O 3 variability in the troposphere as observed by IASI over 2008-2016: Contribution of atmospheric chemistry and dynamics

• Published in: Journal of Geophysical Research: Atmospheres
• Main Authors: Wespes, Catherine, Hurtmans, Daniel, Clerbaux, Cathy, Coheur, Pierre-François
• Other Authors: Spectroscopie de l'atmosphère, Service de Chimie Quantique et Photophysique, Université libre de Bruxelles (ULB), TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2017
• Subjects: IASI; Tropospheric ozone; [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]; [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; Arctic; North Atlantic; North Atlantic oscillation
• Online Access: https://hal-insu.archives-ouvertes.fr/insu-01451930; https://hal-insu.archives-ouvertes.fr/insu-01451930/document; https://hal-insu.archives-ouvertes.fr/insu-01451930/file/2016JD025875.pdf; https://doi.org/10.1002/2016JD025875

International audience We analyze the ozone (O 3 ) variability in the troposphere (from ground to 300 hPa) using eight years (January 2008 – March 2016) of O 3 profile measurements provided by the Infrared Atmospheric Sounding Interferometer (IASI) onboard 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 - SF, Quasi-Biennial Oscillations - QBO, North Atlantic Oscillation - NAO, El Niño/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 mid- and high latitudes where a significant 4-month time-lag in the response of O 3 to ENSO is identified for the first time.