Sensitivity analysis of the surface ozone and fine particulate matter to meteorological parameters in China

Abstract

Abstract. Meteorological conditions play important roles in the formation of ozone (O3) and fine particulate matter (PM2.5). China has been suffering from serious regional air pollution problems, characterized by high concentrations of surface O3 and PM2.5. In this study, the Community Multiscale Air Quality (CMAQ) model was used to quantify the sensitivity of surface O3 and PM2.5 to key meteorological parameters in different regions of China. Six meteorological parameters were perturbed to create different meteorological conditions, including temperature (T), wind speed (WS), absolute humidity (AH), planetary boundary layer height (PBLH), cloud liquid water content (CLW) and precipitation (PCP). Air quality simulations under the perturbed meteorological conditions were conducted in China in January and July of 2013. The changes in O3 and PM2.5 concentrations due to individual meteorological parameters were then quantified. T has a great influence on the daily maximum 8 h average O3 (O3-8 h) concentrations, which leads to O3-8 h increases by 1.7 in January in Chongqing and 1.1 ppb K−1 in July in Beijing. WS, AH, and PBLH have a smaller but notable influence on O3-8 h with maximum change rates of 0.3 ppb %−1, −0.15 ppb %−1, and 0.14 ppb %−1, respectively. T, WS, AH, and PBLH have important effects on PM2.5 formation of both in January and July. In general, PM2.5 sensitivities are negative to T, WS, and PBLH and positive to AH in most regions of China. The sensitivities in January are much larger than in July. PM2.5 sensitivity to T, WS, PBLH, and AH in January can be up to −5 µg m−3 K−1, −3 µg m−3 %−1, −1 µg m−3 %−1, and +0.6 µg m−3 %−1, respectively, and in July it can be up to −2 µg m−3 K−1, −0.4 µg m−3 %−1, −0.14 µg m−3 %−1, and +0.3 µg m−3 %−1, respectively. Other meteorological factors (CLW and PCP) have negligible effects on O3-8 h (less than 0.01 ppb %−1) and PM2.5 (less than 0.01 µg m−3 %−1). The results suggest that surface O3 and PM2.5 concentrations can change significantly due to changes in meteorological parameters, and it is necessary to consider these effects when developing emission control strategies in different regions of China.

Substantial changes in gaseous pollutants and chemical compositions in fine particles in the North China Plain during the COVID-19 lockdown period: anthropogenic vs. meteorological influences

“…Among all of the pollutants, the deweathered Zn, Cr, Fe, Pb, and Ca experienced decrease rates of more than 50 % due to the lockdown measures. It was well known that Zn, Cr, and Fe originated mainly from the metallurgical industry (Sun et al, 2018;Zhu et al, 2018), while Pb might be derived from coal-fired power plants (Cui et al, 2019;Meng et al, 2020). During the COVID-19 outbreak, most of the industries have been shut down, and energy production by coal-fired power plants was reduced by one-third (Chang et al, 2020).…”

Driving Forces of Changes in Air Quality during the COVID-19 Lockdown Period in the Yangtze River Delta Region, China

“… 11 − 14 A recent study suggested that PM 2.5 in China is sensitive to a few key meteorological parameters, such as wind speed, planetary boundary layer height (PBLH), temperature, and relative humidity (RH), while O 3 is mainly sensitive to temperature. 15 Therefore, variations in meteorological conditions before and during the lockdown could contribute to the changes in PM 2.5 and O 3 concentrations. However, it remains unclear about the respective impacts of emission reduction and meteorological conditions on air quality during the lockdown.…”

Large-scale synoptic drivers of co-occurring summertime ozone and PM<sub>2.5</sub> pollution in eastern China

“…On the other hand, summer typhoon activities might have weakened the WPSH intensity over the YRD region, leading to the eastward retreat and northward shift of the WPSH. As a result, the high WS across coastal areas was able to ease the ground-level O 3 pollution (Shu et al, 2016). For the BTH and PRD regions, the high PF tended to suppress the production of O 3 .…”

“…Consequently, there were 167, 117, 52 and 32 d for Type 1, Type 2, Type 3 and Type 4 over the study period, respectively. Since the WPSH's movement is generally affected by the weather phenomena of its surrounding climatic systems (such as typhoons and the Tibetan high) (Ge et al, 2019;Liu and You, 2020;Shu et al, 2016;Wang et al, 2019), it may have resulted in a shortterm southward retreat during the advancement of the WPSH (e.g., around 10 August 2018) and a short-term northward advancement during its process of retreat (e.g., 21 and 29 August 2016). For instance, tropical storm NEPARTAK generated at 00:00 UTC (08:00 BJT) 3 July 2016 over the western North Pacific and upgraded to a super typhoon at 12:00 UTC (20:00 BJT) 5 July 2016 (Fig.…”

“…Furthermore, the number of annual extreme PM 2.5 days was highly positively correlated with extreme RH min /T max days, and the correlation coefficient between PM 2.5 and RH min (T max ) was highest in urban and suburban (rural) regions. Shi et al (2020) studied the sensitivity of O 3 -8 h (O 3 8 h moving average) and PM 2.5 associated with meteorological parameters. Their study focused on the air pollution and meteorological conditions between January and July 2013, with the results showing that temperature could have had the greatest impact on the daily maximum O 3 -8 h, while the PM 2.5 sensitivities were negatively (positively) correlated with temperature, WS and BLH (absolute humidity) in most regions of China.…”