On the distributions of long‐lived tracers and chlorine species in the middle atmosphere

Solomon, Susan; García, Rolando R.

doi:10.1029/jd089id07p11633

Cited by 104 publications

(51 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The almost constant Cl cycle over latitude may be attributed to the global distribution of Cl species. For instance, the abundance of ClO which is a source of active Cl is approximately two times higher than at 60 • latitude in the tropics in March (Solomon and Garcia, 1984). The increase of ClO at mid-and high latitudes may compensate for the effect of the increased solar zenith angle at these latitudes.…”

Section: The Daily Ozone Cyclementioning

confidence: 99%

Daily ozone cycle in the stratosphere: global, regional and seasonal behaviour modelled with the Whole Atmosphere Community Climate Model

2014

View full text Add to dashboard Cite

Abstract. The Whole Atmosphere Community Climate Model (WACCM) is utilised to study the daily ozone cycle and underlying photochemical and dynamical processes. The analysis is focused on the daily ozone cycle in the middle stratosphere at 5 hPa where satellite-based trend estimates of stratospheric ozone are most biased by diurnal sampling effects and drifting satellite orbits. The simulated ozone cycle shows a minimum after sunrise and a maximum in the late afternoon. Further, a seasonal variation of the daily ozone cycle in the stratosphere was found. Depending on season and latitude, the peak-to-valley difference of the daily ozone cycle varies mostly between 3 and 5 % (0.4 ppmv) with respect to the midnight ozone volume mixing ratio. The maximal variation of 15 % (0.8 ppmv) is found at the polar circle in summer. The global pattern of the strength of the daily ozone cycle is mainly governed by the solar zenith angle and the sunshine duration. In addition, we find synoptic-scale variations in the strength of the daily ozone cycle. These variations are often anti-correlated to regional temperature anomalies and are due to the temperature dependence of the rate coefficients k 2 and k 3 of the Chapman cycle reactions. Further, the NO x catalytic cycle counteracts the accumulation of ozone during daytime and leads to an anti-correlation between anomalies in NO x and the strength of the daily ozone cycle. Similarly, ozone recombines with atomic oxygen which leads to an anti-correlation between anomalies in ozone abundance and the strength of the daily ozone cycle. At higher latitudes, an increase of the westerly (easterly) wind cause a decrease (increase) in the sunshine duration of an air parcel leading to a weaker (stronger) daily ozone cycle.

show abstract

Section: The Daily Ozone Cyclementioning

confidence: 99%

Daily ozone cycle in the stratosphere: global, regional and seasonal behaviour modelled with the Whole Atmosphere Community Climate Model

2014

View full text Add to dashboard Cite

show abstract

“…Early descriptions of the chlorine partitioning were given by Brasseur and and Solomon and Garcia [1984], while a more recent study is described by Michelsen et al [1996]. In the middle stratosphere, inorganic chlorine (Cly) essentially consists of •75% of HC1 and --•25% of C10 [Zander et al, 1996].…”

Section: Evolutionmentioning

confidence: 99%

Temporal evolution of chlorine monoxide in the middle stratosphere

Ricaud¹,

Chipperfield²,

Waters³

et al. 2000

J. Geophys. Res.

View full text Add to dashboard Cite

“…CH 4 has long been known to play an important role in partitioning stratospheric chlo- rine (Solomon and Garcia, 1984). Specifically, the reaction Cl + CH 4 → HCl + CH 3 means that active chlorine (ClO x = Cl + ClO) should vary inversely with CH 4 .…”

Section: Chlorine Monoxide (Clo)mentioning

confidence: 99%

Persistence of upper stratospheric wintertime tracer variability into the Arctic spring and summer

et al. 2016

View full text Add to dashboard Cite

Abstract. Using data from the Aeronomy of Ice in the Mesosphere (AIM) and Aura satellites, we have categorized the interannual variability of winter-and springtime upper stratospheric methane (CH 4 ). We further show the effects of this variability on the chemistry of the upper stratosphere throughout the following summer. Years with strong wintertime mesospheric descent followed by dynamically quiet springs, such as 2009, lead to the lowest summertime CH 4 . Years with relatively weak wintertime descent, but strong springtime planetary wave activity, such as 2011, have the highest summertime CH 4 . By sampling the Aura Microwave Limb Sounder (MLS) according to the occultation pattern of the AIM Solar Occultation for Ice Experiment (SOFIE), we show that summertime upper stratospheric chlorine monoxide (ClO) almost perfectly anticorrelates with the CH 4 . This is consistent with the reaction of atomic chlorine with CH 4 to form the reservoir species, hydrochloric acid (HCl). The summertime ClO for years with strong, uninterrupted mesospheric descent is about 50 % greater than in years with strong horizontal transport and mixing of high CH 4 air from lower latitudes. Small, but persistent effects on ozone are also seen such that between 1 and 2 hPa, ozone is about 4-5 % higher in summer for the years with the highest CH 4 relative to the lowest. This is consistent with the role of the chlorine catalytic cycle on ozone. These dependencies may offer a means to monitor dynamical effects on the high-latitude upper stratosphere using summertime ClO measurements as a proxy. Additionally, these chlorine-controlled ozone decreases, which are seen to maximize after years with strong uninterrupted wintertime descent, represent a new mechanism by which mesospheric descent can affect polar ozone. Finally, given that the effects on ozone appear to persist much of the rest of the year, the consideration of winter/spring dynamical variability may also be relevant in studies of ozone trends.

show abstract

On the distributions of long‐lived tracers and chlorine species in the middle atmosphere

Cited by 104 publications

References 48 publications

Daily ozone cycle in the stratosphere: global, regional and seasonal behaviour modelled with the Whole Atmosphere Community Climate Model

Daily ozone cycle in the stratosphere: global, regional and seasonal behaviour modelled with the Whole Atmosphere Community Climate Model

Temporal evolution of chlorine monoxide in the middle stratosphere

Persistence of upper stratospheric wintertime tracer variability into the Arctic spring and summer

Contact Info

Product

Resources

About