Interannual variability of tropospheric trace gases and aerosols: The role of biomass burning emissions

Abstract

Fires are responsible for a range of gaseous and aerosol emissions. However, their influence on the interannual variability of atmospheric trace gases and aerosols has not been systematically investigated from a global perspective. We examine biomass burning emissions as a driver of interannual variability of large-scale abundances of short-lived constituents such as carbon monoxide (CO), hydroxyl radicals (OH), ozone, and aerosols using the Goddard Institute for Space Studies ModelE composition-climate model and a range of observations, with an emphasis on satellite information. Our model captures the observed variability of the constituents examined in most cases, but with substantial underestimates in boreal regions. The strongest interannual variability on a global scale is found for carbon monoxide (~10% for its global annual burden), while the lowest is found for tropospheric ozone (~1% for its global annual burden). Regionally, aerosol optical depth shows the largest variability which exceeds 50%. Areas of strong variability of both aerosols and CO include the tropical land regions (especially Equatorial Asia and South America) and northern high latitudes, while even regions in the northern midlatitudes experience substantial interannual variability of aerosols. Ozone variability peaks over equatorial Asia in boreal autumn, partly due to varying biomass burning emissions, and over the western and central Pacific in the rest of the year, mainly due to meteorological fluctuations. We find that biomass burning emissions are almost entirely responsible for global CO interannual variability, and similarly important for OH variability. The same is true for global and regional aerosol variability, especially when not taking into account dust and sea-salt particles. We show that important implications can arise from such interannual influences for regional climate and air quality.

Simulating the Black Saturday 2009 smoke plume with an interactive composition‐climate model: Sensitivity to emissions amount, timing, and injection height

“…Global chemical transport models (CTMs) and composition‐climate models (CCMs) have been used to investigate global effects of such emissions, which can be large both from an atmospheric chemistry [ Mao et al ., ] and from a climate [ Ward et al ., ] point of view. Studying the effects of biomass burning on the large‐scale spatial and temporal variability of atmospheric composition has been done with both types of models [ Voulgarakis et al ., , ].…”

Tropospheric Ozone Assessment Report: Assessment of global-scale model performance for global and regional ozone distributions, variability, and trends

“…This is calculated as the difference between observed monthly mean column ozone over two broad regions in the western and eastern Pacific ocean; see Figure 8 for an example. Reproducing the observed magnitude of ozone enhancements over the western tropical Pacific/Indonesia during El Niño requires simulations with interannually-varying biomass burning emissions (Doherty et al, 2006;Nassar et al, 2008;Inness et al, 2015;Voulgarakis et al, 2015), but the same is not true for the eastern Pacific where ENSO-related ozone variability is largely controlled by changes in dynamics as opposed to emissions (Oman et al, 2013;Lin et al, 2014).…”

The global methane budget 2000–2012

“…Pinatubo eruption, Dlugokencky et al, 1996), to biomass burning (Voulgarakis et al, 2015) and to anthropogenic activities. For instance, the recent increase of the oxidizing capacity of the troposphere in South and East Asia, associated with increasing NO x emissions and decreasing CO emissions (Mijling et al, 2013;Yin et al, 2015), possibly enhances CH 4 consumption and therefore limits the atmospheric impact of increasing emissions (Dalsøren et al, 2009).…”