Observations show that the interannual variability of the Northern Hemisphere (NH) extratropical winter stratosphere is strongly correlated with the quasi-biennial oscillation (QBO) of tropical stratospheric winds, particularly during early winter. Most current general circulation models (GCMs) do not exhibit a QBO and therefore do not represent this important mode of tropical-extratropical interaction. In this study we examine the QBO-extratropical correlation using a 150-year GCM simulation in which a QBO occurs. Since no external forcings or interannual variations in sea surface temperatures are imposed, the modelled tropical-extratropical interactions represent an internal mode of atmospheric variability. The QBO itself is spontaneously forced by a combination of resolved and parameterized waves. The effects of this QBO on the climatological mean state and its interannual variability are considered, both by comparison with a control simulation (also 150 years in length, but with no QBO) and by compositing winters according to the phase of the QBO. Careful attention is given to the definition of QBO phase. Comparisons of the model results with observations (reanalysis data) are also made. QBO-induced changes in the climatological state of the model are found to have high statistical significance above the tropopause. In the extratropical winter stratosphere, these mean-state changes arise predominantly from the influence of the QBO on the propagation and dissipation of planetary-scale waves. This behaviour is shown to depend on the seasonal cycle, which argues for the usefulness of considering tropical-extratropical interactions in a GCM context. QBO influence on the interannual variability of the extratropical winter stratosphere is also seasonal, and the tropical-extratropical interaction is sensitive to the phase alignment of the QBO with respect to the annual cycle. This phase alignment is strongly affected by the seasonality of QBO phase transitions, which - due to the QBO being spontaneously generated, rather than having an imposed period - is somewhat realistic in the model. This leads to fluctuations in the strength of the modelled tropical-extratropical interaction occurring on a decadal timescale as an internal mode of atmospheric variability.

This thesis provides highlights of the atmospheric research conducted during the program of studies 2003-07. The theme is variability of the winds at mesospheric heights (60-100 km) due to Planetary Waves (PW, 2-30 days) over middle and high latitudes. Considerable energy and momentum are transported by atmospheric waves, and their global characteristics are required to understand many phenomena and explain coupling processes within the atmosphere. The vertical propagation of PW from the upper troposphere to the mesosphere is investigated by applying the Morlet wavelet and wave number analysis to the MetO (United Kingdom Meteorological Office) stratospheric assimilated fields, TOMS total (column) ozone, and Medium Frequency (MFR) and Meteor Wind (MWR) radar measurements. The results show that large-scale eastward propagating PW dominate at tropopause and low stratospheric heights, while westward PW become comparable or even stronger in the upper stratosphere and above during months other than summer. There are also strong seasonal dependences of the PW activity in each of the stratospheric and mesospheric regions, which are attributed, at least partially, to the influence of the background wind on PW propagation. Longitudinal variations in PW activity are explained by longitudinal variations in these winds.<p>During summer (westward zonal winds) PW activity is reduced in the stratosphere and only relatively fast westward propagating PW, such as quasi 2-day wave (Q2DW), are able to reach mesospheric heights from below. The results obtained using 14 years of MFR data at Saskatoon provide a unique climatology (70-100 km) of this wave: in addition to summer activity the Q2DW is also present at low mesospheric heights in winter, especially when the eastward winds are weak; there are significant interannual variations in Q2DW activity in both seasons. Strong latitudinal and longitudinal differences in Q2DW occurrence and amplitude are shown from the comparisons of wind data at several stations.<p>During winter, when zonal winds are eastward, the PW coupling between stratosphere and mesosphere is stronger than during other seasons. Detailed data analysis has been performed for the Arctic winter of 2004/05, for which the stratospheric state is described using conventional zonal mean parameters as well as the newer Q-diagnostic. Spectral analyses for this winter show relatively weak PW activity at stratospheric and mesospheric heights and strong latitudinal and longitudinal differences of mean winds and PW characteristics consistent with the form and location of the polar vortex. <p>In addition to the vertical coupling it has also been shown that weaker horizontal inter-hemispheric coupling occurs during equinoctial months, when eastward winds dominate globally. It is demonstrated that with favorable conditions, planetary waves with 10, 16 and 25 day periods penetrate to the opposite hemisphere.

