May 16 – 19, 2022
Utrecht
Europe/Amsterdam timezone

The Organization and Vertical Structure of Shallow Convection in Marine Cold-Air Outbreaks, based on Cold-Air Outbreaks in the Marine Boundary Layer Experiment (COMBLE): Developing the Framework for an Intercomparison Modeling Study

May 17, 2022, 11:00 AM
15m
Public Library (Utrecht)

Public Library

Utrecht

Neude 11, 3512 AE Utrecht, the Netherlands

Speaker

Bart Geerts (University of Wyoming)

Description

The Arctic’s complex atmospheric environment remains a large source of uncertainty for numerical models across a range of scales, especially during cold-air outbreaks (CAOs). Under CAO conditions, the convective boundary layer grows rapidly with increasing fetch and intricate cloud structures transition from narrow rolls near the ice edge to cells downstream. To study the CAO cloud regime, the Cold-air Outbreaks in the Marine Boundary Layer Experiment (COMBLE) was conducted from December 2019 to May 2020. Here we study an exemplary case from 12-13 March 2020. Results from numerical simulations using a Lagrangian large-eddy simulation approach suggest that the transition from convective rolls to cells is reasonably well captured. Nonetheless, we find that discernable differences in cloud parameters important to energy and water budgets arise among two modeling platforms. Given the wealth of COMBLE data, we are motivated to initiate a community-wide intercomparison modeling study of the 12-13 March 2020 case. This presentation will first highlight initial results from our simulations of the CAO event, including model sensitivities to microphysical parameters, as well as strength of surface forcing. Then, we will provide overarching goals and plans for the proposed intercomparison study in an effort to solicit interest from various modeling groups.

Primary author

Co-authors

Ann Fridlind (NASA/GISS) Bart Geerts (University of Wyoming) Branko Kosovic (NCAR) Christian Lackner (University of Wyoming) Florian Tornow (NASA/GISS) Lulin Xue (NCAR) Mikhail Ovchinnikov (PNNL) Pavlos Kollias (State University of New York at Stony Brook) Peng Wu (PNNL) Xue Zheng (LLNL) Yonggang Wang (State University of New York at Oswego) Yunyan Zhang (LLNL) Zackary Mages (State University of New York at Stony Brook)

Presentation materials

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