scholarly journals The vertical variability of black carbon observed in the atmospheric boundary layer during DACCIWA

2020 ◽  
Vol 20 (13) ◽  
pp. 7911-7928 ◽  
Author(s):  
Barbara Altstädter ◽  
Konrad Deetz ◽  
Bernhard Vogel ◽  
Karmen Babić ◽  
Cheikh Dione ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Atmospheric Boundary Layer ◽  
Black Carbon ◽  
West African Monsoon ◽  
Ground Level ◽  
Cloud Base ◽  
Small Scale ◽  
Vertical Profiles ◽  
Scale Modelling ◽  
Reactive Trace Gases

Abstract. This study underlines the important role of the transported black carbon (BC) mass concentration in the West African monsoon (WAM) area. BC was measured with a micro-aethalometer integrated in the payload bay of the unmanned research aircraft ALADINA (Application of Light-weight Aircraft for Detecting IN situ Aerosol). As part of the DACCIWA (Dynamics–Aerosol–Chemistry–Cloud Interactions in West Africa) project, 53 measurement flights were carried out at Savè, Benin, on 2–16 July 2016. A high variability of BC (1.79 to 2.42±0.31 µg m−3) was calculated along 155 vertical profiles that were performed below cloud base in the atmospheric boundary layer (ABL). In contrast to initial expectations of primary emissions, the vertical distribution of BC was mainly influenced by the stratification of the ABL during the WAM season. The article focuses on an event (14 and 15 July 2016) which showed distinct layers of BC in the lowermost 900 m above ground level (a.g.l.). Low concentrations of NOx and CO were sampled at the Savè supersite near the aircraft measurements and suggested a marginal impact of local sources during the case study. The lack of primary BC emissions was verified by a comparison of the measured BC with the model COSMO-ART (Consortium for Small-scale Modelling–Aerosols and Reactive Trace gases) that was applied for the field campaign period. The modelled vertical profiles of BC led to the assumption that the measured BC was already altered, as the size was mainly dominated by the accumulation mode. Further, calculated vertical transects of wind speed and BC presume that the observed BC layer was transported from the south with maritime inflow but was mixed vertically after the onset of a nocturnal low-level jet at the measurement site. This report contributes to the scope of DACCIWA by linking airborne BC data with ground observations and a model, and it illustrates the importance of a more profound understanding of the interaction between BC and the ABL in the WAM region.

scholarly journals The Vertical Variability of Black Carbon Observed in the Atmospheric Boundary Layer during DACCIWA

2019 ◽  
Author(s):  
Barbara Altstädter ◽  
Konrad Deetz ◽  
Bernhard Vogel ◽  
Karmen Babić ◽  
Cheikh Dione ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Atmospheric Boundary Layer ◽  
Black Carbon ◽  
West African Monsoon ◽  
Transport Processes ◽  
Small Scale ◽  
Scale Modelling ◽  
Research Aircraft ◽  
Reactive Trace Gases ◽  
Vertical Variability

Abstract. The vertical variability of the black carbon (BC) mass concentration in the atmospheric boundary layer (ABL) is analysed during the West-African Monsoon (WAM) season. BC was measured with a micro aethalometer (model AE51, AethLabs) integrated in the payload bay of the unmanned research aircraft ALADINA (Application of Light-weight Aircraft for Detecting IN situ Aerosol) as part of the field experiment of the DACCIWA (Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa) project. In total, 53 measurement flights were performed at the local airfield of Save, Benin, in the period of 2–16 July 2016. The mean results show a high variability of BC (1.79 to 2.42 ± 0.31 μg/m3) influenced by the stratification of the ABL during the WAM. The model COSMO-ART (Consortium for Small-scale Modelling–Aerosols and Reactive Trace gases) was applied for the field campaign period and used in order to investigate possible sources of the measured BC. The model output was compared with the BC data on two selected measurement days (14 and 15 July 2016). The modeled vertical profiles of BC show that the observed BC was already altered, as the size was mainly dominated by the accumulation mode. Further, the calculated vertical transects of wind speed and BC showed that the measured BC layer was transported from the south with maritime inflow, but was mixed vertically after to the onset of the nocturnal low-level jet (NLLJ) at the measurement site. The validations and the ground observations of gas concentrations NOx and CO confirm that primary emission could be excluded during the case study, in contrast to initially expected. The case underlines the important role of BC transport processes in the WAM area.

