Background
Eastern China now (2017.01) are suffering severe haze with striking concentration of PM2.5.
Haze, with low visibility and complex chemical components threatens billions of persons' health.
But when I look through the pollutants concentration all over the country, I found some phenomenon interesting.
General
Here is a snapshot of PM2.5 concentration distribution map of eastern china (clipped from aqistudy.cn).
The circle with red and purple color represent the high ground-level loading of PM2.5.
From the figure above, we can identify the locations with high PM2.5 conc.
Meanwhile, I also clipped the O3 concentration distribution at the same time.
From the figure above, we can observe that O3 pollution are not severe in haze zone.
Actually, the conc of Ozone are lower in the area which the PM2.5 conc are higher.
The real-time data are also presented here a supplement. I choose Beijing, Xi'an (two large city in China), Zhoushan(an island in Eastern China Sea), Sanya(nearby the southern China Sea)
City | PM2.5 | NO2 | SO2 | O3
-------------------------------------
Beijing | 229 | 109 | 30 | 7
Xi'an | 381 | 147 | 34 | 12
Zhoushan | 20 | 28 | 14 | 70
Sanya | 16 | 9 | 2 | 77
### units: ug/m3
IMHO, the high conc of PM2.5 and low conc of O3 can be explained as follows:
High loading of Aerosol -> strong extinction effect -> week solar radiation -> O3 formation slow down
Here is another figure I clipped from Cheng et al. Sci. Adv. 2016. It depicts the NO2 and O3 conc in different PM2.5 level.
An Special case
Look at the city of Anqing (30.5319° N, 117.1151° E), its PM2.5 and O3 concentration has a strange phenomenon. I clipped some figure of its air quality status (2016-01-04 local 12:00:00)
Fig 1 Anqing City and Chizhou CityThese two nearby cities are in the distance less than 60 Km, has the similar PM2.5 conc with different O3 conc
Fig 2 Anqing City and its surrounding areaWhat attract me is the high conc O3 of Anqing City comparing with its nearby area. And I found this feature is rare in China.
Anyone has some theory to explain that? Any discussion or advises would be great!