dependent cloud model was used online in WRF-Chem to estimate injection heights as well as the final emission rates. It was shown that with the inclusion of the intense wildfires of the 2004 fire season in the model simulations, the interaction of the aerosols with the atmospheric radiation led to significant modifications of vertical profiles of temperature and moisture in cloud-free areas. On the other hand, when clouds were present, the high concentrations of fine aerosol (PM2.5) and the resulting large numbers of Cloud Condensation Nuclei (CCN) had a strong impact on clouds and microphysics, with decreased precipitation coverage and precipitation amounts during the first 12 hours of the integration, but significantly stronger storms during the afternoon hours.

  17. Stationary Plasma Thruster Plume Characteristics

    NASA Technical Reports Server (NTRS)

    Myers, Roger M.; Manzella, David H.

    1994-01-01

    Stationary Plasma Thrusters (SPT's) are being investigated for application to a variety of near-term missions. This paper presents the results of a preliminary study of the thruster plume characteristics which are needed to assess spacecraft integration requirements. Langmuir probes, planar probes, Faraday cups, and a retarding potential analyzer were used to measure plume properties. For the design operating voltage of 300 V the centerline electron density was found to decrease from approximately 1.8 x 10 exp 17 cubic meters at a distance of 0.3 m to 1.8 X 10 exp 14 cubic meters at a distance of 4 m from the thruster. The electron temperature over the same region was between 1.7 and 3.5 eV. Ion current density measurements showed that the plume was sharply peaked, dropping by a factor of 2.6 within 22 degrees of centerline. The ion energy 4 m from the thruster and 15 degrees off-centerline was approximately 270 V. The thruster cathode flow rate and facility pressure were found to strongly affect the plume properties. In addition to the plume measurements, the data from the various probe types were used to assess the impact of probe design criteria

  18. Constraints on a plume in the mid-mantle beneath the Iceland region from seismic array data

    USGS Publications Warehouse

    Pritchard, M.J.; Foulger, G.R.; Julian, B.R.; Fyen, J.

    2000-01-01

    Teleseismic P waves passing through low-wave-speed bodies in the mantle are refracted, causing anomalies in their propagation directions that can be measured by seismometer arrays. Waves from earthquakes in the eastern Pacific and western North America arriving at the NORSAR array in Norway and at seismic stations in Scotland pass beneath the Iceland region at depths of ~ 1000-2000 km. Waves arriving at NORSAR have anomalous arrival azimuths consistent with a low-wave-speed body at a depth of ~ 1500 km beneath the Iceland-Faeroe ridge with a maximum diameter of ~ 250 km and a maximum wave-speed contrast of ~ 1.5 per cent. This agrees well with whole-mantle tomography results, which image a low-wave-speed body at this location with a diameter of ~ 500 km and a wave-speed anomaly of ~ 0.5 per cent, bearing in mind that whole-mantle tomography, because of its limited resolution, broadens and weakens small anomalies. The observations cannot resolve the location of the body, and the anomaly could be caused in whole or in part by larger bodies farther away, for example by a body imaged beneath Greenland by whole-mantle tomography.

  19. Global pyrogeography: the current and future distribution of wildfire.

    PubMed

    Krawchuk, Meg A; Moritz, Max A; Parisien, Marc-André; Van Dorn, Jeff; Hayhoe, Katharine

    2009-01-01

    Climate change is expected to alter the geographic distribution of wildfire, a complex abiotic process that responds to a variety of spatial and environmental gradients. How future climate change may alter global wildfire activity, however, is still largely unknown. As a first step to quantifying potential change in global wildfire, we present a multivariate quantification of environmental drivers for the observed, current distribution of vegetation fires using statistical models of the relationship between fire activity and resources to burn, climate conditions, human influence, and lightning flash rates at a coarse spatiotemporal resolution (100 km, over one decade). We then demonstrate how these statistical models can be used to project future changes in global fire patterns, highlighting regional hotspots of change in fire probabilities under future climate conditions as simulated by a global climate model. Based on current conditions, our results illustrate how the availability of resources to burn and climate conditions conducive to combustion jointly determine why some parts of the world are fire-prone and others are fire-free. In contrast to any expectation that global warming should necessarily result in more fire, we find that regional increases in fire probabilities may be counter-balanced by decreases at other locations, due to the interplay of temperature and precipitation variables. Despite this net balance, our models predict substantial invasion and retreat of fire across large portions of the globe. These changes could have important effects on terrestrial ecosystems since alteration in fire activity may occur quite rapidly, generating ever more complex environmental challenges for species dispersing and adjusting to new climate conditions. Our findings highlight the potential for widespread impacts of climate change on wildfire, suggesting severely altered fire regimes and the need for more explicit inclusion of fire in research on global

  20. Global Pyrogeography: the Current and Future Distribution of Wildfire

    PubMed Central

    Krawchuk, Meg A.; Moritz, Max A.; Parisien, Marc-André; Van Dorn, Jeff; Hayhoe, Katharine

    2009-01-01

    Climate change is expected to alter the geographic distribution of wildfire, a complex abiotic process that responds to a variety of spatial and environmental gradients. How future climate change may alter global wildfire activity, however, is still largely unknown. As a first step to quantifying potential change in global wildfire, we present a multivariate quantification of environmental drivers for the observed, current distribution of vegetation fires using statistical models of the relationship between fire activity and resources to burn, climate conditions, human influence, and lightning flash rates at a coarse spatiotemporal resolution (100 km, over one decade). We then demonstrate how these statistical models can be used to project future changes in global fire patterns, highlighting regional hotspots of change in fire probabilities under future climate conditions as simulated by a global climate model. Based on current conditions, our results illustrate how the availability of resources to burn and climate conditions conducive to combustion jointly determine why some parts of the world are fire-prone and others are fire-free. In contrast to any expectation that global warming should necessarily result in more fire, we find that regional increases in fire probabilities may be counter-balanced by decreases at other locations, due to the interplay of temperature and precipitation variables. Despite this net balance, our models predict substantial invasion and retreat of fire across large portions of the globe. These changes could have important effects on terrestrial ecosystems since alteration in fire activity may occur quite rapidly, generating ever more complex environmental challenges for species dispersing and adjusting to new climate conditions. Our findings highlight the potential for widespread impacts of climate change on wildfire, suggesting severely altered fire regimes and the need for more explicit inclusion of fire in research on global

  1. Trophic regions of a hydrothermal plume dispersing away from an ultramafic-hosted vent-system: Von Damm vent-site, Mid-Cayman Rise

    NASA Astrophysics Data System (ADS)

    Bennett, Sarah A.; Coleman, Max; Huber, Julie A.; Reddington, Emily; Kinsey, James C.; McIntyre, Cameron; Seewald, Jeffrey S.; German, Christopher R.