Tropospheric ozone pollution is a world-wide problem, based on studies reported from locations as diverse as India, Hong Kong, Taiwan, South Korea, Germany, Spain, Greece, Canada, and the United States. Ozone is a serious pollutant in the troposphere due to its adverse effects on the health of plants, and on the respiratory systems, eyes, and mucous membranes of humans. Due to the seriousness of the issue, the ozone problem in the Atlanta, Georgia metropolitan area was investigated. A review of the literature revealed a research deficiency, since no environment-to-circulation analysis of the ozone problem in the Atlanta metropolitan area could be found. Therefore such a study was conducted, in order to determine how high ozone days in Atlanta were related to atmospheric patterns and meteorological variables. Statistical analysis of radiosonde data, and data from eleven air quality monitoring stations in metropolitan Atlanta, for the summer months of 2000-2003, revealed a relationship between high ozone days and both high- and low- pressure patterns, as well as between high ozone days and higher temperature and lower dew point temperature. The data revealed two groups of stations differentiated by geography, and also suggested transport of precursor chemicals as a factor at some stations. This research may assist policy-makers as well as policy-implementers in elucidating associations or mechanisms that can assist efforts to reduce tropospheric ozone concentrations in the Atlanta area.

New technologies and new rotorcraft operations are being developed in order to meet new environmental requirements such as noise reduction and less pollutant emissions. In this project a parametric study was developed over a tilt rotor model in order to assess the environmental impact in terms of operational parameter and fuel burned looking at pollutant emission released into the air such as NOx, CO, UHC, PM, CO2 & H2O In order to perform the study previously stated, a computational tool build on Simulink titled tilt rotor mission performance was developed to run a single mission profile as a base line making different operational variations on every mission segment looking at deviations over fuel burned and pollutant emissions. The contribution of pollutant emissions during the cruise segment was compared to other phases obtaining 80% of CO2 and H2O, 75% of CO and UHC, 77% of NOx, and 78% of PM. Also, comparing the distance flown of the tilt rotor with some turboprop aircraft, it was found that the fuel burned and levels of CO2 are higher using tilt rotor rather than turboprop aircraft. On the other hand this is much better than helicopters.

Observations show that the interannual variability of the Northern Hemisphere (NH) extratropical winter stratosphere is strongly correlated with the quasi-biennial oscillation (QBO) of tropical stratospheric winds, particularly during early winter. Most current general circulation models (GCMs) do not exhibit a QBO and therefore do not represent this important mode of tropical-extratropical interaction. In this study we examine the QBO-extratropical correlation using a 150-year GCM simulation in which a QBO occurs. Since no external forcings or interannual variations in sea surface temperatures are imposed, the modelled tropical-extratropical interactions represent an internal mode of atmospheric variability. The QBO itself is spontaneously forced by a combination of resolved and parameterized waves. The effects of this QBO on the climatological mean state and its interannual variability are considered, both by comparison with a control simulation (also 150 years in length, but with no QBO) and by compositing winters according to the phase of the QBO. Careful attention is given to the definition of QBO phase. Comparisons of the model results with observations (reanalysis data) are also made. QBO-induced changes in the climatological state of the model are found to have high statistical significance above the tropopause. In the extratropical winter stratosphere, these mean-state changes arise predominantly from the influence of the QBO on the propagation and dissipation of planetary-scale waves. This behaviour is shown to depend on the seasonal cycle, which argues for the usefulness of considering tropical-extratropical interactions in a GCM context. QBO influence on the interannual variability of the extratropical winter stratosphere is also seasonal, and the tropical-extratropical interaction is sensitive to the phase alignment of the QBO with respect to the annual cycle. This phase alignment is strongly affected by the seasonality of QBO phase transitions, which - due to the QBO being spontaneously generated, rather than having an imposed period - is somewhat realistic in the model. This leads to fluctuations in the strength of the modelled tropical-extratropical interaction occurring on a decadal timescale as an internal mode of atmospheric variability.

