Climatology and some dynamic features of inversions in Iceland

It is well known that atmospheric inversions may be decisive for the response of the atmospheric flow to an encounter with mountains.  In the literature, there has indeed been focus on this impact of inversions on the flow, but less focus on the inversions themselves; when, where and why the occur.  In this study, a large set of upper-air data from Iceland is explored to assess the climatology of inversions, and to some extent, the characteristics of the flow associated with statically stable layers in the troposphere.  The data reveal high frequency of tropospheric inversions, typically at 800-900 hPa.  The maximum frequency is from late winter until late autumn, with a minimum in mid-winter.  In the summer, the mean elevation of the inversions is lower than in the late winter and in the autumn.  Inversions in southerly flow are typically associated with moderate baroclinicity and advection of relatively warm airmasses above the inversion.  Inversions in northerly flow do not show this characteristic.   Case studies indicate substantial variability in synoptic-scale flow patterns leading to inversions.