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Planetary boundary layer height estimation
Růžičková, Barbora ; Zíková, Naděžda (advisor) ; Holubová Šmejkalová, Adéla (referee)
The planetary boundary layer height (PBLH) is a key parameter for investigating interactions between the Earth's surface and the atmosphere, especially for air quality assessment and pollutants' dispersion. The PBLH is highly variable in time and space as is influenced by a number of factors originating both in the atmosphere and at the Earth's surface. In this bachelor thesis, the PBLH and mixing layer height (MLH) measured at the National Atmospheric Observatory Košetice over the three-year period 2020-2022 using the Vaisala CL61 ceilometer were evaluated. For both observed variables, a significant difference was found between the values measured in summer and winter: 1710 ± 760 m and 1010 ± 650 m for PBLH, 920 ± 700 m and 420 ± 330 m for MLH. Significant diurnal variability was also observed, with maxima at 15:00 UTC and minima at 03:00 UTC for PBLH and maxima at 14:00 UTC and minima at 22:00 UTC for MLH. The relationship between planetary boundary layer height and the occurrence of cyclonic and anticyclonic synoptic situations was also investigated, but was not conclusive due to the complexity of the weather patterns of each synoptic situation. Keywords: atmospheric boundary layer, mixing layer, ceilometer, ground-based remote sensing, atmospheric vertical profile
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Use of the ceilometer data to explainig changes in pollutants concetration gradient in the air during the day
Komínková, Kateřina ; Holoubek, Ivan
For the interpretation of air pollutants concentrations, the one of the key parameter is the atmospheric boundary layer (ABL) evolution during a day and night. The ABL is a broad concept that includes different states of airflow dynamics in the part of troposphere closest to the Earth's surface (0-2 km above the surface), which has an effect in this area. A lot of air flow changes occur in the ABL during the day. For the measurement of substances concentrations in the air the development of mixing layer (ML) in the light part of the day is very important. A lot of ground remote sensing methods was developed for determination of ABL height during the day, one of them which can be very simply operated is to use data from ceilometer. However, the obtained outputs cannot be directly interpreted. In addition, in the case of the terrain measurements a lot of cases when ABL height values cannot be determined because the ceilometer measurement is disturbed can occur.\n\n
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