Measurement report: Vertical distribution of biogenic and anthropogenic secondary organic aerosols in the urban boundary layer over Beijing during late summer

Abstract. Secondary organic aerosol (SOA) plays a significant role in atmospheric chemistry. However, little is known about the vertical profiles of SOA in the urban boundary layer (UBL). This knowledge gap constrains the SOA simulation in chemical transport models. Here, the aerosol samples were synchronously collected at 8, 120, and 260 m based on a 325 m meteorological tower in Beijing from 15 August to 10 September 2015. Strict emission controls were implemented during this period for the 2015 China Victory Day parade. Here, we observed that the total concentration of biogenic SOA tracers increased with height. The fraction of SOA from isoprene oxidation increased with height, whereas the fractions of SOA from monoterpenes and sesquiterpenes decreased, and 2,3-dihydroxy-4-oxopentanoic acid (DHOPA), a tracer of anthropogenic SOA from toluene oxidation, also increased with height. The complicated vertical profiles of SOA tracers highlighted the need to characterize SOA within the UBL. The mass concentration of estimated secondary organic carbon (SOC) ranged from 341 to 673 ng C m−3. The increase in the estimated SOC fractions from isoprene and toluene with height was found to be more related to regional transport, whereas the decrease in the estimated SOC from monoterpenes and sesquiterpene with height was more subject to local emissions. Emission controls during the parade reduced SOC by 4 %–35 %, with toluene SOC decreasing more than the other SOC. This study demonstrates that vertical distributions of SOA within the UBL are complex, and the vertical profiles of SOA concentrations and sources should be considered in field and modeling studies in the future.

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Measurement report: Vertical distribution of biogenic and anthropogenic secondary organic aerosols in the urban boundary layer over Beijing during late summer

10.5194/acp-2021-136 ◽

2021 ◽

Author(s):

Hong Ren ◽

Wei Hu ◽

Lianfang Wei ◽

Siyao Yue ◽

Jian Zhao ◽

...

Keyword(s):

Boundary Layer ◽

Atmospheric Chemistry ◽

Secondary Organic Aerosols ◽

Organic Aerosols ◽

Late Summer ◽

Urban Boundary Layer ◽

Vertical Profiles ◽

Emission Controls ◽

Vertical Distributions ◽

Modelling Studies

Abstract. Secondary organic aerosols (SOA) play a significant role in atmospheric chemistry. However, little is known about the vertical profiles of SOA in the urban boundary layer (UBL). This gap in the knowledge constrains the SOA simulation in chemical transport models. Here, we synchronously collected aerosol samples at 8 m, 120 m and 260 m based on a 325-m meteorological tower in urban Beijing from August 15th to September 10th, 2015. Strict emission controls were implemented during this period for the 2015 China Victory Day Parade. The sum of biogenic SOA tracers increased with height. The fraction of SOA from isoprene oxidation increased, whereas the fraction of monoterpene and sesquiterpene SOA decreased with height. The 2,3-dihydroxy-4-oxopentanoic acid (DHOPA), one tracer of anthropogenic SOA from toluene oxidation, also increased with height. The complicated vertical profiles of SOA tracers highlighted the needs to measure SOA within the UBL. The sum of estimated secondary organic carbon (SOC) ranged from 341 to 673 ngC m−3. The increase in the SOC fraction from isoprene and toluene with height was found to be more related to regional transport whereas the decrease in the SOC from monoterpene and sesquiterpene with height was more subject to local emissions. Emission controls during the parade reduced SOC by 4–35 % with toluene SOC decreasing more than the other SOC. This study demonstrates that vertical distributions of SOA within the UBL are complex, and the vertical profiles of SOA concentrations and sources should be considered in the future field and modelling studies.

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Molecular characterization of size-segregated organic aerosols in the urban boundary layer in wintertime Beijing by FT-ICR MS

Faraday Discussions ◽

10.1039/d0fd00084a ◽

2021 ◽

Author(s):

Qiaorong Xie ◽

Sihui Su ◽

Shuang Chen ◽

Qiang Zhang ◽

Siyao Yue ◽

...

Keyword(s):

Boundary Layer ◽

Size Distribution ◽

Molecular Characterization ◽

Organic Aerosols ◽

Urban Boundary Layer ◽

Vertical Profiles ◽

Unique Information ◽

Ft Icr Ms ◽

Ft Icr

Our study provides unique information on the vertical profiles and size distribution of urban organic aerosols by FT-ICR MS.

