Ackerley, D, Birch, CE, Garcia-Carreras, L et al. (2 more authors) (2018) The physical processes that cause nocturnal rainfall over north-west Australia and their representation in high- and low-resolution models with parametrized convection. Quarterly Journal of the Royal Meteorological Society, 144 (711B). pp. 511-528. ISSN 0035-9009
Abstract
The diurnal cycle of precipitation in the Tropics is represented poorly in general circulation models (GCMs), which is primarily attributed to the representation of moist convection. Nonetheless, in areas where precipitation is driven by the diurnal cycle in the synoptic‐scale flow, GCMs may represent that circulation–rainfall relationship well. Over northwest Australia there is a tendency for precipitation to peak overnight where the diurnal cycle of the heat low circulation leads to the development of strong convergence after local sunset. In order to assess the heat low–precipitation relationship in more detail, a case‐study approach is used to investigate the actual ‘weather’ that is responsible for night‐time precipitation. The study shows that, where there is sufficient moisture, precipitation typically forms along convergence zones that coincide with boundaries between relatively moist and dry air masses (termed a ‘dryline’). A convergence line detection algorithm is then used to identify the fraction of observed nocturnal rainfall that is associated with any convergence zones. The same evaluation is then undertaken for a relatively high‐resolution (MetUM) and low‐resolution (ACCESS1.0) GCM, which simulate rainfall‐generation processes similar to the observations. Finally, the convergence line detection/precipitation algorithm is run on other GCM data (from CMIP5) to see whether the same processes occur despite different model configurations (i.e. physics), which appears to be the case.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | This article is protected by copyright. All rights reserved. This is the peer reviewed version of the following article: Ackerley, D., Birch, C.E., Garcia-Carreras, L., Lavender, S.L. and Weller, E. (2017), The physical processes that cause nocturnal rainfall over north-west Australia and their representation in high- and low-resolution models with parametrized convection. Quarterly Journal of the Royal Meteorological Society. doi:10.1002/qj.3223, which has been published in final form at https://doi.org/10.1002/qj.3223. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | nocturnal; rainfall; convergence; dryline; heat low; CMIP5; MetUM; northwest Australia |
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 Jan 2018 13:21 |
Last Modified: | 14 Dec 2018 01:38 |
Status: | Published |
Publisher: | Wiley |
Identification Number: | 10.1002/qj.3223 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:126149 |