Birch, CE and Reeder, MJ (2013) Wave-cloud lines over northwest Australia. Quarterly Journal of the Royal Meteorological Society, 139 (674). 1311 - 1326. ISSN 0035-9009
Abstract
The frequency of occurrence and formation mechanisms of wave-cloud lines off the northwest coast of Australia are investigated. Prior to the present study, little was known about these wave-cloud lines. Apart from being spectacular atmospheric phenomenon in their own right, these wave clouds can have a role in the secondary initiation of convection and can be a hazard to low-flying aircraft. A climatology of wave clouds, produced from visible satellite imagery, suggests two main types of cloud lines form over northwest Australia. The first are bore-like waves, similar in structure to the ‘morning glory’ of northeast Australia, and occur at least 2 to 3 times per month throughout the entire year. The second type are convectively generated cloud lines, which are more circular in shape, appear to originate from convective storms and occur at least 0.5 to 1.5 times per month during the wet season. High-resolution, nested simulations are performed with the Met Office Unified Model for case-studies of each type of wave. The bore-like waves occurred in the presence of synoptic-scale, low-level southeasterly flow and a heat low along the northwest coast of Australia. At night, the offshore southeasterlies accelerate into the heat low and collide with the onshore sea breeze. The southeasterlies override the sea breeze and the wave-cloud lines form at the leading edge of this front. The convectively generated waves radiate outwards from the convective storms producing compensating subsidence and adiabatic warming. These waves take the form of n=2 mode wave fronts, which span the entire depth of the troposphere and are similar in structure to waves produced by deep convection which are described in previous studies.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | This is the peer reviewed version of the following article: Birch, CE and Reeder, MJ (2013) Wave-cloud lines over northwest Australia. Quarterly Journal of the Royal Meteorological Society, 139 (674). 1311 - 1326, which has been published in final form at http://dx.doi.org/10.1002/qj.2043. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving. |
Keywords: | bore; gravity wave; convection; sea breeze; morning glory; heat low; MetUM |
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) |
Depositing User: | Symplectic Publications |
Date Deposited: | 12 Nov 2015 12:31 |
Last Modified: | 16 Nov 2016 09:41 |
Published Version: | http://dx.doi.org/10.1002/qj.2043 |
Status: | Published |
Publisher: | Wiley |
Identification Number: | 10.1002/qj.2043 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:85895 |