Abstract
We compare the relationship between the Arctic Oscillation (AO) and ozone concentration in the lower stratosphere over the Arctic during 1980–1994 (P1) and 2007–2019 (P2) in January and February using reanalysis datasets. The out-of-phase relationship between the AO and ozone in the lower stratosphere is significant in January during P1 and February during P2, but it is insignificant in January during P2 and February during P1. The variable links between the AO and ozone in the lower stratosphere over the Arctic in January and February are not caused by changes in the spatial pattern of AO but are related to the anomalies in the planetary wave propagation between the troposphere and stratosphere. The upward propagation of the planetary wave in the stratosphere related to the positive phase of AO significantly weakens in January during P1 and in February during P2, which may be related to negative buoyancy frequency anomalies over the Arctic. When the AO is in the positive phase, the anomalies of planetary wave further contribute to the negative ozone anomalies via weakening the Brewer–Dobson circulation and decreasing the temperature in the lower stratosphere over the Arctic in January during P1 and in February during P2.
Highlights
The Arctic Oscillation (AO) is the predominantly zonally symmetric mode of atmospheric variability in the extratropical Northern Hemisphere, which is characterized by the sea-saw in sea level pressure (SLP) anomalies between the Arctic and mid-latitudes and is most active in winter [1]
Either in January or February, the EOF1 of ozone in the lower stratosphere over the Arctic and SLP from ERA-Interim in January and February are consistent with those from MERRA2. These results suggest that the close relationship between the ozone concentration in the lower stratosphere and SLP in January and February are mainly contributed by their EOF1—that is, there are negative anomalies of ozone in the lower stratosphere over the Arctic during the positive phase of AO
We study the unstable relationship between the AO and the ozone in the lower stratosphere in January and February throughout 1980–2019 using MERRA-2 dataset
Summary
The Arctic Oscillation (AO) is the predominantly zonally symmetric mode of atmospheric variability in the extratropical Northern Hemisphere, which is characterized by the sea-saw in sea level pressure (SLP) anomalies between the Arctic and mid-latitudes and is most active in winter [1]. As a radiatively and chemically active gas in the stratosphere, is closely related to the climate changes in the Northern Hemisphere (e.g., [10,11,12]), especially the polar vortex in the stratosphere [13]. The subtropical jet could influence the planetary wave in the stratosphere propagated from the troposphere [20], which could further alter the ozone concentration in the stratosphere over the Arctic by modulating the stratospheric circulation [21]. The question of the relationships between the AO and ozone in the lower stratosphere over the Arctic in January and February is still unclear. The relationships between the AO and ozone concentrations in the lower stratosphere over the Arctic in January and February are investigated.
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