The modelled values of CRE (CREFIR, CREAW and CRE) for optically thick clouds (optical depth, τ=10) are shown in the left panels of Fig. 4; observed values (explained below) are shown in the right panels for comparison.
Modelled values of effective diffusion in kaolin were typically around 0.015 m2/yr, which are nearly three times lower than the molecular diffusion in free solution and 10 times greater than the value obtained for clamped bentonite (constant volume and constant confining pressure).
While the determination of the vertical drift is based on criteria for matching the calculated and observed F-region peak heights over the magnetic equator, the meridional winds over the Brazilian low-latitude region and over its conjugate locations are calculated by comparisons based on the observed and modelled values of hmF2 and foF2.
In order to isolate the magnetospheric (and induced) magnetic field signals from the Swarm satellite data, modelled values of the core, lithospheric (and later the ionospheric, see Section 2.4) field are subtracted from each datum.
Our study has some limitations; we used distance to the nearest road to estimate traffic exposure at the current address, as modelled values of NO2 and NOx were only available for 73% of the study population.
Modelled values of NO2 and NOx were only available for some of the study participants (60% and 77%); instead, the distance from the participants' home address to the nearest densely trafficked road was used as a measure of exposure to traffic pollution (the distance to road with 10 000 cars and modelled 2006 values of NO2 and NOx have a correlation coefficient of −0.57 and −0.53 respectively).
To further investigate the situation, we looked at the correlation between the modelled values and measured levels of NO2 at 24 measuring stations spatially distributed throughout the central parts of Umea.
Computation of expected numbers of deaths taking into account the reported (rather than true) CMI is done to calculate standardised mortality ratios on the basis of the modelled values.
It produced a residual of 0.0748 and a correlation coefficient of 0.9893 between the modelled values and the measured values.
We assumed that the differences between the natural logarithms of observed and modelled values were normally distributed with standard deviation v, which we also estimated.
