Global three‐dimensional simulations of ozone depletion under postwar conditions

Abstract

Oxides of nitrogen (NOx) produced in nuclear fireballs could catalytically destroy stratospheric ozone. Since the NOx would be deposited in the upper troposphere and lower stratosphere below the level of maximum ozone concentration, earlier one‐dimensional model results showed that the potential ozone destruction rate was limited by the slow rate of vertical diffusion of NOx into the stratosphere. In the current study, the presence of a massive amount of smoke which absorbs solar energy in the upper atmosphere introduces three important changes. First, solar‐driven lofting of smoke‐filled air displaces ozone‐rich stratospheric air with ozone‐poor air from the troposphere; at the same time ozone from the northern hemisphere is shifted into the southern hemisphere. Secondly, the modified large‐scale circulation rapidly pushes NOx upward, which mixes NOx into the ozone layer much more quickly than previously thought. Finally, the heating of the stratosphere caused by the solar heating of the rising smoke increases the rates of catalytic chemical reactions that destroy ozone. Thus, NOx acts as a chemical catalyst and smoke acts as a thermal catalyst for ozone destruction. The results of simulation using general circulation model (GCM) suggest a rapid ozone depletion in the northern hemisphere. The smoke‐induced transport alone can reduce the O3 column by 15–20 Dobson units between the tropics and 60°N after 20 days of simulation. With the chemical reactions included,∼15% of ozone is depleted between 25°N and 75°N after 20 days.

Atmospheric effects and societal consequences of regional scale nuclear conflicts and acts of individual nuclear terrorism

“…In addition, soot reaching the stratosphere would cause strong local heating of the stratosphere, which in turn would alter chemical reaction rates and further perturb stratospheric dynamics. In previous simulations of large-scale nuclear smoke clouds (Kao et al, 1990), such interactive effects reduced total ozone by 50% at some Northern Hemisphere locations, while increasing it by a similar amount at places in the Southern Hemisphere, all within 20 days of the detonations. Soot, like other stratospheric particles, may also catalyze chemical reactions involving key species such as HCl, leading to accelerated ozone loss.…”

“…However, stratospheric soot injections, as projected here, might lead to substantial ozone perturbations. First, radiative heating by soot deposited in the upper troposphere would force ozone-poor air to rise into the stratosphere, displacing ozone-rich air (Kao et al, 1990;Robock et al, 2007). In addition, soot reaching the stratosphere would cause strong local heating of the stratosphere, which in turn would alter chemical reaction rates and further perturb stratospheric dynamics.…”

Transfer of organic Br and Cl from the Biosphere to the Atmosphere during the Cretaceous/Tertiary Impact: Implications for the stratospheric Ozone Layer

“…In their treatment, because very little sunlight reaches the surface the first days after the nuclear blasts, a thermal inversion occurs which prevents downward diffusion of heat and, additionally, sunlight heats the top of the smoke cloud making the atmosphere above unstable, thus Oceanic production and atmospheric oxidation cease, the mixing layer depth is halved and the sea conc. is raised due to release of intracellular CH 3 Br 6 0 for 10 yr, 5 0 until yr 1, 0.5 until yr 1, Mixed scenario 0.3 0.2 until yr 3, 0.7 until yr 3, afterwards 0.6 until yr 6, 1 afterwards 1 afterwards lofting the plume (Kao et al, 1990). Indeed, smoke from California fires in 1987 has been observed to strengthen a valley inversion cooling the surface by several degrees (Robock, 1988).…”

“…It has been argued, that fireconvection can entrain trace gases and smoke to the stratosphere . Kao et al (1990) modelled post-nuclear war conditions taking into account solar heating of the smoke plume. In their treatment, because very little sunlight reaches the surface the first days after the nuclear blasts, a thermal inversion occurs which prevents downward diffusion of heat and, additionally, sunlight heats the top of the smoke cloud making the atmosphere above unstable, thus Oceanic production and atmospheric oxidation cease, the mixing layer depth is halved and the sea conc.…”

Климат И Дым: Оценка Физических Эффектов, Приводящих К Ядерной Зиме

“…Новые численные расчеты нарушений стратосфер ного озонового слоя, вызванных крупными инжекциями дыма и окислов азота предсказывают возможность долговременного (на несколько лет) глобального, на 50% и более, уменьшения озона [162]. Расчеты, вы полненные с использованием GCM с учетом интерактивного переноса дыма и озона, а также реакций показывают, что нагретое облако дыма (во время ядерной войны), поднимаясь в стратосферу Северного полуша рия физически перемещает слой окружающего озона в направлении Юж ного полушария.…”