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 ◽  
...  

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.

2011 ◽  
Vol 11 (3) ◽  
pp. 7321-7374 ◽  
Author(s):  
R. J. Yokelson ◽  
I. R. Burling ◽  
S. P. Urbanski ◽  
E. L. Atlas ◽  
K. Adachi ◽  
...  

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.


2021 ◽  
Author(s):  
Julissa Rojas-Sandoval

Abstract E. berteroana is widely distributed throughout lowland tropical dry forest from southern Mexico to northern Peru, and in the Greater Antilles. This species occurs naturally from low to mid-altitudes 300-600 m, however it has been planted up to the 1000 m. It grows in humid areas with an average temperature of 25.5°C and an average annual rainfall of 3500 mm. E. berteroana is important in agroforestry, for it replenishes the soil and fertilizes companion crops. This species is commonly used for live fencing from Mexico to northern South America (Russo, 1993). In Costa Rica it is also widely used for fence posts (Nygren, 1993). After pruning E. berteroana produces a great volume of large leaf shoots in only three to four weeks. Biomass production of E. berteroana living fence varied according to pruning frequency (CATIE, 1989a, 1989b). The fence produced the most woody biomass when pruned every 12 months, the least biomass when pruned every three months, and 6-month pruning produced the most edible biomass. Live fencing of E. berteroana can also provide cuttings for additional posts, and a vigorous tree can produce 10 or more cuttings of 5-15 cm diameter every two years. E. berteroana is not recommended as a shade tree because it has a fragile stem and does not provide enough shade. The leaves contain 40% crude protein, 4% nitrogen, and are commonly used as fodder for cattle, rabbits and goats (Russo, 1993). Unfortunately, leaf fall occurs in the dry season when forage is important because pasture quality decreases (Beer et al., 1989). Other uses of E. berteroana are, windbreaks, dyes, insecticides, poles to grow crops such as black pepper, Piper nigrum, Dioscorea alata (yam), Sechium edule or Passiflora ligularis (granadilla). This species also forms a useful mulch for annual crops such as maize (Russo, 1993). This species may be used for fuelwood and construction, although the timber is not used extensively because it is light, coarse, unattractive and lacks durability. The stem bark of E. berteroana contains a prenylated flavanone. This compound has an anti-fungal activity against Cladosporium cucumerinum (Russo, 1993). In El Salvador the bark of E. berteroana is used to poison dogs and wild animals. E. berteroana is a fast growing species, and is easy to propagate by seed layering, marcotting, cuttings, and particularly large stakes more than 2.5 m long. The stakes are usually cut at the end of the dry season or the beginning of the rains. They may be planted immediately, or stored vertically or laid individually on the ground for up to two weeks in a cool, shady place (Viquez, 1993). Flowering occurs October-February and fructification between May-June. The species produces large quantities of red beans every year, a kilogram of seed contains 3000-3500 seeds. The seed is orthodox, and has a hard, impermeable seed coat and should be scarified either with sandpaper, a knife, or soaking in warm water (40°C) for 12 hours, to aid germination. E. berteroana has germination rates of 85-90%, when using seed collected from the previous year which has been stored in cold chambers at 5°C with a relative humidity of 30-40%. The shoot borer Terastia meticulosalis has been observed on E. berteroana. Damage can be critical in newly sown agroforestry plantings, there have been reports of serious attacks on small trees (generally those less than 1.5 m tall) associated with black pepper. The adults of Phyllophaga menetriesi feed on the young foliage of this species.


