On the interpretation of in situ HONO observations via photochemical steady state

A substantial body of recent literature has shown that boundary layer HONO levels are higher than can be explained by simple, established gas-phase chemistry, to an extent that implies that additional HONO sources represent a major, or the dominant, precursor to OH radicals in such environments. This conclusion may be reached by analysis of point observations of (for example) OH, NO and HONO, alongside photochemical parameters; however both NO and HONO have non-negligible atmospheric lifetimes, so these approaches may be problematic if substantial spatial heterogeneity exists. We report a new dataset of HONO, NOx and HOx observations recorded at an urban background location, which support the existence of additional HONO sources as determined elsewhere. We qualitatively evaluate the possible impacts of local heterogeneity using a series of idealised numerical model simulations, building upon the work of Lee et al. (J. Geophys. Res., 2013, DOI: 10.1002/2013JD020341). The simulations illustrate the time required for photostationary state approaches to yield accurate results following substantial perturbations in the HOx/NOx/NOy chemistry, and the scope for bias to an inferred HONO source from NOx and VOC emissions in either a positive or negative sense, depending upon the air mass age following emission. To assess the extent to which these impacts may be present in actual measurements, we present exploratory spatially resolved measurements of HONO and NOx abundance obtained using a mobile instrumented laboratory. Measurements of the spatial variability of HONO in urban, suburban and rural environments show pronounced changes in abundance are found in proximity to major roads within urban areas, indicating that photo-stationary steady state (PSS) analyses in such areas are likely to be problematic. The measurements also show areas of very homogeneous HONO and NOx abundance in rural, and some suburban, regions, where the PSS approach is likely to be valid. Implications for future exploration of HONO production mechanisms are discussed

Investigating the impact of covid-19 socialisation restrictions on children’s spiritual well-being: Case Studies from Poland and the UK

Parent and practitioners observations were examined to pro�vide insights into the impact of covid-19 restrictions on children’s spiritual well-being, specifically related to reduced physical meeting of church communities in two case study contexts: Poland and the UK. Exploration of the four domains of spiritual wellbeing was carried out (Fisher 1998), with specific focus on how the abrupt changes in the communal domain may have impacted on other aspects of the child’s spiritual well-being. Significant variations in the response by churches during the pandemic were overlaid by disparate perceptions of the spiritual needs of children in these con�texts. The extent to which these responses dovetailed with parental responsibilities and expectations of the church was considered alongside awareness of the changed nature of church’s activity with children during the pandemic

Characterization of gaseous emission sourves by FT-IR emission spectroscopy

FT-IR emission spectrometry is used to detect the thermal radiation of warm exhausts, yielding in one measurement all information about the compounds present. Software units for the spectra retrieval has been developed, based on radiative transfer line-by-line calculations, a multi-layer plume model, and least-squares fit procedures. Measurements were performed with mobile commercial K300 spectrometer (MCT- or InSb-detector). Temperature and concentrations of CO, CO2, N2O, NO, HCl, SO2 and H2O in smoke stack plumes from thermal power plants and municipal incinerators, of CO2, H2O, CO and CH4 from flares, and of CO, CO2, NO and H2O in exhausts of aircraft engines were determined

Messung der Emissionsindizes in Flugzeugabgasen auf Flughäfen und in Fackelabgasen mittels FTIR-Emissionsspektrometrie (Measurement of emission indices in aircraft exhaust at airports and in flare exhaust by FTIR emission spectrometry)

Emissions from vented sources are often important inputs for the development of emission inventories and contribute to local air pollution and global enhancement of greenhouse gases. Aircraft engines and flares as e.g. at natural gas exploration and in the chemical industry are part of these emission sources. A passive measurement technique as FTIR emission spectrometry is often more cost effective and faster in operation for the determination of the composition of hot exhausts of this kind than other measurement systems as e.g. in situ techniques. In the framework of these investigations the measurements were performed by a measurement van which is equipped with an FTIR spectrometer of high spectral resolution coupled with a telescope and a three-axis movable mirror for rapid orientation towards the emission sources. At airports the emission indices of CO2, CO, NO and N2O of standing aircraft were determined. The concentrations of CO2, CH4, CO and NO were measured in flare exhausts. The measuring time is about one minute