资源环境科技发展态势分析平台

We analyze the ozone (O-3) variability in the troposphere (from ground to 300 hPa) using 8 years (January 2008 to March 2016) of O-3 profile measurements provided by the Infrared Atmospheric Sounding Interferometer (IASI) on board the MetOp satellite. The capability of IASI to monitor the year-to-year variability in that layer is examined first in terms of vertical sensitivity, a priori contribution, and correlations in the deseasonalized anomalies with the upper layers. We present global patterns of the main geophysical drivers (e.g., solar flux, Quasi-biennal Oscillation-QBO, North Atlantic Oscillation-NAO, and El Nino-Southern Oscillation-ENSO) of IASI O-3 variations, obtained by applying appropriate annual and seasonal multivariate regression models on time series of spatially gridded averaged O-3. The results show that the models are able to explain most of the O-3 variability captured by IASI. Large O-3 changes in the North Arctic/Euro-Atlantic sector and over the equatorial band are attributed to the NAO and the QBO effects, respectively. ENSO is modeled as the main contributor to the O-3 variations in the tropical band where direct effects of warm and cool ENSO phases are highlighted with a clear tropical-extratropical gradient. A strong west-east gradient in the tropics is also found and likely reflects an indirect effect related to ENSO dry conditions. Finally, we also show that the ENSO perturbs the O-3 variability far from the tropics into middle and high latitudes where a significant 4-month time-lag in the response of O-3 to ENSO is identified for the first time.