Publication Date:
2023-03-30
Description:
Boreal fires have increased during the last years and are projected to become more intense and frequent as a consequence of climate change. Wildfires produce a wide range of effects on the Arctic climate and ecosystem, and understanding these effects is crucial for predicting the future evolution of the Arctic region. This study focuses on the impact of the long-range transport of biomass-burning aerosol into the atmosphere and the corresponding radiative perturbation in the shortwave frequency range. As a case study, we investigate an intense biomass-burning (BB) event which took place in summer 2017 in Canada and subsequent northeastward transport of gases and particles in the plume leading to exceptionally high values (0.86) of Aerosol Optical Depth (AOD) at 500 nm measured in northwestern Greenland on 21 August 2017. This work characterizes the BB plume measured at the Thule High Arctic Atmospheric Observatory (THAAO; 76.53∘N, 68.74∘W) in August 2017 by assessing the associated shortwave aerosol direct radiative impact over the THAAO and extending this evaluation over the broader region (60∘N–80∘N, 110∘W–0∘E). The radiative transfer simulations with MODTRAN6.0 estimated an aerosol heating rate of up to 0.5 K/day in the upper aerosol layer (8–12 km). The direct aerosol radiative effect (ARE) vertical profile shows a maximum negative value of −45.4 Wm−2 for a 78∘ solar zenith angle above THAAO at 3 km altitude. A cumulative surface ARE of −127.5 TW is estimated to have occurred on 21 August 2017 over a portion (∼3.1×106 km2) of the considered domain (60∘N–80∘N, 110∘W–0∘E). ARE regional mean daily values over the same portion of the domain vary between −65 and −25 Wm−2. Although this is a limited temporal event, this effect can have significant influence on the Arctic radiative budget, especially in the anticipated scenario of increasing wildfires.
Description:
This research was partially funded by the Italian Ministry of University and Research
(MIUR) within the framework of OASIS-YOPP—Observations of the Arctic Stratosphere In Support
of YOPP (PNRA 2016–2018); CLARA2—CLouds And Radiation in the Arctic and Antarctica (PNRA
2019–2021), and ECAPAC—Effects of changing albedo and precipitation on the Arctic climate (PRA
2021–2023). The work of F. Calì Quaglia and G. Muscari was also partially funded under the INGV
environmental project MACMAP—A Multidisciplinary Analysis of Climate change indicators in the
Mediterranean And Polar regions (2020–2023). The NCAR FTIR observation program at Thule, Greenland
is supported under contract by the National Aeronautics and Space Administration (NASA).
The National Center for Atmospheric Research (NCAR) is sponsored by the U.S. National Science
Foundation (NSF). The Thule work is also supported by the NSF Office of Polar Programs (OPP).
Description:
Published
Description:
313
Description:
5A. Ricerche polari e paleoclima
Description:
JCR Journal
Keywords:
biomass-burning (BB)
;
wildfires
;
Arctic
;
aerosol radiative effect
;
01.01. Atmosphere
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
