Using the Whole Atmosphere Community Climate Model version 6, stratospheric ozone in the Last Glacial Maximum (LGM) is investigated. It is shown that, compared with preindustrial (PI) times, LGM modeled stratospheric temperatures are increased by up to 8 K, leading to faster ozone destruction rates for gas phase reactions, especially via the Chapman mechanism. On the other hand, stratospheric hydroxyl radical (OH) and nitrogen oxides (NO_x) concentrations are decreased by 10–20%, which decreases catalytic ozone destruction, thereby decreasing ozone loss rates. The net effect of these two compensating mechanisms in the upper stratosphere (above 15 hPa) is a vertically integrated 1–3 Dobson unit (DU) decrease during the LGM. In the lower stratosphere (tropopause to 15 hPa), changes in the stratospheric overturning circulation and resulting transport dominate changes in ozone. Consistent with a weakening of the residual circulation in the LGM, lower stratospheric ozone is increased by 2–5 DU in the tropics and decreased by 5–10 DU in the extratropics, but the latter is partly compensated by ozone increases due to a lower tropopause. It is found that tropospheric ozone is decreased by about 5 DU in the LGM versus PI. Combined changes in stratospheric and tropospheric ozone lead to a decrease in total ozone column everywhere except over the northeast North America, equatorial Indian and West Pacific Oceans. Surface ultraviolet radiation in the LGM versus PI is increased over the Northern Hemisphere middle and high latitudes, especially over the ice caps, and over the Southern Hemisphere near 60°S.

中文翻译：

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最后一次冰川最大时期的平流层臭氧

使用“整个大气层社区气候模型”第6版，调查了最后一次冰期最大值（LGM）中的平流层臭氧。结果表明，与工业化之前的时间相比，LGM模拟的平流层温度最多可增加8 K，从而导致气相反应的臭氧破坏速率更快，尤其是通过查普曼机制。另一方面，平流层羟基（OH）和氮氧化物（NO _x）浓度降低了10–20％，从而减少了催化性臭氧破坏，从而降低了臭氧损失率。这两个补偿机制在平流层上部（高于15 hPa）的净效应是LGM期间垂直积分的1-3 Dobson单位（DU）减小。在平流层下部（对流层顶至15 hPa），平流层翻转环流的变化以及由此产生的传输起着臭氧变化的主导作用。与LGM中残留循环的减弱相一致，平流层中较低的臭氧在热带地区增加2–5 DU，在温带热带中减少5–10 DU，但后者由于对流层顶降低而部分被臭氧增加所补偿。 。发现与GM相比，LGM的对流层臭氧减少了约5 DU。平流层和对流层臭氧的综合变化导致除北美东北部，赤道印度洋和西太平洋以外的所有地方的总臭氧柱减少。在北半球中高纬度地区，特别是在冰盖和南半球，接近60°S时，LGM与PI的表面紫外线辐射增加。