International Living With a Star Workshop 2013, 2013/06/24-6/28, Irkutsk, Russia

This thesis provides highlights of the atmospheric research conducted during the program of studies 2003-07. The theme is variability of the winds at mesospheric heights (60-100 km) due to Planetary Waves (PW, 2-30 days) over middle and high latitudes. Considerable energy and momentum are transported by atmospheric waves, and their global characteristics are required to understand many phenomena and explain coupling processes within the atmosphere. The vertical propagation of PW from the upper troposphere to the mesosphere is investigated by applying the Morlet wavelet and wave number analysis to the MetO (United Kingdom Meteorological Office) stratospheric assimilated fields, TOMS total (column) ozone, and Medium Frequency (MFR) and Meteor Wind (MWR) radar measurements. The results show that large-scale eastward propagating PW dominate at tropopause and low stratospheric heights, while westward PW become comparable or even stronger in the upper stratosphere and above during months other than summer. There are also strong seasonal dependences of the PW activity in each of the stratospheric and mesospheric regions, which are attributed, at least partially, to the influence of the background wind on PW propagation. Longitudinal variations in PW activity are explained by longitudinal variations in these winds.<p>During summer (westward zonal winds) PW activity is reduced in the stratosphere and only relatively fast westward propagating PW, such as quasi 2-day wave (Q2DW), are able to reach mesospheric heights from below. The results obtained using 14 years of MFR data at Saskatoon provide a unique climatology (70-100 km) of this wave: in addition to summer activity the Q2DW is also present at low mesospheric heights in winter, especially when the eastward winds are weak; there are significant interannual variations in Q2DW activity in both seasons. Strong latitudinal and longitudinal differences in Q2DW occurrence and amplitude are shown from the comparisons of wind data at several stations.<p>During winter, when zonal winds are eastward, the PW coupling between stratosphere and mesosphere is stronger than during other seasons. Detailed data analysis has been performed for the Arctic winter of 2004/05, for which the stratospheric state is described using conventional zonal mean parameters as well as the newer Q-diagnostic. Spectral analyses for this winter show relatively weak PW activity at stratospheric and mesospheric heights and strong latitudinal and longitudinal differences of mean winds and PW characteristics consistent with the form and location of the polar vortex. <p>In addition to the vertical coupling it has also been shown that weaker horizontal inter-hemispheric coupling occurs during equinoctial months, when eastward winds dominate globally. It is demonstrated that with favorable conditions, planetary waves with 10, 16 and 25 day periods penetrate to the opposite hemisphere.

The tropospheric oxidation of unsaturated hydrocarbons is a central issue in atmospheric chemistry. These hydrocarbons are emitted into the atmosphere from both natural and anthropogenic sources, and their atmospheric oxidation leads to different atmospheric pollutants, including ground level ozone, photochemical smog and secondary organic aerosols. Isoprene and 1,3-butadiene represent a biogenic and an anthropogenic hydrocarbon, respectively, which primarily undergo electrophilic addition of OH radical, followed by chain propagating radical reactions. Their oxidation is the major source for ground level ozone formation in both rural and urban area and understanding their chemistry is essential for regional air quality modeling. Until recently, most of the studies of isoprene chemistry have been non-isomer specific, reflecting the reactivity of combined pathways and therefore were insensitive to specific details of the isomeric pathways. An isomeric selective approach to studying unsaturated hydrocarbon oxidation is described in this dissertation. A synthesized precursor, whose photolysis can provide a route to the formation of energy selected single isomer in the isoprene oxidation pathway, enables the study of important channels that are difficult to unravel in non isomer specific experiments. The major addition channel in OH isoprene oxidation has been studied following the isomeric selective approach and using Laser Photolysis-Laser Induced Fluorescence (LP-LIF) as the primary experimental technique. The study reveals important information about the oxidative chemistry of the δ-peroxy radicals, accounting for about 20 percent of missing carbon balance in isoprene oxidation, and isomeric specific rate constants. A similar approach was applied to study the oxidation of 1,3-butadiene, and the photolytic precursor for the dominant hydroxy alkyl isomer in the OH initiated oxidation of 1,3-butadiene was synthesized. The subsequent experiments and analysis revealed detailed information about the oxidative chemistry accounting for approximately 26 percent of the missing chemistry. Finally, non isomeric selective OH cycling experiments were carried out on the1,3-butadiene system. By analyzing the OH cycling data with the combined information obtained from the isomeric specific studies of the two isomeric channels of 1,3-butadiene oxidation, the relative branching between the two isomeric channels of OH-1,3-butadiene oxidation was determined.

