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Due to the highly flammable biota and a shortfall of precipitation in Australia, wildfires (bushfires) are connected with Australia's ecology and culture. These wildfires affect air quality, emitting ammonia (NH3) and fine particulate matter (PM2.5), among other pollutants, into the atmosphere. Record breaking temperatures and drought contributed to the unprecedented 2019–2020 Australian wildfire season in Southeastern Australia. The objective of this study is to calculate emissions of PM2.5and NH3from wildfires from December 29, 2019, to January 4, 2020 and to analyze the air quality impact on Southeast Australia associated with these mega wildfires. Emissions of PM2.5and NH3were calculated using a combination of satellite data for burn area and land classification and emissions factors from the literature. The impact of PM2.5in Southeast Australia, Southwest shore of New Zealand, and the inner part of Australia were estimated by performing a Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) analysis. The results of this work show that fire activity in the study region produced 526 569 125 kg of NH3and 41 167 586 kg of PM2.5during the period of interest. Between December 29, 2019, and January 4, 2020, hourly concentrations of PM2.5reached 2496.1 μg m−3in Australia and 48.8 μg m−3in New Zealand, exceeding the national standard of 25 μg m−3a total of 100 and 2 times, respectively, which suggests the influence the fires have on air quality in the region.

ABSTRACTEmissions of ammonia (NH3), oxides of nitrogen (NOx; NO +NO2), and nitrous oxide (N2O) from biomass burning were quantified on a global scale for 2001 to 2015. On average biomass burning emissions at a global scale over the period were as follows: 4.53 ± 0.51 Tg NH3year−1, 14.65 ± 1.60 Tg NOxyear−1, and 0.97 ± 0.11 Tg N2O year−1. Emissions were comparable to other emissions databases. Statistical regression models were developed to project NH3, NOx, and N2O emissions from biomass burning as a function of burn area. Two future climate scenarios (RCP 4.5 and RCP 8.5) were analyzed for 2050–2055 (“mid-century”) and 2090–2095 (“end of century”). Under the assumptions made in this study, the results indicate emissions of all species are projected to increase under both the RCP 4.5 and RCP 8.5 climate scenarios.Implications: This manuscript quantifies emissions of NH3, NOx, and N2O on a global scale from biomass burning from 2001–2015 then creates regression models to predict emissions based on climate change. Because reactive nitrogen emissions have such an important role in the global nitrogen cycle, changes in these emissions could lead to a number of health and environmental impacts.

Ammonia (NH3) in the atmosphere contributes to the formation of airborne fine particulate matter (PM2.5), which is associated with adverse human health effects. The emission, transport, reactions, and deposition of NH3in the atmosphere are modeled using the Community Multiscale Air Quality (CMAQ) model, within the U.S. National Air Quality Forecast Capability (NAQFC). The purpose of this current work is to evaluate the capability of the NAQFC CMAQ model and to identify potential improvements to NH3emissions estimates and prediction methods. This study focuses on CMAQ predictions of atmospheric NH3in North Carolina, including a region with intensive animal production and enhanced NH3emissions. The CMAQ model is run for July 2011 using a version of the 2011 National Emissions Inventory in which agricultural NH3emissions were adjusted to reflect the lower end of the range of estimates from the current process‐based emissions model. The NAQFC CMAQ model overpredicted atmospheric NH3at a continuous monitor in Clinton, NC, within the region of intensive animal production. The average concentration measured by the monitor was 6.6 ppbv, while the average predicted by the model was 10.5 ppbv, a 60% overprediction. Outside of the region of intensive animal production, both measured and modeled NH3concentrations were low, 1.3 ppbv or less. The model underpredicted wet deposition of NH4+and dry deposition of NH3. It is believed that the overestimation of NH3at Clinton is attributable at least in part to the underestimation of wet and dry deposition in North Carolina. The National Air Quality Forecast System model overpredicted ammonia at a continuous monitor in a region of intensive animal productionModel predictions for ammonia were improved by using State permit information for locations of animal feeding operationsThe model underpredicted wet deposition of ammonium ion and dry deposition of ammonia in eastern North Carolina

Correction for ‘Estimating NH3and PM2.5emissions from the Australia mega wildfires and the impact of plume transport on air quality in Australia and New Zealand’ by Ece Ari Akdemir et al., Environ. Sci.: Atmos., 2022, https://doi.org/10.1039/d1ea00100k.