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The OSIRIS instrument on board the Odin satellite uses limb viewing techniques to measure scattered sunlight and so determine the vertically resolved concentrations of atmospheric constituents including ozone. Initially, a proof of concept instrument was built and tested. This instrument, the Developmental Model, is now housed at the third floor clean room of the Physics Building on the University of Saskatchewan campus. <p> The Developmental Model was incorporated into a system designed to monitor scattered sunlight above Saskatoon. The system was set up to transmit skylight to the Developmental Model using a fiber optic cable and to perform all measurements automatically and with minimal user interaction. The system was calibrated to determine the pixel to wavelength response. Characterizations of the point spread function and relative intensity response of the detector were also made. A shutter system was designed and constructed to measure the detector dark current. An enclosure was built on the top of the Physics Building to provide a weather proof environment and so allow data collection throughout the year. Zenith sky measurements were taken during twilight hours to provide information on the depth of absorption in the Chappuis band, an indicator of the total ozone column. The absorption depth was converted to a Dobson Unit measurement for the ozone column. <p> Analysis of collected data provides two conclusions. The first is that a measurement set in the presence of clouds shows different signatures than a clear measurement set. The second conclusion is the detection of a diurnal trend in the total ozone column with greater amounts measured in the morning. The OSIRIS USASK Observatory is now operational and collecting data for future analysis of scattered sunlight measurements above Saskatoon.

The OSIRIS instrument on board the Odin satellite uses limb viewing techniques to measure scattered sunlight and so determine the vertically resolved concentrations of atmospheric constituents including ozone. Initially, a proof of concept instrument was built and tested. This instrument, the Developmental Model, is now housed at the third floor clean room of the Physics Building on the University of Saskatchewan campus. <p> The Developmental Model was incorporated into a system designed to monitor scattered sunlight above Saskatoon. The system was set up to transmit skylight to the Developmental Model using a fiber optic cable and to perform all measurements automatically and with minimal user interaction. The system was calibrated to determine the pixel to wavelength response. Characterizations of the point spread function and relative intensity response of the detector were also made. A shutter system was designed and constructed to measure the detector dark current. An enclosure was built on the top of the Physics Building to provide a weather proof environment and so allow data collection throughout the year. Zenith sky measurements were taken during twilight hours to provide information on the depth of absorption in the Chappuis band, an indicator of the total ozone column. The absorption depth was converted to a Dobson Unit measurement for the ozone column. <p> Analysis of collected data provides two conclusions. The first is that a measurement set in the presence of clouds shows different signatures than a clear measurement set. The second conclusion is the detection of a diurnal trend in the total ozone column with greater amounts measured in the morning. The OSIRIS USASK Observatory is now operational and collecting data for future analysis of scattered sunlight measurements above Saskatoon.

The tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) and Precipitation Radar (PR) data are used in this study to reveal diurnal variations of precipitation over the Tropics (30&#9702;S &#8722; 30&#9702;N) from January, 1998, to December 2002. The TMI data were used for the regions over oceans and islands and the PR data was used over continents. The observations are sorted regionally to examine the difference in diurnal cycle of rainfall over ocean, island, and continental regions. The rain rate is averaged over individual two hour intervals of local time in each region to include more observations in order to reduce the sampling error. F-test is used to determine those regions whose diurnal cycle is detected at the 95% confidence level. In most oceanic regions there is a maximum at 0400 LST - 0700 LST. The amplitude of diurnal variation over ocean regions with small total rain is a little higher than that of the ocean regions with heavy total rain. The diurnal cycle peaks at 0700 LST - 0800 LST over islands with rainfall variation similar to surrounding oceanic regions. A maximum at 1400 LST - 1500 LST was found in areas over continents with heavy total rain, while the maximum occured at 1900 LST - 2100 LST over continents with lesser total rain. The amplitudes of variation over continents with heavy total rain and with small total rain do not show significant differences. The diurnal cycle in in JJA (June, July, August) and DJF (December, January, February) varies with latitude over continents. A seasonal cycle of diurnal cycle can also be found in some oceanic regions. The diurnal cycle annual change is not evident over continents, while the diurnal cycle annual change over oceans exists in some regions. Island regions in this paper exhibit no evident seasonal and annual diurnal change.

Abstract This paper reports the quantification of the evaporative emissions from gasoline-poweredmotor vehicles in South Africa under various conditions including high temperatures. Three vehicles with and without evaporative emission control systems have been tested to quantify gasoline evaporative emissions, including both diurnal and running loss emissions. Measurements were made in a Sealed Housing for Evaporative Determination over a range of ambient temperatures. The standard diurnal test shows that evaporative emissions increase progressively with increasing fuel temperature. South African gasoline poweredmotor vehicles exhibitedevaporative emissions 10 times higher than that allowed by the United States Environmental Protection Agency. The extended-time diurnal test shows that the fuel emittedfrom gasoline-poweredmotor vehicles in South Africa is about 97 million litres of gasoline every year.

