Advancing knowledge of Arctic sea ice interactions with tropopause polar vortices and Arctic cyclones
Abstract
This project proposes to conduct fundamental research to quantify the role in which Tropopause Polar Vortices (TPVs) are an extended-range prediction barrier over the Arctic. We are investigating the following hypotheses: (1) Synoptic-scale Arctic surface cyclonepredictability is limited by errors originating in upstream TPVs, and (2) Limited observations of clouds and water vapor, combined with the relatively small horizontal scale of TPVs, limitthe predictability of TPVs and sea ice. These hypotheses will be tested using a fully-coupled Earth system modeling framework with Version 2 of the Community Earth System Model (CESM2) in this study.We will quantify which variables have the greatest impact on the evolution of the Arctic cyclones, TPVs, and sea ice in a case study of a typical Arctic cyclone. This will be carried out by performing Observing System Simulation Experiments (OSSEs) using the CESM2 model with the Spectral-Element atmospheric dynamical core with ensemble data assimilation using the Data Assimilation (DA) Research Testbed (DART). Ensemble spread characteristics will isolate the conditions in which there is reduced predictability over the Arctic, andensemble members with fully-coupled processes will distinguish events with active feedbacks between TPVs, surface cyclones, and sea ice from non-events. Given the small spatial scale and infrequent direct observations of TPVs because of their location over relatively datasparse regions, OSSE experiments using ensemble data assimilation with DART will quantify the specific features of TPVs most important to Arctic cyclone predictability. Improved knowledge of the important processes affecting TPVs will improve weather and climateprediction by improving the representation of these processes in numerical models.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 09, 2024
- Source ID
- N000142412718
Entities
People
- Steven Cavallo
Organizations
- Office of Naval Research
- United States Navy
- University of Oklahoma