scholarly journals Isotopic signatures of methane emissions from tropical fires, agriculture and wetlands: the MOYA and ZWAMPS flights

2021 ◽  
Vol 380 (2215) ◽  
Author(s):  
◽  
Euan G. Nisbet ◽  
Grant Allen ◽  
Rebecca E. Fisher ◽  
James L. France ◽  
...  
Keyword(s):  
Forest Fires ◽  
Urban Pollution ◽  
Dry Forest ◽  
Isotopic Signatures ◽  
African Cattle ◽  
Methane Budget ◽  
Methane Fluxes ◽  
Smoke Pollution ◽  
Southern Amazonia ◽  
Agricultural Areas

We report methane isotopologue data from aircraft and ground measurements in Africa and South America. Aircraft campaigns sampled strong methane fluxes over tropical papyrus wetlands in the Nile, Congo and Zambezi basins, herbaceous wetlands in Bolivian southern Amazonia, and over fires in African woodland, cropland and savannah grassland. Measured methane δ 13 C CH 4 isotopic signatures were in the range −55 to −49‰ for emissions from equatorial Nile wetlands and agricultural areas, but widely −60 ± 1‰ from Upper Congo and Zambezi wetlands. Very similar δ 13 C CH 4 signatures were measured over the Amazonian wetlands of NE Bolivia (around −59‰) and the overall δ 13 C CH 4 signature from outer tropical wetlands in the southern Upper Congo and Upper Amazon drainage plotted together was −59 ± 2‰. These results were more negative than expected. For African cattle, δ 13 C CH 4 values were around −60 to −50‰. Isotopic ratios in methane emitted by tropical fires depended on the C3 : C4 ratio of the biomass fuel. In smoke from tropical C3 dry forest fires in Senegal, δ 13 C CH 4 values were around −28‰. By contrast, African C4 tropical grass fire δ 13 C CH 4 values were −16 to −12‰. Methane from urban landfills in Zambia and Zimbabwe, which have frequent waste fires, had δ 13 C CH 4 around −37 to −36‰. These new isotopic values help improve isotopic constraints on global methane budget models because atmospheric δ 13 C CH 4 values predicted by global atmospheric models are highly sensitive to the δ 13 C CH 4 isotopic signatures applied to tropical wetland emissions. Field and aircraft campaigns also observed widespread regional smoke pollution over Africa, in both the wet and dry seasons, and large urban pollution plumes. The work highlights the need to understand tropical greenhouse gas emissions in order to meet the goals of the UNFCCC Paris Agreement, and to help reduce air pollution over wide regions of Africa. This article is part of a discussion meeting issue 'Rising methane: is warming feeding warming? (part 2)'.

Detection of Russian Fires Using MOPITT and MODIS Data

2005 ◽  
Vol 277-279 ◽  
pp. 816-823
Author(s):  
Sang Hee Lee ◽  
Gi Hyuk Choi ◽  
Hyo Suk Lim ◽  
Joo Hee Lee ◽  
Kwon Ho Lee ◽  
...  
Keyword(s):  
East Asia ◽  
Forest Fires ◽  
Eastern China ◽  
Northeast Asia ◽  
Smoke Aerosol ◽  
Modis Data ◽  
Smoke Pollution ◽  
Moderate Resolution ◽  
Large Fires ◽  
Moderate Resolution Imaging Spectroradiometer

The great fires were detected through the Moderate Resolution Imaging Spectroradiometer (MODIS) observations over Northeast Asia. The large amount of smoke produced near Lake Baikal was transported to East Asia using high Aerosol Optical Thickness (AOT) as seen through the satellite images. The smoke pollution from the Russian forest fires would sometimes reach Korea through Mongolia and eastern China. In May 2003, a number of large fires blazed through eastern Russian, producing a thick, widespread pall of smoke over much of East Asia. This study focuses on the identification of the carbon monoxide (CO) for MOPITT released from MOPITT primarily into East Asia during the Russian Fires. In the wake of the fires, the 700hPa MOPITT retrieved CO concentrations which reached up to 250ppbv. Smoke aerosol retrieval using a separation technique was also applied to the MODIS data observed in 14-22 May 2003. Large AOT, 2.0 ~ 5.0, was observed over Korea on 20 May 2003 due to the influence of the long range transport of smoke aerosol plume from the Russian Fires.

