An investigation of the atmospheric wave dynamics in the polar region using ground based instruments
- Authors: Khanyile, Bhekumuzi Sfundo
- Date: 2011
- Subjects: Gravity waves , Atmospheric physics -- South Africa , Riometer , Gravity -- Measurement , Rossby waves
- Language: English
- Type: Thesis , Masters , MSc (Physics)
- Identifier: vital:11592 , http://hdl.handle.net/10353/447 , Gravity waves , Atmospheric physics -- South Africa , Riometer , Gravity -- Measurement , Rossby waves
- Description: Abstract This study presents the characteristics of small-scale gravity waves in the mesosphere region as derived from the imaging riometer data at high altitude (~90 km) over SANAE (72˚S, 3˚W). Wavelet analysis and FFT (Fast Fourier transform) have been applied to extract short period gravity wave parameters for the year 2000. The horizontal wavelength, phase speed and observed period of gravity waves are typically 10-100 km, 5-60 m.s-1 and 3-60 minutes, respectively. The horizontal propagation direction is north-eastward throughout the year. This could probably be due to selective filtering by the zonal wind. Zonal and meridional winds in the region of the MLT (mesosphere and lower thermosphere) have been measured using HF radars at high latitudes in the southern hemisphere. Data from January 2000 to December 2003 have been used with the aim of investigating the characteristics of planetary wave activity at ~90 km. For SANAE and Halley stations, 2-, 5-, 10-, 16- and 20-day planetary waves are dominant in summer and winter. The results show the seasonal variations of the mean winds, which are caused by the internal variability of the quasi stationary planetary waves. Planetary wave coupling processes between UKMO assimilated and mesospheric data have also been investigated. The cross wavelet results show a strong coupling during winter months. The results suggest that planetary waves are generated at lower atmospheric heights and propagate upwards into mesospheric heights. However, not all observed disturbances in mesospheric heights can be explained by the propagation of planetary waves from lower atmospheric heights.
- Full Text:
- Date Issued: 2011
An investigation of the atmospheric wave dynamics in the polar region using ground based instruments
- Authors: Khanyile, Bhekumuzi Sfundo
- Date: 2011
- Subjects: Gravity waves , Atmospheric physics -- South Africa , Riometer , Gravity -- Measurement , Rossby waves
- Language: English
- Type: Thesis , Masters , MSc (Physics)
- Identifier: vital:11592 , http://hdl.handle.net/10353/447 , Gravity waves , Atmospheric physics -- South Africa , Riometer , Gravity -- Measurement , Rossby waves
- Description: Abstract This study presents the characteristics of small-scale gravity waves in the mesosphere region as derived from the imaging riometer data at high altitude (~90 km) over SANAE (72˚S, 3˚W). Wavelet analysis and FFT (Fast Fourier transform) have been applied to extract short period gravity wave parameters for the year 2000. The horizontal wavelength, phase speed and observed period of gravity waves are typically 10-100 km, 5-60 m.s-1 and 3-60 minutes, respectively. The horizontal propagation direction is north-eastward throughout the year. This could probably be due to selective filtering by the zonal wind. Zonal and meridional winds in the region of the MLT (mesosphere and lower thermosphere) have been measured using HF radars at high latitudes in the southern hemisphere. Data from January 2000 to December 2003 have been used with the aim of investigating the characteristics of planetary wave activity at ~90 km. For SANAE and Halley stations, 2-, 5-, 10-, 16- and 20-day planetary waves are dominant in summer and winter. The results show the seasonal variations of the mean winds, which are caused by the internal variability of the quasi stationary planetary waves. Planetary wave coupling processes between UKMO assimilated and mesospheric data have also been investigated. The cross wavelet results show a strong coupling during winter months. The results suggest that planetary waves are generated at lower atmospheric heights and propagate upwards into mesospheric heights. However, not all observed disturbances in mesospheric heights can be explained by the propagation of planetary waves from lower atmospheric heights.
- Full Text:
- Date Issued: 2011
Determinants of foreign direct investments in the motor industry in South Africa
- Authors: Onceya, Siyabulela
- Date: 2011
- Subjects: Investments, Foreign -- South Africa , Automobile industry and trade -- South Africa , Motor industry -- South Africa , Industrial policy -- South Africa
- Language: English
- Type: Thesis , Masters , M Com
- Identifier: vital:11459 , http://hdl.handle.net/10353/545 , Investments, Foreign -- South Africa , Automobile industry and trade -- South Africa , Motor industry -- South Africa , Industrial policy -- South Africa
- Description: The recent surge in foreign capital inflows into developing countries has generated interest among researchers wanting to analyse the major determinants of Foreign Direct Investments in the motor industry (FDIsm). This dissertation investigates the determinants of FDI in the motor industry in South Africa. The underpinning theoretical literature in this study is the Micro-level theory of FDI and the Eclectic theory as well as empirical literature from several authors. The study used quarterly time series data, which covers the period 1994q1- 2008q4. FDIs are modeled as the function of economic growth, interest rates, exchange rate, education and the openness of the country. The variables in the model are tested for stationarity. Cointegration analysis was also used to test for long run relationships between the variables. The trace and the maximum eigenvalue tests suggest that there are at least two cointegration relationships, an error correction modelling technique is used to establish the determinants of foreign direct investment. The error correction model was estimated which provided both long run and short run parameter estimates. The results show that economic growth, education and the openness of the country are positively related to foreign direct investment in the motor industry. Interest rates and exchange rates negatively affect foreign direct investment in the motor industry in South Africa. The results of this study are also supported by the impulse response and variance decomposition tests. The policy recommendation that emanate from this study is that efforts should be made to boost the level of economic growth in order to enhance and attract more foreign investors. It is therefore important for the government to purse policies that will encourage economic growth.
- Full Text:
- Date Issued: 2011
- Authors: Onceya, Siyabulela
- Date: 2011
- Subjects: Investments, Foreign -- South Africa , Automobile industry and trade -- South Africa , Motor industry -- South Africa , Industrial policy -- South Africa
- Language: English
- Type: Thesis , Masters , M Com
- Identifier: vital:11459 , http://hdl.handle.net/10353/545 , Investments, Foreign -- South Africa , Automobile industry and trade -- South Africa , Motor industry -- South Africa , Industrial policy -- South Africa
- Description: The recent surge in foreign capital inflows into developing countries has generated interest among researchers wanting to analyse the major determinants of Foreign Direct Investments in the motor industry (FDIsm). This dissertation investigates the determinants of FDI in the motor industry in South Africa. The underpinning theoretical literature in this study is the Micro-level theory of FDI and the Eclectic theory as well as empirical literature from several authors. The study used quarterly time series data, which covers the period 1994q1- 2008q4. FDIs are modeled as the function of economic growth, interest rates, exchange rate, education and the openness of the country. The variables in the model are tested for stationarity. Cointegration analysis was also used to test for long run relationships between the variables. The trace and the maximum eigenvalue tests suggest that there are at least two cointegration relationships, an error correction modelling technique is used to establish the determinants of foreign direct investment. The error correction model was estimated which provided both long run and short run parameter estimates. The results show that economic growth, education and the openness of the country are positively related to foreign direct investment in the motor industry. Interest rates and exchange rates negatively affect foreign direct investment in the motor industry in South Africa. The results of this study are also supported by the impulse response and variance decomposition tests. The policy recommendation that emanate from this study is that efforts should be made to boost the level of economic growth in order to enhance and attract more foreign investors. It is therefore important for the government to purse policies that will encourage economic growth.
- Full Text:
- Date Issued: 2011
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