Vertical profiles of aerosol black carbon in the atmospheric boundary layer over a tropical coastal station: Perturbations during an annular solar eclipse

2011 ◽  
Vol 99 (3-4) ◽  
pp. 471-478 ◽  
Author(s):  
S. Suresh Babu ◽  
V. Sreekanth ◽  
K. Krishna Moorthy ◽  
Mannil Mohan ◽  
N.V.P. Kirankumar ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Atmospheric Boundary Layer ◽  
Black Carbon ◽  
Solar Eclipse ◽  
Vertical Profiles ◽  
Coastal Station ◽  
Annular Solar Eclipse

scholarly journals EMPOL 1.0: a new parameterization of pollen emission in numerical weather prediction models

2013 ◽  
Vol 6 (6) ◽  
pp. 1961-1975 ◽  
Author(s):  
K. Zink ◽  
A. Pauling ◽  
M. W. Rotach ◽  
H. Vogel ◽  
P. Kaufmann ◽  
...  
Keyword(s):  
Numerical Weather Prediction ◽  
Prediction Models ◽  
Weather Prediction ◽  
Birch Pollen ◽  
Small Scale ◽  
Pollen Emission ◽  
Numerical Weather ◽  
Pollen Concentrations ◽  
Scale Modelling ◽  
Reactive Trace Gases

Abstract. Simulating pollen concentrations with numerical weather prediction (NWP) systems requires a parameterization for pollen emission. We have developed a parameterization that is adaptable for different plant species. Both biological and physical processes of pollen emission are taken into account by parameterizing emission as a two-step process: (1) the release of the pollen from the flowers, and (2) their entrainment into the atmosphere. Key factors influencing emission are temperature, relative humidity, the turbulent kinetic energy and precipitation. We have simulated the birch pollen season of 2012 using the NWP system COSMO-ART (Consortium for Small-scale Modelling – Aerosols and Reactive Trace Gases), both with a parameterization already present in the model and with our new parameterization EMPOL. The statistical results show that the performance of the model can be enhanced by using EMPOL.

Study of Thermal Activity in The Mixing Layer During First Generated Single Cloud by Using Combined Observation From Boundary Layer Radar, Doppler Lidar and Time Lapse Camera 

2021 ◽  
Author(s):  
Ginaldi Ari Nugroho ◽  
Kosei Yamaguchi ◽  
Eiichi Nakakita ◽  
Masayuki K. Yamamoto ◽  
Seiji Kawamura ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Time Series ◽  
Atmospheric Boundary Layer ◽  
Vertical Velocity ◽  
Time Lapse ◽  
Small Scale ◽  
Thermal Activity ◽  
Doppler Lidar ◽  
Cumulus Cloud ◽  
Scale Perturbation

<p>Detailed observation of small scale perturbation in the atmospheric boundary layer during the first generated cumulus cloud are conducted. Our target is to study this small scale perturbation, especially related to the thermal activity at the first generated cumulus cloud. The observation is performed during the daytime on August 17, 2018, and September 03, 2018. Location is focused in the urban area of Kobe, Japan. High-resolution instruments such as Boundary Layer Radar, Doppler Lidar, and Time Lapse camera are used in this observation. Boundary Layer Radar, and Doppler Lidar are used for clear air observation. Meanwhile Time Lapse Camera are used for cloud existence observation. The atmospheric boundary layer structure is analyzed based on vertical velocity profile, variance, skewness, and estimated atmospheric boundary layer height. Wavelet are used to observe more of the period of the thermal activity. Furthermore, time correlation between vertical velocity time series from height 0.3 to 2 km and image pixel of generated cloud time series are also discussed in this study.</p>

scholarly journals Unmanned Aerial Systems for Investigating the Polar Atmospheric Boundary Layer—Technical Challenges and Examples of Applications

Atmosphere ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 416 ◽  
Author(s):  
Astrid Lampert ◽  
Barbara Altstädter ◽  
Konrad Bärfuss ◽  
Lutz Bretschneider ◽  
Jesper Sandgaard ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Atmospheric Boundary Layer ◽  
Low Temperatures ◽  
Open Water ◽  
Future Research ◽  
Small Scale ◽  
Unmanned Aerial Systems ◽  
Research Activities ◽  
Aerial Systems ◽  
The Impact

Unmanned aerial systems (UAS) fill a gap in high-resolution observations of meteorological parameters on small scales in the atmospheric boundary layer (ABL). Especially in the remote polar areas, there is a strong need for such detailed observations with different research foci. In this study, three systems are presented which have been adapted to the particular needs for operating in harsh polar environments: The fixed-wing aircraft M 2 AV with a mass of 6 kg, the quadrocopter ALICE with a mass of 19 kg, and the fixed-wing aircraft ALADINA with a mass of almost 25 kg. For all three systems, their particular modifications for polar operations are documented, in particular the insulation and heating requirements for low temperatures. Each system has completed meteorological observations under challenging conditions, including take-off and landing on the ice surface, low temperatures (down to −28 ∘ C), icing, and, for the quadrocopter, under the impact of the rotor downwash. The influence on the measured parameters is addressed here in the form of numerical simulations and spectral data analysis. Furthermore, results from several case studies are discussed: With the M 2 AV, low-level flights above leads in Antarctic sea ice were performed to study the impact of areas of open water within ice surfaces on the ABL, and a comparison with simulations was performed. ALICE was used to study the small-scale structure and short-term variability of the ABL during a cruise of RV Polarstern to the 79 ∘ N glacier in Greenland. With ALADINA, aerosol measurements of different size classes were performed in Ny-Ålesund, Svalbard, in highly complex terrain. In particular, very small, freshly formed particles are difficult to monitor and require the active control of temperature inside the instruments. The main aim of the article is to demonstrate the potential of UAS for ABL studies in polar environments, and to provide practical advice for future research activities with similar systems.

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