scholarly journals Forest Fires in Greece and Their Economic Impacts on Agriculture

2020 ◽  
Author(s):  
Dimitra Stougiannidou ◽  
Eleni Zafeiriou ◽  
Yannis Raftoyannis
Keyword(s):  
Literature Review ◽  
Forest Fires ◽  
Rural Economy ◽  
Economic Impacts ◽  
Secondary Data ◽  
Indirect Costs ◽  
Ex Post ◽  
Time Space ◽  
The Cost ◽  
Agricultural Areas

Forest fires have increased in the last decades, due to many factors such as climate change, land use change and management. In Greece, wildfires burn cultivated lands and affect significantly the rural economy and society. However, the economic impacts of forest fires on agricultural areas has not been estimated, and this is our aim. After an extended literature review and consultation with the stakeholders, we decided to build a model with many variables. The total cost of fire depends on the cost of prevention and suppression measures, and also direct and indirect costs. Direct costs, as adjusted for the immediate effects of fire, are divided into two categories: direct damages instantaneous and direct losses induced. Direct damages are estimated by a function that calculates the instantaneous damage in permanent crops, seasonal crops, livestock, infrastructure, construction and machinery. Direct losses are estimated by a function that calculates fire-induced costs in permanent crops, seasonal crops, livestock, additional borrowing costs and services costs. For the composition of the time-space model, we will use secondary data, as well as data originated from fieldwork. The literature review showed that the ex post analysis involving detailed consultation with a representative sample of affected farms, provides a more consistent appraisal.

scholarly journals δ 13 C methane source signatures from tropical wetland and rice field emissions

2021 ◽  
Vol 380 (2215) ◽  
Author(s):  
James L. France ◽  
Rebecca E. Fisher ◽  
David Lowry ◽  
Grant Allen ◽  
Marcos F. Andrade ◽  
...  
Keyword(s):  
Rice Field ◽  
Ambient Air ◽  
Atmospheric Methane ◽  
Isotopic Signatures ◽  
Methane Budget ◽  
Significant Seasonal Variation ◽  
Methane Source ◽  
Wetland Extent ◽  
Term Monitoring

The atmospheric methane (CH 4 ) burden is rising sharply, but the causes are still not well understood. One factor of uncertainty is the importance of tropical CH 4 emissions into the global mix. Isotopic signatures of major sources remain poorly constrained, despite their usefulness in constraining the global methane budget. Here, a collection of new δ 13 C CH 4 signatures is presented for a range of tropical wetlands and rice fields determined from air samples collected during campaigns from 2016 to 2020. Long-term monitoring of δ 13 C CH 4 in ambient air has been conducted at the Chacaltaya observatory, Bolivia and Southern Botswana. Both long-term records are dominated by biogenic CH 4 sources, with isotopic signatures expected from wetland sources. From the longer-term Bolivian record, a seasonal isotopic shift is observed corresponding to wetland extent suggesting that there is input of relatively isotopically light CH 4 to the atmosphere during periods of reduced wetland extent. This new data expands the geographical extent and range of measurements of tropical wetland and rice δ 13 C CH 4 sources and hints at significant seasonal variation in tropical wetland δ 13 C CH 4 signatures which may be important to capture in future global and regional models. This article is part of a discussion meeting issue ‘Rising methane: is warming feeding warming? (part 2)’.

