|
|
PROCESSING OF THE DATA MEASURED WITH CLOUD CONDENSATION NUCLEI COUNTER IN YEAR 2020 FOR SUBMISSION TO EBAS DATABASE
Moravec, Pavel ; Jindra, Tomáš ; Wagner, Zdeněk ; Ždímal, Vladimír
Aerosol particles in the atmosphere that allow water vapor to condense and form cloud droplets are called Cloud Condensation Nuclei (CCN). Elevated concentrations of CCN tend to increase the concentration and decrease the size of cloud droplets. This can lead to suppression of precipitation in shallow and short-lived clouds and to greater convective overturning and more precipitation in deep convective clouds, Rose et al.(2010). The response of cloud properties and precipitation processes to increasing anthropogenic aerosol concentrations represents one of the largest uncertainties in the current understanding of climate change. One of the fundamental challenges is to determine the ability of aerosol particles to act as CCN under relevant atmospheric conditions. Knowledge of the spatial and temporal distribution in the atmosphere is essential to incorporate the effects of CCN into meteorological models of all scales, Huang et al. (2007). Long-term CCN measurements are performed at aerosol monitoring sites such as those forming ACTRIS (Aerosols, Clouds, and Trace Gases Research Infrastructure) network. Measured data are then submitted to the EBAS database, where they are available for the other ACTRIS researchers. In this paper, we present our experience with the processing of the data measured with CCNC for submission to the EBAS database. The data prepared for submission to EBAS from year 2020 are also presented.
Plný tet:  PDF
|
|
|
(IN)DEPENDENCE OF AEROSOL ACTIVATION ON CLOUD POSITION
Zíková, Naděžda ; Pokorná, Petra ; Sedlák, Pavel ; Sokol, Zbyněk ; Ždímal, Vladimír
Five in situ campaigns focused on aerosol-cloud interactions were conducted at Mount Milešovka in the Czech Republic to gain more insight into aerosol activation and its dependence on meteorological parameters, mainly vertical air velocity and position within the cloud. The activated fraction was calculated from the difference of concentrations measured behind the whole air inlet and the PM2.5 inlet. The liquid water content (LWC) was calculated from visibility, cloud base position was estimated from ceilometer data. Vertical air velocity was estimated from cloud radar. No strong dependence was found between visibility and vertical velocity, suggesting that the clouds at the station are mostly of advection or inversion origin. Both visibility and LWC depend on the position within the cloud, with the highest LWC values found when the station was between 100 and 400 m above the cloud base, independently of the actual value.
Fulltext: PDF
|
|
|
INTRODUCTION TO PRAGUE AEROSOL CALIBRATION CENTER
Ondráček, Jakub ; Roztočil, Petr
In general, the PACC offers a range of services, from calibration and consulting to methodology and technical development. Furthermore, the PACC has the capacity to organize and perform training for microphysical (including optical in the near future) aerosol in-situ instrumentation. The equipment at the PACC is fully in-line with the state of-the-art aerosol instrumentation (starting from various aerosol generators for welldefined nanoparticles, reference instruments, and newly designed calibration lines) and the laboratory space is flexible for various types of instrument calibration/verification/intercomparison or testing of newly developed, cutting-edge equipment.
Plný tet: PDF
|
guest ::
