Nav: Home

Vertical measurements of air pollutants in urban Beijing

March 02, 2018

Severe haze episodes with surprisingly high concentrations of fine particles (PM2.5) still occur in fall and winter seasons in Beijing, although the air quality has been improved in recent years. Air pollution often shows strong vertical differences in Beijing. For example, we can feel fresh air with a good visibility at the peak of a mountain on a hazy day, while the city is actually buried in a low visibility and severely polluted air. In the urban area, we also often observe the coexistence of haze and blue sky (Figure 1). To gain an in-depth understanding of the vertical evolution characteristics of air pollutants within urban boundary layer, a team of the State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, CAS, used a container that can travel on the Beijing 325 m Meteorological Tower for the vertically resolved measurements of light extinction coefficient of dry fine particles, gaseous NO2, and black carbon (BC) (Figure 2) from ground surface to 260 m during daytime, and 200 m at nighttime. Simultaneously, non-refractory submicron aerosol (NR-PM1) species including organics, sulfate, nitrate, ammonium and chloride, were measured at ground level and 260 m on the tower with an Aerodyne High-Resolution Aerosol Mass Spectrometer (HR- AMS) and an Aerosol Chemical Speciation Monitor (ACSM), respectively. Four distinct types of vertical profiles were illustrated, and the vertical convection as indicated by mixing layer height, temperature inversion, and local emissions are three major factors affecting the changes in vertical profiles. The team found that the temperature inversion coupled by the interactions of different air masses elucidated the "blue sky - haze" co-existent phenomenon as shown in Figure 1. The tower-based vertically resolved measurements prove to be essential supplements to lidar measurements with a blind zone, typically below 200 m. The findings have recently been published in Atmospheric Chemistry & Physics).
-end-


Institute of Atmospheric Physics, Chinese Academy of Sciences

Related Air Pollutants Articles:

Lab on a chip could monitor health, germs and pollutants
Imagine wearing a device that continuously analyzes your sweat or blood for different types of biomarkers, such as proteins that show you may have breast cancer or lung cancer.
More natural dust in the air improves air quality in eastern China
Man-made pollution in eastern China's cities worsens when less dust blows in from the Gobi Desert, according to a study published May 11 in Nature Communications.
Study measures air pollution increase attributable to air conditioning
A new University of Wisconsin-Madison study shows that the electricity production associated with air conditioning causes emissions of sulfur dioxide, nitrogen oxides and carbon dioxide to increase by hundreds to thousands of metric tons, or 3 to 4 percent per degree Celsius (or 1.8 degrees Fahrenheit).
US streams carry surprisingly extensive mixture of pollutants
Many US waterways carry a variety of pollutants, but not much is known about the composition or health effects of these chemical combinations.
Melting snow contains a toxic cocktail of pollutants
With spring finally here and warmer temperatures just around the corner, snow will slowly melt away, releasing us from the clutches of winter.
New technologies in the air by NTU Singapore and Camfil to improve indoor air quality
Nanyang Technological University, Singapore (NTU Singapore) and Swedish company Camfil, a global leader in the air filtration industry, are collaborating to develop innovative solutions to improve air filtration efficiency and indoor air quality.
Evolution in action: How some fish adapt to pollutants
New genetic analyses of fish reveal how some have managed to evolve and adapt to live in polluted water.
Why air pollutants make some people vulnerable to atopic dermatitis
Researchers announce the results of a study into why air pollutants cause some people to be more susceptible to atopic dermatitis, a kind of skin inflammation.
Can early life exposure to pollutants predispose for disease?
Some studies indicate that early life exposure to pollutants such as PCBs and phthalates can predispose people to disease.
High blood pressure linked to short-, long-term exposure to some air pollutants
High blood pressure was associated with short-term and long-term exposure to some air pollutants commonly associated with the burning / combustion of fossil fuels, dust and dirt.

Related Air Pollutants Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Setbacks
Failure can feel lonely and final. But can we learn from failure, even reframe it, to feel more like a temporary setback? This hour, TED speakers on changing a crushing defeat into a stepping stone. Guests include entrepreneur Leticia Gasca, psychology professor Alison Ledgerwood, astronomer Phil Plait, former professional athlete Charly Haversat, and UPS training manager Jon Bowers.
Now Playing: Science for the People

#524 The Human Network
What does a network of humans look like and how does it work? How does information spread? How do decisions and opinions spread? What gets distorted as it moves through the network and why? This week we dig into the ins and outs of human networks with Matthew Jackson, Professor of Economics at Stanford University and author of the book "The Human Network: How Your Social Position Determines Your Power, Beliefs, and Behaviours".