TELON, la parte final de la trilogía HISTORIAS DE CHUECA salió a la venta el pasado viernes y la respuesta ha sido abrumadora. La librería. Yo ya les voy avisando de que TELON “no es exactamente lo que parece” y espero que ustedes Publicado por ABEL ARANA en martes, diciembre 07, El lector del día es ROBERTO BIELDFERNER que, como habrán comprobado tiene un apellido fácil de cojones de pronunciar. A Roberto me.
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Many major atmospheric sources have been studied extensively with a wide range of instrumentation. This includes, for example, temperate forest biogenic emissions e.
Biomass burning BB is the second largest global emitter of CO 2total greenhouse gases, and non-methane araan gases NMOGswith the latter being precursors for ozone O 3 and secondary organic aerosol OA.
Aranq, many important, complex BB emission sources have been rarely, if ever, characterized by comprehensive field measurements Akagi et al. The largest of these undersampled BB sources is peatland fires, which occur primarily in boreal forests and in the tropics, especially the Indonesian provinces of Sumatra, Kalimantan, and Papua as well as Malaysian Borneo.
Once the glowing fronts are burning under a layer of ash or have undercut the peat, the fire is virtually impossible to extinguish by commonly available means and it can burn slowly, both horizontally and downward to the water table for months. Peat fires can also re-emerge and ignite surface fuels, but the smoldering consumption of large quantities of belowground fuel, which produces smoke that is initially weakly lofted, is a key ecological and atmospheric characteristic of peatland fires Tosca et al.
The local air quality impacts of peat fires can be dramatic. With unfavorable transport, locally generated smoke may be dispersed to numerous major population centers regionally where much reduced but more widespread exposure and health effects are a potential concern e. Since peat is a semi-fossilized fuel accumulation rates are a wbel millimeters per year; Wieder et al.
With accelerated deforestation and building of drainage canals e. In many disturbed areas the absence of the original peat-swamp forest’s moist under-canopy microclimate that acted to deter ignition or slow fire spread results in increased fire activity Cochrane et al. The disturbed-area surface fuels are usually a minor component of the total available fuel but are present in sufficient amounts to be an ignition source for the peat.
Previously, tropical peat fire emissions had only been measured in detail in a few laboratory experiments e. Further, the emissions from burning one peat sample from Sumatra Christian et al. This variability makes it unclear how to optimize regional emissions inventories and the mean and variability in lab studies could also potentially reflect artifacts arising from sample collection, storage, or handling procedures. As a result, field measurements were a critical priority.
In this paper we present our October—November ground-based field measurements of trace gases and aerosols directly in 35 different peat fire plumes in the vicinity of Palangkaraya, Central Kalimantan, in the mostly disturbed western part of the EMRP Page et al.
We present and discuss our trace gas emission factors EFs; grams of a compound per kilogram peat burned measured by a cart-based, mobile Fourier transform infrared spectrometer FTIR and by filling whole air sampling WAS canisters for subsequent lab analyses. We present and discuss our measurements of aerosol optical properties and mass measured by photoacoustic extinctiometers PAX and gravimetric filter sampling.
Our field measurements enable us to assess emissions of the main greenhouse gases emitted by fires, many ozone and organic aerosol precursors, several air toxics, and the absorbing BrC that dominates the direct radiative forcing of peat fire smoke. Finally, we compare our field data to lab results published inIPCC guidelines, and the recent FLAME-4 lab measurements of burning Indonesian peat to gain additional insight into the emissions of air toxics and precursors not measured in the field and assess the overall value of lab studies of burning peat.
Additional aerosol results based on our filter sampling in the field coupled with a large suite of subsequent analyses will be reported in a companion paper Jayarathne et al. Different amounts of roots; sound or rotten logs; charred logs, char, and ash from previous burns; and mineral soil are frequently mixed in with the peat along with varying amounts of water. Traditional peat classification schemes can be less straightforward for disturbed areas.
For instance, ferns and grasses can contribute fibrous roots to a layer of older, even sapric, material. This is because the glowing front pre-dries the fuel as it advances. Peat combustion can occur as a glowing front in an expanding pit or undercut, but with direct access to surface air Huang et al.
The heat from glowing combustion pyrolyzes the adjacent peat, producing relatively more organic gases and copious amounts of white smoke with high OA content e. Wind increases the glowing front temperature. Oxygen availability is likely higher for lateral spreading than downward spreading fire and the overburden in downward spreading fires may scavenge some emissions.
LA COLUMNA DE ABEL ARANA: TELONYA FALTA MENOS
Occasionally peat can support brief, small flames if the surface peat is not too dense, or has high flammable abdl content or at high wind speeds Yokelson et al. All smoke sampling was conducted directly in the visible plumes Fig.
S1 and arna background sampling was conducted just outside usually upwind of the plumes in paired fashion. The surface fuels at all sites were nonexistent or limited to ferns, charred logs, twlon patchy second growth forest, but they were neither present in heavy loading nor burning in most cases. This provided data for 27 plumes, each assigned a letter identifier in our tables from A—Z to AA.
Eight additional plumes were quickly, opportunistically, sampled by aeana WAS, which was the fastest sampling method to complete. The full set of filter-based analyses will be reported separately Jayarathne et al.
The sites and fires sampled included a variety of peat types, disturbance levels, spread modes, burn depths, etc. A site map is given in Fig. Plume C included emissions from surface peat that were partially impacted by flames during wind gusts. This site was the least disturbed of the sites we sampled but had been logged aabel was known to have burned once before the fire we sampled. In addition, site 2 was close enough to a canal that its hydrology would have been impacted.
The other plumes sampled were burning in hemic and fibric peat types.
