A51A-01
Quantitative evaluation of smoke source strengths and impacts by infusing satellite fire- strength measurements in transport models.
Chemical transport models currently derive their smoke emission sources from counts of fire hot spots detected from satellites, usually with single daily overpasses. However, fires vary in size and strength, with a significant diurnal trend, making the use of pixel counts measured at the same time of day very unreliable for estimating smoke sources. Fortunately, the Moderate-resolution Imaging Spectro-radiometer (MODIS) twin sensors onboard the Terra and Aqua satellites, not only detect fires everywhere at four strategic times of day, but also measure their strength in the form of fire radiative power (FRP) or rate of release of fire radiative energy (FRE). FRP is now also being derived from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) sensor onboard the geostationary Meteosat-8 platform, which observes Africa and Europe virtually every 15 mins. The SEVIRI measurements show that MODIS 4-times-a-day measurements capture the essence of the fire diurnal cycle. Therefore, MODIS is currently the only satellite data source ideal for estimating daily smoke emissions globally. In a number of recent studies, FRP has been found to be directly proportional to both the rate of biomass consumption and the rate of smoke aerosol emission. Indeed, (1) a combustion factor (Fc), which relates FRE to burned biomass was established, and (2) a FRE-based emission coefficient (Ce), which is a simple coefficient to convert FRP (or FRE) to smoke aerosol emissions was derived for different parts of the world. The results obtained from satellite have been reproduced in the laboratory, and the ingestion of FRP in models is now being tested using the Goddard Global Ozone Chemistry Aerosol Radiation and Transport (GOCART) model. Although MODIS has been in operation since the last 6 years, regrettably, this rare but formidable data resource it provides (FRP) has been left largely unutilized. In this presentation, we will show the preliminary results of using FRP to improve the smoke emission source characterization and impacts analysis in different parts of the globe.
A51A-02
Forest Fires in Southwestern Amazonia During 2005: Extent and Distribution in Eastern Acre State, Brazil
The extended drought in western Amazonia during 2005 provided the conditions for wild fires that spread in old- growth rain forests and cleared areas of the contiguous areas of Madre de Dios, Peru, Acre, Brazil, and Pando, Bolivia, collectively known as the MAP Region. The greatest extent of the wild fires occurred in eastern Acre State with 60,000 km2 of diverse land uses that range from intensely occupied colonization areas, large cattle ranches, extractive and biological reserves and indigenous areas. At the request of the Public Ministry of Acre and other government agencies we analyzed Landsat 5 and CBERS 2 imagery for forests with canopies affected by fires, using visual interpretation and manual digitalization of polygons. Accuracy assessment was done with 180 aerial photos. The total area of forest with canopies affected by fires was 267,000 ha, roughly five times recent annual deforestation rates for Acre State. Omission and commission errors were 28% and 2%, respectively. Burn scars in non-forest areas were determined using ASTER and CBERS 2 imagery via supervised classification. Total open area with burn scars was 203,000 ha. The total of open area and forests affected by fires exceeded 470,000 ha due to three factors: (1) some images used did not include the last weeks of burning; (2) ground fires in forests that did not affect the canopy and therefore were not detected; and (3) concern of the interpreters to avoid commission errors. Of the twelve municipalities of eastern Acre, most affected were Acrelandia, Placido de Castro, Epitaciolandia with >31%, >19% and >17% of the municipality affected, respectively). The largest impact, >114,000 ha, occurred in the Rio Branco Municipality. Similar patterns of burning occurred in Pando and in Madre de Dios. The environmental, social and economic disaster that these fires produced may be a harbinger of future impacts in southwestern Amazonia if current climate predictions prove to be correct.
A51A-03
A basin-wide assessment of the GOES and MODIS active fire products for the Brazilian Amazon
This LBE-ECO Phase III study is designed to assess the performance of active fire products which have been used to delineate the fire dynamics in the Brazilian Amazon basin and which are routinely used to feed biomass burning emissions models for the region. The initial analyses are focused primarily on the creation of a validated long term (1995-present) record for the WF-ABBA active fire product using GOES East geostationary satellite data. Active fire masks were produced for 285 ASTER and ETM+ scenes distributed across the Brazilian Amazon representing our ground truth for the validation of the WF-ABBA. For comparison purposes we also included the MODIS/Terra "Thermal Anomalies" (MOD14) data in our analyses. Approximately 14,500 fire pixels were analyzed for the GOES data and 7,300 fire pixels were analyzed for the MODIS data. We found that at the 50% detection probability mark (p<0.001), the GOES fire product requires four times more active fire area than it is necessary for MODIS to achieve the same probability of detection. However, the higher observation frequency of GOES resulted in less than 40% omission error compared to 80% with MODIS. Basin-wide commission errors for MODIS and GOES were approximately 15 and 17%, respectively. Commission errors were higher over areas of active deforestation due to the high thermal contrast between the deforested sites and the adjacent green forests which can cause multiple false detections. Burnt area estimates were also produced based on ETM+ data to assess the average burnt area size associated with the coarse resolution active fire data above. For this application over 2,700 burn scar polygons were digitized representing all major biomass burning regions across the Brazilian Amazon. Burn scar polygons were then intersected with the MODIS/Terra and Aqua active fire data. 50% of all polygons containing active fires in the MODIS imagery showed a burnt area size larger than 300ha. Burnt areas of less than 100ha in size represented 15% of all cases analyzed. These results are expected to have important implications for fire related studies in the Brazilian Amazon region which rely on satellite active fire data, and more specifically on the GOES and MODIS products. Further work will be pursued to create a unified fire diurnal cycle map that can be used to model time dependent variables (e.g.: emissions). Emission modeling studies will also be addressed at the subsequent phases of this study project by feeding models with the optimized data sets described above.
