Full Text Available
Note: Clicking the button above will open the full text document at the original institutional repository in a new window.
The diurnal cycle of cloud cover over southern and central Africa
Includes abstract.
Saved in:
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Thesis |
| Language: | English |
| Published: |
Department of Environmental and Geographical Science
2014
|
| Subjects: | |
| Tags: |
No Tags, Be the first to tag this record!
|
| _version_ | 1867613212308930560 |
|---|---|
| access_status_str | Open Access |
| author | Coop, Lisa Jane |
| author2 | Hewitson, Bruce |
| author_browse | Coop, Lisa Jane Hewitson, Bruce |
| author_facet | Hewitson, Bruce Coop, Lisa Jane |
| author_sort | Coop, Lisa Jane |
| collection | Thesis |
| description | Includes abstract. |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/4838 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:32:33.381Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2014 |
| publishDateRange | 2014 |
| publishDateSort | 2014 |
| publisher | Department of Environmental and Geographical Science |
| publisherStr | Department of Environmental and Geographical Science |
| record_format | dspace |
| source_str | UCTD — University of Cape Town Open Access Repository |
| spelling | oai:open.uct.ac.za:11427/4838 The diurnal cycle of cloud cover over southern and central Africa Coop, Lisa Jane Hewitson, Bruce Tadross, Mark Environmental and Geographical Science Includes abstract. Includes bibliographical references (leaves 113-119). The current understanding of the temporal and spatial distribution of clouds over southern and central Africa is poor and the regional processes governing cloud occurrence is only weakly understood. This study seeks to improve the current understanding of cloud diurnal variability over this region by providing a base-line diurnal climatology of lowlevel, mid-level and high-level cloud cover. Diurnal variations of cloudiness are examined using ten years of cloud data from latest version of the International Satellite Cloud Climatology Project (ISCCP-D1). The broad seasonal average diurnal variability is explored across the region. Thereafter a more detailed analysis of regionally specific variability is made using a Self-Organising Map. The findings of this study are in broad agreement with previous work. Cloud over the southern and central African region shows clear spatial organisation, most significantly associated with the location of the Intertropical Convergence Zone. The diurnal variation of high-level cloud is large, closely correlated to its mean and is enhanced by orographic features. Minimum high-level cloud occurs at 1100 LST and maximum extent is reached during the evening around 1800 LST, except in locations experiencing deep convection which displayed a redevelopment of cloud in the early morning (0300 LST). This redevelopment of HLCA is hypothesised to be due to the destabilization of the upper troposphere through nighttime cloud radiative cooling. Mid-level cloud exhibits smaller diurnal variations, reaching maximum coverage at approximately 0300 LST. Clouds at this level are severely obscured by higher clouds and therefore the detected diurnal variation is due to both real and artificial signals and care needs to be taken in interpreting the results. Low-level cloud shows strong diurnal variations when not obscured by higher clouds, reaching a maximum just after midday. The results of this study are interpreted in terms of the life-cycle of deep convective cloudiness. A number of mechanisms are suggested to explain the regional differences in diurnal variations with land surface heating being the primary mechanism. 2014-07-31T08:04:22Z 2014-07-31T08:04:22Z 2008 Master Thesis Masters MSc http://hdl.handle.net/11427/4838 eng application/pdf Department of Environmental and Geographical Science Faculty of Science University of Cape Town |
| spellingShingle | Environmental and Geographical Science Coop, Lisa Jane The diurnal cycle of cloud cover over southern and central Africa |
| thesis_degree_str | Master's |
| title | The diurnal cycle of cloud cover over southern and central Africa |
| title_full | The diurnal cycle of cloud cover over southern and central Africa |
| title_fullStr | The diurnal cycle of cloud cover over southern and central Africa |
| title_full_unstemmed | The diurnal cycle of cloud cover over southern and central Africa |
| title_short | The diurnal cycle of cloud cover over southern and central Africa |
| title_sort | diurnal cycle of cloud cover over southern and central africa |
| topic | Environmental and Geographical Science |
| url | http://hdl.handle.net/11427/4838 |
| work_keys_str_mv | AT cooplisajane thediurnalcycleofcloudcoveroversouthernandcentralafrica AT cooplisajane diurnalcycleofcloudcoveroversouthernandcentralafrica |