The LIBOR market model in the South African setting

Includes abstract.Includes bibliographical references (leaves 91-92)

Role of Antarctic Circumpolar Current in decadal climate variability over southern Africa

第6回極域科学シンポジウム分野横断セッション：[IG] 全球環境変動を駆動する南大洋・南極氷床11月17日（火）　国立極地研究所 2階 大会議

Nested climate modelling over Southern Africa with a semi-langrangian limited area model

Please read the abstract in the section 00front of this documentDissertation (MSc)--University of Pretoria, 2006.Geography, Geoinformatics and MeteorologyMScUnrestricte

Role of Weddell Sea ice in South Atlantic atmospheric variability

We investigated the role of Weddell Sea ice in atmospheric variability over the South Atlantic by conducting observational data analysis and coupled general circulation model (CGCM) experiments. Weddell Sea ice exhibits a pronounced interannual variability in early austral summer (November-January). Low sea-ice concentration (SIC) anomalies in the Weddell Sea are strongly associated with anticyclonic atmospheric circulation anomalies in the South Atlantic. Composite analysis reveals that the low SIC anomalies in the Weddell Sea may be attributed to increased solar radiation and northwesterly wind anomalies. The low SIC anomalies, in turn, contribute to warmer skin temperature in the band of 60-70°S and enhance the near-surface atmospheric stability north of this band, implying favorable conditions for sustaining the anticyclonic circulation anomalies in the South Atlantic. This intriguing association between the SIC and atmospheric circulation anomalies is also simulated in CGCM experiments, e.g. when the interannual sea surface temperature variability in the tropics and mid-latitudes is suppressed. These results suggest that Weddell Sea ice, which may undergo interannual variation via air-sea-ice interactions in the high latitudes, influences atmospheric variability over the South Atlantic

Launching the e-product marketing event

Photos from the library e-product marketing event, 17 August 2006. For more photos, please contact [email protected]

A synoptic decomposition of rainfall over the Cape south coast of South Africa

A synoptic climatology is derived for the Cape south coast region of South Africa by application of the self-organizing map (SOM) technique. The SOM is applied to average daily low-level circulation fields, as represented by sea-level pressure anomalies for the period 1979–2011. This coastal region receives rainfall all-year round with slight peaks during March–April and with more pronounced peaks during August and October–November. The synoptic forcing responsible for this annual multimodal rainfall distribution is identified, and the relative contribution of different synoptic types to the annual rainfall is quantified. Ridging high pressure systems contribute to 46 % of the annual rainfall, while tropical–temperate troughs contribute 28 %. Cut-off lows (COLs) co-occurring with ridging highs and tropical–temperate troughs are associated with 16 % of the annual rainfall total. The contribution of ridging high pressure systems decreases from south to north, whilst the opposite is true for tropical–temperate troughs. COLs, ridging high pressure systems and tropical– temperate troughs are associated with the March–April rainfall peak, while COLs are largely associated with the August rainfall peak. Ridging high pressure systems and to a lesser extent tropical–temperate troughs, are responsible for the October peak observed along the coast, while the November peak over the adjacent interior regions is associated with COLs that occur in combination with the tropical– temperate troughs during this month.Water Research Commission (Project K5/2257/1) and the Applied Centre for Climate and Earth System Studies (ACCESS) in South Africa.http://link.springer.com/journal/3822016-05-31hb201

Subseasonal deterministic prediction skill of low-level geopotential height affecting southern Africa

The NCEP CFSv2 and ECMWF hindcasts are used to explore the deterministic subseasonal predictability of the 850-hPa circulation of a large domain over the Atlantic and Indian Oceans that is relevant to the weather and climate of the southern African region. For NCEP CFSv2, 12 years of hindcasts, starting on 1 January 1999 and initialized daily for four ensemble members up to 31 December 2010 are verified against ERA-Interim reanalysis data. For ECMWF, 20 years of hindcasts (1995–2014), initialized once a month for all the months of the year are employed in a parallel analysis to investigate the predictability of the 850-hPa circulation. The ensemble mean for 7-day moving averages is used to assess the prediction skill for all the start dates in each month of the year, with a focus on the start dates in each month that are representative of the week-3 and week-4 hindcasts. The correlation between the anomaly patterns over the study domain shows skill over persistence up into the week-3 hindcasts for some months. The spatial distribution of the correlation between the anomaly patterns show skill over persistence to notably reduce over the domain by week 3. A prominent area where prediction skill survives the longest, occur over central South America and the adjacent Atlantic Ocean.NRFhttps://journals.ametsoc.org/view/journals/wefo/wefo-overview.xmldm2022Geography, Geoinformatics and Meteorolog

Tropical systems from the southwest Indian Ocean making landfall over the Limpopo River Basin, southern Africa : a historical perspective

The study provides perspective on the contribution of landfalling tropical systems (cyclones, depressions, storms and lows) from the southwest Indian Ocean (SWIO) towards rainfall over the eastern interior of southern Africa, over the period 1948-2008. Although these systems contribute to < 10% of the annual rainfall occurring over the region, their relative contribution to local and widespread heavy rainfall events is shown to be highly significant. About 50% of widespread heavy rainfall events over northeastern South Africa are caused by landfalling tropical systems. Fourier analysis performed on the time series of rainfall occurring over notheastern South Africa in association with these systems reveals the existence of a quasi-18-year cycle. The cycle coincides with the well-known quasi-18-year Dyer-Tyson cycle in rainfall over the summer rainfall region of South Africa. These results suggest that atmospheric and surface conditions leading to wet phases of the Dyer-Tyson cycle also favour the landfall and subsequent westward movement of tropical systems from the SWIO over southern Africa – and their eventual contribution to rainfall over northeastern South Africa and southern Zimbabwe.Water Research Commission, South Africa (WRC Project No. K5/1847).http://www3.interscience.wiley.com/journal/4735/hom

Human resources for ART in the Free State public health sector: recording achievements, identifying challenges

The shortage of human resources for health poses a serious threat to public sector ART in South Africa. In the Free State, recruitment of staff for ART emphasises the challenges of securing the necessary number and categories of health professionals. Amongst others, not all posts were filled, and some appointments left vacancies in other programmes and facilities. Practice indicates that sites should be staffed according to the demand for the service, instead of general staffing norms. It is argued that health workers who currently do not work in the programme should receive training in ART in order to spread workloads more evenly in facilities. The realities of staff frustrations and discontent also call for improved supervision and support. The study suggests that the strengthening of the health system via human resources for ART is still to transpire. To achieve this, improved strategic planning is required