    2013-02-01

    Abstract Deep-sea ultramafic-hosted vent systems have the potential to provide large amounts of metabolic energy to both autotrophic and heterotrophic microorganisms in their dispersing hydrothermal <span class="hlt">plumes</span>. Such vent-systems release large quantities of hydrogen and methane to the water column, both of which can be exploited by autotrophic microorganisms. Carbon cycling in these hydrothermal <span class="hlt">plumes</span> may, therefore, have an important influence on open-ocean biogeochemistry. In this study, we investigated an ultramafic-hosted system on the Mid-Cayman Rise, emitting metal-poor and hydrogen sulfide-, methane-, and hydrogen-rich hydrothermal fluids. Total organic carbon concentrations in the <span class="hlt">plume</span> ranged between 42.1 and 51.1 μM (background = 43.2 ± 0.7 μM (n = 5)) and near-field <span class="hlt">plume</span> samples with elevated methane concentrations imply the presence of chemoautotrophic primary production and in particular methanotrophy. In parts of the <span class="hlt">plume</span> characterized by persistent potential temperature anomalies but lacking elevated methane concentrations, we found elevated organic carbon concentrations of up to 51.1 μM, most likely resulting from the presence of heterotrophic communities, their extracellular products and vent larvae. Elevated carbon concentrations up to 47.4 μM were detected even in far-field <span class="hlt">plume</span> samples. Within the Von Damm hydrothermal <span class="hlt">plume</span>, we have used our data to hypothesize a microbial food web in which chemoautotrophy supports a heterotrophic community of microorganisms. Such an active microbial food web would provide a source of labile organic carbon to the deep ocean that should be considered in any future studies evaluating sources and sinks of carbon from hydrothermal venting to the deep ocean.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010AnRFM..42..391W&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010AnRFM..42..391W&link_type=ABSTRACT"><span id="translatedtitle">Turbulent <span class="hlt">Plumes</span> in Nature</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Woods, Andrew W.</p> <p>2010-01-01</p> <p>This review describes a range of natural processes leading to the formation of turbulent buoyant <span class="hlt">plumes</span>, largely relating to volcanic processes, in which there are localized, intense releases of energy. Phenomena include volcanic eruption columns, bubble <span class="hlt">plumes</span> in lakes, hydrothermal <span class="hlt">plumes</span>, and <span class="hlt">plumes</span> beneath the ice in polar oceans. We assess how the dynamics is affected by heat transfer, particle fallout and recycling, and Earth's rotation, as well as explore some of the mixing of the ambient fluid produced by <span class="hlt">plumes</span> in a confined geometry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/14601','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/14601"><span id="translatedtitle">The national <span class="hlt">wildfire</span> prediction program: a key piece of the <span class="hlt">wildfire</span> solution</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bossert, J E; Bradley, M M; Hanson, H P; Schomer, C L; Sumikawa, D A</p> <p>1999-08-06</p> <p>Lawrence Livermore National Laboratory and Los Alamos National Laboratory have developed an initiative for a National <span class="hlt">Wildfire</span> Prediction Program. The program provides guidance for fire managers throughout the country, assisting them to efficiently use limited fire-fighting resources. To achieve maximum cost leveraging, the program builds upon existing physics-based atmospheric and <span class="hlt">wildfire</span> modeling efforts, a proven emergency response infrastructure, state-of-the-art computer science, and the world's most advanced supercomputers to create a comprehensive <span class="hlt">wildfire</span> prediction system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008JMS....74..783P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008JMS....74..783P"><span id="translatedtitle">Measuring the thicknesses of the freshwater-layer <span class="hlt">plume</span> and sea ice in the land-fast ice <span class="hlt">region</span> of the Mackenzie Delta using helicopter-borne sensors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Prinsenberg, S. J.; Peterson, I. K.; Holladay, J. S.</p> <p>2008-12-01</p> <p>Helicopter-borne sensors have been used since the early 1990s to monitor ice properties in support of winter marine transportation along the east coast of Canada. The observations are used in ice chart production and to validate ice hazard identification algorithms using satellite advanced synthetic aperture radar (ASAR) imagery. In this study we evaluated the sensors' additional capability to monitor the freshwater <span class="hlt">plume</span> characteristic beneath land-fast ice. During the Canadian Arctic Shelf Exchange Study (CASES) data were collected over the Mackenzie Delta in the southern Beaufort Sea where a buoyant river <span class="hlt">plume</span> exists. Results showed that the electromagnetic-laser system could describe not only the ice properties but also the horizontal distribution of the freshwater <span class="hlt">plume</span> depths that decreased in depth stepwise offshore as the flow of the buoyant <span class="hlt">plume</span> was restricted by a series of ridge-rubble fields running parallel to the coast. Relative to the 2 m mean ice thickness, the <span class="hlt">plume</span> layer depth varied from zero under mobile offshore pack ice to 3 m inshore of the third set of ridge-rubble fields.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ready.gov/wildfires','NIH-MEDLINEPLUS'); return false;" href="https://www.ready.gov/wildfires"><span id="translatedtitle"><span class="hlt">Wildfires</span></span></a></p> <p><a target="_blank" href="http://medlineplus.gov/">MedlinePlus</a></p> <p></p> <p></p> <p>... Hazardous Materials Incidents Home Fires Household Chemical Emergencies Hurricanes Landslides & Debris Flow Nuclear Blast Nuclear Power Plants ... Hazardous Materials Incidents Home Fires Household Chemical Emergencies Hurricanes Landslides & Debris Flow Nuclear Blast Nuclear Power Plants ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1814737L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1814737L"><span id="translatedtitle">Influence of <span class="hlt">wildfires</span> on the variability and trend of ozone concentrations in the U.S. Intermountain West</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lu, Xiao; Zhang, Lin; Zhao, Yuanhong; Yue, Xu</p> <p>2016-04-01</p> <p><span class="hlt">Wildfires</span> are important sources of ozone by emitting large amounts of NOx and NMVOC, main ozone precursors at both global and <span class="hlt">regional</span> scales. Their influences on ozone in the U.S. Intermountain West have recently received much interest because surface ozone concentrations over that <span class="hlt">region</span> showed an increasing trend in the past two decades likely due to increasing <span class="hlt">wildfire</span> emissions in a warming climate. Here we use the Lagrangian particle dispersion model (FLEXPART) as well as the GEOS-Chem chemical transport model to estimate <span class="hlt">wildfires</span>' contribution on summer (June, July and August; JJA) ozone concentration variations, trends, and extremely high ozone events over the US Intermountain West for the past 22 years (1989-2010). We combine the resident time estimated from the FLEXPART 5-day backward trajectories and a high-resolution fire inventory to define a fire index representing the impact of <span class="hlt">wildfires</span> on ozone concentration at a particular site for each day of summers 1989-2010. Over 26,000 FLEXPART back-trajectories are conducted for the whole time period and for 13 CASTNet surface monitoring sites. We build a stepwise multiple linear regression (SMLR) model of daily ozone concentrations using fire index and other meteorological variables for each site. The SMLR models explain 53% of the ozone variations (ranging from 12% to 68% for each site). We show that ozone produced from <span class="hlt">wildfires</span> (calculated from SMLR model) are of high variability at daily scale (ranging from 0.1 ppbv to 20.7 ppbv), but are averaged to lower values of about 0.25-3.5 ppbv for summer mean. We estimate that <span class="hlt">wildfires</span> magnify inter-annual variations of the <span class="hlt">regional</span> mean summer ozone for about 32%, compared to the result with <span class="hlt">wildfires</span> impact excluded from the SMLR model. <span class="hlt">Wildfire</span> ozone enhancements increase at a rate of 0.04 ppbv per year, accouting for about 20% of the <span class="hlt">regional</span> summer ozone trend during 1989-2010. Removing <span class="hlt">wildfires</span>' impact would reduce 35% (46%) of the high-ozone days with</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=10534&hterms=blew&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dblew','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=10534&hterms=blew&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dblew"><span id="translatedtitle">Dust <span class="hlt">Plume</span> off Mauritania</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2007-01-01</p> <p>A thick <span class="hlt">plume</span> of dust blew off the coast of Mauritania in western Africa on October 2, 2007. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua satellite observed the dust <span class="hlt">plume</span> as it headed toward the southwest over the Atlantic Ocean. In this image, the dust varies in color from nearly white to medium tan. The dust <span class="hlt">plume</span> is easier to see over the dark background of the ocean, but the <span class="hlt">plume</span> stretches across the land surface to the east, as well. The dust <span class="hlt">plume</span>'s structure is clearest along the coastline, where relatively clear air pockets separate distinct puffs of dust. West of that, individual pillows of dust push together to form a more homogeneous <span class="hlt">plume</span>. Near its southwest tip, the <span class="hlt">plume</span> takes on yet another shape, with stripes of pale dust fanning out toward the northwest. Occasional tiny white clouds dot the sky overhead, but skies are otherwise clear.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GeoRL..4210541S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GeoRL..4210541S"><span id="translatedtitle">Modeling Europa's dust <span class="hlt">plumes</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Southworth, B. S.; Kempf, S.; Schmidt, J.</p> <p>2015-12-01</p> <p>The discovery of Jupiter's moon Europa maintaining a probably sporadic water vapor <span class="hlt">plume</span> constitutes a huge scientific opportunity for NASA's upcoming mission to this Galilean moon. Measuring properties of material emerging from interior sources offers a unique chance to understand conditions at Europa's subsurface ocean. Exploiting results obtained for the Enceladus <span class="hlt">plume</span>, we simulate possible Europa <span class="hlt">plume</span> configurations, analyze particle number density and surface deposition results, and estimate the expected flux of ice grains on a spacecraft. Due to Europa's high escape speed, observing an active <span class="hlt">plume</span> will require low-altitude flybys, preferably at altitudes of 5-100 km. At higher altitudes a <span class="hlt">plume</span> may escape detection. Our simulations provide an extensive library documenting the possible structure of Europa dust <span class="hlt">plumes</span>, which can be quickly refined as more data on Europa dust <span class="hlt">plumes</span> are collected.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.P53B4015G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.P53B4015G"><span id="translatedtitle">Radiation Chemistry of Potential Europa <span class="hlt">Plumes</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gudipati, M. S.; Henderson, B. L.</p> <p>2014-12-01</p> <p>Recent detection of atomic hydrogen and atomic oxygen and their correlation to potential water <span class="hlt">plumes</span> on Europa [Roth, Saur et al. 2014] invoked significant interest in further understanding of these potential/putative <span class="hlt">plumes</span> on Europa. Unlike on Enceladus, Europa receives significant amount of electron and particle radiation. If the <span class="hlt">plumes</span> come from trailing hemisphere and in the high radiation flux <span class="hlt">regions</span>, then it is expected that the <span class="hlt">plume</span> molecules be subjected to radiation processing. Our interest is to understand to what extent such radiation alterations occur and how they can be correlated to the <span class="hlt">plume</span> original composition, whether organic or inorganic in nature. We will present laboratory studies [Henderson and Gudipati 2014] involving pulsed infrared laser ablation of ice that generates <span class="hlt">plumes</span> similar to those observed on Enceladus [Hansen, Esposito et al. 2006; Hansen, Shemansky et al. 2011] and expected to be similar on Europa as a starting point; demonstrating the applicability of laser ablation to simulate <span class="hlt">plumes</span> of Europa and Enceladus. We will present results from electron irradiation of these <span class="hlt">plumes</span> to determine how organic and inorganic composition is altered due to radiation. Acknowledgments:This research was enabled through partial funding from NASA funding through Planetary Atmospheres, and the Europa Clipper Pre-Project. B.L.H. acknowledges funding from the NASA Postdoctoral Program for an NPP fellowship. Hansen, C. J., L. Esposito, et al. (2006). "Enceladus' water vapor <span class="hlt">plume</span>." Science 311(5766): 1422-1425. Hansen, C. J., D. E. Shemansky, et al. (2011). "The composition and structure of the Enceladus <span class="hlt">plume</span>." Geophysical Research Letters 38. Henderson, B. L. and M. S. Gudipati (2014). "<span class="hlt">Plume</span> Composition and Evolution in Multicomponent Ices Using Resonant Two-Step Laser Ablation and Ionization Mass Spectrometry." The Journal of Physical Chemistry A 118(29): 5454-5463. Roth, L., J. Saur, et al. (2014). "Transient Water Vapor at Europa's South</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21274205','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21274205"><span id="translatedtitle"><span class="hlt">Plume</span> detachment from a magnetic nozzle</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Deline, Christopher A.; Bengtson, Roger D.; Breizman, Boris N.; Tushentsov, Mikhail R.; Jones, Jonathan E.; Chavers, D. Greg; Dobson, Chris C.; Schuettpelz, Branwen M.