Photochemistry and transport of tropospheric ozone and its precursors in urban and remote environments

Tropospheric ozone (O3) adversely affects human health, reduces crop yields, and contributes to climate forcing. To limit these effects, the processes controlling O3 abundance as well as that of its precursor molecules must be fully characterized. Here, I examine three facets of O3 production, both in heavily polluted and remote environments. First, using in situ observations from the DISCOVER-AQ field campaign in the Baltimore/Washington region, I evaluate the emissions of the O3 precursors CO and NOx (NOx = NO + NO2) in the National Emissions Inventory (NEI). I find that CO/NOx emissions ratios derived from observations are 21% higher than those predicted by the NEI. Comparisons to output from the CMAQ model suggest that CO in the NEI is accurate within 15 ± 11%, while NOx emissions are overestimated by 51-70%, likely due to errors in mobile sources. These results imply that ambient ozone concentrations will respond more efficiently to NOx controls than current models suggest. I then investigate the source of high O3 and low H2O structures in the Tropical Western Pacific (TWP). A combination of in situ observations, satellite data, and models show that the high O3 results from photochemical production in biomass burning plumes from fires in tropical Southeast Asia and Central Africa; the low relative humidity results from large-scale descent in the tropics. Because these structures have frequently been attributed to mid-latitude pollution, biomass burning in the tropics likely contributes more to the radiative forcing of climate than previously believed. Finally, I evaluate the processes controlling formaldehyde (HCHO) in the TWP. Convective transport of near surface HCHO leads to a 33% increase in upper tropospheric HCHO mixing ratios; convection also likely increases upper tropospheric CH3OOH to ~230 pptv, enough to maintain background HCHO at ~75 pptv. The long-range transport of polluted air, with NO four times the convectively controlled background, intensifies the conversion of HO2 to OH, increasing OH by a factor of 1.4. Comparisons between the global chemistry model CAM-Chem and observations show that consistent underestimates of HCHO by CAM-Chem throughout the troposphere result from underestimates in both NO and acetaldehyde.

Development Begins at Home: Women and the Domestic Economy in Brazil, 1945-1975

A number of historians of twentieth-century Latin America have identified ways that national labor laws, civil codes, social welfare programs, and business practices contributed to a gendered division of society that subordinated women to men in national economic development, household management, and familial relations. Few scholars, however, have critically explored women's roles as consumers and housewives in these intertwined realms. This work examines the Brazilian case after the Second World War, arguing that economic policies and business practices associated with “developmentalism” [Portuguese: desenvolvimentismo] created openings for women to engage in debates about national progress and transnational standards of modernity. While acknowledging that an asymmetry of gender relations persisted, the study demonstrates that urban women expanded their agency in this period, especially over areas of economic and family life deemed "domestic." This dissertation examines periodicals, consumer research statistics, public opinion surveys, personal interviews, corporate archives, the archives of key women’s organizations, and government officials’ records to identify the role that women and household economies played in Brazilian developmentalism between 1945 and 1975. Its principal argument is that business and political elites attempted to define gender roles for adult urban women as housewives and mothers, linking their management of the household to familial well-being and national modernization. In turn, Brazilian women deployed these idealized roles in public to advance their own economic interests, especially in the management of household finances and consumption, as well as to expand legal rights for married women, and increase women’s participation in the workforce. As the market for women's labor expanded with continued industrialization, these efforts defined a more active role for women in the economy and in debates about the trajectory of national development policies.