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Comparison of tethered balloon vertical profiles of particulate matter size distributions with lidar ceilometer backscatter in the nocturnal urban boundary layer

International Journal of Environment and Pollution ◽

10.1504/ijep.2010.032251 ◽

2010 ◽

Vol 41 (1/2) ◽

pp. 155 ◽

Cited By ~ 2

Author(s):

Derek Van der Kamp ◽

Ian G. McKendry

Keyword(s):

Boundary Layer ◽

Particulate Matter ◽

Urban Boundary Layer ◽

Size Distributions ◽

Vertical Profiles ◽

Tethered Balloon

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GOSAT CH4 Vertical Profiles over the Indian Subcontinent: Effect of a Priori and Averaging Kernels for Climate Applications

Remote Sensing ◽

10.3390/rs13091677 ◽

2021 ◽

Vol 13 (9) ◽

pp. 1677

Author(s):

Dmitry A. Belikov ◽

Naoko Saitoh ◽

Prabir K. Patra ◽

Naveen Chandra

Keyword(s):

Boundary Layer ◽

Atmospheric Chemistry ◽

Lower Stratosphere ◽

Indian Subcontinent ◽

A Priori ◽

Convective Transport ◽

Vertical Profiles ◽

Global Monsoon ◽

Upper Troposphere ◽

Post Monsoon

We examined methane (CH4) variability over different regions of India and the surrounding oceans derived from thermal infrared (TIR) band observations (TIR CH4) by the Thermal and Near-infrared Sensor for carbon Observation—Fourier Transform Spectrometer (TANSO-FTS) onboard the Greenhouse gases Observation SATellite (GOSAT) for the period 2009–2014. This study attempts to understand the sensitivity of the vertical profile retrievals at different layers of the troposphere and lower stratosphere, on the basis of the averaging kernel (AK) functions and a priori assumptions, as applied to the simulated concentrations by the MIROC4.0-based Atmospheric Chemistry-Transport Model (MIROC4-ACTM). We stress that this is of particular importance when the satellite-derived products are analyzed using different ACTMs other than those used as retrieved a priori. A comparison of modeled and retrieved CH4 vertical profiles shows that the GOSAT/TANSO-FTS TIR instrument has sufficient sensitivity to provide critical information about the transport of CH4 from the top of the boundary layer to the upper troposphere. The mean mismatch between TIR CH4 and model is within 50 ppb, except for the altitude range above 150 hPa, where the sensitivity of TIR CH4 observations becomes very low. Convolved model profiles with TIR CH4 AK reduces the mismatch to less than the retrieval uncertainty. Distinct seasonal variations of CH4 have been observed near the atmospheric boundary layer (800 hPa), free troposphere (500 hPa), and upper troposphere (300 hPa) over the northern and southern regions of India, corresponding to the southwest monsoon (July–September) and post-monsoon (October–December) seasons. Analysis of the transport and emission contributions to CH4 suggests that the CH4 seasonal cycle over the Indian subcontinent is governed by both the heterogeneous distributions of surface emissions and the influence of the global monsoon divergent wind circulations. The major contrast between monsoon, and pre- and post-monsoon profiles of CH4 over Indian regions are noticed near the boundary layer heights, which is mainly caused by seasonal change in local emission strength with a peak during summer due to increased emissions from the paddy fields and wetlands. A strong difference between seasons in the middle and upper troposphere is caused by convective transport of the emission signals from the surface and redistribution in the monsoon anticyclone of upper troposphere. TIR CH4 observations provide additional information on CH4 in the region compared to what is known from in situ data and total-column (XCH4) measurements. Based on two emission sensitivity simulations compared to TIR CH4 observations, we suggest that the emissions of CH4 from the India region were 51.2 ± 4.6 Tg year−1 during the period 2009–2014. Our results suggest that improvements in the a priori profile shape in the upper troposphere and lower stratosphere (UT/LS) region would help better interpretation of CH4 cycling in the earth’s environment.

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Vertical Distributions of Primary and Secondary Aerosols in Urban Boundary Layer: Insights into Sources, Chemistry, and Interaction with Meteorology

Environmental Science & Technology ◽

10.1021/acs.est.1c00479 ◽

2021 ◽

Vol 55 (8) ◽

pp. 4542-4552

Author(s):

Lu Lei ◽

Yele Sun ◽

Bin Ouyang ◽

Yanmei Qiu ◽

Conghui Xie ◽

...