</p> <p>2009-03-15</p> <p>High-powered electric propulsion thrusters utilizing a magnetized plasma require that plasma exhaust detach from the applied magnetic field in order to produce thrust. This paper presents experimental results demonstrating that a sufficiently energetic and flowing plasma can indeed detach from a magnetic nozzle. Microwave interferometer and probe measurements provide <span class="hlt">plume</span> density, electron temperature, and ion flux measurements in the nozzle <span class="hlt">region</span>. Measurements of ion flux show a low-beta plasma <span class="hlt">plume</span> which follows applied magnetic field lines until the plasma kinetic pressure reaches the magnetic pressure and a high-beta <span class="hlt">plume</span> expanding ballistically afterward. Several magnetic configurations were tested including a reversed field nozzle configuration. Despite the dramatic change in magnetic field profile, the reversed field configuration yielded little measurable change in <span class="hlt">plume</span> trajectory, demonstrating the <span class="hlt">plume</span> is detached. Numerical simulations yield density profiles in agreement with the experimental results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MmSAI..87..192L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MmSAI..87..192L"><span id="translatedtitle">Simulation of Europa's water <span class="hlt">plume</span> .</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lucchetti, A.; Cremonese, G.; Schneider, N. M.; Plainaki, C.; Mazzotta Epifani, E.; Zusi, M.; Palumbo, P.</p> <p></p> <p><span class="hlt">Plumes</span> on Europa would be extremely interesting science and mission targets, particularly due to the unique opportunity to obtain direct information on the subsurface composition, thereby addressing Europa's potential habitability. The existence of water <span class="hlt">plume</span> on the Jupiter's moon Europa has been long speculated until the recent discover. HST imaged surpluses of hydrogen Lyman alpha and oxygen emissions above the southern hemisphere in December 2012 that are consistent with two 200 km high <span class="hlt">plumes</span> of water vapor (Roth et al. 2013). In previous works ballistic cryovolcanism has been considered and modeled as a possible mechanism for the formation of low-albedo features on Europa's surface (Fagents et al. 2000). Our simulation agrees with the model of Fagents et al. (2000) and consists of icy particles that follow ballistic trajectories. The goal of such an analysis is to define the height, the distribution and the extension of the icy particles falling on the moon's surface as well as the thickness of the deposited layer. We expect to observe high albedo <span class="hlt">regions</span> in contrast with the background albedo of Europa surface since we consider that material falling after a cryovolcanic <span class="hlt">plume</span> consists of snow. In order to understand if this phenomenon is detectable we convert the particles deposit in a pixel image of albedo data. We consider also the limb view of the <span class="hlt">plume</span> because, even if this detection requires optimal viewing geometry, it is easier detectable in principle against sky. Furthermore, we are studying the loss rates due to impact electron dissociation and ionization to understand how these reactions decrease the intensity of the phenomenon. We expect to obtain constraints on imaging requirements necessary to detect potential <span class="hlt">plumes</span> that could be useful for ESA's JUICE mission, and in particular for the JANUS camera (Palumbo et al. 2014).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AtmRe.164...49H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AtmRe.164...49H"><span id="translatedtitle">Impact of <span class="hlt">wildfire</span>-induced land cover modification on local meteorology: A sensitivity study of the 2003 <span class="hlt">wildfires</span> in Portugal</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hernandez, Charles; Drobinski, Philippe; Turquety, Solène</p> <p>2015-10-01</p> <p><span class="hlt">Wildfires</span> alter land cover creating changes in dynamic, vegetative, radiative, thermal and hydrological properties of the surface. However, how so drastic changes induced by <span class="hlt">wildfires</span> and how the age of the burnt scar affect the small and meso-scale atmospheric boundary layer dynamics are largely unknown. These questions are relevant for process analysis, meteorological and air quality forecast but also for <span class="hlt">regional</span> climate analysis. Such questions are addressed numerically in this study on the case of the Portugal <span class="hlt">wildfires</span> in 2003 as a testbed. In order to study the effects of burnt scars, an ensemble of numerical simulations using the Weather Research and Forecasting modeling system (WRF) have been performed with different surface properties mimicking the surface state immediately after the fire, few days after the fire and few months after the fire. In order to investigate such issue in a seamless approach, the same modelling framework has been used with various horizontal resolutions of the model grid and land use, ranging from 3.5 km, which can be considered as the typical resolution of state-of-the art <span class="hlt">regional</span> numerical weather prediction models to 14 km which is now the typical target resolution of <span class="hlt">regional</span> climate models. The study shows that the combination of high surface heat fluxes over the burnt area, large differential heating with respect to the preserved surroundings and lower surface roughness produces very intense frontogenesis with vertical velocity reaching few meters per second. This powerful meso-scale circulation can pump more humid air from the surroundings not impacted by the <span class="hlt">wildfire</span> and produce more cloudiness over the burnt area. The influence of soil temperature immediately after the <span class="hlt">wildfire</span> ceases is mainly seen at night as the boundary-layer remains unstably stratified and lasts only few days. So the intensity of the induced meso-scale circulation decreases with time, even though it remains until full recovery of the vegetation</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.6862K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.6862K"><span id="translatedtitle">Lateral <span class="hlt">plume</span> spreading in a medium size river <span class="hlt">plume</span> using surface Lagrangian drifters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kakoulaki, Georgia; MacDonald, Daniel; Cole, Kelly</p> <p>2016-04-01</p> <p>Groups of 27 Lagrangian drifters deployed in the Merrimack River <span class="hlt">plume</span> over twelve tides, with river discharges ranging between 150-800 m3/s, are used to understand the external forcing mechanisms responsible for the extent of spreading in river <span class="hlt">plumes</span>. The transition of buoyant flow from a confined estuary to an unconfined coastal ocean introduces the complicated phenomenon of lateral spreading, which occurs preferentially near the surface and results in a flow that spreads laterally as <span class="hlt">plume</span> water propagates forward in the direction of mean flow. In this work, the temporal and spatial scales of the active spreading <span class="hlt">region</span> are estimated in the sampled <span class="hlt">plumes</span> and related to environmental parameters at the river mouth such as inflow river discharge, initial drifter velocity at the point of release, initial reduced gravity and initial internal wave speed. The initial wave speed was found to be the environmental parameter that best predicts the magnitude of the spatial and temporal scales of the active spreading <span class="hlt">region</span>. Previous studies have asserted the importance of initial <span class="hlt">plume</span> parameters in near-field <span class="hlt">plume</span> evolution and here we extrapolate this idea to the mid-field. Interestingly, we find that that lateral <span class="hlt">plume</span> spreading is arrested at approximately one inertial radius from the river mouth. We therefore propose that the shutdown of spreading is controlled almost exclusively by Coriolis force and it is responsible for converting spreading motion to spinning motion after the mid field <span class="hlt">region</span>. The outcomes of this research are widely applicable to other energetic, medium size river <span class="hlt">plume</span> systems and to the author's knowledge this is the first study to estimate lateral <span class="hlt">plume</span> expansion using observations beyond the immediate near field <span class="hlt">region</span> of a river <span class="hlt">plume</span>. This work will provide further development in understanding <span class="hlt">plume</span> dynamics and the fundamental physical processes that influence coastal ecosystems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/505313','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/505313"><span id="translatedtitle">A transport model for prediction of <span class="hlt">wildfire</span> behavior</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Linn, R.R.</p> <p>1997-07-01</p> <p><span class="hlt">Wildfires</span> are a threat to human life and property, yet they are an unavoidable part of nature. In the past people have tried to predict <span class="hlt">wildfire</span> behavior through the use of point functional models but have been unsuccessful at adequately predicting the gross behavior of the broad spectrum of fires that occur in nature. The majority of previous models do not have self-determining propagation rates. The author uses a transport approach to represent this complicated problem and produce a model that utilizes a self-determining propagation rate. The transport approach allows one to represent a large number of environments including transition <span class="hlt">regions</span> such as those with nonhomogeneous vegetation and terrain. Some of the most difficult features to treat are the imperfectly known boundary conditions and the fine scale structure that is unresolvable, such as the specific location of the fuel or the precise incoming winds. The author accounts for the microscopic details of a fire with macroscopic resolution by dividing quantities into mean and fluctuating parts similar to what is done in traditional turbulence modelling. The author develops a complicated model that includes the transport of multiple gas species, such as oxygen and volatile hydrocarbons, and tracks the depletion of various fuels and other stationary solids and liquids. From this model the author also forms a simplified local burning model with which he performs a number of simulations for the purpose of demonstrating the properties of a self-determining transport-based <span class="hlt">wildfire</span> model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1510598A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1510598A"><span id="translatedtitle">Impacts of Boreal <span class="hlt">wildfire</span> emissions on Arctic tropospheric ozone: a multi-model analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Arnold, Steve; Emmons, Louisa; Monks, Sarah; Law, Kathy; Tilmes, Simone; Turquety, Solene; Thomas, Jennie; Bouarar, Idir; Raut, Jean-Christophe; Flemming, Johannes; Huijnen, Vincent; Mao, Jingqiu; Duncan, Bryan; Steenrod, Steve; Strode, Sarah; Yoshida, Yasuko</p> <p>2013-04-01</p> <p>Observations suggest that the Arctic has warmed rapidly in the past few decades compared with observed global-mean temperature increases. Model calculations suggest that changes in short-lived pollutants such as ozone and aerosol may have contributed significantly to this warming. Arctic tropospheric budgets of short-lived pollutants are impacted by long-range transport of gases and aerosols from Europe, Asia and N. America, but also by Boreal <span class="hlt">wildfires</span> in summer. Our understanding of how Boreal fires impact Arctic budgets of climate-relevant atmospheric constituents is limited, and is reliant on sparse observations and models of tropospheric chemistry. In particular, the role of Boreal fires in the Arctic tropospheric ozone budget is poorly constrained, and has been the subject of some controversy, with different studies suggesting both minor and major roles for fires as a source of Arctic ozone. A better understanding of Boreal fire influence on Arctic ozone and aerosol is essential for improving the reliability of our projections of future Arctic and Northern Hemisphere climate change, especially in light of proposed climate-fire feedbacks which may enhance the intensity and extent of high latitude <span class="hlt">wildfire</span> under a warming climate. Here we use results from the POLARCAT Model Intercomparison Project (POLMIP) and observations collected in the Arctic troposphere as part of International Polar Year in 2008, to evaluate simulated Arctic tropospheric ozone and how it is influenced by Boreal fire emissions in a series of state-of-the-art global atmospheric chemical transport models. By following large <span class="hlt">plumes</span> exported from Siberian and North American Boreal fire <span class="hlt">regions</span> in both the models and observations, we show that different models produce a wide range of influence on Arctic tropospheric ozone from fires, despite using identical emissions and having broadly consistent transport patterns. We demonstrate that the different models display highly varied NOy partitioning</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25894116','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25894116"><span id="translatedtitle"><span class="hlt">Wildfire</span> altering terrestrial precursors of disinfection byproducts in forest detritus.