Modulation of daily PM<sub>2.5</sub> concentrations over China in winter by large-scale circulation and climate change
<p>We use the United Kingdom Earth System Model, UKESM1, to investigate the influence of the winter large-scale circulation on daily concentrations of PM<span class="inline-formula"><sub>2.5</sub></span> (particulate matter with an aerodynamic diameter of 2.5 ...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2023-03-01
|
| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://acp.copernicus.org/articles/23/2829/2023/acp-23-2829-2023.pdf |
| Summary: | <p>We use the United Kingdom Earth System Model, UKESM1, to
investigate the influence of the winter large-scale circulation on daily
concentrations of PM<span class="inline-formula"><sub>2.5</sub></span> (particulate matter with an aerodynamic
diameter of 2.5 <span class="inline-formula">µ</span>m or less) and their sensitivity to emissions over
major populated regions of China over the period 1999–2019. We focus on the
Yangtze River delta (YRD), where weak flow of cold, dry air from the north and weak inflow of maritime air are particularly conducive to air pollution.
These provide favourable conditions for the accumulation of local pollution
but limit the transport of air pollutants into the region from the north.
Based on the dominant large-scale circulation, we construct a new index
using the north–south pressure gradient and apply it to characterise PM<span class="inline-formula"><sub>2.5</sub></span> concentrations over the region. We show that this index can effectively distinguish different levels of pollution over YRD and explain
changes in PM<span class="inline-formula"><sub>2.5</sub></span> sensitivity to emissions from local and surrounding
regions. We then project future changes in PM<span class="inline-formula"><sub>2.5</sub></span> concentrations using
this index and find an increase in PM<span class="inline-formula"><sub>2.5</sub></span> concentrations over the
region due to climate change that is likely to partially offset the effect
of emission control measures in the near-term future. To benefit from future
emission reductions, more stringent emission controls are required to offset
the effects of climate change.</p> |
|---|---|
| ISSN: | 1680-7316 1680-7324 |