Unexpectedly low ozone concentration in midlatitude tropospheric ice clouds: A case study



Raman lidar measurements of ozone, water vapor, and cirrus optical properties over northern Germany (53.4°N, 10.4deg;E) in autumn 1995 are presented. In contrast to smooth ozone profiles with values of 50 to 100 ppbv in a cloud-free and dry upper troposphere, pronounced minima in the ozone distribution with values close to zero were found several times in the presence of ice cloud layers.