Dynamic spectra processed from data recorded on magnetic tape at the mid-latitude Ralston station (Alberta) in 1967 have been studied in detail. The Pc3,4 pulsations appear to behave in a much more complicated manner than reported by other observers at low-latitude stations. The variation of the Pc3,4 frequency at Ralston assumes different forms from one day to another, the pattern depending largely upon the general level of magnetic disturbance represented by the K(p)-index. It appears, however, that most of the Pc3,4 spectra analysed may be classified into one of, or a combination of, four well-defined diurnal patterns under steady magnetospheric conditions. An interpretation is offered to explain the existence as well as the fine structure of these four diurnal patterns. The crux of the present interpretation is that Ralston, under moderate magnetospheric agitation, may pick up micropulsation activities originating from the plasmasphere and/or the plasmatrough depending upon its position relative to the plasmapause. Eigen oscillations of modified Alfven mode (poloidal oscillation) in these two magnetospheric regions are considered to be the prime sources of the ground observed Pc3,4 magnetic pulsations. Such suggestion is reinforced by observations made simultaneously at other mid- and high-latitude stations. Other morphological properties of Pc3 and Pc4 are discussed in the light of the new interpretation. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

The three-spot wrasse (Halichoeres trimaculatus) is distributed in and around the coral reefs and shallow rocky areas in the tropical and subtropical Indo-Pacific regions. This species displays a distinct diurnal behavior, burrowing under the sand at dusk and emerging out of the sand at dawn, which appears to be synchronized to the photoperiod. In this thesis, the hypothesis tested was that this unique life-style subjected the animal to daily hypoxia exposure while under the sand at night. The measurements of oxygen concentration in the sand around the fish at night confirmed a complete lack of oxygen. The study had three specific objectives: i) obtain a tissue-specific temporal profile of the hypoxia-related molecular and biochemical responses in wrasse over a 24 h diurnal cycle, ii) determine the responses that were unique to sand dwelling and iii) determine if the responses seen at night in the sand are similar to an anoxic response in this species. Wrasse were maintained in a flow-through seawater aquaria (29 ±1°C), with sand at the bottom for the fish to hide, and kept under natural photoperiod. The fish were sampled at 10:00, 14:00, 18:00, 21:00, 24:00, 3:00, and 6:00 clock time and plasma and tissue (brain, liver, gill, heart and muscle) were collected to determine the molecular and biochemical responses over a 24 h period. Fish were also sampled from aquaria without sand at night to determine the responses that were specific to hiding in the sand, while fish exposed to nitrogen gas bubbling for 6 and 12 h served as the anoxic group. A partial cDNA sequence of the hypoxia-inducible factor (HIF)-1α and neuroglobin (two genes that are hypoxia-responsive) were cloned and sequenced from the liver and brain, respectively, and their expression was determined using real-time quantitative PCR. HIF-1α mRNA abundance was higher in the brain compared to the liver and the gills, while a clear pattern of diurnal change in tissue HIF-1α and brain neuroglobin gene expressions was not observed at night relative to the fish during the day. However, wrasse brain showed a significant reduction in glycogen content at night under the sand and this corresponded with a higher hexokinase activity and increased glucose level suggesting enhanced glycolytic capacity. The plasma glucose and lactate levels were significantly lower at night, while in sand, relative to the day. The lower plasma glucose at night corresponded with a significant drop in liver gluconeogenic capacity (reduction in phosphoenolpyruvate carboxykinase, a key gluconeogenic enzyme, activity), while the lower lactate levels support a lack of activity along with the absence of glycogen breakdown in the muscle. Overall, there was a reduction in the metabolic capacity in the gills, heart, liver and muscle, but not the brain, supporting a tissue-specific metabolic reorganization as an adaptive strategy to cope with sand-dwelling in the wrasse. The molecular and biochemical responses seen in the wrasse at night in the sand was dissimilar to that seen in fish exposed to anoxia, leading to the conclusion that this species is not experiencing a complete lack of oxygen while under the sand. Also, the lack of muscle movement associated with sand dwelling at night limits anaerobic glycolysis for energy production, thereby eliminating lactate accumulation that was evident in fish exposed to anoxia. Taken together, wrasse showed a tissue-specific difference in metabolic capacity at night while hiding under the sand. While the mechanism involved in this tissue-specific energy repartitioning at night is unclear, one hypothesis involves selective increase in blood flow to the brain, while limiting peripheral circulation, as a means to maintain oxygen and glucose delivery to this critical tissue while the fish is hiding under the sand. The higher metabolic capacity of the brain, but not other tissues, at night under the sand suggests that maintaining the brain function is essential for the diurnal life-style in this animal.