2012 ◽  
Vol 69 (3) ◽  
pp. 1037-1053 ◽  
Author(s):  
Omar Torres ◽  
Hiren Jethva ◽  
P. K. Bhartia

Abstract A large fraction of the atmospheric aerosol load reaching the free troposphere is frequently located above low clouds. Most commonly observed aerosols above clouds are carbonaceous particles generally associated with biomass burning and boreal forest fires, and mineral aerosols originating in arid and semiarid regions and transported across large distances, often above clouds. Because these aerosols absorb solar radiation, their role in the radiative transfer balance of the earth–atmosphere system is especially important. The generally negative (cooling) top-of-the-atmosphere direct effect of absorbing aerosols may turn into warming when the light-absorbing particles are located above clouds. The actual effect depends on the aerosol load and the single scattering albedo, and on the geometric cloud fraction. In spite of its potential significance, the role of aerosols above clouds is not adequately accounted for in the assessment of aerosol radiative forcing effects due to the lack of measurements. This paper discusses the basis of a simple technique that uses near-UV observations to simultaneously derive the optical depth of both the aerosol layer and the underlying cloud for overcast conditions. The two-parameter retrieval method described here makes use of the UV aerosol index and reflectance measurements at 388 nm. A detailed sensitivity analysis indicates that the measured radiances depend mainly on the aerosol absorption exponent and aerosol–cloud separation. The technique was applied to above-cloud aerosol events over the southern Atlantic Ocean, yielding realistic results as indicated by indirect evaluation methods. An error analysis indicates that for typical overcast cloudy conditions and aerosol loads, the aerosol optical depth can be retrieved with an accuracy of approximately 54% whereas the cloud optical depth can be derived within 17% of the true value.


2021 ◽  
Author(s):  
Evelyn Jäkel ◽  
Tim Carlsen ◽  
André Ehrlich ◽  
Manfred Wendisch ◽  
Michael Schäfer ◽  
...  

Abstract. The size and shape of snow grains directly impacts the reflection by a snowpack. In this article, different approaches to retrieve the optical-equivalent snow grain size (ropt) or, alternatively, the specific surface area (SSA) using satellite, airborne, and ground-based observations are compared and used to evaluate ICON-ART (ICOsahedral Non-hydrostatic – Aerosols and Reactive Trace gases) simulations. The study is focused on low Sun and partly rough surface conditions encountered during a three-week campaign conducted North of Greenland in March/April 2018 within the framework of the PAMARCMiP (Polar Airborne Measurements and Arctic Regional Climate Model Simulation Project) project. Further, we propose an adjusted airborne retrieval method by using the albedo at 1700 nm wavelength. This reduced the effect of atmospheric masking and improved the sensitivity on ropt. From this approach we achieved a significantly improved uncertainty (


2017 ◽  
Vol 71 (11) ◽  
pp. 778-778
Author(s):  
Céline Pascale ◽  
Daiana Leuenberger ◽  
Myriam Guillevic ◽  
Andreas Ackermann ◽  
Bernhard Niederhauser

2021 ◽  
Author(s):  
Roland Potthast ◽  
Wolfgang Müller ◽  
Barbara Früh ◽  
Peter Korn ◽  
Susanne Brienen ◽  
...  

<p>ICON-seamless entwickelt ein neues Erdsystemmodell, als Grundlage für Wettervorhersage, saisonale und dekadische Klimavorhersagen, bis hin zu Klimaprojektionen. Dabei nutzen wir die Expertise, die ICON-NWV als zuverlässiges Modell für numerische Wettervorhersage (NWV) betreibt und pflegt sowie die Erfahrungen mit der ersten ICON-Erdsystemversion basierend auf der Physik der MPI-Atmosphäre ECHAM. Das Ziel ist, gemeinsame Komponenten für alle meteorologischen Zeitskalen nutzen zu können. Der erste Schritt entwickelt ein Modell für saisonale und dekadische Zeitskalen.</p> <p>ICON-seamless baut auf der Kopplung der Komponenten ICON-NWV (Atmosphäre) und ICON-O (Ozean) auf. Mit Hilfe des speziell entwickelten Kopplungs-Tools YAC können beide Komponenten Variablen austauschen, die für die Wechselwirkung zwischen Atmosphäre und Ozean wichtig sind. Auch die Parametrisierung von Meereis stellt einen wichtigen Baustein dar. Zur Wiedergabe eines geschlossenen hydrologischen Kreislaufs und um den Kohlenstoffkreislauf sauber darzustellen, wird ferner ein geeignetes Bodenmodell, ICON-L, an die Atmosphärenphysik von ICON-NWV gekoppelt. Zudem werden transiente Aerosolfelder, Treibhausgase, und Strahlungsantriebe neu in ICON-NWV eingelesen, um historische Zeiträume nachzuvollziehen. Parallel hierzu werden die ART Module (Aerosol and Reactive Trace gases), die eine dynamische Behandlung von Gasen und Aerosolen gestatten, an die modifizierte Modellphysik angepasst. Eine intensive Modelldiagnostik unterstützt das Tuning. Für die zukünftige Verwendung im Bereich der (Wetter- und) Klimavorhersagen wird parallel die gekoppelte Datenassimilation entwickelt.</p> <p>Wir geben einen Überblick über den aktuellen Stand der Entwicklung, der Experimente und potentieller Anwendungsbereiche.</p>


