Manoeuvring in Uncertainty : On Agency, Strategies and Negotiations
Sub-Saharan Africa has seen wide-ranging economic and political change alongside civil and international wars. This volume focuses on the radical social uncertainties there, and how social actors perceive and cope with them in their everyday lives. It also suggests some ways to conceptualize both the actions and the environment of uncertainty.
Uncertain Future(s) : Perceptions on Time between the Immediate and the Imagined
In the last decade, the notion of uncertainty has gained prominence in anthropological debates. So has the debate on future. Yet, the conceptualisation of uncertainty has barely been linked to the future(s) and its temporal relations. This lack of linkage seems astonishing in so far as uncertainty relates closely to the unpredictability of the future. Uncertain situations engender ambivalent experiences and affects towards an unknown future embracing hope, desire and opportunity as well as fear, despair and suffering. Theoretically, the future is always unknown and unpredictable, but usually people are able to anticipate the future as it is more conversant than in uncertain situations, which challenge future outlooks and knowledge practices. Anthropologists have dedicated attention to uncertain situations ranging from everyday uncertainties under precarious conditions to crises and critical events of individual or collective existential uncertainty. Various ethnographies have described, for instance, responses to (natural) disasters (Hastrup 2011, Luig 2012), displacement/ migration (Colson 1971, Hänsch 2012, Jackson 2013), famine (Spittler 1989), diseases, especially HIV/AIDS (Haram & Yamba 2009, Jenkins et al. 2005, Kroeker 2015), as well as being young and becoming an adult during times of war, violent conflict and decline (Vigh 2006, Christiansen et al. 2006, Oldenburg 2016).
Frequency distributions of the mixing height over an urban area from SODAR data
The height of the mixing-layer (MLH) is an important parameter in the assessment of the dilution of primarily emitted or secondarily formed air pollutants in the atmospheric boundary-layer. A continuous measurement of MLH is possible only by remote sensing. Here, 17 months of SODAR data have been analysed automatically to derive the MLH over the city of Hannover in Northern Germany. In contrast to earlier studies the MLH has been determined from vertical profiles of the acoustic backscatter intensity and from the variance of the vertical velocity component. The results are presented in form of monthly frequency distributions and mean daily courses of MLH. These statistical evaluations of MLH show a clear annual course and interannual variability. The study shows the possibility to derive meaningful climatological information from long-term SODAR measurements for air quality issues.