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Jun-Jian; Dahlgren, Randy A; Erşan, Mahmut S; Karanfil, Tanju; Chow, Alex T</p> <p>2015-05-19</p> <p><span class="hlt">Wildfire</span> occurrence and intensity are increasing worldwide causing severe disturbances to forest watersheds used for potable water supply. The effects of <span class="hlt">wildfire</span> on drinking water quality are not well understood, especially in terms of terrestrial dissolved organic matter (DOM) and DOM-associated formation of disinfection byproducts (DBP). As the forest floor layer is a major source of terrestrial DOM, we investigated characteristics and DBP formation of water extractable organic matter (WEOM) from the 0-5 cm depth of nonburned detritus (control) and burned detritus with black ash (moderate severity) and white ash (high severity) associated with the 2013 Rim Fire in California. Spectroscopic results suggested that the aromaticity of WEOM followed white ash > control > black ash and fluorescence <span class="hlt">region</span> II (excitation 220-250 nm; emission 330-380 nm) of the emission-excitation-matrix was identified as a potential burn severity indicator. Compared to the control, WEOM from white and black ashes had lower reactivity in forming trihalomethanes (55%-of-control) and haloacetic acids (67%-of-control), but higher reactivity in forming the more carcinogenic haloacetonitrile after chlorination (244%-of-control) and N-nitrosodimethylamine after chloramination (229%-of-control). There was no change in reactivity for chloral hydrate formation, while WEOM from black ash showed a higher reactivity for haloketone formation (150%-of-control). Because <span class="hlt">wildfire</span> consumed a large portion of organic matter from the detritus layer, there was lower water extractable organic carbon (27%-of-control) and organic nitrogen (19%-of-control) yields in ashes. Consequently, the <span class="hlt">wildfire</span> caused an overall reduction in water extractable terrestrial DBP precursor yield from detritus materials. PMID:25894116</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.9765R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.9765R"><span id="translatedtitle">Volcanic <span class="hlt">Plume</span> Chemistry: Models, Observations and Impacts</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roberts, Tjarda; Martin, Robert; Oppenheimer, Clive; Griffiths, Paul; Braban, Christine; Cox, Tony; Jones, Rod; Durant, Adam; Kelly, Peter</p> <p>2010-05-01</p> <p>Volcanic <span class="hlt">plumes</span> are highly chemically reactive; both in the hot, near-vent <span class="hlt">plume</span>, and also at ambient temperatures in the downwind <span class="hlt">plume</span>, as the volcanic gases and aerosol disperse into the background atmosphere. In particular, DOAS (Differential Optical Absortpion Spectroscopy) observations have identified BrO (Bromine Monoxide) in several volcanic <span class="hlt">plumes</span> degassing into the troposphere. These observations are explained by rapid in-<span class="hlt">plume</span> autocatalytic BrO-chemistry that occurs whilst the <span class="hlt">plume</span> disperses, enabling oxidants such as ozone from background air to mix with the acid gases and aerosol. Computer modelling tools have recently been developed to interpret the observed BrO and predict that substantial ozone depletion occurs downwind. Alongside these modelling developments, advances in in-situ and remote sensing techniques have also improved our observational understanding of volcanic <span class="hlt">plumes</span>. We present simulations using the model, <span class="hlt">Plume</span>Chem, that predict the spatial distribution of gases in volcanic <span class="hlt">plumes</span>, including formation of reactive halogens BrO, ClO and OClO that are enhanced nearer the <span class="hlt">plume</span> edges, and depletion of ozone within the <span class="hlt">plume</span> core. The simulations also show that in-<span class="hlt">plume</span> chemistry rapidly converts NOx into nitric acid, providing a mechanism to explain observed elevated in-<span class="hlt">plume</span> HNO3. This highlights the importance of coupled BrO-NOx chemistry, both for BrO-formation and as a production mechanism for HNO3 in BrO-influenced <span class="hlt">regions</span> of the atmosphere. Studies of coupled halogen-H2S-chemistry are consistent with in-situ Alphasense electrochemical sensor observations of H2S at a range of volcanoes, and only predict H2S-depletion if Cl is additionally elevated. Initial studies regarding the transformations of mercury within volcanic <span class="hlt">plumes</span> suggest that significant in-<span class="hlt">plume</span> conversion of Hg0 to Hg2+ can occur in the downwind <span class="hlt">plume</span>. Such Hg2+ may impact downwind ecology through enhanced Hg-deposition, and causing enhanced biological uptake of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.P31B1251G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.P31B1251G"><span id="translatedtitle">Numerical Simulations of Europa Hydrothermal <span class="hlt">Plumes</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Goodman, J. C.; Lenferink, E.</p> <p>2009-12-01</p> <p>The liquid water interiors of Europa and other icy moons of the outer solar system are likely to be driven by geothermal heating from the sea floor, leading to the development of buoyant hydrothermal <span class="hlt">plumes</span>. These <span class="hlt">plumes</span> potentially control icy surface geomorphology, and are of interest to astrobiologists. We have performed a series of simulations of these <span class="hlt">plumes</span> using the MITGCM. We assume in this experiment that Europa's ocean is deep (of order 100 km) and unstratified, and that <span class="hlt">plume</span> buoyancy is controlled by temperature, not composition. A series of experiments was performed to explore a limited <span class="hlt">region</span> of parameter space, with ocean depth H ranging from 50 to 100 km deep, source heat flux Q between 1 and 10 GW, and values of the Coriolis parameter f between 30% and 90% of the Europa average value. As predicted by earlier work, the <span class="hlt">plumes</span> in our simulations form narrow cylindrical chimneys (a few km across) under the influence of the Coriolis effect. These <span class="hlt">plumes</span> broaden over time until they become baroclinically unstable, breaking up into cone-shaped eddies when they become 20-35 km in diameter; the shed eddies are of a similar size. Large-scale currents in the <span class="hlt">region</span> of the <span class="hlt">plume</span> range between 1.5 and 5 cm/s; temperature anomalies in the <span class="hlt">plume</span> far from the seafloor are tiny, varying between 30 and 160 microkelvin. Variations in <span class="hlt">plume</span> size, shape, speed, and temperature are in excellent agreement with previous laboratory tank experiments, and in rough agreement with theoretical predictions. <span class="hlt">Plume</span> dynamics and geometry are controlled by a "natural Rossby number" which depends strongly on depth H and Coriolis parameter f, but only weakly on source heat flux Q. However, some specific theoretical predictions are not borne out by these simulations. The time elapsed between startup of the source and the beginning of eddy-shedding is much less variable than predicted; also, the <span class="hlt">plume</span> temperature varies with ocean depth H when our theory says it should not. Both of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.V51E2558F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.V51E2558F"><span id="translatedtitle">Tracking Iceland <span class="hlt">Plume</span> Motion Using Trace Element Geochemistry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fitton, J. G.; Walters, R. L.; Jones, S. M.</p> <p>2011-12-01</p> <p>The Greenland-Scotland Ridge (GSR) is a hotspot track built by interaction between the Mid Atlantic Ridge (MAR) and the Iceland mantle <span class="hlt">plume</span>. Unlike most other hotspot tracks built by ridge-<span class="hlt">plume</span> interaction, the GSR is 2 to 3 times wider than the <span class="hlt">plume</span> conduit in the upper mantle. (This unusual wide morphology arises because Icelandic crust changes significantly in thickness within a few million years of accretion, probably mainly by viscous flow in the hot lower crust). The upshot is that the GSR cannot be compared directly with theoretical <span class="hlt">plume</span> tracks from hotspot reference frame models. However, it is possible to track the position of the Iceland <span class="hlt">plume</span> conduit using the trace element geochemistry of basaltic lavas. Away from the <span class="hlt">plume</span> conduit, plate spreading drives upwelling of mantle through the melting <span class="hlt">region</span>. Above the <span class="hlt">plume</span> conduit, <span class="hlt">plume</span>-driven flow forces mantle through the lower part of the melting <span class="hlt">region</span> faster than the plate-driven upwelling rate. The average depth of melting is therefore greater directly above the <span class="hlt">plume</span> conduit than away from the <span class="hlt">plume</span> conduit, and this difference in average melting depth means that melts generated directly above the <span class="hlt">plume</span> conduit are relatively enriched in incompatible trace elements. Joint modelling of trace element compositions and crustal thickness can also be used to establish location of melting relative to the <span class="hlt">plume</span> conduit. To date, these concepts have been used only to explain compositional variations in modern (post-glacial) Icelandic lavas; in this study we show that the same concepts can be applied to map the location of the <span class="hlt">plume</span> conduit throughout the onshore Icelandic geological record (since the middle Miocene, c. 16 Ma). The <span class="hlt">plume</span> track thus determined is in reasonable agreement with theoretical tracks calculated under the assumption that the Iceland <span class="hlt">Plume</span> has remained fixed relative to other Indo-Atlantic hotspots. This result also supports the idea that episodic relocations of the onshore part of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011ACP....11.5719S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011ACP....11.5719S"><span id="translatedtitle">An investigation of methods for injecting emissions from boreal <span class="hlt">wildfires</span> using WRF-Chem during ARCTAS</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sessions, W. R.; Fuelberg, H. E.; Kahn, R. A.; Winker, D. M.</p> <p>2011-06-01</p> <p>The Weather Research and Forecasting Model (WRF) is considered a "next generation" mesoscale meteorology model. The inclusion of a chemistry module (WRF-Chem) allows transport simulations of chemical and aerosol species such as those observed during NASA's Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) in 2008. The ARCTAS summer deployment phase during June and July coincided with large boreal <span class="hlt">wildfires</span> in Saskatchewan and Eastern Russia. One of the most important aspects of simulating <span class="hlt">wildfire</span> <span class="hlt">plume</span> transport is the height at which emissions are injected. WRF-Chem contains an integrated one-dimensional <span class="hlt">plume</span> rise model to determine the appropriate injection layer. The <span class="hlt">plume</span> rise model accounts for thermal buoyancy associated with fires and local atmospheric stability. This paper describes a case study of a 10 day period during the Spring phase of ARCTAS. It compares results from the <span class="hlt">plume</span> model against those of two more traditional injection methods: Injecting within the planetary boundary layer, and in a layer 3-5 km above ground level. Fire locations are satellite derived from the GOES <span class="hlt">Wildfire</span> Automated Biomass Burning Algorithm (WF_ABBA) and the MODIS thermal hotspot detection. Two methods for preprocessing these fire data are compared: The prep_chem_sources method included with WRF-Chem, and the Naval Research Laboratory's Fire Locating and Monitoring of Burning Emissions (FLAMBE). Results from the simulations are compared with satellite-derived products from the AIRS, MISR and CALIOP sensors. When FLAMBE provides input to the 1-D <span class="hlt">plume</span> rise model, the resulting injection heights exhibit the best agreement with satellite-observed injection heights. The FLAMBE-derived heights are more realistic than those utilizing prep_chem_sources. Conversely, when the planetary boundary layer or the 3-5 km a.g.l. layer were filled with emissions, the resulting injection heights exhibit less agreement with observed <span class="hlt">plume</span> heights</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_13");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_13");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70171505','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70171505"><span id="translatedtitle"><span class="hlt">Wildfire</span> risk as a socioecological pathology</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Fischer, A. Paige; Spies, Thomas A; Steelman, Toddi A; Moseley, Cassandra; Johnson, Bart R; Bailey, John D.; Ager, Alan A; Bourgeron, Patrick S.; Charnley, Susan; Collins, Brandon M.; Kline, Jeffrey D; Leahy, Jessica E; Littell, Jeremy; Millington, James D A; Nielsen-Pincus, Max; Olsen, Christine S; Paveglio, Travis B; Roos, Christopher I.; Steen-Adams, Michelle M; Stevens, Forrest R; Vukomanovic, Jelena; White, Eric M; Bowman, David M J S</p> <p>2016-01-01</p> <p><span class="hlt">Wildfire</span> risk in temperate forests has become a nearly intractable problem that can be characterized as a socioecological “pathology”: that is, a set of complex and problematic interactions among social and ecological systems across multiple spatial and temporal scales. Assessments of <span class="hlt">wildfire</span> risk could benefit from recognizing and accounting for these interactions in terms of socioecological systems, also known as coupled natural and human systems (CNHS). We characterize the primary social and ecological dimensions of the <span class="hlt">wildfire</span> risk pathology, paying particular attention to the governance system around <span class="hlt">wildfire</span> risk, and suggest strategies to mitigate the pathology through innovative planning approaches, analytical tools, and policies. We caution that even with a clear understanding of the problem and possible solutions, the system by which human actors govern fire-prone forests may evolve incrementally in imperfect ways and can be expected to resist change even as we learn better ways to manage CNHS.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFMGC21B..06W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFMGC21B..06W"><span id="translatedtitle">Projecting Climate Change Impacts on <span class="hlt">Wildfire</span> Probabilities</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Westerling, A. L.; Bryant, B. P.; Preisler, H.</p> <p>2008-12-01</p> <p>We present preliminary results of the 2008 Climate Change Impact Assessment for <span class="hlt">wildfire</span> in California, part of the second biennial science report to the California Climate Action Team organized via the California Climate Change Center by the California Energy Commission's Public Interest Energy Research Program pursuant to Executive Order S-03-05 of Governor Schwarzenegger. In order to support decision making by the State pertaining to mitigation of and adaptation to climate change and its impacts, we model <span class="hlt">wildfire</span> occurrence monthly from 1950 to 2100 under a range of climate scenarios from the Intergovernmental Panel on Climate Change. We use six climate change models (GFDL CM2.1, NCAR PCM1, CNRM CM3, MPI ECHAM5, MIROC3.2 med, NCAR CCSM3) under two emissions scenarios--A2 (C02 850ppm max atmospheric concentration) and B1(CO2 550ppm max concentration). Climate model output has been downscaled to a 1/8 degree (~12 km) grid using two alternative methods: a Bias Correction and Spatial Donwscaling (BCSD) and a Constructed Analogues (CA) downscaling. Hydrologic variables have been simulated from temperature, precipitation, wind and radiation forcing data using the Variable Infiltration Capacity (VIC) Macroscale Hydrologic Model. We model <span class="hlt">wildfire</span> as a function of temperature, moisture deficit, and land surface characteristics using nonlinear logistic regression techniques. Previous work on <span class="hlt">wildfire</span> climatology and seasonal forecasting has demonstrated that these variables account for much of the inter-annual and seasonal variation in <span class="hlt">wildfire</span>. The results of this study are monthly gridded probabilities of <span class="hlt">wildfire</span> occurrence by fire size class, and estimates of the number of structures potentially affected by fires. In this presentation we will explore the range of modeled outcomes for <span class="hlt">wildfire</span> in California, considering the effects of emissions scenarios, climate model sensitivities, downscaling methods, hydrologic simulations, statistical model specifications for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMGC32B..01T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMGC32B..01T"><span id="translatedtitle"><span class="hlt">Wildfire</span> Risk Management: Challenges and Opportunities</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thompson, M.; Calkin, D. E.; Hand, M. S.; Kreitler, J.