Validation of Short-Lived Climate Forcer Modelling by Ground-Based Near-Infrared Fourier Transform Spectroscopy
Résumé
The Arctic Monitoring and Assessment Programme (AMAP), a working group of the Arctic Council, studies and documents the effects of climate change and pollution on Arctic climate, with the intent of informing policy recommendations. One subject of interest is the impact of Short-Lived Climate Forcers (SLCFs), atmospheric components with lifetimes shorter than that of carbon dioxide; the 2021 AMAP Assessment Report is focused on the climate and health effects of SLCFs in the Arctic and globally. AMAP uses multiple models to determine levels of SLCFs in the Arctic. These models include CESM, CMAM, DEHM, EMEP-MSC-W, GEM-MACH, GEOS-Chem, MATCH, MATCH-SALSA, MRI-ESM2, UKESM1, and WRF-Chem. This work compares outputs from these models for carbon monoxide and, where possible, methane, to data from ground-based Fourier Transform Infrared (FTIR) Spectrometers focused on the near-infrared spectral region. These spectrometers are part of the Total Carbon Column Observing Network (TCCON) and are located in Eureka (Nunavut, Canada), Ny Ålesund (Spitzbergen, Norway), and Sodankylä (Finland). The model outputs are mixing ratios given at three-hour intervals for the years 2009, 2014 and 2015; these are transformed as necessary to be compared to the TCCON column-averaged dry air mole fraction (Xgas) data product. TCCON has been used for many validation studies in the past and these stations in particular provide an essential high Arctic data set with very low site-to-site bias. We will assess the ability of the AMAP models to simulate high Arctic CO and CH4 in order to better understand their suitability to inform SLCF policies.