Collaborative Research: Advancing knowledge of Arctic sea ice interactions with tropopause polar vortices and Arctic cyclones

University Of Oklahoma Norman Campus, Norman OK

Investigators

Abstract

In recent decades Arctic sea ice has become more mobile and thinner, leading to an increasingly important role of Arctic cyclones in sea ice loss, which can occur at an astonishing rate of 0.5 million square kilometers (about 200,000 square miles) within a 3-day period. This research aims to understand the critical mechanisms that determine the location, strength, evolution, and characteristics of Arctic cyclones (ACs) and tropopause polar vortices (TPVs), and their potential for influencing sea ice break-up and decline. TPVs are an important precursor to the development and evolution of ACs and are also one of the longest-lived features in the Earth’s lower atmosphere. Yet their locations in data-sparse regions of the Arctic and their relatively small spatial scale make it difficult to observe and understand their detailed structure and resulting impacts on the Earth’s climate. Fundamental differences exist between the dynamics of cyclones in middle latitudes and the Arctic. For example, atmospheric vortices rather than waves play a more significant role in cyclone lifecycles and radiative processes have increased importance in maintaining and strengthening TPVs. Thus, the correct treatment of cloud and radiative processes in models is likely critical to accurately defining the structure and intensity of TPVs and ACs. The data needed to expand knowledge of these Arctic processes is currently limited due to the relatively sparse Arctic conventional observing network and the difficulties in obtaining high-quality measurements of Arctic clouds and moisture from satellite-based remote sensing. This project will also assess where new data are needed. This project will investigate the coupling of TPVs and ACs with the underlying sea surface and sea ice during the summer and advance our knowledge of how this coupling can lead to rapid sea ice loss. Researchers will test the hypothesis that an accurate representation of the vertical distribution of water vapor is necessary to represent the radiative heating required to evolve and intensify TPVs and ACs. The researchers will combine observations with state-of-the-art high-resolution numerical weather models and fully-coupled Earth-System models through coupled ensemble data assimilation for multi-scale studies. The team will perform observing system simulation experiments (OSSEs) as well as observing system experiments (OSEs) using atmospheric data from an aircraft field campaign and routinely available satellite and atmospheric data to estimate the observation impacts in a variety of well-defined scenarios. Knowledge gained from detailed simulations and observations of the processes that cause error growth will lead to improvements in weather and climate prediction by improving the representation of these processes in Earth-system numerical models across a wide range of scales, which is a main priority in the 2022-2026 Arctic Research Plan by The Interagency Arctic Research Policy Committee (IARPC). Students at all levels will have an opportunity to work with the data produced in this project, with a focus towards broadening participation from chronically underrepresented groups in STEM fields and in Oklahoma, including students identifying as Native Americans, members of First Nations, Indigenous people, and American Indians. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.