</p> <p>2014-12-01</p> <p>In this presentation we address federal <span class="hlt">wildfire</span> risk management largely through the lens of economics, targeting questions related to costs, effectiveness, efficiency, and tradeoffs. Beyond risks to resources and assets such as wildlife habitat, watersheds, and homes, <span class="hlt">wildfires</span> present financial risk and budgetary instability for federal <span class="hlt">wildfire</span> management agencies due to highly variable annual suppression costs. Despite its variability, the costs of <span class="hlt">wildfire</span> management have continued to escalate and account for an ever-growing share of overall agency budgets, compromising abilities to attain other objectives related to forest health, recreation, timber management, etc. Trends associated with a changing climate and human expansion into fire-prone areas could lead to additional suppression costs in the future, only further highlighting the need for an ability to evaluate economic tradeoffs in investments across the <span class="hlt">wildfire</span> management spectrum. Critically, these economic analyses need to accurately capture the complex spatial and stochastic aspects of <span class="hlt">wildfire</span>, the inherent uncertainty associated with monetizing environmental impacts of <span class="hlt">wildfire</span>, the costs and effectiveness of alternative management policies, and linkages between pre-fire investments and active incident management. Investing in hazardous fuels reduction and forest restoration in particular is a major policy lever for pre-fire risk mitigation, and will be a primary focus of our presentation. Evaluating alternative fuel management and suppression policies could provide opportunities for significant efficiency improvements in the development of risk-informed management fire management strategies. Better understanding tradeoffs of fire impacts and costs can help inform policy questions such as how much of the landscape to treat and how to balance investments in treating new areas versus maintaining previous investments. We will summarize current data needs, knowledge gaps, and other factors</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002AGUSM.P22A..02M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002AGUSM.P22A..02M"><span id="translatedtitle">Volcanic <span class="hlt">Plumes</span> on Io: Old Friends and Recent Surprises</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McEwen, A. S.</p> <p>2002-05-01</p> <p>One of the most spectacular phenomena on Io are the active volcanic <span class="hlt">plumes</span>. Nine <span class="hlt">plumes</span> were observed during the Voyager 1 encounter in 1979: Pele (300 km high), Loki (150 km; 2 <span class="hlt">plumes</span>), and 6 smaller "Prometheus-type" <span class="hlt">plumes</span>. When Voyager 2 imaged Io 4 months later, all of the these <span class="hlt">plumes</span> were detected except Pele, and there were two new large red <span class="hlt">plume</span> deposits (Surt and Aten) similar to the deposits of Pele. These 2 new <span class="hlt">plume</span> vents were at relatively high latitudes (45N and 48S) whereas the others were more equatorial. Galileo observed a total of 10 <span class="hlt">plumes</span> prior to 2000, 4 of which were erupting from the same volcanic complexes as in 1979, so there was a total of 15 volcanic centers with observed <span class="hlt">plumes</span>, all equatorial except Masubi at 44S. We found that Prometheus-type <span class="hlt">plumes</span> wander, apparently erupting from rootless vents where silicate lava flows over volatile-rich ground. Red deposits, on the other hand, seem to mark the deep vents for silicate lava. Galileo and HST also showed that Pele is normally detectable only at UV wavelengths or at very high phase angles, and was in an anomalous state during the Voyager 1 encounter. The only good candidate for a "stealth" SO2 gas <span class="hlt">plume</span> visible only in eclipse was seen over Acala, although some Prometheus-type <span class="hlt">plumes</span> appeared much larger in eclipse. The existence of many much smaller <span class="hlt">plumes</span> was predicted from Voyager observations of bright streaks radial to Pele, but Galileo has not confirmed this hypothesis. From the joint Galileo-Cassini observations within a few days of Jan 1, 2001 we were surprised to see a giant new <span class="hlt">plume</span> (400 km high) over Tvashtar Catena (63 N) with UV color properties and a 1200-km diameter red <span class="hlt">plume</span> deposit, both very similar to Pele. In the I31 flyby (August 2001) Galileo flew through the <span class="hlt">region</span> occupied by the Tvashtar <span class="hlt">plume</span> 7 months earlier. The images did not detect a <span class="hlt">plume</span>, but SO2 may have been detected by the plasma science experiment. However, the images did reveal a giant (500 km</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016HESS...20.2745N&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016HESS...20.2745N&link_type=ABSTRACT"><span id="translatedtitle">A post-<span class="hlt">wildfire</span> response in cave dripwater chemistry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nagra, Gurinder; Treble, Pauline C.; Andersen, Martin S.; Fairchild, Ian J.; Coleborn, Katie; Baker, Andy</p> <p>2016-07-01</p> <p>Surface disturbances above a cave have the potential to impact cave dripwater discharge, isotopic composition and solute concentrations, which may subsequently be recorded in the stalagmites forming from these dripwaters. One such disturbance is <span class="hlt">wildfire</span>; however, the effects of <span class="hlt">wildfire</span> on cave chemistry and hydrology remains poorly understood. Using dripwater data monitored at two sites in a shallow cave, beneath a forest, in southwest Australia, we provide one of the first cave monitoring studies conducted in a post-fire regime, which seeks to identify the effects of <span class="hlt">wildfire</span> and post-fire vegetation dynamics on dripwater δ18O composition and solute concentrations. We compare our post-<span class="hlt">wildfire</span> δ18O data with predicted dripwater δ18O using a forward model based on measured hydro-climatic influences alone. This helps to delineate hydro-climatic and fire-related influences on δ18O. Further we also compare our data with both data from Golgotha Cave - which is in a similar environment but was not influenced by this particular fire - as well as <span class="hlt">regional</span> groundwater chemistry, in an attempt to determine the extent to which <span class="hlt">wildfire</span> affects dripwater chemistry. We find in our forested shallow cave that δ18O is higher after the fire relative to modelled δ18O. We attribute this to increased evaporation due to reduced albedo and canopy cover. The solute response post-fire varied between the two drip sites: at Site 1a, which had a large tree above it that was lost in the fire, we see a response reflecting both a reduction in tree water use and a removal of nutrients (Cl, Mg, Sr, and Ca) from the surface and subsurface. Solutes such as SO4 and K maintain high concentrations, due to the abundance of above-ground ash. At Site 2a, which was covered by lower-middle storey vegetation, we see a solute response reflecting evaporative concentration of all studied ions (Cl, Ca, Mg, Sr, SO4, and K) similar to the trend in δ18O for this drip site. We open a new avenue for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930005146','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930005146"><span id="translatedtitle">Mantle <span class="hlt">plumes</span> on Venus revisited</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kiefer, Walter S.</p> <p>1992-01-01</p> <p>The Equatorial Highlands of Venus consist of a series of quasicircular <span class="hlt">regions</span> of high topography, rising up to about 5 km above the mean planetary radius. These highlands are strongly correlated with positive geoid anomalies, with a peak amplitude of 120 m at Atla Regio. Shield volcanism is observed at Beta, Eistla, Bell, and Atla <span class="hlt">Regiones</span> and in the Hathor Mons-Innini Mons-Ushas Mons <span class="hlt">region</span> of the southern hemisphere. Volcanos have also been mapped in Phoebe Regio and flood volcanism is observed in Ovda and Thetis <span class="hlt">Regiones</span>. Extensional tectonism is also observed in Ovda and Thetis <span class="hlt">Regiones</span>. Extensional tectonism is also observed in many of these <span class="hlt">regions</span>. It is now widely accepted that at least Beta, Atla, Eistla, and Bell <span class="hlt">Regiones</span> are the surface expressions of hot, rising mantel <span class="hlt">plumes</span>. Upwelling <span class="hlt">plumes</span> are consistent with both the volcanism and the extensional tectonism observed in these <span class="hlt">regions</span>. The geoid anomalies and topography of these four <span class="hlt">regions</span> show considerable variation. Peak geoid anomalies exceed 90 m at Beta and Atla, but are only 40 m at Eistla and 24 m at Bell. Similarly, the peak topography is greater at Beta and Atla than at Eistla and Bell. Such a range of values is not surprising because terrestrial hotspot swells also have a side range of geoid anomalies and topographic uplifts. Kiefer and Hager used cylindrical axisymmetric, steady-state convection calculations to show that mantle <span class="hlt">plumes</span> can quantitatively account for both the amplitude and the shape of the long-wavelength geoid and topography at Beta and Atla. In these models, most of the topography of these highlands is due to uplift by the vertical normal stress associated with the rising <span class="hlt">plume</span>. Additional topography may also be present due to crustal thickening by volcanism and crustal thinning by rifting. Smrekar and Phillips have also considered the geoid and topography of <span class="hlt">plumes</span> on Venus, but they restricted themselves to considering only the geoid-topography ratio and did not</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMGC21B0964N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMGC21B0964N"><span id="translatedtitle">Satellite data driven modeling system for predicting air quality and visibility during <span class="hlt">wildfire</span> and prescribed burn events</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nair, U. S.; Keiser, K.; Wu, Y.; Maskey, M.; Berendes, D.; Glass, P.; Dhakal, A.; Christopher, S. A.</p> <p>2012-12-01</p> <p>The Alabama Forestry Commission (AFC) is responsible for <span class="hlt">wildfire</span> control and also prescribed burn management in the state of Alabama. Visibility and air quality degradation resulting from smoke are two pieces of information that are crucial for this activity. Currently the tools available to AFC are the dispersion index available from the National Weather Service and also surface smoke concentrations. The former provides broad guidance for prescribed burning activities but does not provide specific information regarding smoke transport, areas affected and quantification of air quality and visibility degradation. While the NOAA operational air quality guidance includes surface smoke concentrations from existing fire events, it does not account for contributions from background aerosols, which are important for the southeastern <span class="hlt">region</span> including Alabama. Also lacking is the quantification of visibility. The University of Alabama in Huntsville has developed a state-of-the-art integrated modeling system to address these concerns. This system based on the Community Air Quality Modeling System (CMAQ) that ingests satellite derived smoke emissions and also assimilates NASA MODIS derived aerosol optical thickness. In addition, this operational modeling system also simulates the impact of potential prescribed burn events based on location information derived from the AFC prescribed burn permit database. A lagrangian model is used to simulate smoke <span class="hlt">plumes</span> for the prescribed burns requests. The combined air quality and visibility degradation resulting from these smoke <span class="hlt">plumes</span> and background aerosols is computed and the information is made available through a web based decision support system utilizing open source GIS components. This system provides information regarding intersections between highways and other critical facilities such as old age homes, hospitals and schools. The system also includes satellite detected fire locations and other satellite derived datasets</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.P11C2113S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.P11C2113S"><span id="translatedtitle">Modeling Europa's Dust <span class="hlt">Plumes</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Southworth, B.; Kempf, S.; Schmidt, J.</p> <p>2015-12-01</p> <p>The discovery of Europa maintaining a probably sporadic water vapor <span class="hlt">plume</span> constitutes a huge scientific opportunity for NASA's upcoming mission to this Galilean moon. Measuring the properties of material emerging from interior sources offers a unique chance to understand conditions at Europa's subsurface ocean. Exploiting results obtained for the Enceladus <span class="hlt">plume</span>, we adjust the ejection model by Schmidt et al. [2008] to the conditions at Europa. In this way, we estimate properties of a possible, yet unobserved dust component of the Europa <span class="hlt">plume</span>. For a size-dependent speed distribution of emerging ice particles we use the model from Kempf et al. [2010] for grain dynamics, modified to run simulations of <span class="hlt">plumes</span> on Europa. Specifically, we model emission from the two <span class="hlt">plume</span> locations determined from observations by Roth et al. [2014] and also from other locations chosen at the closest approach of low-altitude flybys investigated in the Europa Clipper study. This allows us to estimate expected fluxes of ice grains on the spacecraft. We then explore the parameter space of Europa dust <span class="hlt">plumes</span> with regard to particle speed distribution parameters, <span class="hlt">plume</span> location, and spacecraft flyby elevation. Each parameter set results in a 3-dimensional particle density structure through which we simulate flybys, and a map of particle fallback ('snowfall') on the surface of Europa. Due to the moon's high escape speed, a Europa <span class="hlt">plume</span> will eject few to no particles that can escape its gravity, which has several further consequences: (i) For given ejection velocity a Europa <span class="hlt">plume</span> will have a smaller scale height, with a higher particle number densities than the <span class="hlt">plume</span> on Enceladus, (ii) <span class="hlt">plume</span> particles will not feed the diffuse Galilean dust ring, (iii) the snowfall pattern on the surface will be more localized about the <span class="hlt">plume</span> location, and will not induce a global m = 2 pattern as seen on Enceladus, and (iv) safely observing an active <span class="hlt">plume</span> will require low altitude flybys, preferably at 50</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://dx.doi.org/10.1371/journal.pone.0033954','USGSPUBS'); return false;" href="http://dx.doi.org/10.1371/journal.pone.0033954"><span id="translatedtitle">Housing arrangement and location determine the likelihood of housing loss due to <span class="hlt">wildfire</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Syphard, Alexandra D.; Keeley, Jon E.; Massada, Avi Bar; Brennan, Teresa J.; Radeloff, Volker C.