Remote sensing of atmospheric gases improves our understanding of the state and evolution of the Earth’s environment. At the beginning of the thesis, the basic principles for the retrieval of concentrations of atmospheric gases from spectra are presented with a focus on ground-based observations. An overview of the characteristic features of different platforms, viewing geometries, measurement sites, and Fourier Transform Spectrometers (FTSs) used in the measurements are provided. The thesis covers four main projects. The first study of the global distribution of atmospheric phosgene was carried out using a total of 5614 measured profiles from the satellite-borne Atmospheric Chemistry Experiment FTS (ACE-FTS) spanning the period February 2004 through May 2006. The phosgene concentrations display a zonally symmetric pattern with the maximum concentration located approximately over the equator, at about 25 km in altitude, and the concentrations decrease towards the poles. A layer of enhanced concentration of phosgene spans the lower stratosphere at all latitudes, with volume mixing ratios of 20-60 pptv. The reasons for the formation of the phosgene distribution pattern are explained by the insolation, lifetime of phosgene and the Brewer-Dobson circulation. The ACE observations show lower phosgene concentrations in the stratosphere than were obtained from previous observations in the 1980s and 1990s due to a significant decrease in source species. The Portable Atmospheric Research Interferometric Spectrometer for the Infrared (PARIS-IR) is a copy of the ACE-FTS that was designed for ground-based and balloon-borne measurements. The first balloon flight was part of the Middle Atmosphere Nitrogen TRend Assessment (MANTRA) 2004 balloon payload. Some useful engineering information was obtained on the thermal performance of the instrument during the flight. As part of the MANTRA program, a ground-based inter-instrument comparison campaign was conducted with the objective of assessing instrument performance, and evaluating data processing routines and retrieval codes. PARIS-IR provides similar quality results for stratospheric species as does the University of Toronto FTS. An advanced study was carried out for the Carbon Cycle science by Fourier Transform Spectroscopy (CC-FTS) mission, which is a proposed future satellite mission to obtain a better understanding of the sources and sinks of greenhouse gases in the Earth’s atmosphere by monitoring total and partial columns of CO2, CH4, N2O, and CO in the near infrared together with the molecular O2 column. To evaluate the spectral regions, resolution, optical components, and spectroscopic parameters required for the mission, ground-based Fourier transform spectra, recorded at Kiruna, Kitt Peak, and Waterloo, were used. Dry air volume mixing ratios of CO2 and CH4 were retrieved from the ground-based observations. A FTS with a spectral resolution of 0.1 cm-1, operating between 2000 and 15000 cm-1, is suggested as the primary instrument for the mission. Further progress in improving the atmospheric retrievals for CO2, CH4 and O2 requires new laboratory measurements to improve the spectroscopic line parameters. Atmospheric observations were made with three FTSs at the Polar Environment Atmospheric Research Laboratory (PEARL) during spring 2006. The vertical column densities of O3, HCl, HNO3, HF, NO2, ClONO2 and NO from PARIS-IR, the Eureka DA8 FTS, and the ACE-FTS show good agreement. Chorine activation and denitrification in the Arctic atmosphere were observed in the extremely cold stratosphere near Eureka, Nunavut, Canada. The observed ozone depletion during the 2006 campaign was attributed to chemical removal.