scholarly journals Kinetic isotope effects of <sup>12</sup>CH<sub>3</sub>D  + OH and <sup>13</sup>CH<sub>3</sub>D  + OH from 278 to 313 K

2016 ◽  
Vol 16 (7) ◽  
pp. 4439-4449 ◽  
Author(s):  
L. M. T. Joelsson ◽  
J. A. Schmidt ◽  
E. J. K. Nilsson ◽  
T. Blunier ◽  
D. W. T. Griffith ◽  
...  
Keyword(s):  
Isotope Effects ◽  
Kinetic Isotope Effects ◽  
State Theory ◽  
Atmospheric Methane ◽  
Isotopic Signatures ◽  
Budget Analysis ◽  
Kinetic Isotope ◽  
Methane Budget ◽  
Source Signal ◽  
Clumped Isotope

Abstract. Methane is the second most important long-lived greenhouse gas and plays a central role in the chemistry of the Earth's atmosphere. Nonetheless there are significant uncertainties in its source budget. Analysis of the isotopic composition of atmospheric methane, including the doubly substituted species 13CH3D, offers new insight into the methane budget as the sources and sinks have distinct isotopic signatures. The most important sink of atmospheric methane is oxidation by OH in the troposphere, which accounts for around 84 % of all methane removal. Here we present experimentally derived methane + OH kinetic isotope effects and their temperature dependence over the range of 278 to 313 K for CH3D and 13CH3D; the latter is reported here for the first time. We find kCH4/kCH3D = 1.31 ± 0.01 and kCH4/k13CH3D = 1.34 ± 0.03 at room temperature, implying that the methane + OH kinetic isotope effect is multiplicative such that (kCH4/k13CH4)(kCH4/kCH3D) = kCH4/k13CH3D, within the experimental uncertainty, given the literature value of kCH4/k13CH4 = 1.0039 ± 0.0002. In addition, the kinetic isotope effects were characterized using transition state theory with tunneling corrections. Good agreement between the experimental, quantum chemical, and available literature values was obtained. Based on the results we conclude that the OH reaction (the main sink of methane) at steady state can produce an atmospheric clumped isotope signal (Δ(13CH3D) = ln([CH4][13CH3D]/[13CH4][CH3D])) of 0.02 ± 0.02. This implies that the bulk tropospheric Δ(13CH3D) reflects the source signal with relatively small adjustment due to the sink signal (i.e., mainly OH oxidation).

scholarly journals Air Quality Impacts of Smoke from Hazard Reduction Burns and Domestic Wood Heating in Western Sydney

Atmosphere ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 557 ◽  
Author(s):  
Maximilien Desservettaz ◽  
Frances Phillips ◽  
Travis Naylor ◽  
Owen Price ◽  
Stephanie Samson ◽  
...  
Keyword(s):  
Air Quality ◽  
Forest Fires ◽  
Total Duration ◽  
Atmospheric Composition ◽  
Gaseous Species ◽  
Hazard Reduction ◽  
Pollution Levels ◽  
Smoke Pollution ◽  
Pm 10 ◽  
Wood Heating

Air quality was measured in Auburn, a western suburb of Sydney, Australia, for approximately eighteen months during 2016 and 2017. A long open-path infrared spectrometer sampled path-averaged concentrations of several gaseous species, while other pollutants such as PM 2.5 and PM 10 were sampled by a mobile air quality station. The measurement site was impacted by a number of indoor wood-heating smoke events during cold winter nights as well as some major smoke events from hazard reduction burning in the spring of 2017. In this paper we compare the atmospheric composition during these different smoke pollution events and assess the relative overall impact on air quality from domestic wood-heaters and prescribed forest fires during the campaign. No significant differences in the composition of smoke from these two sources were identified in this study. Despite the hazard reduction burning events causing worse peak pollution levels, we find that the overall exposure to air toxins was greater from domestic wood-heaters due to their higher frequency and total duration. Our results suggest that policy-makers should place a greater focus on reducing wood-smoke pollution in Sydney and on communicating the issue to the public.