</p> <p>2012-01-01</p> <p>Surging <span class="hlt">wildfires</span> across the globe are contributing to escalating residential losses and have major social, economic, and ecological consequences. The highest losses in the U.S. occur in southern California, where nearly 1000 homes per year have been destroyed by <span class="hlt">wildfires</span> since 2000. <span class="hlt">Wildfire</span> risk reduction efforts focus primarily on fuel reduction and, to a lesser degree, on house characteristics and homeowner responsibility. However, the extent to which land use planning could alleviate <span class="hlt">wildfire</span> risk has been largely missing from the debate despite large numbers of homes being placed in the most hazardous parts of the landscape. Our goal was to examine how housing location and arrangement affects the likelihood that a home will be lost when a <span class="hlt">wildfire</span> occurs. We developed an extensive geographic dataset of structure locations, including more than 5500 structures that were destroyed or damaged by <span class="hlt">wildfire</span> since 2001, and identified the main contributors to property loss in two extensive, fire-prone <span class="hlt">regions</span> in southern California. The arrangement and location of structures strongly affected their susceptibility to <span class="hlt">wildfire</span>, with property loss most likely at low to intermediate structure densities and in areas with a history of frequent fire. Rates of structure loss were higher when structures were surrounded by wildland vegetation, but were generally higher in herbaceous fuel types than in higher fuel-volume woody types. Empirically based maps developed using housing pattern and location performed better in distinguishing hazardous from non-hazardous areas than maps based on fuel distribution. The strong importance of housing arrangement and location indicate that land use planning may be a critical tool for reducing fire risk, but it will require reliable delineations of the most hazardous locations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3314688','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3314688"><span id="translatedtitle">Housing Arrangement and Location Determine the Likelihood of Housing Loss Due to <span class="hlt">Wildfire</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Syphard, Alexandra D.; Keeley, Jon E.; Massada, Avi Bar; Brennan, Teresa J.; Radeloff, Volker C.</p> <p>2012-01-01</p> <p>Surging <span class="hlt">wildfires</span> across the globe are contributing to escalating residential losses and have major social, economic, and ecological consequences. The highest losses in the U.S. occur in southern California, where nearly 1000 homes per year have been destroyed by <span class="hlt">wildfires</span> since 2000. <span class="hlt">Wildfire</span> risk reduction efforts focus primarily on fuel reduction and, to a lesser degree, on house characteristics and homeowner responsibility. However, the extent to which land use planning could alleviate <span class="hlt">wildfire</span> risk has been largely missing from the debate despite large numbers of homes being placed in the most hazardous parts of the landscape. Our goal was to examine how housing location and arrangement affects the likelihood that a home will be lost when a <span class="hlt">wildfire</span> occurs. We developed an extensive geographic dataset of structure locations, including more than 5500 structures that were destroyed or damaged by <span class="hlt">wildfire</span> since 2001, and identified the main contributors to property loss in two extensive, fire-prone <span class="hlt">regions</span> in southern California. The arrangement and location of structures strongly affected their susceptibility to <span class="hlt">wildfire</span>, with property loss most likely at low to intermediate structure densities and in areas with a history of frequent fire. Rates of structure loss were higher when structures were surrounded by wildland vegetation, but were generally higher in herbaceous fuel types than in higher fuel-volume woody types. Empirically based maps developed using housing pattern and location performed better in distinguishing hazardous from non-hazardous areas than maps based on fuel distribution. The strong importance of housing arrangement and location indicate that land use planning may be a critical tool for reducing fire risk, but it will require reliable delineations of the most hazardous locations. PMID:22470499</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.H51I0728K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.H51I0728K"><span id="translatedtitle">Evaluation of <span class="hlt">wildfire</span> patterns at the wildland-urban fringe across the continental U.S.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kinoshita, A. M.; Hogue, T. S.</p> <p>2014-12-01</p> <p><span class="hlt">Wildfires</span> threaten ecosystems and urban development across the United States, posing significant implications for land management and natural processes such as watershed hydrology. This study investigates the spatial association between large <span class="hlt">wildfires</span> and urbanization. Several geospatial dataset are combined to map <span class="hlt">wildfires</span> (Monitoring Trends in Burn Severity for 1984 to 2012) and housing density (SILVIS Lab Spatial Analysis for Conservation and Sustainability decadal housing density for 1940 to 2030) relative to natural wildlands across the contiguous U.S. Several buffers (i.e. 25 km) are developed around wildlands (Protected Areas Database of the United States) to quantify the change and relationship in spatial fire and housing density patterns. Since 1984, <span class="hlt">wildfire</span> behavior is cyclical and follows general climatology, where warmer years have more and larger fires. Ignition locations also follow transportation corridors and development which provide easy accessibility to wildlands. In California, both fire frequency and total acres burned exhibit increasing trends (statistically significant at 95%). The 1980s average <span class="hlt">wildfire</span> frequency and total acres burned was 3100 fires and approximately 1200 km2, respectively. These numbers have increased to 2200 fires and over 1500 km2 in the 2010 to 2012 period alone. Initial observations also show that decennial population and area burned for four major Californian counties (Los Angeles, San Bernardino, San Diego, and Shasta) show strong correlation between the last decade of burned area, urban-fringe proximity, and urbanization trends. Improving our understanding of human induced <span class="hlt">wildfire</span> regimes provides key information on urban fringe communities most vulnerable to the <span class="hlt">wildfire</span> risks and can help inform <span class="hlt">regional</span> development planning.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006JGRD..11123S60V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006JGRD..11123S60V"><span id="translatedtitle">Significant enhancements of nitrogen oxides, black carbon, and ozone in the North Atlantic lower free troposphere resulting from North American boreal <span class="hlt">wildfires</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Val MartíN, M.; Honrath, R. E.; Owen, R. C.; Pfister, G.; Fialho, P.; Barata, F.</p> <p>2006-12-01</p> <p>Extensive <span class="hlt">wildfires</span> burned in northern North America during summer 2004, releasing large amounts of trace gases and aerosols into the atmosphere. Emissions from these <span class="hlt">wildfires</span> frequently impacted the PICO-NARE station, a mountaintop site situated 6-15 days downwind from the fires in the Azores Islands. To assess the impacts of the boreal <span class="hlt">wildfire</span> emissions on the levels of aerosol black carbon (BC), nitrogen oxides and O3 downwind from North America, we analyzed measurements of CO, BC, total reactive nitrogen oxides (NOy), NOx (NO + NO2) and O3 made from June to September 2004 in combination with MOZART chemical transport model simulations. Long-range transport of boreal <span class="hlt">wildfire</span> emissions resulted in large enhancements of CO, BC, NOy and NOx, with levels up to 250 ppbv, 665 ng m-3, 1100 pptv and 135 pptv, respectively. Enhancement ratios relative to CO were variable in the <span class="hlt">plumes</span> sampled, most likely because of variations in <span class="hlt">wildfire</span> emissions and removal processes during transport. Analyses of ΔBC/ΔCO, ΔNOy/ΔCO and ΔNOx/ΔCO ratios indicate that NOy and BC were on average efficiently exported in these <span class="hlt">plumes</span> and suggest that decomposition of PAN to NOx was a significant source of NOx. High levels of NOx suggest continuing formation of O3 in these well-aged <span class="hlt">plumes</span>. O3 levels were also significantly enhanced in the <span class="hlt">plumes</span>, reaching up to 75 ppbv. Analysis of ΔO3/ΔCO ratios showed distinct behaviors of O3 in the <span class="hlt">plumes</span>, which varied from significant to lower O3 production. We identify several potential reasons for the complex effects of boreal <span class="hlt">wildfire</span> emissions on O3 and conclude that this behavior needs to be explored further in the future. These observations demonstrate that boreal <span class="hlt">wildfire</span> emissions significantly contributed to the NOx and O3 budgets in the central North Atlantic lower free troposphere during summer 2004 and imply large-scale impacts on direct radiative forcing of the atmosphere and on tropospheric NOx and O3.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11.5489A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11.5489A"><span id="translatedtitle">Application of <span class="hlt">wildfire</span> simulation models for risk analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ager, A.; Finney, M.</p> <p>2009-04-01</p> <p><span class="hlt">Wildfire</span> simulation models are being widely used by fire and fuels specialists in the U.S. to support tactical and strategic decisions related to the mitigation of <span class="hlt">wildfire</span> risk. Much of this application has resulted from the development of a minimum travel time (MTT) fire spread algorithm (M. Finney) that makes it computationally feasible to simulate thousands of fires and generate burn probability and intensity maps over large areas (10,000 - 2,000,000 ha). The MTT algorithm is parallelized for multi-threaded processing and is imbedded in a number of research and applied fire modeling applications. High performance computers (e.g., 32-way 64 bit SMP) are typically used for MTT simulations, although the algorithm is also implemented in the 32 bit desktop FlamMap3 program (www.fire.org). Extensive testing has shown that this algorithm can replicate large fire boundaries in the heterogeneous landscapes that typify much of the wildlands in the western U.S. In this paper, we describe the application of the MTT algorithm to understand spatial patterns of burn probability (BP), and to analyze <span class="hlt">wildfire</span> risk to key human and ecological values. The work is focused on a federally-managed 2,000,000 ha landscape in the central interior <span class="hlt">region</span> of Oregon State, USA. The fire-prone study area encompasses a wide array of topography and fuel types and a number of highly valued resources that are susceptible to fire. We quantitatively defined risk as the product of the probability of a fire and the resulting consequence. Burn probabilities at specific intensity classes were estimated for each 100 x 100 m pixel by simulating 100,000 <span class="hlt">wildfires</span> under burn conditions that replicated recent severe <span class="hlt">wildfire</span> events that occurred under conditions where fire suppression was generally ineffective (97th percentile, August weather). We repeated the simulation under milder weather (70th percentile, August weather) to replicate a "wildland fire use scenario" where suppression is minimized to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.9958B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.9958B"><span id="translatedtitle">Boreal <span class="hlt">wildfire</span> emissions from Alaska, USA and Zabaikalsky krai, Russia 2002-2012</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barrett, Kirsten</p> <p>2015-04-01</p> <p>Boreal forests are the largest terrestrial biome, and account for 27% of global forest cover and a major sink of atmospheric carbon. Increasing <span class="hlt">wildfire</span> activity in some boreal <span class="hlt">regions</span> threatens accumulated carbon stocks through combustion, decomposition, and reduced potential for future uptake. There is substantial spatial variability in boreal <span class="hlt">wildfire</span> characteristics, particularly at the continental scale, which results from differences in climate and vegetation composition between boreal forests in Eurasia and North America. Quantifying boreal <span class="hlt">wildfire</span> characteristics such as frequency and intensity at a global scale is possible using active fire detection datasets such as those available from AVHRR and MODIS. This study uses the MODIS MCD14ML to compare <span class="hlt">wildfire</span> emissions (calculated from Fire Radiative Energy) from Interior Alaska, USA and Zabaikalsky krai, Russia between 2002 and 2012. Both <span class="hlt">regions</span> have experienced increasing fire frequency and severity over the last several decades, likely in response to changing temperature and precipitation regimes. The two <span class="hlt">regions</span> are similar in size and cumulative emissions, but boreal <span class="hlt">wildfires</span> in Alaska are generally more intense and produce more emissions per unit area. <span class="hlt">Wildfire</span> emissions in the Alaskan Interior are also higher due to a longer "residence time" of fires, which may smoulder in the duff layer for several weeks after a front has passed. This "residual burning" accounted for an average of 64% of active fire detections in Interior Alaska, and 47% of those from Zabaikalye, although interannual variability was substantial. The fraction of residual burning was higher in both <span class="hlt">regions</span> during larger fire years, when presumably more biomass is available to sustain combustion. The relationship between burned area and fraction of residual burning was stronger in Alaska, possibly due to a greater tendency for ground fires to smoulder in thick duff layers found in black spruce-sphagnum dominated areas. Although</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ACP....1510983P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ACP....1510983P"><span id="translatedtitle">Influence of the aerosol solar extinction on photochemistry during the 2010 Russian <span class="hlt">wildfires</span> episode</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Péré, J. C.; Bessagnet, B.; Pont, V.; Mallet, M.; Minvielle, F.