scholarly journals Efficient Vertical Transport of Black Carbon in the Planetary Boundary Layer

2020 ◽  
Vol 47 (15) ◽  
Author(s):  
Dantong Liu ◽  
Kang Hu ◽  
Delong Zhao ◽  
Shuo Ding ◽  
Yunfei Wu ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Black Carbon ◽  
Planetary Boundary Layer ◽  
Vertical Transport

scholarly journals Reduced volatility of aerosols from surface emission to the top of planetary boundary layer

2021 ◽  
Author(s):  
Quan Liu ◽  
Dantong Liu ◽  
Yangzhou Wu ◽  
Kai Bi ◽  
Wenkang Gao ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Planetary Boundary Layer ◽  
Daily Basis ◽  
Atomic Ratio ◽  
Vertical Transport ◽  
Aerosol Composition ◽  
Volatile Substances ◽  
Surface Emission ◽  
Convective Mixing ◽  
Surface Environment

Abstract. Aerosols from surface emission can be transported upwards through convective mixing in the planetary boundary layer (PBL), subsequently interacting with clouds, serving important sources to nucleate droplets or ice particles. However, the evolution of aerosol composition during this vertical transport has yet to be explicitly understood. In this study, simultaneous measurements of detailed aerosol compositions were conducted at both sites of urban Beijing (50 m a.s.l.) and HaiTuo mountain (1344 m a.s.l.) during wintertime, representing the anthropogenically polluted surface environment and the top of PBL respectively. The pollutants from surface emissions were observed to reach the mountain site on daily basis through daytime PBL connective mixing. From surface to the top of PBL, we found efficient transport or formation for lower-volatile species (black carbon, sulphate and low-volatile organic aerosol, OA); however notable reduction of semi-volatile substances, such as the fractions of nitrate and semi-volatile OA reduced by 74 % and 76 % respectively, during the upward transport. This implied the evaporation process may have occurred, in repartitioning the condensed semi-volatile substances to gas-phase, when aerosols were transported and exposed to a cleaner environment. Combining with the oxidation processes, these led to enhanced oxidation state of OA at the top of the PBL compared to surface environment, with an increase of oxygen to carbon atomic ratio by 0.2. Such reduction of aerosol volatility during vertical transport may be important in modifying its viscosity, nucleation activity and atmospheric lifetime.

Investigation of the association of black carbon and PM1 with planetary boundary layer in China

2021 ◽  
Author(s):  
Yong Zhang ◽  
Chuanjiang Zhang ◽  
Mengyun Lou ◽  
Junli Jin ◽  
Qing Zhou ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Black Carbon ◽  
Planetary Boundary Layer

scholarly journals Reduced volatility of aerosols from surface emissions to the top of the planetary boundary layer

2021 ◽  
Vol 21 (19) ◽  
pp. 14749-14760
Author(s):  
Quan Liu ◽  
Dantong Liu ◽  
Yangzhou Wu ◽  
Kai Bi ◽  
Wenkang Gao ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Planetary Boundary Layer ◽  
Daily Basis ◽  
Atomic Ratio ◽  
Vertical Transport ◽  
Aerosol Composition ◽  
Surface Emission ◽  
Convective Mixing ◽  
Upward Transport ◽  
Surface Environment

Abstract. Aerosols from surface emission can be transported upwards through convective mixing in the planetary boundary layer (PBL), which subsequently interact with clouds, serving as important sources to nucleate droplets or ice particles. However, the evolution of aerosol composition during this vertical transport has yet to be explicitly understood. In this study, simultaneous measurements of detailed aerosol compositions were conducted at two sites, namely urban Beijing (50 m above sea level – a.s.l.) and Haituo mountain (1344 m a.s.l.) during wintertime, representing the anthropogenically polluted surface environment and the top of the PBL, respectively. The pollutants from surface emissions were observed to reach the mountain site on daily basis through daytime PBL convective mixing. From the surface to the top of PBL, we found efficient transport or formation of lower-volatility species (black carbon, sulfate, and low-volatile organic aerosol, OA); however, a notable reduction in semivolatile substances, such as the fractions of nitrate and semivolatile OA reduced by 74 % and 76 %, respectively, during the upward transport. This implies that the mass loss of these semivolatile species was driven by the evaporation process, which repartitioned the condensed semivolatile substances to the gas phase when aerosols were transported and exposed to a cleaner environment. In combination with the oxidation processes, these led to an enhanced oxidation state of OA at the top of the PBL compared to surface environment, with an increase of oxygen to carbon atomic ratio by 0.2. Such a reduction in aerosol volatility during vertical transport may be important in modifying its viscosity, nucleation activity, and atmospheric lifetime.

scholarly journals Enhanced heating rate of black carbon above the planetary boundary layer over megacities in summertime

2019 ◽  
Vol 14 (12) ◽  
pp. 124003
Author(s):  
Dantong Liu ◽  
Delong Zhao ◽  
Zhenzhen Xie ◽  
Chenjie Yu ◽  
Ying Chen ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Black Carbon ◽  
Heating Rate ◽  
Planetary Boundary Layer

scholarly journals Sensitivity of an Idealized Tropical Cyclone to the Configuration of the Global Forecast System–Eddy Diffusivity Mass Flux Planetary Boundary Layer Scheme

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 284
Author(s):  
Evan A. Kalina ◽  
Mrinal K. Biswas ◽  
Jun A. Zhang ◽  
Kathryn M. Newman
Keyword(s):  
Boundary Layer ◽  
Planetary Boundary Layer ◽  
Weather Prediction ◽  
Intensity Change ◽  
Rapid Intensification ◽  
Forecast System ◽  
Stability Functions ◽  
Non Local ◽  
The Stability ◽  
Heat And Moisture

The intensity and structure of simulated tropical cyclones (TCs) are known to be sensitive to the planetary boundary layer (PBL) parameterization in numerical weather prediction models. In this paper, we use an idealized version of the Hurricane Weather Research and Forecast system (HWRF) with constant sea-surface temperature (SST) to examine how the configuration of the PBL scheme used in the operational HWRF affects TC intensity change (including rapid intensification) and structure. The configuration changes explored in this study include disabling non-local vertical mixing, changing the coefficients in the stability functions for momentum and heat, and directly modifying the Prandtl number (Pr), which controls the ratio of momentum to heat and moisture exchange in the PBL. Relative to the control simulation, disabling non-local mixing produced a ~15% larger storm that intensified more gradually, while changing the coefficient values used in the stability functions had little effect. Varying Pr within the PBL had the greatest impact, with the largest Pr (~1.6 versus ~0.8) associated with more rapid intensification (~38 versus 29 m s−1 per day) but a 5–10 m s−1 weaker intensity after the initial period of strengthening. This seemingly paradoxical result is likely due to a decrease in the radius of maximum wind (~15 versus 20 km), but smaller enthalpy fluxes, in simulated storms with larger Pr. These results underscore the importance of measuring the vertical eddy diffusivities of momentum, heat, and moisture under high-wind, open-ocean conditions to reduce uncertainty in Pr in the TC PBL.

Assessing the Influence of Aerosol on Radiation and Its Roles in Planetary Boundary Layer Development

2021 ◽  
Vol 35 (2) ◽  
pp. 384-392
Author(s):  
Zhigang Cheng ◽  
Yubing Pan ◽  
Ju Li ◽  
Xingcan Jia ◽  
Xinyu Zhang ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Planetary Boundary Layer ◽  
Boundary Layer Development ◽  
Layer Development
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