Observations of ozone structures in the Arctic polar vortex

Abstract

Lidar and balloon measurements at the new observatory, AStrO (80.05°N, 86.42°W), near Eureka, in the Canadian Arctic, have revealed laminations inside the ozone layer both inside and outside the polar vortex. These observations have been conducted by the lidar group of the Institute for Space and Terrestrial Science during February–March 1993 and the winters of 1993–1994 and 1994–1995. Observations of the vortex edge region were obtained as it passed over Eureka, revealing ozone profiles rich in structure. This paper discusses the observed ozone structures and their relationship to vortex filaments, the vortex edge structure, low‐ozone pockets, motion of the vortex edge region in the ozone profiles, and observed temperatures. Complementing the observations are back trajectories, potential vorticity maps, and Lagrangian domain‐filling potential vorticity trajectories. The relations of magnitude and thickness of the laminations to their positions relative to the vortex are revealed by presenting data as a function of potential vorticity. Mechanisms for the formation and transport of the laminae are discussed, as well as their role as a possible exchange mechanism of air masses across the polar vortex boundary. From observations of the laminations and their relation to potential vorticity, it is suggested that motion of the vortex, sometimes associated with warmings, is involved in the formation of laminations, which are subsequently advected as filamentary structures.