Influence of El Niño–Southern Oscillation on the interannual variability of tropospheric ozone in the northern midlatitudes

Abstract

[1] We use the Goddard Earth Observing System Chem (GEOS-Chem) model to interpret long-term measurements of tropospheric ozone (O 3 ) and carbon monoxide (CO) and to investigate the factors that contribute to their interannual variation (IAV) during the period from 1987 to 2005. The model reproduces relatively well the observed IAV of CO.

Tropospheric Ozone Assessment Report: Assessment of global-scale model performance for global and regional ozone distributions, variability, and trends

“…For instance, a simulation over 1987-2005 with assimilated meteorology but a parameterized stratospheric ozone source was unable to match the observed interannual variability of extratropical ozone (Koumoutsaris et al, 2008). Furthermore, the interannual variability (standard deviation) of midtropospheric ozone derived from ozonesonde and aircraft measurements is three times larger than that simulated in a CTM with a parameterized stratospheric ozone source (Hess and Zbinden, 2013).…”

“…Furthermore, the interannual variability (standard deviation) of midtropospheric ozone derived from ozonesonde and aircraft measurements is three times larger than that simulated in a CTM with a parameterized stratospheric ozone source (Hess and Zbinden, 2013). Both models in these studies were unable to reproduce the observed lowozone anomaly following the 1991 Pinatubo volcanic eruption, although they do capture some aspects of the observed 1998-1999 high-ozone anomaly at northern mid-latitudes, which was associated at least in part with an increase in the STT ozone flux following the 1997-8 El Niño (Koumoutsaris et al, 2008;Hess and Zbinden, 2013). A few studies show that CTMs with a climatological stratosphere underestimate observed ozone abundances at high northern latitudes in winter-spring (Hu et al, 2017) and in stratospheric intrusions that penetrate into the lower troposphere (Hudman et al, 2004;Zhang et al, 2011).…”

“…A single CCM study, using observed SSTs, reproduced the tropical ozone response to ENSO variability but not shorter timescales related to the MJO (Ziemke et al, 2015). Over northern mid-latitudes, ENSO events can affect the interannual variability of hemispheric pollution transport by modulating the strength and position of the subtropical jet stream, particularly in the Pacific-North America sector (Trenberth et al, 1998;Koumoutsaris et al, 2008;Li and Lau, 2012;Lin et al, 2014). Continuous ozone measurements at Mauna Loa Observatory (located in the subtropical North Pacific) since 1974 (Oltmans et al, 1996) can provide a benchmark for evaluating the ability of CCMs to represent tropospheric ozone variability in response to mid-latitude ENSO teleconnections.…”

Tropospheric ozone and its precursors from the urban to the global scale from air quality to short-lived climate forcer

“…In addition, changes in emissions, especially biomass burning, associated with ENSO affect the ozone burden across the tropics . ENSO has also been linked to column ozone changes above Europe with positive anomalies of tropospheric ozone column and surface ozone occurring in the spring following an El Niño year, for a variety of reasons including changes in STE, biomass burning emissions and pollution transport pathways from Asia and North America (Koumoutsaris et al, 2008). Voulgarakis et al (2010) used a global chemical transport model to determine the interannual variability in the global tropospheric ozone burden for the period 1996-2000, which included the strong El Niño event of 1997-1998.…”

Climatology and long-term evolution of ozone and carbon monoxide in the UTLS at northern mid-latitudes, as seen by IAGOS from 1995 to 2013

“…during the O 3 recovery after Pinatubo's eruption in 1991, followed by the global anomaly subsequent to the extreme El-Niño event of 1997 (Koumoutsaris et al, 2008).…”