</p> <p>2015-10-01</p> <p>In this work, impact of aerosol solar extinction on the photochemistry over eastern Europe during the 2010 <span class="hlt">wildfires</span> episode is discussed for the period from 5 to 12 August 2010, which coincides to the peak of fire activity. The methodology is based on an online coupling between the chemistry-transport model CHIMERE (extended by an aerosol optical module) and the radiative transfer code TUV. Results of simulations indicate an important influence of the aerosol solar extinction, in terms of intensity and spatial extent, with a reduction of the photolysis rates of NO2 and O3 up to 50 % (in daytime average) along the aerosol <span class="hlt">plume</span> transport. At a <span class="hlt">regional</span> scale, these changes in photolysis rates lead to a 3-15 % increase in the NO2 daytime concentration and to an ozone reduction near the surface of 1-12 %. The ozone reduction is shown to occur over the entire boundary layer, where aerosols are located. Also, the total aerosol mass concentration (PM10) is shown to be decreased by 1-2 %, on average during the studied period, caused by a reduced formation of secondary aerosols such as sulfates and secondary organics (4-10 %) when aerosol impact on photolysis rates is included. In terms of model performance, comparisons of simulations with air quality measurements at Moscow indicate that an explicit representation of aerosols interaction with photolysis rates tend to improve the estimation of the near-surface concentration of ozone and nitrogen dioxide as well as the formation of inorganic aerosol species such as ammonium, nitrates and sulfates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=GL-2002-002296&hterms=Russia&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DRussia','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=GL-2002-002296&hterms=Russia&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DRussia"><span id="translatedtitle"><span class="hlt">Wildfires</span>, smoke, and burn scars, near Yakutsk, Russia</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2002-01-01</p> <p>The Lena River in central Siberia is hidden beneath a veil of smoke from multiple <span class="hlt">wildfires</span> burning around the city of Yakutsk, Russia. Fires have been burning in the <span class="hlt">region</span> off and on since late May 2002, and may be agricultural in cause. This image was acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra satellite on July 23, 2002. In the false=-color image, vegetation is bright green, smoke is blueish-white, and burned areas are reddish-brown. In both images, fire detections are marked with red outlines. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.P52A..01N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.P52A..01N"><span id="translatedtitle"><span class="hlt">Plumes</span> on Enceladus: Lessons for Europa?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nimmo, F.</p> <p>2014-12-01</p> <p>The possible detection of a water vapour <span class="hlt">plume</span> on Europa [1] suggests resemblances to Enceladus, a cryovolcanically active satellite [2]. How does this activity work, and what lesson does Enceladus have for <span class="hlt">plumes</span> on Europa? The inferred vapour column densities of the Europa [1] and Enceladus [3] <span class="hlt">plumes</span> are similar, but the inferred velocity and mass flux of the former are higher. At Enceladus, the inferred <span class="hlt">plume</span> strength is modulated by its orbital position [4,5], suggesting that tides opening and closing cracks control the eruption behaviour [6,7]. An additional source of stress potentially driving eruptions is the effect of slow freezing of the ice shell above[7,8]. The original detection of the Europa <span class="hlt">plume</span> was close to apocentre, when polar fractures are expected to be in tension [1]. Follow-up observations at the same orbital phase did not detect a <span class="hlt">plume</span> [9], although the Galileo E12 magnetometer data may provide evidence for an earlier <span class="hlt">plume</span> [Khurana, pers. comm.]. One possible explanation for the <span class="hlt">plume</span>'s disappearance is that longer-period tidal effects are playing a role; there are hints of similar secular changes in the Enceladus data [4,5]. Another is that detectability of the Europa plumein the aurora observations also depends on variations in electron density (which affects the UV emission flux) [9]. Or it may simply be that eruptive activity on Europa is highly time-variable, as on Io. At Enceladus, the <span class="hlt">plume</span> scale height is independent of orbital position and <span class="hlt">plume</span> brightness [5]. This suggests that the vapour velocity does not depend on crack width, consistent with supersonic flow through a near-surface throat. The large scale height inferred for the Europa <span class="hlt">plume</span> likewise suggests supersonic behaviour. Continuous fallback of solid <span class="hlt">plume</span> material at Enceladus affects both the colour [10] and surface texture [2] of near-polar <span class="hlt">regions</span>. Less frequent <span class="hlt">plume</span> activity would produce subtler effects; whether the sparse available imagery at Europa [11</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=42459&keyword=drag&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=74090518&CFTOKEN=67848882','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=42459&keyword=drag&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=74090518&CFTOKEN=67848882"><span id="translatedtitle">COOLING TOWER <span class="hlt">PLUME</span> MODEL</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>A review of recently reported cooling tower <span class="hlt">plume</span> models yields none that is universally accepted. The entrainment and drag mechanisms and the effect of moisture on the <span class="hlt">plume</span> trajectory are phenomena which are treated differently by various investigators. In order to better under...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009EnMan..44..441C&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009EnMan..44..441C&link_type=ABSTRACT"><span id="translatedtitle">Situating Hazard Vulnerability: People's Negotiations with <span class="hlt">Wildfire</span> Environments in the U.S. Southwest</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Collins, Timothy W.; Bolin, Bob</p> <p>2009-09-01</p> <p>This article is based on a multimethod study designed to clarify influences on <span class="hlt">wildfire</span> hazard vulnerability in Arizona’s White Mountains, USA. Findings reveal that multiple factors operating across scales generate socially unequal <span class="hlt">wildfire</span> risks. At the household scale, conflicting environmental values, reliance on fire insurance and firefighting institutions, a lack of place dependency, and social vulnerability (e.g., a lack of financial, physical, and/or legal capacity to reduce risks) were found to be important influences on <span class="hlt">wildfire</span> risk. At the <span class="hlt">regional</span>-scale, the shift from a resource extraction to environmental amenity-based economy has transformed ecological communities, produced unequal social distributions of risks and resources, and shaped people’s social and environmental interactions in everyday life. While working-class locals are more socially vulnerable than amenity migrants to <span class="hlt">wildfire</span> hazards, they have also been more active in attempting to reduce risks in the aftermath of the disastrous 2002 Rodeo-Chediski fire. Social tensions between locals and amenity migrants temporarily dissolved immediately following the disaster, only to be exacerbated by the heightened perception of risk and the differential commitment to hazard mitigation displayed by these groups over a 2-year study period. Findings suggest that to enhance <span class="hlt">wildfire</span> safety, environmental managers should acknowledge the environmental benefits associated with hazardous landscapes, the incentives created by risk management programs, and the specific constraints to action for relevant social groups in changing human-environmental context.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.A51Q0348N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.A51Q0348N"><span id="translatedtitle">Quantifying the Effects of <span class="hlt">Wildfire</span> Severity on Snow Water Equivalent in the Sierra Nevada</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nguyen, A.; Cunningham, S.; Sodergren, C.; Anzelc, J.; Cate, N.; Arya, V.</p> <p>2015-12-01</p> <p>Snowpack in the Sierra Nevada is a crucial component of the California water supply. Climate change effects on forest ecosystems in this <span class="hlt">region</span> have reduced snowpack and resulted in earlier snowmelt. <span class="hlt">Wildfire</span> frequency and severity in the Sierra Nevada have also increased, due to higher temperatures, drought, and a legacy of fire suppression policies leading to fuel loads augmented beyond the historic range of variability. These combined factors have the potential to severely impact California water supply. Using 2014 California Basin Characterization Model (BCM) climate data and automated classification of various Landsat imagery, this study geospatially quantified the effects of low, moderate, and high- severity <span class="hlt">wildfire</span> on snowpack and snow water equivalent (SWE) in the Sierra Nevada. An assessment of modeled SWE data were also conducted to examine its usefulness in better understanding areas effected by <span class="hlt">wildfire</span>. Results indicate little to no significant change in post-fire SWE for high and moderate severity <span class="hlt">wildfire</span>, however, delineated a significant decrease in post-fire SWE in the low severity <span class="hlt">wildfire</span>. Additionally, tests show little no significant change in fractional snow cover post-fire. This use of remote sensing and modeled data will assist in decision and policy making related to management of forest ecosystems and water resources within the Sierra Nevada.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_13");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_13");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/20981570','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/20981570"><span id="translatedtitle">Advancing effects analysis for integrated, large-scale <span class="hlt">wildfire</span> risk assessment.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Thompson, Matthew P; Calkin, David E; Gilbertson-Day, Julie W; Ager, Alan A</p> <p>2011-08-01</p> <p>In this article, we describe the design and development of a quantitative, geospatial risk assessment tool intended to facilitate monitoring trends in <span class="hlt">wildfire</span> risk over time and to provide information useful in prioritizing fuels treatments and mitigation measures. The research effort is designed to develop, from a strategic view, a first approximation of how both fire likelihood and intensity influence risk to social, economic, and ecological values at <span class="hlt">regional</span> and national scales. Three main components are required to generate <span class="hlt">wildfire</span> risk outputs: (1) burn probability maps generated from <span class="hlt">wildfire</span> simulations, (2) spatially identified highly valued resources (HVRs), and (3) response functions that describe the effects of fire (beneficial or detrimental) on the HVR. Analyzing fire effects has to date presented a major challenge to integrated risk assessments, due to a limited understanding of the type and magnitude of changes wrought by <span class="hlt">wildfire</span> to ecological and other nonmarket values. This work advances <span class="hlt">wildfire</span> effects analysis, recognizing knowledge uncertainty and appropriately managing it through the use of an expert systems approach. Specifically, this work entailed consultation with 10 fire and fuels program management officials from federal agencies with fire management responsibilities in order to define quantitative resource response relationships as a function of fire intensity. Here, we demonstrate a proof-of-concept application of the wildland fire risk assessment tool, using the state of Oregon as a case study. PMID:20981570</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70044756','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70044756"><span id="translatedtitle">Mapping <span class="hlt">wildfire</span> burn severity in the Arctic Tundra from downsampled MODIS data</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Kolden, Crystal A.; Rogan, John</p> <p>2013-01-01</p> <p><span class="hlt">Wildfires</span> are historically infrequent in the arctic tundra, but are projected to increase with climate warming. Fire effects on tundra ecosystems are poorly understood and difficult to quantify in a remote <span class="hlt">region</span> where a short growing season severely limits ground data collection. Remote sensing has been widely utilized to characterize <span class="hlt">wildfire</span> regimes, but primarily from the Landsat sensor, which has limited data acquisition in the Arctic. Here, coarse-resolution remotely sensed data are assessed as a means to quantify <span class="hlt">wildfire</span> burn severity of the 2007 Anaktuvuk River Fire in Alaska, the largest tundra <span class="hlt">wildfire</span> ever recorded on Alaska's North Slope. Data from Landsat Thematic Mapper (TM) and downsampled Moderate-resolution Imaging Spectroradiometer (MODIS) were processed to spectral indices and correlated to observed metrics of surface, subsurface, and comprehensive burn severity. Spectral indices were strongly correlated to surface severity (maximum R2 = 0.88) and slightly less strongly correlated to substrate severity. Downsampled MODIS data showed a decrease in severity one year post-fire, corroborating rapid vegetation regeneration observed on the burned site. These results indicate that widely-used spectral indices and downsampled coarse-resolution data provide a reasonable supplement to often-limited ground data collection for analysis and long-term monitoring of <span class="hlt">wildfire</span> effects in arctic ecosystems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23750590','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23750590"><span id="translatedtitle">Air quality impact and physicochemical aging of biomass burning aerosols during the 2007 San Diego <span class="hlt">wildfires</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zauscher, Melanie D; Wang, Ying; Moore, Meagan J K; Gaston, Cassandra J; Prather, Kimberly A</p> <p>2013-07-16</p> <p>Intense <span class="hlt">wildfires</span> burning >360000 acres in San Diego during October, 2007 provided a unique opportunity to study the impact of <span class="hlt">wildfires</span> on local air quality and biomass burning aerosol (BBA) aging. The size-resolved mixing state of individual particles was measured in real-time with an aerosol time-of-flight mass spectrometer (ATOFMS) for 10 days after the fires commenced. Particle concentrations were high county-wide due to the <span class="hlt">wildfires</span>; 84% of 120-400 nm particles by number were identified as BBA, with particles <400 nm contributing to mass concentrations dangerous to public health, up to 148 μg/m(3). Evidence of potassium salts heterogeneously reacting with inorganic acids was observed with continuous high temporal resolution for the first time. Ten distinct chemical types shown as BBA factors were identified through positive matrix factorization coupled to single particle analysis, including particles comprised of potassium chloride and organic nitrogen during the beginning of the <span class="hlt">wildfires</span>, ammonium nitrate and amines after an increase of relative humidity, and sulfate dominated when the air mass back trajectories passed through the Los Angeles port <span class="hlt">region</span>. Understanding BBA aging processes and quantifying the size-resolved mass and number concentrations are important in determining the overall impact of <span class="hlt">wildfires</span> on air quality, health, and climate. PMID:23750590</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23980897','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23980897"><span id="translatedtitle">Impact of <span class="hlt">wildfires</span> on ozone exceptional events in the Western u.s.