Martin Van Damme

Doubling of annual ammonia emissions from the peat fires in Indonesia during the 2015 El Niño

In the autumn of 2015, thousands of square kilometers of forest and peatlands in Indonesia went up in flames. Among the primary species emitted by fires, ammonia (NH 3 ) is of special relevance for air quality. Here we derive daily and total NH 3 emission fluxes over the affected area using satellite measurements for the years 2008-2015. The 2015 fires emitted an estimated 1.4-8.2 Tg of NH 3 (with a maximum of 0.06-0.33 Tg day −1 ). On an annual basis, the 2015 NH 3 emissions are a factor 2-3 larger than in the previous seven years. We derive NH 3 emission factors for peat soils, which are found to be 2.5-8 times lower than those used in the GFASv1.2 emission inventory, but in excellent agreement with those reported in other recent studies. Finally, we estimate that 3.28×10 9 m 3 peat soil was consumed during these 2015 fires, corresponding to an average burn depth of 39 cm.In the autumn of 2015, thousands of square kilometers of forest and peatlands in Indonesia went up in flames. Among the primary species emitted by fires, ammonia (NH 3 ) is of special relevance for air quality. Here we derive daily and total NH 3 emission fluxes over the affected area using satellite measurements for the years 2008–2015. The 2015 fires emitted an estimated 1.4–8.2 Tg of NH 3 (with a maximum of 0.06–0.33 Tg d −1 ). On an annual basis, the 2015 NH 3 emissions are a factor 2–3 larger than in the previous 7 years. We derive NH 3 emission factors for peat soils, which are found to be 2.5–8 times lower than those used in the GFASv1.2 emission inventory but in excellent agreement with those reported in other recent studies. Finally, we estimate that 3.28 × 109 m 3 peat soil was consumed during these 2015 fires, corresponding to an average burn depth of 39 cm.

Remote sensing and in situ measurements of methane and ammonia emissions from a megacity dairy complex: Chino, CA☆

Methane (CH4) and ammonia (NH3) directly and indirectly affect the atmospheric radiative balance with the latter leading to aerosol generation. Both have important spectral features in the Thermal InfraRed (TIR) that can be studied by remote sensing, with NH3 allowing discrimination of husbandry from other CH4 sources. Airborne hyperspectral imagery was collected for the Chino Dairy Complex in the Los Angeles Basin as well as in situ CH4, carbon dioxide (CO2) and NH3 data. TIR data showed good spatial agreement with in situ measurements and showed significant emissions heterogeneity between dairies. Airborne remote sensing mapped plume transport for ∼20xa0km downwind, documenting topographic effects on plume advection. Repeated multiple gas in situ measurements showed that emissions were persistent on half-year timescales. Inversion of one dairy plume found annual emissions of 4.1xa0×xa0105xa0kg CH4, 2.2xa0×xa0105xa0kg NH3, and 2.3xa0×xa0107xa0kg CO2, suggesting 2300, 4000, and 2100 head of cattle, respectively, and Chino Dairy Complex emissions of 42xa0Gg CH4 and 8.4xa0Gg NH3 implying ∼200k cows, ∼30% more than Peischl etxa0al. (2013) estimated for June 2010. Far-field data showed chemical conversion and/or deposition of Chino NH3 occurs within the confines of the Los Angeles Basin on a four to sixxa0h timescale, faster than most published rates, and likely from higher Los Angeles oxidant loads. Satellite observations from 2011 to 2014 confirmed that observed in situ transport patterns were representative and suggests much of the Chino Dairy Complex emissions are driven towards eastern Orange County, with a lesser amount transported to Palm Springs, CA. Given interest in mitigating husbandry health impacts from air pollution emissions, this study highlights how satellite observations can be leveraged to understand exposure and how multiple gas in situ emissions studies can inform on best practices given that emissions reduction of one gas could increase those of others.