Abstract
<title>Abstract</title> <p> The Arctic-boreal region’s carbon balance is shifting, with major implications for global climate. Models predict high carbon emissions by 2100, consisting of greenhouse gases, carbon dioxide (CO <sub>2</sub> ) and methane (CH <sub>4</sub> ), thus a representative carbon flux monitoring network is crucial to constrain fluxes. Eddy flux towers are increasingly used to inform models, and the area towers represent define model limitations. The Arctic-boreal flux tower network has grown from one to over 100 over past decades, however, towers are not designed to have broad regional representation. We analyzed flux tower network improvements made between 2022 and 2024, when targeted sites were added in part by the Permafrost Pathways project. We assessed the representativeness of active sites for four measurement categories: growing season CO <sub>2</sub> , growing season CH <sub>4</sub> , year-round CO <sub>2</sub> , and year-round CH <sub>4</sub> . Sixteen new or upgraded sites improved representation over 23–55% of the Arctic-boreal region across categories. Seventy-five percent of the region was well represented given improvements in growing season CO <sub>2</sub> measurements; however, only 45% of the domain was well represented for year-round CH <sub>4</sub> . We show targeted improvements can obtain better representativeness with limited sites, but continued upgrades are necessary to close gaps, particularly in Russia where gaps remain large. </p>