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- Clean Air Journal = Tydskrif vir Skoon Lug
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- Volume 22, Issue 2, 2012
Clean Air Journal = Tydskrif vir Skoon Lug - Volume 22, Issue 2, 2012
Volume 22, Issue 2, 2012
Source: Clean Air Journal = Tydskrif vir Skoon Lug 22, pp 2 –6 (2012)More Less
Mariepskop forms part of the northernmost edge of the Drakensberg Mountain range and is known for its complex topography associated with meso-scale atmospheric circulation, and therefore its numerous climatic zones. The mountain hosts a high biodiversity. The peak of Mariepskop lies at approximately 1900m Above Mean Sea Level (AMSL), which is higher than the surrounding escarpment to the east. Its foothills also extend well into the Lowveld at about 700 m AMSL. Mariepskop is therefore ideal for studying airflow exchange between the industrial Highveld and the Lowveld with its diversity of natural resources. It is also ideal for detecting global warming signals on altitudinal gradients extending from the Lowveld to altitudes above the Highveld escarpment. In this study long-term National Centre for Atmospheric Research I National Centre for Environmental Prediction (NCAR/NCEP) wind data at two atmospheric pressure levels (850 and 700 hPa), as well as near-surface temperature data, were obtained for the Mariepskop region for the summer (December-January-February: DJF (1981-2011 )) and winter (June-July-August: JJA (1980-2012)) seasons. The data was used to study synoptic wind flow across the mountain in the upper (700 hPa) and lower (800 hPa) atmosphere, as well as near-surface temperature gradients. During the summer season, east-south-easterly and south-easterly winds were found to be the most prominent. These winds are commonly associated with both continental and ridging anticyclonic conditions. During winter, the predominant wind direction at 850 hPa is south-easterly, which is also due to the influence of ridging anticyclones, while at 700 hPa the dominant winter wind direction becomes west-south-west, which is due to the more frequent eastward passing of cyclonic frontal systems across the Highveld towards the Lowveld. Long-term near-surface temperatures exhibit a weak increasing linear temperature trend for both seasons, which might be due to global warming.
Source: Clean Air Journal = Tydskrif vir Skoon Lug 22, pp 14 –16 (2012)More Less
It has been shown that large numbers of low-income SA households use wood for domestic cooking and space-heating purposes and are exposed to high concentrations of air pollutants emitted from the unsophisticated appliances being utilised. Although the related problem of exposure to coal smoke from domestic fires has been and is being addressed, wood smoke exposure remains a pressing problem. The design of a more efficient wood using appliance therefore has the potential to reduce the particulate matter exposure of a considerable portion of the SA population. This paper presents the design of a natural draft wood gasification stove for domestic use based on the inverted downdraft principle. Prototypes have been built in two sizes, suitable for relatively unsophisticated manufacturing techniques. The results of performance testing as well emission factor determination are presented. It is shown that simple wood gasification stoves can at least be used for cooking, with a considerable reduction in exposure of household members to particulate matter inhalation.
Source: Clean Air Journal = Tydskrif vir Skoon Lug 22, pp 17 –19 (2012)More Less
In 2009 the United Nations Environment Programme (UNEP) was mandated by its Governing Council to develop a global legally binding instrument for mercury. An Intergovernmental Negotiating Committee (INC) was established to prepare the instrument before the 27th UNEP Governing Council Meeting in February 2013. This instrument will have significant and far-reaching effects for South Africa, due to our economy's reliance on fossil fuels, in particular coal fired power generation. South Africa is currently rated as the 6th largest emitter of mercury in the world with annual emissions estimated at around 50 tons. This paper will look at the draft text of the instrument after the 4th round of negotiations and highlight some of the potential implications for South Africa. It must be highlighted that the text of the instrument is still under negotiations and the observations and remarks made in this paper are not the official position of the Government of South Africa.