A51A-04
Effects of Changes in Anthropogenic and Biogenic Emissions on the Ozone Air Quality over the United States
Changes in surface ozone air quality are very likely in the coming decades in response to changes in climate and precursor emissions from both anthropogenic and biogenic sources. The effects of changes in anthropogenic and biogenic emissions on ozone are distinct. Changes in anthropogenic emissions include most ozone precursors including NOx, CO and VOC emissions while changes in biogenic emissions contribute primarily to VOC emissions. The resulting relative abundances of NOx versus VOC differ from each other, leading to different magnitudes/patterns of ozone responses. This study uses a global chemical transport model to investigate the effects of climate and emission changes on summertime surface ozone levels over the United States during the 21st century under the IPCC A1fi and B1 scenarios, with emphasis on the combined and separate contributions of changes in anthropogenic and biogenic emissions. The global modeling accounts for the ozone response within the context of global climate and emission changes. Preliminary results show that, by the late 21st century, ozone would increase (decrease) more than 20 ppb over the U.S. due to enhancements (reductions) of anthropogenic emissions under A1fi (B1). In addition, there would be as much as a 20 ppb increase of ozone under the A1fi scenario due to increases in biogenic emissions. This study suggests that increases in biogenic emissions would significantly affect the ozone air quality under highly-warming climate scenarios, making it that much more difficult to meet acceptable ozone levels in the future.
A51A-05
Urbanization Effects on air Quality and Climate in the Acapulco Area Using a Prognostic Meteorological and air Quality Model
The effects of urbanization growth on the Acapulco coastal metropolitan area were estimated by using a prognostic meteorological and air quality model. To this end three urbanization scenarios are proposed: The current Acapulco urban area that we call "Control Scenario" and two possible urban growths that we call "Scenario 1" and "Scenario 2". We estimated the urban growth of scenarios 1 and 2, using economic factors, population distribution and historical data. The urban distribution in the "Control Scenario" was taken from the aerial photographs of Acapulco and processed by a Geographic Information System (GIS).The variables devised for the scenarios comparison was a Comfort Index based on humidity and temperature and the Potential Exposure Index for Ozone. The model used was the Penn State/NCAR MM5 mesoscale meteorological model and the Multiscale Climate and Chemistry Model (MCCM). Since there is no local information, the emissions were estimated by using data of similar socio- economic urban areas where emission data is available. The meteorology and air quality models were calibrated using data of a measuring campaign performed in December 2005. This is a preliminary effort to propose a planned urban expansion for Acapulco from the point of view of air quality and urban climate.
A51A-06
Air Pollution Radiative Forcing From Specific Emissions Sectors at 2030: Prototype for a New IPCC Bar Chart
Reduction of short-lived air pollutants provides a way to mitigate global warming in the short-term with ancillary benefits to human health. However, the radiative forcings of short-lived air pollutants depend on the location and source type of the precursor emissions. We apply the GISS atmospheric composition-climate model to quantify near future (2030 A1B) ozone (O3) and sulfate global mean direct radiative forcing impacts from 6 emissions sectors from 7 geographic regions. At 2030 the net forcings for the emissions sectors (including O3, sulfate, black and organic carbon forcings) are (in mW/m2): transportation = +106; biomass burning = +69; domestic = +38; power = -158; industry = -124. Hence the transportation sector is the most attractive target to counter global warming via reduction of short-lived air pollutants. Substantial transportation sector O3 forcings come from all regions (5-12 mW/m2). Central and Southern Africa and South America contribute the largest biomass burning O3 forcings (11-15 mW/m2). Domestic biofuel emissions from East Asia, South Asia and Central and South Africa and power and industry emissions from East Asia also contribute substantial O3 forcings (7-15mW/m2). The global mean sulfate forcings are dominated by the power and industry sectors with largest contributions from East Asia, South Asia and North Africa and Middle East (-30 to -50 mW/m2). Linear relationships exist between global mean radiative forcing by O3 and biomass burning and domestic biofuel CO precursor emissions independent of the region of origin with sensitivity of 0.02mW/m2/TgCO. Similarly, linear relationships are available for global mean radiative forcing by sulfate and SO2 precursor emissions that depend upon region but are independent of the emissions sector with sensitivities ranging from -3 to -12mW/m2/TgS. Such emissions to forcing diagnostics will assist development of climate-motivated policy for O3 and sulfate.
A51A-07
Persistence versus growth: How sub-sectors affect the inevitability of future emissions
Some emissions—like those of black and organic carbon aerosols—vary by orders of magnitude depending on the combustion technology used. This means that a disproportionate fraction of emissions may come from the highest-emitting sources. Some of these sources may be resistant to change for social, economic, or political reasons. Thus, treating entire economic sectors as entities for which change can be broadly modeled is too simplistic. Emission changes are a composite of (a) growth in new, low-emitting sources; (b) growth in conventional, polluting sources; and (c) turnover of old technology stock. While this is true for traditional climate actors such as carbon dioxide, the importance of change in a small fraction of polluting sources is greater for aerosols and process-dependent trace gases. Future emissions are inevitable either if old stock persists, or if technology improvements cannot balance growth. We examine possible future transitions for two major contributors to global atmospheric pollution— vehicles and residential solid fuels—using a model driven with econometric relationships for technology choice. We use the Community Atmosphere Model developed at the National Center for Atmospheric Research to determine regionally-specific forcing values for aerosols. We apportion aerosol forcing changes in each region to growth and to persistent emitters. This suggests the most important actions that can alter aerosol forcing within the near future.