LA COLUMNA DE ABEL ARANA: LOS LECTORES DE “TELÓN”: ROBERTO BIELDFERNER
The South Bridge West site was revisited. The South Bridge East site was revisited. Some shallow peat combustion was sampled at this site, known locally as Tangkiling Road. We note for other researchers that the soft peat surface was not easily traversed with the rolling cart, which usually had to be carried.
In addition, all equipment was protected from underlying ash and dust with a tarp. In the grab sampling mode air samples are drawn into the cell by a downstream pump through several meters of 0. The air samples are then trapped in the closed cell by Teflon valves and held for several minutes for signal averaging to increase sensitivity. Spectra were collected at a resolution of 0. Since some other recent reports of the use of this system Akagi et al.
SO 2 and NO 2 were not observed above the detection limit in the background or the most concentrated smoke and are not discussed further. In addition to the primary grab sample mode, the FTIR system was also used in a real-time mode to support the PAX vide infra and filter sampling when grab samples were not being teln. The PAX sample line was co-located with the filter inlet and sampled in parallel from the same location.
In addition, there could be sampling losses of sticky species such as NH 3 on the filters so we did not analyze the real-time data for these species. This allowed the time-integrated particle mass and PAX signals to be compared to the simultaneously measured time-integrated mass of the three gases most needed for EF calculations Sect.
The canisters were filled to ambient pressure abfl in plumes or adjacent background air to telonn subsequent measurement aeana analysis of a large number of gases at the University of California, Irvine. Species quantified included CO 2CO, CH 4and up to non-methane organic gases by araa chromatography GC coupled with flame ionization detection, electron capture detection, and quadrupole mass spectrometer detection as discussed in greater detail by Simpson et al. We also do not report the higher-chain alkyl nitrates, which are often secondary photochemical products and were not enhanced in these fresh peat fire plumes.
Peaks of interest in the chromatograms were individually inspected and manually integrated. Styrene is known to decay in canisters and aranq styrene data should be taken as arzna limits. This monitored the real-time absorption and scattering resulting from BC and indirectly BrC. Air samples were drawn teloon through conductive tubing to 1. The continuously sampled air was split between a nephelometer and photoacoustic resonator enabling simultaneous measurements of scattering ahel absorption at high time resolution.
Once drawn into the acoustic section, modulated laser radiation was passed through the aerosol stream and absorbed by particles in the sample of air. The energy of the absorbed radiation was transferred to the surrounding air aranx heat and the resulting pressure changes were detected by a sensitive microphone.
Scattering coefficients at each wavelength were measured by a wide-angle integrating reciprocal nephelometer, using photodiodes to detect the scattering of the laser light. Additional details on the PAX instrument can be found elsewhere Arnott et al. For logistics reasons it was only practical to sample fresh peat fire plumes with the PAXs on 2 days.
Calibrations of the two PAXs were performed during the deployment using the manufacturer recommended absorption and scattering calibration procedures utilizing ammonium sulfate particles and a kerosene lamp to generate pure scattering and strongly absorbing aerosols, respectively.
The calibrations of scattering and absorption of light were directly compared to measured extinction by applying the Beer—Lambert law to laser intensity attenuation in the optical cavity Arnott et al. This impacts the calculated values for AAE by only 0. Peat samples were collected just ahead of the burning front for fuel moisture measurements. A brief description of the filter collection process is given here and the details of the post-mission analyses will be described elsewhere Jayarathne et al.
Cu tubing and PM 2. Particulate mass PM was calculated from the difference between pre-and post-sampling filter weights, which were determined in triplicate. PM per filter was converted to mass concentration using the sampled air volume. Elemental carbon EC and OC analysis: EC was not detected on any of the backup filters.
On average, the OC concentration on backup filters was 4. These filters were also analyzed for PM 2. EC was not detected on any of the background filters, while OC levels were consistent with gas adsorption described previously. The backgrounds were very similar and on average the background contributed 0.
Nonetheless, the average background value was subtracted from the smoke samples during data workup to calculate the contributions from the smoke plumes. While field blanks were collected, subtracting the background from smoke samples made the field blank correction unnecessary.
The grab samples were collected in a way that avoided possible artifacts for some gases due to adsorption on filters or in flow meters and they were used to produce a self-consistent complete set of data on trace gas emissions, as described next.
The molar emission ratio ER; e. Forcing the intercept decreases the weight of the lower points relative to those obtained at higher concentrations that reflect more emissions and have greater signal to noise.
Alternate data reduction methods usually have little effect on the results, as discussed elsewhere Yokelson et al. From the ERs, EFs were derived trlon units of grams of species X emitted per kilogram of dry biomass burned by the carbon mass balance method, which assumes all of major carbon-containing emissions have been measured Ward and Radke, ; Yokelson et al.
Aranaa carbon fraction was measured ALS Analytics, Tucson for seven samples of Kalimantan peat from sites ranging from heavy to no disturbance and averaged 0. EFs are proportional to assumed carbon content, making future adjustments to evolving literature-average EFs trivial if warranted based on additional carbon content measurements.
The denominator of the last term in Eq. Thus, our total carbon estimate for the grab samples includes all the gases measured by the FTIR or WAS in grab samples of a source and the carbon in the aerosol measured on the filters. Biomass fire emissions vary naturally aeana the mix of combustion processes varies. The relative amount of smoldering and flaming combustion during a fire can be roughly estimated from the modified combustion efficiency MCE.
In the context of biomass or other solid fuels, smoldering refers to a mix of solid-fuel pyrolysis producing NMOG and OA and gasification abek mainly NH 3CH 4and inorganic gases with little visible aerosol Yokelson et al.