The three-spot wrasse (Halichoeres trimaculatus) is distributed in and around the coral reefs and shallow rocky areas in the tropical and subtropical Indo-Pacific regions. This species displays a distinct diurnal behavior, burrowing under the sand at dusk and emerging out of the sand at dawn, which appears to be synchronized to the photoperiod. In this thesis, the hypothesis tested was that this unique life-style subjected the animal to daily hypoxia exposure while under the sand at night. The measurements of oxygen concentration in the sand around the fish at night confirmed a complete lack of oxygen. The study had three specific objectives: i) obtain a tissue-specific temporal profile of the hypoxia-related molecular and biochemical responses in wrasse over a 24 h diurnal cycle, ii) determine the responses that were unique to sand dwelling and iii) determine if the responses seen at night in the sand are similar to an anoxic response in this species. Wrasse were maintained in a flow-through seawater aquaria (29 ±1°C), with sand at the bottom for the fish to hide, and kept under natural photoperiod. The fish were sampled at 10:00, 14:00, 18:00, 21:00, 24:00, 3:00, and 6:00 clock time and plasma and tissue (brain, liver, gill, heart and muscle) were collected to determine the molecular and biochemical responses over a 24 h period. Fish were also sampled from aquaria without sand at night to determine the responses that were specific to hiding in the sand, while fish exposed to nitrogen gas bubbling for 6 and 12 h served as the anoxic group. A partial cDNA sequence of the hypoxia-inducible factor (HIF)-1α and neuroglobin (two genes that are hypoxia-responsive) were cloned and sequenced from the liver and brain, respectively, and their expression was determined using real-time quantitative PCR. HIF-1α mRNA abundance was higher in the brain compared to the liver and the gills, while a clear pattern of diurnal change in tissue HIF-1α and brain neuroglobin gene expressions was not observed at night relative to the fish during the day. However, wrasse brain showed a significant reduction in glycogen content at night under the sand and this corresponded with a higher hexokinase activity and increased glucose level suggesting enhanced glycolytic capacity. The plasma glucose and lactate levels were significantly lower at night, while in sand, relative to the day. The lower plasma glucose at night corresponded with a significant drop in liver gluconeogenic capacity (reduction in phosphoenolpyruvate carboxykinase, a key gluconeogenic enzyme, activity), while the lower lactate levels support a lack of activity along with the absence of glycogen breakdown in the muscle. Overall, there was a reduction in the metabolic capacity in the gills, heart, liver and muscle, but not the brain, supporting a tissue-specific metabolic reorganization as an adaptive strategy to cope with sand-dwelling in the wrasse. The molecular and biochemical responses seen in the wrasse at night in the sand was dissimilar to that seen in fish exposed to anoxia, leading to the conclusion that this species is not experiencing a complete lack of oxygen while under the sand. Also, the lack of muscle movement associated with sand dwelling at night limits anaerobic glycolysis for energy production, thereby eliminating lactate accumulation that was evident in fish exposed to anoxia. Taken together, wrasse showed a tissue-specific difference in metabolic capacity at night while hiding under the sand. While the mechanism involved in this tissue-specific energy repartitioning at night is unclear, one hypothesis involves selective increase in blood flow to the brain, while limiting peripheral circulation, as a means to maintain oxygen and glucose delivery to this critical tissue while the fish is hiding under the sand. The higher metabolic capacity of the brain, but not other tissues, at night under the sand suggests that maintaining the brain function is essential for the diurnal life-style in this animal.

The seasonality, lunar and diurnal periodicity of planulation of five scleractinian corals, Seriatopora hystrix, Stylophora pistillata, Pocillopora damicornis, Euphyllia glabrescens and Tubastraea aurea, were compared. Corals were collected monthly and maintained in outdoor, flow-through systems to quantify the number of larvae released. Planulation of the five species occurred throughout the year. The long period of reproduction may be related to the warm mean seawater temperature in Nanwan Bay. S. pistillata released few larvae during late summer and early fall, suggesting the seasonality of reproduction. The pattern of lunar cycle can be classified into three strategies: (1) Planulation of S. hystrix and P. damicornis showed clear lunar periodicity and the peak of larval release shifted with different months. The peak of planulation occurred around the full moon in winter then shifted gradually to the first quarter moon phase in summer. The phase shift of larval release may be related to the seasonal variation of seawater temperature and the sudden temperature drops caused by upwelling. (2) Planulation of S. pistillata showed clear lunar periodicity and the peak of larval release occurred around the full moon. This may promote the larval dispersal. (3) E. glabrescens and T. aurea showed clearly lunar periodicity and the peak of larval release changed with different months. The peak of planulation shifted from full moon to new moon during winter and spring while it shifted from new moon to full moon during summer and fall. The pattern of diurnal cycle also can be classified into three strategies: (1) Planulation of S. hystrix and S. pistillata revealed a well-defined diurnal pattern with most planulae being released close to sunrise. (2) P. damicornis and E. glabrescens released larvae throughout the day, with two peaks occurring in the early morning and in the night. Corals of all three pocilloporids and E. glabrescens timed larvae release relative to the light-dark cycle suggesting that diurnal cycle determined when larvae were released. Larvae released in the dark may have lower risk of predation effect. Furthermore, the peak planulation occurred close to sunrise may be advantageous for some mature larvae to have light cues for quick settlement within the natal reef. (3) The azooxanthellate coral T. aurea released larvae throughout the day with no apparent cycle. These results suggest that zooxanthellae may play a role in regulating the diurnal cycle.

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