Addressing climate change is a major undertaking. Agricultural soil has the potential to assist in decreasing the concentration of GHGs in the atmosphere by storing CO2 in the soil. Carbon offset markets have been suggested as a cost effective means of reducing GHG emissions. Farmers can increase their soil sink potential by applying Beneficial Management Practices (BMPs) that enhance carbon sequestration through improvements to soil, nutrient and livestock management practices (Fulton et. al., 2005). Whether or not a market for carbon offsets will emerge depends on a number of factors which mainly are related to the profitability of the BMPs and the costs of implementing a carbon contract. Provided that a market for carbon offsets emerges, the effectiveness of the market depends, in part, on the degree to which buyers and sellers in the market comply with the terms of the contracts they sign. The resource costs associated with monitoring and verification may result in incomplete monitoring. As long as monitoring is not perfect, non-compliance will be an issue. <p>The analysis that will be performed in this thesis introduces non-compliance in the economic analysis of carbon-offset market. The purpose of this work is to examine the overall cost effectiveness of the carbon-offset market when introducing non-compliance. <p>Firstly the theoretical model investigates the incentives for different farmers to participate in the carbon offsets market as well as incentives for engaging in cheating. The model recognizes farmers heterogeneity with respect to cost differences and examines the economic determinants of farmers non-compliance as well as the consequences of non-compliance on the performance of the carbon-offset market. Results support the standard finding that the extent of producers non-compliance decreases with an increase in the audit probability and/or an increase in the penalty per unit of non-compliance. In addition, the number of producers participating in the carbon offsets market is shown to increase with an increase in the carbon-offset price.<p> The analysis then introduces intermediaries in the market that will take care of trading carbon offsets as well as monitoring producers. The traders role in this study is played by an IOF (investor owned-firm) or a PA (producers association). Within the IOF, the analysis focuses on the monopoly and oligopoly structures. The key role of the traders is to guarantee, based on the amount of monitoring that is undertaken, that the emitters purchase only carbon offsets that actually correspond to sequestered carbon. The analysis then examines three cases for the group that monitors farmers compliance a group owned by for-profit traders, a government-run agency and a group owned by the PA trader. This part of the thesis examines what impact the involvement of the traders in the carbon-offset market has on non-compliance, as well as how the structure of the monitoring group affects non-compliance and the amount of carbon offsets traded in the market. The results of the analysis show that the monitoring groups always undertake sufficient monitoring to ensure that full compliance is achieved thus, while non-compliance is possible, it does not occur in equilibrium. The finding suggests that the formation of a government monitoring agency can potentially increase traded output and lower the price paid by emitters, still these changes are likely to be small, particularly when the trading sector is monopolistic. The overall analysis in this chapter shows that the optimal amount of enforcement, and as a result the cost effectiveness of a carbon-offset market, depends on the nature of the organization that undertakes the enforcement. <p>The next consideration of the thesis is the heterogeneity attributed to the timing of sequestration by different farmers. The analysis focuses on the carbon offsets pooling by considering two structures for the aggregator: a for-profit aggregator and a producers association. Pooling resources enables the farmers to benefit from economies of scale. The pricing schedule used by the aggregator is a two-part tariff. The two-part tariff is used as a way of providing an incentive for the farmers sequestering large amounts of carbon to participate in the pool. The study considers two alternatives for the coefficients that might be used to decide on the amount of carbon offsets to which each farmer will be entitled: default coefficient and custom coefficients. Each situation is modeled in a principal agent framework. <p>The analysis examines how the aggregator will target the monitoring service for different group of farmers. The investigation reveals that, under different scenarios, a PA or a FPA (for-profit aggregator) might lead to the formation of a heterogeneous pool or a homogeneous pool of each type. <p>The last issue investigated in this dissertation is the coexistence of a FPA and a PA in the default coefficient case. The analysis show that both aggregator structures can exist together in the market in the same time if the savings in the monitoring costs made possible by the PA are smaller than the cost of organizing the pool. If this condition is not satisfied the FPA cannot survive in the market and the producers association will dominate. <p>In addition to providing a better understanding of how the carbon-offset market may perform when introducing non-compliance, the results of this study can assist in assessing the cost effectiveness of the carbon-offset market when enforcement is undertaken by different organizations. Furthermore, the last consideration of the pooling option might help in selecting which type of pool a heterogeneous or a homogeneous one might perform better under different alternatives.

The determination of accurate volatile organic compound (VOC) and greenhouse gas (GHG) partitioning coefficients for air-water interfaces is essential for pollution and global climate modeling. In the atmosphere, oceans, and groundwater the concentration of dissolved salts is high enough to significantly alter the air-water partitioning behavior of the VOC or GHG, prohibiting the use of literature data or predictive models that omit the salt effect. Despite the great need for air-water partitioning data of the VOCs and GHGs threatening the environment, there is a lack of air-water partitioning data in the presence of dissolved salt. Furthermore, there are large disagreements between reported data from different research groups, which hamper model development. Henry s constants of several VOCs with salts were measured with a new high-throughput headspace gas chromatography (HTHSGC) method to create a library of internally consistent air-water partition coefficients for modeling. The VOCs studied included a homologous series of 1-alkanols, 2-ketones, organic sulfides, and the principle components of gasoline including: toluene, ethylbenzene, o-xylene, methyl tertbutyl ether, and ethyl tertbutyl ether. A model with temperature-independent parameters based on dilute solution theory was developed using the library of data to resolve the disagreements between literature sources and perform a priori prediction of salt effects. The model correlated air-water partitioning data in the form of Henry s constants over temperature ranges as wide as 300 Kelvin, salt concentrations up to 4 molal, and pressures up to 1000 bar. Extrapolations of up to 50 K, and 1 molal salt and 100 bar pressure can also safely be performed to eliminate the need for additional experiments. The temperature-independent salt effect parameter was found to be directly proportional to the critical volume of the VOC and all homologous VOCs explored followed the same linear trend allowing a priori prediction of the salt effect for unexplored compounds.

The effects of water vapor and carbon dioxide on temperature and heat transfer in the troposphere layer, which is less than the altitude of 10 km, in the atmosphere are presented in this work. Accounting for realistic temperature- and pressure- or concentration-dependent radiative properties, this work systematically evaluates heat transfer encountered in atmosphere. For simplicity, the heat transfer is assumed to be one-dimensional and pure conduction and radiation modes. The solar irradiation penetrates through the atmosphere within its short wavelength range near around visible range between 0.4-0.7 £gm, and absorbed and reflected by the earth ground with a gray body property. The ground emits radiation in longwave range. Water vapor is transparent to longwave range 8-12 £gm and absorbed in five long wavelength bands centered at 71, 6.3, 2.7, 1.87, 1.38 £gm, whereas carbon dioxide is absorbed in four long wavelength bands centered at 15, 4.3, 2.7 and 2.0 £gm. The computed results quantitatively show that water vapor and carbon dioxide are the most important factors affecting temperature difference around 2 Celsius degrees.

