How is NH3 formed in atmosphere?
The largest source of NH3 emissions is agriculture, including animal husbandry and NH3-based fertilizer applications. Other sources of NH3 include industrial processes, vehicular emissions and volatilization from soils and oceans.
What are primary organic aerosols?
Primary organic aerosol (POA) constitutes the emissions from both natural (vegetation and micro-organisms) and anthropogenic sources such as combustion of fossil fuels and biofuels, and open biomass burning (forest fire).
How are secondary organic aerosols formed?
Secondary Organic Aerosol (SOA) is formed– by definition –when low volatility oxidation products of volatile organic compounds (VOCs) deposit onto existing particles or form new particles. SOA accounts for a major fraction of the global atmospheric aerosol burden.
What is the main source of ammonia?
Ammonia is produced for commercial fertilizers and other industrial applications. Natural sources of ammonia include the decomposition or breakdown of organic waste matter, gas exchange with the atmosphere, forest fires, animal and human waste, and nitrogen fixation processes.
What is the difference between primary and secondary aerosols?
Their variability is due to the numerous sources and varying formation mechanisms (Figure 1). Aerosol particles are either emitted directly to the atmosphere (primary aerosols) or produced in the atmosphere from precursor gases (secondary aerosols). Primary aerosols consist of both inorganic and organic components.
What is organic carbon aerosols?
Organic carbon (OC) aerosols are the fraction of carbonaceous aerosols which contain compounds of carbon, while black carbon (BC) is operationally defined as the absorbing component of aerosols. The sources of carbonaceous aerosols may be either primary or secondary.
What are secondary inorganic aerosols?
Secondary inorganic aerosols (SIA; i.e., sulfate, nitrate, and ammonium) are the predominant components of fine particles (PM2.5) in China, making up about 30–40% of total PM2.5 mass annually1,2, and even over 50% of PM2.5 mass during some heavy pollution episodes3.
What are secondary organic compounds?
Secondary is a term used in organic chemistry to classify various types of compounds (e. g. alcohols, alkyl halides, amines) or reactive intermediates (e. g. alkyl radicals, carbocations).
What is the composition of aerosols?
Aerosols are suspensions of liquid and solid particles in the atmosphere, excluding clouds and precipitation. The aerosol particle sizes range from 10−4 to 10 μm, falling under the following broad categories: sulfates, black carbon, organic carbon, dust, and sea salt.
How are aerosols emitted in the atmosphere?
Secondary aerosol particles are produced in the atmosphere from precursor gases by condensation of vapours on pre-existing particles or by nucleation of new particles. A considerable fraction of the mass of secondary aerosols is formed through cloud processing (Ervens et al. 2011).