new wildfire smoke research improves climate modeling accuracyco-authored by a texas a&m scientist a new study shows that wildfire smoke cools the climate more than current climate computer models assumejan 25 2021smoke from forest fires in wetter climates such as oregon (above) tends to be brighter and have more of a cooling effect on the climate than smoke emitted from dry bushfires scientists say (photo: istock)smoke from bushfires in places such as australia (above) tends to be darker and have more of a warming effect on the climate (photo: istock)a new study on biomass-burning aerosols has shown that that smoke from wildfires has more of a cooling effect on the climate system than most climate models assume dr xiaohong liu professor in the department of atmospheric sciences at texas a&m served as corresponding author of the research which was recently published in nature communications when wildfires burn forests and grasslands biomass-burning aerosols are produced forming smoke clouds the composition size and mixing state of biomass-burning aerosols determine the optical properties of the smoke plumes in the atmosphere and those properties determine how much the smoke clouds absorb and scatter the solar radiation the researchers compared climate models predictions to large amounts of wildfire data collected in field sites around the world as well in laboratory experiments and they found major differences we collected field data from across the globe and we found that the models make a lot of assumptions about the physical and optical properties of the biomass-burning aerosols and those assumptions were not accurate liu said climate models such as those examined in this study are used to create important climate change reports such as the intergovernmental panel on climate change (ipcc) assessment that is published about every seven years he explained in this study we evaluate the climate models used in the ipcc assessment and we found out that these models assume biomass-burning smoke is more light-absorbing than our data actually shows liu said our study shows that biomass-burning has a more net-cooling effect than previously thought the study was led by dr hunter brown who recently received his phd from the university of wyoming and was advised by liu during his time as a professor at the university of wyoming from 2013-2019 brown recently joined lius team at texas a&m as a postdoctoral researcher to continue his research on biomass-burning aerosols we found that many of the most advanced climate models simulate biomass-burning aerosols or smoke that is darker or more light absorbing than what we see in observations brown said this has implications for the climate predictions made by these models observations and models used in the study covered a wide temporal range africa south america and southeastern asia in addition to boreal fire regions were chosen because these are the largest contributors to biomass-burning smoke emissions in the world brown said these biomass-burning aerosols are extremely complicated liu said the complexity involves the aerosols physical and chemical properties which are determined by the fires burning conditions and the fuel types such as dry grasslands or forests the smoke is very complicated north american forest fire smoke is very different than australian bush fire smoke because of the different types of fuel and burning conditions he said they can produce darker or brighter smoke and the chemical evolution of the smoke in the atmosphere can be very complicatedsmoke from the mullen fire seen from laramie wyoming in october 2020 different radiative and microphysical properties of the particulates that make up smoke from fires such as this play a role in their impact on regional and global climate liu said (photo by dr hunter brown)liu directed this research which involved both modelers and observationalists around the world the national center for atmospheric research (ncar)-wyoming supercomputing center was used for all of the data processing and the model sensitivity simulations now we have a better understanding of the properties of these biomass-burning aerosols so that now then we can improve the models and improve predictions liu said the team incorporated its findings into the ncar climate model and found that the modifications improved the models accuracy in predicting wildfires effects on climate read the full study by leslie lee 09