title: Day-time and night-time concentrations of airborne iron particles in the atmosphere of Madrid.
abstract: Specific measurements of iron aerosol have been made over a 70 days period at a semi-urban site of Madrid. Measurements were made with the idea of assessing the relative contributions of day-time and night-time concentrations to daily ones. Statistics of day-time, night-time, daily and survey time period concentrations are given. Time variations were studied as well, clearly showing daily cyclical pattern identified by applying time spectral analysis. This periodicity is undoubtedly due to level differences between day-time and night-time concentrations of aerosol. Day-time average level ranged from 0.23 to 5.13 micrograms/m3 over the entire survey period (70 days) in contrast with night-times ones ranging from 0.17 to 3.04 micrograms/m3. Night-time/day-time concentration ratio shows a highly consistent value, 0.430 + 0.25 (sigma) during this period. On occasion when diffusion conditions are similar, this ratio increases to 0.518 + 0.18 (sigma). Day-time, night-time and daily concentrations correlation matrix suggests that former is the best daily level indicator.
authors.affiliation: Departamento Fisica Aire, Facultad Ciencias Fisicas, Universidad Complutense, Madrid, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Valero
authors.forename: M C
authors.initials: MC
authors.lastname: Mura
mesh_terms: D000336:Aerosols; D000393:Air Pollutants / Q000032:analysis*; D004058:Diffusion; D004784:Environmental Monitoring / Q000295:instrumentation; D007501:Iron / Q000032:analysis*; D013030:Spain; D013997:Time Factors; D014504:Urban Health; D014919:Wind
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D007501:Iron