2002 ◽  
Vol 62 (2) ◽  
pp. 339-346 ◽  
Author(s):  
J. RAGUSA-NETTO

Figs are a remarkable food resource to frugivores, mainly in periods of general fruit scarcity. Ficus calyptroceras Miq. (Moraceae) is the only fig species in a type of dry forest in western Brazil. In this study I examined the fruiting pattern as well as fig consumption by birds in F. calyptroceras. Although rainfall was highly seasonal, fruiting was aseasonal, since the monthly proportion of fruiting trees ranged from 4% to 14% (N = 50 trees). I recorded 22 bird species feeding on figs. In the wet season 20 bird species ate figs, while in the dry season 13 did. Parrots were the most important consumers. This group removed 72% and 40% of the figs consumed in the wet and dry seasons, respectively. No bird species increases fig consumption from dry to wet season. However, a group of bird species assumed as seed dispersers largely increases fig consumption from wet to dry season, suggesting the importance of this resource in the period of fruit scarcity. The results of this study points out the remarkable role that F. calyptroceras plays to frugivorous birds, in such a dry forest, since its fruits were widely consumed and were available all year round.


1985 ◽  
Vol 15 (1-2) ◽  
pp. 77-120 ◽  
Author(s):  
P.J. Crutzen ◽  
M.T. Coffey ◽  
A.C. Delany ◽  
J. Greenberg ◽  
P. Haagenson ◽  
...  

Field measurement programs in Brazil during the dry season months of August and September in 1979 and 1980 have demonstrated the great importance of the continental tropics in global air chemistry. Especially in the mixed layer, the air composition over land is much different from that over the ocean and the land areas are clearly longe scale sources of many inportant trace gases. During the dry season much biomass, burning takes place especially in the cerrado regions leading to substantial emission of air pollutants, such as CO, NOx, N2O, CH4 and other hydrocarbons. Ozone concentrations are alsoenhanced due to photochemical reactions. Biogenic organic emissions from tropical forests play likewise an important role in the photochemistry of the atmosphere. Carbon monoxide was found to be present in high concentrations in the boundary layer of the tropical forest, but ozone concentrations were much lower than in the cerrado.


Check List ◽  
2016 ◽  
Vol 12 (2) ◽  
pp. 1862 ◽  
Author(s):  
Miguel Briones-Salas ◽  
Natalia Martín-Regalado ◽  
Mario C. Lavariega

The tropical dry forests of Mexico are one of the world’s biodiversity hotspots. To contribute to the knowledge of mammal diversity and conservation of the central coast of Oaxaca State, southern Mexico, we conducted field surveys in the area. Additional information was obtained from literature and museum databases. In order to compare the taxonomic similitude between areas along the Planicie Costera del Pacífico province we performed a taxonomic similarity analysis using data from the literature and the present study. A total of 49 species of mammals belonging to 19 families and eight orders were recorded. The maximum number of species was recorded in deciduous forest (n = 46), followed by semideciduous forest (n = 11). The similarity index was low (<50%) between areas along the Planicie costera del Pacífico, indicating higher species turnover. The high mammal diversity, the presence of endemic (8%), threatened species (16%), and voluntary conservation areas highlight the importance of this region.


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