It is a puzzle as to why more severe haze formed during the New Year Holiday in 2020 (NYH‐
20), when China was in an unprecedented state of shutdown to contain the coronavirus …

Unexpectedly frequent severe haze episodes were observed in Beijing during February–
March in 2021 after two phases of clean air action plan (2013–2020), yet the causes …

Nitrate comprises the largest fraction of fine particulate matter in China during severe haze.
Consequently, strict control of nitrogen oxides (NO x) emissions has been regarded as an …

Despite the significant reduction in atmospheric pollutant levels during the COVID-19
lockdown, the presence of haze in the North China Plain remained a frequent occurrence …

Following the emergence of a novel coronavirus in Wuhan, China instituted shutdown
measures starting in late January and continuing into February 2020 to arrest the spread of …

To control the spread of the 2019 novel coronavirus (COVID-19), China imposed nationwide
restrictions on the movement of its population (lockdown) after the Chinese New Year of …

Extreme haze episodes repeatedly shrouded Beijing during the winter of 2012–2013,
causing major environmental and health problems. To better understand these extreme …

In January 2013, a long-lasting episode of severe haze occurred in central and eastern
China, and it attracted attention from all sectors of society. The process and evolution of …

Severe hazes occurred during 2016–2017 winter manifested winter haze was still a tough
challenge in Beijing since the unprecedented haze in January 2013. Three haze episodes …

We investigate the rapid formation and evolutionary mechanisms of an extremely severe
and persistent haze episode that occurred in northern China during winter 2015 using …