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jaffe, Daniel A; Wigder, Nicole; Downey, Nicole; Pfister, Gabriele; Boynard, Anne; Reid, Stephen B</p> <p>2013-10-01</p> <p><span class="hlt">Wildfires</span> generate substantial emissions of nitrogen oxides (NOx) and volatile organic compounds (VOCs). As such, <span class="hlt">wildfires</span> contribute to elevated ozone (O3) in the atmosphere. However, there is a large amount of variability in the emissions of O3 precursors and the amount of O3 produced between fires. There is also significant interannual variability as seen in median O3, organic carbon and satellite derived carbon monoxide mixing ratios in the western U.S. To better understand O3 produced from <span class="hlt">wildfires</span>, we developed a statistical model that estimates the maximum daily 8 h average (MDA8) O3 as a function of several meteorological and temporal variables for three urban areas in the western U.S.: Salt Lake City, UT; Boise, ID; and Reno, NV. The model is developed using data from June-September 2000-2012. For these three locations, the statistical model can explain 60, 52, and 27% of the variability in daily MDA8. The Statistical Model Residual (SMR) can give information on additional sources of O3 that are not explained by the usual meteorological pattern. Several possible O3 sources can explain high SMR values on any given day. We examine several cases with high SMR that are due to <span class="hlt">wildfire</span> influence. The first case considered is for Reno in June 2008 when the MDA8 reached 82 ppbv. The <span class="hlt">wildfire</span> influence for this episode is supported by PM concentrations, the known location of <span class="hlt">wildfires</span> at the time and simulations with the Weather and Research Forecasting Model with Chemistry (WRF-Chem) which indicates transport to Reno from large fires burning in California. The contribution to the MDA8 in Reno from the California <span class="hlt">wildfires</span> is estimated to be 26 ppbv, based on the SMR, and 60 ppbv, based on WRF-Chem. The WRF-Chem model also indicates an important role for peroxyacetyl nitrate (PAN) in producing O3 during transport from the California <span class="hlt">wildfires</span>. We hypothesize that enhancements in PAN due to <span class="hlt">wildfire</span> emissions may lead to <span class="hlt">regional</span> enhancements in O3 during high</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.6855M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.6855M"><span id="translatedtitle">FIRESTORM: Modelling the water quality risk of <span class="hlt">wildfire</span>.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mason, C. I.; Sheridan, G. J.; Smith, H. G.; Jones, O.; Chong, D.; Tolhurst, K.</p> <p>2012-04-01</p> <p>,000 pre-processed spatially distributed fire intensity and flame height maps, generated by a fire behaviour simulator. This part of the model predicts the annual risk of the water supply catchment burning and the spatial extent and severity of the burn. These spatial fire severity maps may be combined with vegetation maps and information on soils to determine initial conditions for modelling of sediment and associated contaminant loads delivered to reservoirs. Erosion and water quality models that form part of the overall model framework include a catchment-scale constituent load model to represent widespread rainfall events and a semi-distributed runoff and erosion connectivity model applied at the small catchment scale for convective storm events. Recent work has shown that localised, intense convective storms may also generate debris flows after fire in south-eastern Australia. Therefore, for the application of the model framework to reservoirs supplying Melbourne, an empirical debris flow erosion model is included. For the localised event models, sediment is routed from sub-catchments through the main channel network to the reservoir boundary. These erosion models are modular so that FIRESTORM may be adapted for use in a <span class="hlt">region</span> of the world that experiences different dominant erosion processes. FIRESTORM will enable water supply managers to estimate the current water quality risk of <span class="hlt">wildfire</span> and allow scenario testing to explore the effect of mitigation strategies (e.g. planned burning, post-fire erosion control measures) designed to reduce fire impacts and the magnitude of loads entering reservoirs. This model will be a valuable new tool for better decision making to protect future water supplies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.A44E..03L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.A44E..03L"><span id="translatedtitle">Assessing the Impacts of <span class="hlt">Wildfire</span> Aerosols on the Diurnal Cycles of Stratocumulus Clouds over Southeast Atlantic Using WRF-Chem</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lu, Z.; Liu, X.; Zhang, Z.</p> <p>2015-12-01</p> <p> significantly increases cloud fraction and LWP during the night and morning. From noon to afternoon, the positive changes in cloud fraction and LWP decrease due to a stronger entrainment process. Meanwhile, the radiative effect of <span class="hlt">wildfire</span> aerosols can slightly mitigate the decreases in cloud fraction and LWP near the coast <span class="hlt">region</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUFM.T41C1322L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFM.T41C1322L"><span id="translatedtitle">Evidence for Little Shallow Entrainment in Starting Mantle <span class="hlt">Plumes</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lohmann, F. C.; Phipps Morgan, J.; Hort, M.</p> <p>2005-12-01</p> <p>Basalts from intraplate or hotspot ocean islands show distinct geochemical signatures. Their diversity in composition is generally believed to result from the upwelling <span class="hlt">plume</span> entraining shallow mantle material during ascent, while potentially also entraining other deep <span class="hlt">regions</span> of the mantle. Here we present results from analogue laboratory experiments and numerical modelling that there is evidence for little shallow entrainment into ascending mantle <span class="hlt">plumes</span>, i.e. most of the <span class="hlt">plume</span> signature is inherited from the source. We conducted laboratory experiments using glucose syrup contaminated with glass beads to visualize fluid flow and origin. The <span class="hlt">plume</span> is initiated by heating from below or by injecting hot, uncontaminated syrup. Particle movement is captured by a CCD camera. In our numerical experiments we solve the Stokes equations for a viscous fluid at infinite Prandtl number with passive tracer particles being used to track fluid flow and entrainment rates, simulating laboratory as well as mantle conditions. In both analogue experiments and numerical models we observe the classical <span class="hlt">plume</span> structure being embedded in a `sheath' of material from the <span class="hlt">plume</span> source <span class="hlt">region</span> that retains little of the original temperature anomaly of the <span class="hlt">plume</span> source. Yet, this sheath ascends in the `slipstream' of the <span class="hlt">plume</span> at speeds close to the ascent speed of the <span class="hlt">plume</span> head, and effectively prevents the entrainment of surrounding material into the <span class="hlt">plume</span> head or <span class="hlt">plume</span> tail. We find that the source <span class="hlt">region</span> is most effectively sampled by an ascending <span class="hlt">plume</span> and that compositional variations in the source <span class="hlt">region</span> are preserved during <span class="hlt">plume</span> ascent. The <span class="hlt">plume</span> center and <span class="hlt">plume</span> sheath combined are composed of up to 85% source material. However, there is also evidence of significant entrainment of up to 30% of surrounding material into the outer layers of the <span class="hlt">plume</span> sheath. Entrainment rates are found to be influenced by mantle composition and structure, with the radial viscosity profile of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19990069571&hterms=geyser&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dgeyser','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19990069571&hterms=geyser&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dgeyser"><span id="translatedtitle">Stealth <span class="hlt">Plumes</span> on Io</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Johnson, T. V.; Matson, Dennis L.; Blaney, Diana L.; Veeder, Glenn J.; Davies, Ashley</p> <p>1995-01-01</p> <p>We suggest that Io's eruptive activity may include a class of previously undetected SO2 geysers. The thermodynamic models for the eruptive <span class="hlt">plumes</span> discovered by Voyager 'involve low to moderate entropy SO2 eruptions. The resulting <span class="hlt">plumes</span> are a mixture of solid and gas which emerge from the vent and follow essentially ballistic trajectories. We show that intrusion of silicate magma into buried SO2 deposits can create the required conditions for high entropy eruptions which proceed entirely in the vapor phase. These purely gaseous <span class="hlt">plumes</span> would have been invisible to Voyager's instruments. Hence, we call them "stealth" <span class="hlt">plumes</span>. Such eruptions could explain the "patchy" SO2 atmosphere inferred from recent UV and micro-wave spectral observations. The magma intrusion rate required to support the required gas production for these <span class="hlt">plumes</span> is a negligible fraction of estimated global magma intrusion rates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993SPIE.1952..227D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993SPIE.1952..227D"><span id="translatedtitle">Surveillance sensor for autonomous <span class="hlt">wildfire</span> detection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>de Vries, Jan S.; Kemp, Rob A. W.</p> <p>1993-11-01</p> <p>Autonomous <span class="hlt">wildfire</span> detection systems may help to reduce hazards resulting from large wildland fires. In many situations <span class="hlt">wildfires</span> start in the duff below trees and shrubs, which are hidden from direct view by groundbased sensors overlooking forests and wildlands. Mid- and thermal infrared measurements only detect <span class="hlt">wildfires</span> when the fire has become a crownfire, and, by then, it usually has developed into a large <span class="hlt">wildfire</span>. Therefore, the early discovery of <span class="hlt">wildfires</span> using groundbased, autonomous sensors should be performed by detecting smoke clouds rather than the heat of the fire, since smoke becomes earlier visible above the trees as a result of convection than the heat of the fire. A demonstration sensor is being developed to show the feasibility of an affordable system for autonomous wildland fire detection. The system is designed to minimize false alarms by simultaneously analyzing the temporal, spatial and spectral information in the acquired imagery. The groundbased sensor will be horizon scanning and will employ linear CCD's for better contrast sensitivity in three different spectral bands.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011AGUFMDI13A2155H&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011AGUFMDI13A2155H&link_type=ABSTRACT"><span id="translatedtitle">Seismically imaging the Afar <span class="hlt">plume</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hammond, J. O.; Kendall, J. M.; Bastow, I. D.; Stuart, G. W.; Keir, D.; Ayele, A.; Ogubazghi, G.; Ebinger, C. J.; Belachew, M.</p> <p>2011-12-01</p> <p><span class="hlt">Plume</span> related flood basalt volcanism in Ethiopia has long been cited to have instigated continental breakup in northeast Africa. However, to date seismic images of the mantle beneath the <span class="hlt">region</span> have not produced conclusive evidence of a <span class="hlt">plume</span>-like structure. As a result the nature and even existence of a <span class="hlt">plume</span> in the <span class="hlt">region</span> and its role in rift initiation and continental rupture are debated. Previous seismic studies using <span class="hlt">regional</span> deployments of sensors in East-Africa show that low seismic velocities underlie northeast Africa, but their resolution is limited to the top 200-300km of the Earth. Thus, the connection between the low velocities in the uppermost mantle and those imaged in global studies in the lower mantle is unclear. We have combined new data from Afar, Ethiopia with 6 other <span class="hlt">regional</span> experiments and global network stations across Ethiopia, Eritrea, Djibouti and Yemen, to produce high-resolution models of upper mantle P- and S- wave velocities to the base of the transition zone. Relative travel time tomographic inversions show that the top 100km is dominated by focussed low velocity zones, likely associated with melt in the lithosphere/uppermost asthenosphere. Below these depths a broad SW-NE oriented sheet like upwelling extends down to the top of the transition zone. Within the transition zone two focussed sharp-sided low velocity <span class="hlt">regions</span> exist: one beneath the Western Ethiopian plateau outside the rift valley, and the other beneath the Afar depression. The nature of the transition zone anomalies suggests that small upwellings may rise from a broader low velocity <span class="hlt">plume</span>-like feature in the lower mantle. This interpretation is supported by numerical and analogue experiments that suggest the 660km phase change and viscosity jump may impede flow from the lower to upper mantle creating a thermal boundary layer at the base of the transition zone. This allows smaller, secondary upwellings to initiate and rise to the surface. Our images of secondary upwellings</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_13");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <center> <div class="footer-extlink text-muted"><small>Some links on this page may take you to non-federal websites. 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