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Tropospheric composition in the Arctic: Impact of long range transport of pollution

English title Tropospheric composition in the Arctic: Impact of long range transport of pollution
Applicant Bey Isabelle
Number 124928
Funding scheme Project funding (Div. I-III)
Research institution Institut für Atmosphäre und Klima ETH Zürich
Institution of higher education EPF Lausanne - EPFL
Main discipline Climatology. Atmospherical Chemistry, Aeronomy
Start/End 01.04.2009 - 31.03.2012
Approved amount 136'556.00
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Keywords (10)

Atmospheric composition and climate; Tropospheric ozone; Aerosols; Black carbon; Biomass burning; Arctic; tropospheric chemistry; long-range transport; climate; global modeling

Lay Summary (English)

Lead
Lay summary
This proposal deals with the atmospheric composition in the Arctic. Climate change is currently proceeding fastest in the Arctic than anywhere else on the planet. One key hypothesis for this fast warming is that short-lived species (including ozone and aerosols) influence the Arctic climate in several ways either directly through radiative forcing and indirectly through clouds and snow/ice albedo. In particular, the role of light absorbing aerosols (such as black carbon) remains largely unknown. There are ample evidences that the Arctic troposphere is characterized by elevated concentrations of particles of different origins both in late winter and spring (the so-called Arctic Haze) but also in summer. The Arctic and summer haze are composed of a mix of particles of different origins and most largely result from long range transport of anthropogenic pollution from mid-latitudes and from wildfires in boreal regions. However, the pathways for the transport of pollution into the Arctic, the relative contributions of various geopolitical regions, as well as the role of biomass burning in boreal forest are not known in a quantitative manner. In this project, we propose to explore two specific questions, including (i) the pathways for long range transport of aerosol and ozone-related pollution from the northern mid-latitudes to the Arctic and (ii) the impact of the boreal wildfires on the Arctic atmospheric composition. We will address these questions using conjointly the fully coupled model of aerosol-chemistry-climate ECHAM5-HAMMOZ as well as a suite of products from various platforms (including satellite such as CALIOP, MISR, MODIS, ground-based stations in the Arctic and pan-Arctic region, and research aircrafts such as those deployed in the framework of the POLARCAT experiment). We are planning to 1) conduct a comprehensive analysis of a boreal wildfire event collected in POLARCAT and to test our model's representation of the processes related to transport of boreal biomass burning pollution; 2) develop a timeseries (annual cycle) of the CALIOP vertically-resolved attenuated backscatter at relevant locations of the northern mid-latitudes to test our model's ability to reproduce the long range transport of pollution towards the Arctic; 3) explore the factor that govern interannual variability in the Arctic composition with a focus over the period from 2006 to 2008. The proposed work will provide an improved quantitative understanding of the processes governing the Arctic composition and ultimately of the processes that govern climate change there but also globally.
Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Employees

Name Institute

Publications

Publication
Pollution transport efficiency toward the Arctic: Sensitivity to aerosol scavenging and source regions
Bourgeois Q, Bey I (2011), Pollution transport efficiency toward the Arctic: Sensitivity to aerosol scavenging and source regions, in JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 116(D08213), 1-18.

Associated projects

Number Title Start Funding scheme
112231 Interannual variability in tropospheric O3 and tropospheric composition in the Arctic 01.04.2006 Project funding (Div. I-III)
112231 Interannual variability in tropospheric O3 and tropospheric composition in the Arctic 01.04.2006 Project funding (Div. I-III)

Abstract

The present proposal (follow-up of the Swiss NSF project 200020-112231) deals with the atmospheric composition in the Arctic. Climate change is proceeding fastest in the Arctic than anywhere else on the planet, which raises concerns because of the possible implications for the global planet. While there are several open questions concerning the processes governing the fast warming in the Arctic, one key hy-pothesis is that short-lived species (including tropospheric ozone and aerosols) influence the Arctic cli-mate in several ways either directly through radiative forcing and indirectly by influencing the clouds and the snow/ice albedo. In particular, the role of light absorbing aerosols (such as black carbon that are emit-ted by both anthropogenic sources and biomass burning) remain largely unknown. There are ample evi-dences that the Arctic troposphere is characterized by elevated concentrations of particles of different origins both in late winter and spring (the so-called Arctic Haze) but also in summer. The Arctic and sum-mer haze are composed of a mix of particles of different origins and most largely results from long range transport of anthropogenic pollution from the mid-latitudes and from the wildfires in boreal regions. How-ever, the pathways for the transport of pollution into the Arctic, the relative contributions of various geopo-litical regions, as well as the role of biomass burning in boreal forest are not known in a quantitative man-ner. In this project, we propose to explore two specific questions, including (i) the pathways for long range transport of aerosol and ozone-related pollution from the northern mid-latitudes to the Arctic and (ii) the impact of the boreal wildfires on the Arctic atmospheric composition. We will address these questions using conjointly the fully coupled model of aerosol-chemistry-climate ECHAM5-HAMMOZ as well as a suite of products from various platforms (including satellite such as CALIOP, MISR, MODIS, ground-based stations in the Arctic and pan-Arctic region, and research aircrafts such as those deployed in the framework of the POLARCAT experiment). We are planning to 1) conduct a comprehensive analysis of a boreal wildfire event collected in POLARCAT and to test our model’s representation of the processes re-lated to transport of boreal biomass burning pollution; 2) develop a timeseries (annual cycle) of the CALIOP vertically-resolved attenuated backscatter at relevant locations of the northern mid-latitudes to test our model’s ability to reproduce the long range transport of pollution towards the Arctic; 3) explore the factor that govern interannual variability in the Arctic composition with a focus over the period from 2006 to 2008. The proposed work will provide an improved quantitative understanding of the processes governing the Arctic composition and ultimately of the processes that govern climate change there but also globally.
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