scholarly journals A Satellite-Based Parameter to Monitor the Aerosol Impact on Convective Clouds

2007 ◽  
Vol 46 (5) ◽  
pp. 660-666 ◽  
Author(s):  
Itamar M. Lensky ◽  
Ron Drori
Keyword(s):  
Forest Fires ◽  
Land Surface ◽  
Cloud Condensation Nuclei ◽  
Urban Air Pollution ◽  
Sensible Heat Flux ◽  
Urban Pollution ◽  
Convective Cloud ◽  
Cloud Base ◽  
Suppression Effect ◽  
Convective Clouds

Abstract A method to monitor the aerosol impact on convective clouds using satellite data is presented. The impacts of forest fires and highly polluting megacities on cloud precipitation formation processes are quantified by the vertical extent above cloud base to which convective cloud tops have to develop for onset of precipitation in terms of temperature difference D15. Large D15 is a manifestation of the precipitation suppression effect of small cloud condensation nuclei aerosols that elevate the altitude where effective precipitation processes are initiated. A warmer land surface with a greater sensible heat flux that increases the updraft velocity at cloud base may also contribute to the same effect. Therefore, D15 is greater for clouds that develop over more polluted and/or warmer surfaces that result from smoke and urban pollution and/or urban heat island, respectively. The precipitation suppression effects of both smoke from forest fires and urban effects can be vividly seen in a case study over Southeast Asia. Typical values of D15 are 1°–6°C for tropical maritime clouds, 8°–15°C for tropical clouds over land, 16°–26°C for urban air pollution, and 18°–39°C for clouds ingesting smoke from forest fires.

The Drought of Amazonia in 2005

2008 ◽  
Vol 21 (3) ◽  
pp. 495-516 ◽  
Author(s):  
José A. Marengo ◽  
Carlos A. Nobre ◽  
Javier Tomasella ◽  
Marcos D. Oyama ◽  
Gilvan Sampaio de Oliveira ◽  
...  
Keyword(s):  
Forest Fires ◽  
El Niño ◽  
El Nino ◽  
Dry Season ◽  
Trade Wind ◽  
Amazon River ◽  
Air Temperatures ◽  
Tropical North Atlantic ◽  
Southern Amazonia ◽  
Southwestern Amazonia

Abstract In 2005, large sections of southwestern Amazonia experienced one of the most intense droughts of the last hundred years. The drought severely affected human population along the main channel of the Amazon River and its western and southwestern tributaries, the Solimões (also known as the Amazon River in the other Amazon countries) and the Madeira Rivers, respectively. The river levels fell to historic low levels and navigation along these rivers had to be suspended. The drought did not affect central or eastern Amazonia, a pattern different from the El Niño–related droughts in 1926, 1983, and 1998. The choice of rainfall data used influenced the detection of the drought. While most datasets (station or gridded data) showed negative departures from mean rainfall, one dataset exhibited above-normal rainfall in western Amazonia. The causes of the drought were not related to El Niño but to (i) the anomalously warm tropical North Atlantic, (ii) the reduced intensity in northeast trade wind moisture transport into southern Amazonia during the peak summertime season, and (iii) the weakened upward motion over this section of Amazonia, resulting in reduced convective development and rainfall. The drought conditions were intensified during the dry season into September 2005 when humidity was lower than normal and air temperatures were 3°–5°C warmer than normal. Because of the extended dry season in the region, forest fires affected part of southwestern Amazonia. Rains returned in October 2005 and generated flooding after February 2006.

scholarly journals Trace gas and particle emissions from open biomass burning in Mexico

