Chemistry-Climate Links for Carbon Monoxide in Northern Hemisphere
Boreal Fire Regions and an Assessment of Global Fire Inventories
Abstract
Fire emissions are a major contributor to atmospheric composition,
affecting atmospheric oxidizing capacity and air quality. Transported
amounts from Northern Hemisphere boreal fires can reach the pristine
Arctic atmosphere as well as impact air quality in populated regions.
Carbon monoxide (CO) is a useful trace gas emitted from fires that can
be used to link extreme fire events with climate variability. We use our
recently developed statistical tool to investigate the climate drivers
of satellite measured CO variability in two Northern Hemisphere boreal
fire regions: northwest Canada and Siberia. Our focus is on quantifying
the ability of climate mode indices for the Pacific, Atlantic, Indian
and Arctic Oceans in predicting CO amounts in these regions. Climate
mode indices El NiƱo Southern Oscillation (ENSO), Tropical North
Atlantic (TNA), the Dipole Mode Index (DMI) and the Arctic Oscillation
(AO) are used to develop statistical models of column CO interannual
variability from the Measurements of Pollution In The Troposphere
(MOPITT) satellite instrument, for the time period covering 2001-2017.
In addition, we assess the ability of fire emission inventories to
reproduce CO, including the Fire Inventory from NCAR (FINN), the NASA
Quick Fire Emissions Dataset (QFED) and the Copernicus Atmosphere
Monitoring Service (CAMS) Global Fire Assimilation System (GFAS). These
are implemented in the NCAR Community Atmosphere Model with chemistry
(CAM-chem) and subsequently evaluated against MOPITT CO observations.
Emission uncertainty contribution to inter-inventory differences are
quantified, and the modeled contribution of fires to CO interannual
variability is determined.