Interactions between Arctic cyclones, tropopause polar vortices, clouds and sea ice: The RALI-THINCE campaign in August 2021
Abstract
RALI-THINICE is a project dedicated to the preparation of an international field campaign in Svalbard in August 2021 involving two instrumented research aircraft and ground-based instrumentation. The main goals of the field campaign are to study (i) the dynamics of Arctic cyclones (ACs) and tropopause polar vortices (TPVs), (ii) their interactions with cloud microphysics and (iii) their impact on underlying sea surface and sea ice and (iv) feedbacks of sea ice on ACs and TPVs. A better knowledge of such processes should improve numerical weather forecasts in the Arctic and should provide a better understanding of rapid sea ice loss events affecting the Arctic in summer. The project is mainly focused on the French contribution to the field campaign and the deployment of the Falcon 20 operated by SAFIRE, the French facility for airborne research. The instrumented aircraft will contain a dropsonde release system,a remote sensing platform RALI composed of a doppler cloud radar, a high-resolution backscatter lidar and an infrared radiometer, together with in-situ probes. The target weather systems include ACs, TPVs and moist intrusion events in the Arctic. Examples of flight plans are presented in the project to highlight how the scientific objectives will be pursued when such weather systems form in the Svalbard region and how the different instruments will be useful to provide complementary information on such systems. TPV analysis requires a high flight level and the use of dropsondes. Low-level moisture intrusions will be quantified via releasing dropsondes and downward profiling by the RALI platform. Measurements of mixed-phase clouds that are ubiquitous in the Arctic and difficult torepresent in state-of-the-art models will be made via the RALI platform and in-situ probes with different flight levels. During the same period, the British Antarctic Survey Twin Otter, the second aircraft to be deployed during the campaign, will measure turbulent fluxes in the atmospheric boundary layer and concurrent sea ice surface properties beneath using remote sensing instruments, aiming to characterise interactions between the sea ice and the lower troposphere. Coordinated flights will be planned between the two aircraft to take advantage of their complementary measurements. Several PIs have experience working together to coordinate the multi-aircraft measurements during the NAWDEX campaign.Finally, the project presents a detailed description of the data products to be delivered to all partners by the French teams after the field campaign. It includes (i) dropsondes datasets, (ii) reflectivity, wind, doppler spectra from the radar, (iii) backscatter profiles from the lidar, (iv) phase categorisation and ice water retrievals from the RALI platform and (v) particle size distribution and water content from in-situ probes. Future collaboration among the American, French and British colleagues after the field campaign is also outlined at the end of the proposal.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 06, 2021
- Source ID
- N000142112117
Entities
People
- Gwendal Riviere
Organizations
- National Center for Scientific Research
- Office of Naval Research
- United States Navy