Keyword(s):

Boundary Layer ◽

Urban Boundary Layer ◽

Vertical Distributions ◽

Secondary Aerosols

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Methane vertical profiles over the Indian subcontinent derived from the GOSAT/TANSO-FTS thermal infrared sensor

10.5194/amt-2020-101 ◽

2020 ◽

Author(s):

Dmitry A. Belikov ◽

Naoko Saitoh ◽

Prabir K. Patra ◽

Naveen Chandra

Keyword(s):

Boundary Layer ◽

Atmospheric Chemistry ◽

Lower Stratosphere ◽

Indian Subcontinent ◽

A Priori ◽

Thermal Infrared ◽

Vertical Profiles ◽

Infrared Sensor ◽

Global Monsoon ◽

Upper Troposphere

Abstract. We examined CH4 variability over different regions of India and the surrounding oceanic regions derived from thermal infrared (TIR) band observations by the Thermal And Near-infrared Sensor for carbon Observation-Fourier Transform Spectrometer (TANSO-FTS) onboard the Greenhouse gases Observation SATellite (GOSAT) and simulated by the updated MIROC4.0-based Atmospheric Chemistry Tracer Model (MIROC4-ACTM) for the period 2009–2014. This study attempts to understand the sensitivity of the vertical profile retrievals at different layers of the troposphere and lower stratosphere, arising from the averaging kernels and a priori assumptions. We stress that this is of particular importance when the satellite derived products are analyzed using a different ACTMs from that is used as retrieval a priori. A comparison of modeled and retrieved CH4 vertical profiles shows the 22 vertical levels of GOSAT/TANSO-FTS TIR retrievals provide critical information about transport from the top of the boundary layer to the upper troposphere and lower stratosphere in a consistent manner. The mean model-GOSAT TIR CH4 mismatch is within 50 ppb, excepting 150 hPa and upward, where the sensitivity of GOSAT/TANSO-FTS TIR observations becomes very low. Convolution of the modeled profiles with GOSAT/TANSO-FTS TIR averaging kernels reduce the mismatch to below uncertainty. Distinct seasonal variations of CH4 have been observed at the upper atmospheric boundary layer (800 hPa), free troposphere (500 hPa), and upper troposphere (200 hPa) levels over northern and southern regions of India corresponding to the southwesterly monsoon (July–September) and post-monsoon (October–December) seasons. Analysis of the transport and emission contributions to CH4 suggests that the CH4 seasonal cycle over the Indian subcontinent is governed by both the heterogeneous distributions of surface emissions and the influence of the global monsoon divergent wind circulations. GOSAT/TANSO-FTS TIR observations provide additional information about CH4 observations in this region compared to what is known from in situ data, which is important for improving the accuracy of emission flux optimization. Based on two emission sensitivity simulations, we suggest that the emissions of CH4 from the India region is 51.2 ± 1.6 Tg yr−1 during the period of 2009–2014.

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Effect of Evaporating Sea Spray on Heat Fluxes in a Marine Atmospheric Boundary Layer

Journal of Physical Oceanography ◽

10.1175/jpo-d-18-0240.1 ◽

2019 ◽

Vol 49 (7) ◽

pp. 1927-1948 ◽

Cited By ~ 1

Author(s):

Yevgenii Rastigejev ◽

Sergey A. Suslov

Keyword(s):

Boundary Layer ◽

Atmospheric Boundary Layer ◽

Air Temperature ◽

Weather Prediction ◽

Heat Fluxes ◽

Total Heat ◽

Vertical Profiles ◽

Marine Atmospheric Boundary Layer ◽

Wide Range ◽

Vertical Distributions

AbstractA detailed analysis of the evaporating ocean spray effect on the vertical latent and sensible heat fluxes in a marine atmospheric boundary layer (MABL) for different droplet sizes, vertical distributions of air temperature, humidity, and turbulent intensity is presented. For our analysis we have employed a two-temperature nonequilibrium MABL model developed in our previous work. The obtained analytical and numerical solutions show that the latent and total heat fluxes are significantly enhanced by large droplets because these droplets produce steep vertical gradients of moisture and air temperature in a MABL. Small droplets, however, do not noticeably change the total heat flux but rather redistribute the energy between its sensible and latent components. It has been shown that evaporating spray affects the turbulent kinetic energy (thus the intensity of the vertical turbulent transport) mostly mechanically by altering the vertical distribution of the mass density of the air–spray mixture rather than thermodynamically by changing vertical profiles of the air temperature and moisture. Furthermore, we have found that the vertical profiles of heat fluxes are approximately self-similar for a wide range of defining parameters, that is, can be approximately scaled to a reference heat profile for a wide range of vertical distributions of the temperature, humidity, and turbulence intensity. The obtained analytical expressions for the vertical heat fluxes affected by the spray presence enable their quick and efficient calculations. This will allow for the future construction of a computationally efficient spray and accurate parameterization to be used in global weather prediction models.

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