Observed changes in stratospheric circulation: decreasing lifetime of N<sub>2</sub>O, 2005–2021
<p>Using Aura Microwave Limb Sounder satellite observations of stratospheric nitrous oxide (N<span class="inline-formula"><sub>2</sub></span>O), ozone, and temperature from 2005 through 2021, we calculate the atmospheric lifetime of N<span class="inlin...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2023-01-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://acp.copernicus.org/articles/23/843/2023/acp-23-843-2023.pdf |
| Summary: | <p>Using Aura Microwave Limb Sounder satellite observations
of stratospheric nitrous oxide (N<span class="inline-formula"><sub>2</sub></span>O), ozone, and temperature from 2005
through 2021, we calculate the atmospheric lifetime of N<span class="inline-formula"><sub>2</sub></span>O to be
decreasing at a rate of <span class="inline-formula">−2.1</span> <span class="inline-formula">±</span> 1.2 %/decade. This decrease is occurring because the N<span class="inline-formula"><sub>2</sub></span>O abundances in the middle tropical stratosphere, where N<span class="inline-formula"><sub>2</sub></span>O is photochemically destroyed, are increasing at
a faster rate than the bulk N<span class="inline-formula"><sub>2</sub></span>O in the lower atmosphere. The cause
appears to be a more vigorous stratospheric circulation, which models
predict to be a result of climate change. If the observed trends in lifetime and implied emissions continue, then the change in N<span class="inline-formula"><sub>2</sub></span>O over the
21st century will be 27 % less than those projected with a fixed lifetime, and the impact on global warming and ozone depletion will be
proportionately lessened. Because global warming is caused in part by
N<span class="inline-formula"><sub>2</sub></span>O, this finding is an example of a negative climate–chemistry feedback.</p> |
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| ISSN: | 1680-7316 1680-7324 |