The effects of water vapor and carbon dioxide on temperature and heat transfer in the troposphere layer, which is less than the altitude of 10 km, in the atmosphere are presented in this work. Accounting for realistic temperature- and pressure- or concentration-dependent radiative properties, this work systematically evaluates heat transfer encountered in atmosphere. For simplicity, the heat transfer is assumed to be one-dimensional and pure conduction and radiation modes. The solar irradiation penetrates through the atmosphere within its short wavelength range near around visible range between 0.4-0.7 £gm , and absorbed and reflected by the earth ground with a black body property. The ground emits radiation in longwave range. Water vapor is transparent to longwave range 8-12 £gm , whereas carbon dioxide is absorbed in three long wavelength bands centered at 15, 10.4 and 9.4 £gm , respectively. The computed results quantitatively show that water vapor and carbon dioxide are the most important factors affecting temperature difference around 2 and 5 Celsius degrees.

Diss.--New Delhi Jawaharlal Nehru Univ.

Univ., Diss.--Utrecht, 2005.

Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 132-137). Also available on the Internet.

The aim of this report was to quantify the accumulation of carbon dioxide (CO2) and methane (CH4) in ice-covered lakes in winter (October-March) during three consecutive years, and to assess whether the concentrations of DIC and CH4, as well as the ratio DIC:CH4 differs between years and between lakes affected by clearcutting and untreated reference lakes. Water- and gas samples were collected from four boreal lakes (two affected by clearcutting and two untreated reference lakes) located in Västerbottens inland in spring. The lakes were found to accumulate on average 91, 55, and 84 mgCm-2d-1 during winters 2012-2013, 2013-2014, and 2014-2015, mostly originating from CO2. The concentrations of DIC (autumn and spring) were higher in the affected clear-cut lakes compared to reference lakes for all years, including the reference year (2012-2013) before clear-cutting. No such difference was found for CH4 or the ratio DIC:CH4. Accumulated concentrations of CO2 and CH4 varied between years while the ratio (accumulated) CO2:CH4 increased over time for all lakes but with no difference between the clear-cut lakes and the reference lakes. The differences between the clear-cut and the reference lakes, hence, are unclear with differences between years likely stemming from natural variations. The effects of clearcutting in catchment areas might be more visible at other times of year not seen in this study which focuses only on winter. The amount of CO2 and CH4 accumulated under ice in lakes was substantial i.e. high-lighting the importance of including winter accumulation of greenhouse-gases in estimations of yearly emissions from lakes.

Syftet med examensarbetet har varit att studera kol i mindre vattendrag med hjälp av jämviktsmodellering i PHREEQC. Fokus har varit dynamik av löst icke organiskt kol (DIC) samt att förstå hur mycket koldioxid (CO2) som avges från mindre vattendrag och om den mängden har signifikant inverkan på den globala kolbalansen. Med hjälp av provtagen data från Krycklans avrinningsområde år 2003-2007 och 2009 har modellering av DIC och pCO2 utförts med målet att se förändring både över säsong och nedströms i ytvattensystemet. För att utvärdera modellen har tillhandahållen data över uppmätt pCO2 använts. Målet var att jämföra modellerade och tillhandahållna pCO2-värden för att se hur väl modellen kunde beskriva verkligheten och om den fungerade bättre för någon plats eller under vissa delar av året. Analysen visade att pCO2-värden för modellen följer uppmätta pCO2-värden förhållandevis bra. Avvikelserna var störst för en av provpunkterna (provpunkt 6). Modellerade pCO2-värden följde de uppmätta pCO2-värden bäst under vårfloden. Modellen och analys av data visade tydliga indikationer på en avgång av CO2 från vattendraget. / The purpose of this Master thesis has been to study carbon flux in creeks. Chemical equilibrium models were produced to this end using PHREEQC. Specifically, dissolved inorganic carbon (DIC) quantities have been studied in order to understand the discharge of carbon dioxide (CO2) from the creek headwaters and how that affects the global carbon balance. Modeling of DIC and pCO2 was conducted using data from 2003-2007 and 2009 sampled at two points in the Krycklan research catchment located in northern Sweden. Seasonal variation of DIC and pCO2 in the two sample points was studied as well as the difference of these quantities between the two points. Evaluation of the model was done in part by comparing predicted pCO2 values with actual values stemming from a previous study leading to an assessment of the validity of the model. One of the sample points showed larger discrepancies between predictedand actual values than the other. Studying the seasonal variation of discrepancies, they were at the minimum during the spring flood. Finally, the analysis showed clear indications of a net CO2 discharge from the creekstretch between the two sample points.