Abstract The junior high school advisor face the key time of student¡¦s personality development. They have to do well on the basic work such as develop student¡¦s value, deliver knowledge and solve their confusion. At the same time, they have to face the unstable element in students¡¦ mind. So it is a challenge to make students¡¦ learn happily and grow up healthily. The research mean to realize the state, correlation and interaction of the advisor¡¦ leadership behavior, classroom atmosphere and learning satisfaction. And then offer concrete suggestion to the junior of advisor and referential members. The research is using the way of survey questionnaire. The subjects are 769 from the students in one junior high school in Kaohsiung. The date is analyzing with various methods of statistic analysis including descriptive statistic analysis, reliability analysis, factor analysis, independent-sample t-test, one-way anova, correlation analysis, regression analysis, After statistic analyze, the important results are as follows: 1.The junior high school advisors¡¦ leadership behavior, classroom atmosphere and learning satisfaction is above average. 2.The sample basic data including students¡¦ sexual and grade. They show significant difference in the junior high school advisors¡¦ leadership behavior, classroom atmosphere and learning satisfaction. 3.The sample background data including advisors¡¦ sexual, marriage and past service. They show significant difference in the junior high school advisors¡¦ leadership behavior, classroom atmosphere and learning satisfaction. 4.There is a positive correlation between the junior high school advisors¡¦ leadership behavior and positive classroom atmosphere. Besides, there is a negative correlation between the junior high school advisors¡¦ leadership behavior. 5.There is a positive correlation between the junior high school advisors¡¦ leadership behavior and learning satisfaction. 6. There is a positive correlation between positive classroom atmosphere and learning satisfaction. Besides, there is a negative relationship between negative classroom atmosphere and learning satisfaction. 7.There is a significant influence between the junior high school advisors¡¦ leadership behavior and classroom atmosphere. 8. There is a significant influence between the junior high school advisors¡¦ leadership behavior and learning satisfaction. 9. There is a significant influence between classroom atmosphere and learning satisfaction.

This study evaluates the simulation of tropical precipitation by the Community Climate Model, Version 3, developed at the National Center for Atmospheric Research. For an evaluation of the annual cycle of precipitation, monthly-mean precipitation rates from an ensemble of CCM3 simulations are compared to those computed from observations of the TRMM satellite over a 44-month period. On regional and sub-regional scales, the comparison fares well over much of the Eastern Hemisphere south of 10&#9702;S and over South America. However, model - satellite differences are large in portions of Central America and the Caribbean, the southern tropical Atlantic, the northern Indian Ocean, and the western equatorial and southern tropical Pacific. Since precipitation in the Tropics is the primary source of latent energy to the general circulation, such large model - satellite differences imply large differences in the amount of latent energy released. Differences are seasonally-dependent north of 10&#9702;N, where model wet biases occur in realistic wet seasons or model-generated artificial wet seasons. South of 10&#9702;N, the model wet biases exist throughout the year or have no recognizable pattern. For an evaluation of the diurnal cycle of precipitation, hourly-averaged precipitation rates from the same ensemble of simulations and for the same 44-month period are compared to observations from the Tropical Rainfall Measuring Mission (TRMM) satellite. Comparisons are made for 15&#9702; longitude ?? 10&#9702; latitude boxes and for larger geographical areas within the Tropics. The temporally- and spatially-averaged hourly precipitation rates from CCM3 and from TRMM are fit to the diurnal harmonic by the method of linear leastsquares regression, and the phases and the amplitudes of the diurnal cycles are compared. The model??s diurnal cycle is too strong over major land masses, particularly over South America (by a factor of 3), and is too weak over many oceans, particularly the northwestern Tropical Pacific (by a factor of 2). The model-satellite phase differences tend to be more homogeneous. The peak in the daily precipitation in the model consistently precedes the observations nearly everywhere. Phase differences are large over Australia, Papua New Guinea, and Saharan Africa, where CCM3 leads TRMM by 4 hours, 5 to 6 hours, and 9 to 11 hours respectively. A model sensitivity experiment shows that increasing the convective adjustment time scale in the model??s deep convective parameterization reduces its positive amplitude bias over land regions but has no effect on the phase of the diurnal cycle.