Woodhams, BJ orcid.org/0000-0003-2070-8279, Barrett, PA, Marsham, JH orcid.org/0000-0003-3219-8472 et al. (6 more authors) (2022) Aircraft observations of the lake‐land breeze circulation over Lake Victoria. Quarterly Journal of the Royal Meteorological Society, 148 (743). pp. 557-580. ISSN 0035-9009
Abstract
The lake–land breeze circulation over Lake Victoria was observed in unprecedented detail with a research aircraft during the HyVic pilot flight campaign in January 2019. An evening and morning flight observed the lake and land breezes respectively under mostly dry conditions. The circulation was observed at various heights along a transect across the lake and onshore in Tanzania. Profiles of the lower troposphere were recorded by dropsondes over the lake and land. Convection-permitting MetUM simulations with different horizontal grid-spacings (including sub-km) were run for the flight periods. During the evening flight, the aircraft crossed the lake breeze front over land at 1627 LT, approximately 50 km to the east of the lake shore, recording a 6 g kg–1 decrease in specific humidity and reversal in wind direction over ~5 km. During the morning flight, a shallow land breeze was observed across the eastern shore at 0545 LT. At least one region of increased and deeper moisture (previously seen in simulations but never observed) was sampled over the lake surface between 0527–0855 LT. This bulge of moisture was likely formed from the lifting of near-surface moist air above the lake by low-level convergence. The observations and model simulations suggest that low-level convergence occurred at the leading edge of the land breeze, which had detached from the main land breeze and independently propagated westward across the lake with wave-like characteristics. The MetUM simulations were able to reasonably reproduce the lake breeze front, bulge feature, and its propagation, which is a major achievement given the sparse observational data for model initialisation in this region. However, some timing, resolution and boundary layer depth biases require further investigation. Overall, this pilot campaign provided an unprecedented snapshot of the Lake Victoria lake–land breeze circulation and motivates a more comprehensive field campaign in the future.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2021 Crown copyright. Quarterly Journal of the Royal Meteorological Society published by John Wiley & Sons Ltd on behalf of Royal Meteorological Society. This article is published with the permission of the Controller of HMSO and the Queen's Printer for Scotland. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
Keywords: | Lake Victoria; East Africa; lake–land breeze circulation; observations; research aircraft |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Inst for Climate & Atmos Science (ICAS) (Leeds) The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > National Centre for Atmos Science (NCAS) (Leeds) |
Funding Information: | Funder Grant number NERC (Natural Environment Research Council) NE/P021077/1 NERC (Natural Environment Research Council) NE/M02038X/1 NERC DTP NE/L002574/1 NERC (Natural Environment Research Council) NE/M02038X/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 08 Sep 2021 11:15 |
Last Modified: | 19 Jul 2022 11:00 |
Status: | Published |
Publisher: | Wiley |
Identification Number: | 10.1002/qj.4155 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:177899 |