2011 ◽  
Vol 11 (14) ◽  
pp. 6787-6808 ◽  
Author(s):  
R. J. Yokelson ◽  
I. R. Burling ◽  
S. P. Urbanski ◽  
E. L. Atlas ◽  
K. Adachi ◽  
...  
Keyword(s):  
Forest Fires ◽  
Large Fraction ◽  
Trace Gases ◽  
Dry Season ◽  
Dry Forest ◽  
Southern Mexico ◽  
Carbonaceous Particles ◽  
Airborne Measurements ◽  
Combustion Sources ◽  
Reactive Trace Gases

Abstract. We report airborne measurements of emission factors (EF) for trace gases and PM2.5 made in southern Mexico in March of 2006 on 6 crop residue fires, 3 tropical dry forest fires, 8 savanna fires, 1 garbage fire, and 7 mountain pine-oak forest fires. The savanna fire EF were measured early in the local dry season and when compared to EF measured late in the African dry season they were at least 1.7 times larger for NOx, NH3, H2, and most non-methane organic compounds. Our measurements suggest that urban deposition and high windspeed may also be associated with significantly elevated NOx EF. When considering all fires sampled, the percentage of particles containing soot increased from 15 to 60 % as the modified combustion efficiency increased from 0.88 to 0.98. We estimate that about 175 Tg of fuel was consumed by open burning of biomass and garbage and as biofuel (mainly wood cooking fires) in Mexico in 2006. Combining the fuel consumption estimates with our EF measurements suggests that the above combustion sources account for a large fraction of the reactive trace gases and more than 90 % of the total primary, fine carbonaceous particles emitted by all combustion sources in Mexico.

Assessment of automated evapotranspiration estimates obtained using the GP-SEBAL algorithm for dry forest vegetation (Caatinga) and agricultural areas in the Brazilian semiarid region

2021 ◽  
Vol 250 ◽  
pp. 106863
Author(s):  
Carlos Eduardo Santos de Lima ◽  
Valéria Sandra de Oliveira Costa ◽  
Josiclêda Domiciano Galvíncio ◽  
Richarde Marques da Silva ◽  
Celso Augusto Guimarães Santos
Keyword(s):  
Forest Vegetation ◽  
Dry Forest ◽  
Semiarid Region ◽  
Brazilian Semiarid ◽  
Agricultural Areas

scholarly journals Methane flux and high-affinity methanotrophic diversity along the chronosequence of a receding glacier in Greenland

2010 ◽  
Vol 51 (56) ◽  
pp. 23-31 ◽  
Author(s):  
Teresa G. Bárcena ◽  
Jacob C. Yde ◽  
Kai W. Finster
Keyword(s):  
Denaturing Gradient Gel Electrophoresis ◽  
Methane Flux ◽  
Oxidation Potential ◽  
Glacier Recession ◽  
Methane Budget ◽  
Methane Uptake ◽  
Methane Fluxes ◽  
Gradient Gel Electrophoresis ◽  
Study Sites

AbstractMethane consumption in upland soils represents an important part of the biologically mediated sink of tropospheric methane. The present study focuses on the role of glacier forefields as a potential methane sink. The role of these environments, though increasing in size, has not yet been taken into account in the global methane budget. Net methane fluxes were analysed based on a static chamber method on a proglacial chronosequence from the Mittivakkat valley, southeast Greenland. Methane uptake could be measured in 7of the 12 study sites, with highest rates in the oldest materials from the chronosequence, suggesting that methane oxidation potential may increase during glacier recession (80–150 years). In the chamber located at the glacier front, net methane production was observed, indicating that the microbial community changes after glacial recession from being net methanogenic to becoming net methanotrophic. Diversity analyses based on denaturing gradient gel electrophoresis (DGGE) from the methanotrophic communities responsible for methane uptake at atmospheric levels demonstrate that methanotrophic microbial diversity changes along the chronosequence and show that there is a tendency to a larger diversity in the oldest part of the chronosequence. Sequencing of DNA retrieved from the DGGE revealed a restricted diversity of the methanotrophic community: GenBank accession numbers HM534684–HM534736.

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