From here, smoke is able to ascend deeply into the lower stratosphere by so-called self-lofting processes. These fire-generated clouds can loft large smoke amounts to the tropopause level in less than an hour ( Rosenfeld et al., 2007 Rodriguez et al., 2020). One typical way for biomass-burning smoke plumes to reach the stratosphere is via pyrocumulonimbus (pyroCb) convection ( Fromm and Servranckx, 2003 Fromm et al., 2010 Peterson et al., 2018 Rodriguez et al., 2020). When reaching the stratosphere, wildfire smoke can sensitively influence the stratospheric composition on a hemispheric scale ( Bond et al., 2013 Baars et al., 2019 Kloss et al., 2019 Yu et al., 2019 Rieger et al., 2021 Ohneiser et al., 2022) and thus can affect the Earth's climate ( Das et al., 2021 Yu et al., 2021 Hirsch and Koren, 2021 Stocker et al., 2021 Heinold et al., 2022 Rieger et al., 2021 Sellitto et al., 2022) and the ozone layer ( Ohneiser et al., 2021, 2022 Voosen, 2021 Yu et al., 2021 Rieger et al., 2021 Stone et al., 2021 Solomon et al., 2022 Bernath et al., 2022 Ansmann et al., 2022). Enormous amounts of biomass-burning smoke were emitted into the atmosphere by fire storms in Canada in 2017 ( Peterson et al., 2018) and Australia in 2019–2020 ( Peterson et al., 2021). ![]() Uncontrolled intense fires over large areas at the regional scale have become more frequent in recent years in many regions on Earth ( Jolly et al., 2015 Peterson et al., 2021). Furthermore, Raman-lidar-based aerosol typing (in Leipzig and the High Arctic) clearly indicated the dominance of smoke in the UTLS aerosol layer since August 2019, most probably also the result of smoke self-lofting. We hypothesize that the formation of a near-tropopause aerosol layer, observed with CALIOP, was the result of self-lofting processes because this is in line with the simulations. Our results indicate that self-lofting contributed to the vertical transport of smoke. We analyzed long-term CALIOP observations of smoke layers and plumes evolving in the UTLS (upper troposphere and lower stratosphere) height region over Siberia and the adjacent Arctic Ocean during the summer season of 2019. To demonstrate the applicability of our self-lofting model, we compared our simulations with the lofting processes in the stratosphere observed with CALIOP after major pyroCb events (Canadian fires in 2017, Australian fires in 2019–2020). We also looked at the influence of different meteorological parameters such as cloudiness, relative humidity, and potential temperature gradient. The sensitivity analysis revealed that the lofting rate strongly depends on aerosol optical thickness (AOT), layer depth, layer height, and black carbon (BC) fraction. As input parameters thermodynamic profiles from CAMS (Copernicus Atmosphere Monitoring Service) reanalysis data, aerosol profiles from ground-based lidar observations, radiosonde potential temperature profiles, CALIOP (Cloud–Aerosol Lidar with Orthogonal Polarization) aerosol measurements, and MODIS (Moderate Resolution Imaging Spectroradiometer) aerosol optical depth retrievals were used. Simulations of absorbed solar radiation by smoke particles and resulting heating rates, which are then converted into lofting rates, are conducted by using the ECRAD (European Centre for Medium-Range Weather Forecasts Radiation) scheme. The further subsequent ascent within the lower stratosphere (caused by self-lofting) is already well documented in the literature. The main goal is to demonstrate that radiative heating of intense smoke plumes is capable of lofting them from the lower and middle free troposphere (injection heights) up to the tropopause without the need of pyrocumulonimbus (pyroCb) convection. This study aims for a detailed analysis of tropospheric and stratospheric smoke lofting rates based on simulations and observations. ![]() This heating is translated into self-lofting of the smoke up to more than 1 km in altitude per day. The absorption of sunlight by optically thick smoke layers results in heating of the ambient air. Wildfire smoke is known as a highly absorptive aerosol type in the shortwave wavelength range.
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