Climatological monthly mean HCN volume mixing ratios measured
by MIPAS (solid lines) at the altitudes of 8 (black), 12 (red), 16 (blue) and
20 km (green) in the latitude bands 60–90∘ (top
row), 30–60∘ (middle row) and 0–30∘ (bottom row)
for the Northern (left column) and Southern Hemisphere (right
column). Black crosses (x) are climatological monthly mean HCN column amounts from
ground-based
FTIR measurements at the NDACC stations Kiruna (top left), Toronto (middle left),
Izaña (bottom left), Arrival Heights (top right) and Lauder (middle right).
For the latitude band 0–30∘S (bottom right) no ground-based data were
available. All data sets are averaged over the time period 2002 to 2012.