A connection from stratospheric ozone to El Niño-Southern Oscillation

Abstract

We use reanalysis and observational data to link the lower stratospheric ozone regulation of the ultraviolet radiation (UV-B) component of solar energy to ENSO modulation. Results indicate that during ENSO extremes, the Walker Circulation (WC) and Brewer Dobson Circulation are related to lower stratospheric ozone alterations east of the date line over the Pacific. These in turn are linked to upper tropospheric anomalous dipole temperature patterns on either side of the equator. The ensuing changes in geopotential height values do not only drive equatorial zonal wind anomalies in the upper troposphere that are reversed at the equatorial surface, but also impact on the intensity of the South Pacific High circulation. When the WC is enhanced, a La Nina type of circulation is indentified but if the circulation cell is inverted, the anomalous circulation results in an El Nino. Though the anomalous lower stratospheric ozone peaks during austral summer it is significant throughout the ENSO lifecycle. Hence, ENSO structure and variability are mainly linked to the lower stratospheric ozone instigated internal dynamics of the Pacific atmosphere. The ENSO forcing most likely originates from the ozone related regulation of the incoming solar UV-B radiation rather than the Pacific Ocean surface.

Is the recovery of stratospheric O<sub>3</sub> speeding up in the Southern Hemisphere? An evaluation from the first IASI decadal record (2008–2017)

“…5) is also consistent with enhanced extratropical planetary waves that propagate into the stratosphere during the warm ENSO phase, resulting in sudden stratospheric warmings and, hence, in enhanced BDC and weaker polar vortices (e.g. Brönnimann et al, 2004;Manzini et al, 2006;Cagnazzo et al, 2009). The very pronounced link between stratospheric O 3 and the ENSO-related dynamical pathways with a time lag of about 3 months is one key finding of the present work.…”

Predicting April Precipitation in the Northwestern United States Based on Arctic Stratospheric Ozone and Local Circulation

“…It suggests that March ASO is linked to April P NWUS variations with a lead time of 1 month. This delayed effect can be explained by the process involved in ASO circulation effects; i.e., stratospheric circulation anomalies caused by ASO need a month to propagate to the troposphere in the Northern Hemisphere middle latitudes (Smith and Polvani, 2014;Calvo et al, 2015;Xie et al, 2016;Ivy et al, 2017). Results from the GPCC (Figures 3B,D) agree with those from the GPCP (Figures 3A,C).…”

“…They found that circulation anomalies associated with March ASO variations can propagate to the northwestern United States, leading to local circulation and water-vapor flux anomalies that can affect April P NWUS . This motivates us to investigate whether the March ASO, which has a leading influence on the surface climate in the Northern Hemisphere (Smith and Polvani, 2014;Calvo et al, 2015;Xie et al, 2016Xie et al, , 2017aXie et al, ,b, 2018Ivy et al, 2017;Ma et al, 2019), can be used along with other factors as a predictor of April P NWUS in a statistical model. Results from this new statistical model will be compared with those of the CFS to assess improvements in the predictability of April P NWUS .…”

Spring Ozone's Connection to South Africa's Temperature and Rainfall

“…In order to detect abrupt changes/shifts, we adopted a manually performed cumulative sum (CUSUM) technique (Wetherill and Brown, 1991), as it performs robustly and is relatively easy to execute (Breaker, 2007;Manatsa and Mukwada, 2017). The analysis of cumulative variables where the cumulative sum of a variable has to be preferred to the variable itself as a measure of performance in climate research has recently gained credibility (Heim et al, 2017;Partanen et al, 2017;Graf and Tomczyk, 2018).…”

“…This emanates from the realization that certain climate driven variables do not only respond instantaneously but also to the accumulated effects over the period of time (Manatsa et al, 2015). In this regard, the CUSUM method enables the shift process to be considered holistically, being composed of sequenced and linked events rather than monthly events that are independent (Manatsa and Mukwada, 2017). We also used the Sequential Regime Shift Detector (SRSD, Rodionov and Overland, 2005) in order to confirm the derived shifts and ascertain their p-values.…”