Department of Atmospheric Physics

The dataset was created to enable analyses of the wintertime air-quality conditions in urban agglomerations in Poland. For this, lidar technique was employed. The dataset comprises the height-resolved optical properties of atmosphere, including information on molecules, aerosol and cloud particles. Lidar measurements were conducted during winter season 2021-2022 in 3 locations: Zabrze (50.3148 N, 18.7712 E), Krakow (50.0671 N, 19.9133 E) and Wroclaw (51.1054 N, 17.0893 E), and during winter season 2023 in Warsaw (52.2109 N, 20.9826 E).

Observations

The lidar measurements in Zabrze (Institute of Environmental Engineering -Polish Academy of Sciences), Krakow (AGH University of Science and Technology) and Wroclaw (University of Wroclaw) were conducted during the POLIMOS-SMOG Campaigns within the framework of “Technical Assistance for Polish Radar and Lidar Mobile Observation System” activities supported by the European Space Research and Technology Centre of the European Space Agency (ESA-ESTEC) using the ESA Mobile Mie-Raman Lidar (EMORAL) developed in POLIMOS.

EMORAL lidar emits simultaneously, coaxially and vertically into the atmosphere the laser pulses at 355, 532, and 1064 nm with 10 Hz pulse repetition rate. The laser pulses scattered by atmospheric constituents in backward directions are detected with 300 mm Cassegrain telescope (field of view: 2-3.6 mrad) with 3.75 m spatial and 60 s temporal resolutions. The detection is done at 8 channels: 3 elastic (355, 532, 1064 nm), 2 depolarization (355, 532 nm), 2 N₂ Raman (387, 607 nm) and H₂O Raman (408 nm) and broad-band fluorescence channel (470 nm). For all channels, analogue and photon-counting detection is performed, except 1064 nm with analog only. The overlap between the laser beam and the full field of view of the telescope is ~250-350 m a.g.l. (see detailed description in Stachlewska et al., 2024).

The lidar measurements in Warsaw (University of Warsaw) were collected at the ACTRIS National Facility in Warsaw accordingly to the observation schedule recommended by the European Lidar Network (EARLINET) using the UW stationary Mie-Raman lidar (PollyXT-UW).

PollyXT-UW lidar emits simultaneously, coaxially and vertically into the atmosphere the laser pulses at 1064, 532, and 355 nm with 20 Hz pulse repetition rate. But backward scattered laser light is collected by 300 mm (far-field) and 50 mm (near-field) Newtonian reflectors with spatial and temporal resolution of 7.5 m and 5 s, respectively. Signals are recorded at 12 channels: 3 elastic FF (355, 532, 1064 nm), 2 elastic NF (355, 532 nm), 2 depolarization (355, 532 nm) and 3 Raman channels FF (387, 607, 408nm) and 2 in NF (387, 607 nm). For all channels, solely photon-counting detection is performed. The full overlap is at NF 120 m a.g.l. and FF 400 ma.g.l. (Engelmann et al., 2016).

Data evaluation

The data evaluation was done using the Lidar, Radar, Microwave radiometer algorithm (LiRaMi; more in Wang et al., 2020) developed at University of Warsaw, whereby Limited LiRaMi, i.e. LiLi algorithm version that uses solely lidar data was applied.

This dataset contain files of optical properties derived as 15 minutes profiles.

The data products are calculated from the analog channels for EMORAL and photon-counting in PollyXT-UW.

Data structure and variables

The dataset contains files in netcdf4 format for each day of observations at four aforementioned locations.

Each of the .nc file has a structure, which contains Variables:

• Location (string)
• Latitude (size: 1x1 [deg])
• Longitude (size: 1x1 [deg])
• time vector (size: 1 x time, [UTC])
• range vector (size: range x 1, [m])
• RCS532p matrix (size: range x time, [V m2]), which contains the data of the range-corrected signal at 532nm, parallel polarization (only in EMORAL case)
• RCS532s matrix (size: range x time, [V m2]), which contains the data of the range-corrected signal at 532nm, perpendicular polarization (only in EMORAL case)
• RCS1064 matrix (size: range x time, [V m2]), which contains the data of the range-corrected signal at 1064nm (only in EMORAL case)
• SR532 matrix (size: range x time, [unitless]), which contains the data of the scattering ratio at 532nm
• ATT_BETA532 matrix (size: range x time, [m2/sr]), which contains the data of the attenuated backscatter coefficient at 532nm, parallel polarization
• C532 constant (size: 1x1, [V sr]), which is the instrumental constant for 532nm (only in EMORAL case)
• SR1064 matrix (size: range x time, [au]), which contains the data of the scattering ratio at 1064nm
• ATT_BETA1064 matrix (size: range x time, [m2/sr]), which contains the data of the attenuated backscatter coefficient at 1064nm
• C1064 constant (size: 1x1, [V sr]), which is the instrumental constant for 1064nm (only in EMORAL case)
• COLOR_RATIO matrix (size: range x time, [au]), which contains the data of color ratio of 532nm and 1064nm.
• PARTICLE_DEPOLARIZATIO_RATIO matrix (size: range x time, [au]), which contains the data of particle depolarization ratio at 532nm
• C constant (size: 1x1, [au]), which is the depolarization constant for 532nm (only in EMORAL case).

References

Stachlewska, I. S., Georgoussis, G., Freudenthaler, V., Hafiz, A., Poczta, P., Louridas, A., Wang, D., Janicka, Ł., Siomos, N., Karasewicz, M., Fortuna, R., Kokkalis, P., Amiridis, V., Byčenkien˙e, S., Drzeniecka-Osiadacz, A., Belegante, L., Nicolae, D., Tzeremes, G., Ribes Pleguezuelo, P., & Schüttemeyer, D. (2024). EMORAL—Mobile Mie-Raman Lidar with Fluorescence, Polarization and Water Vapor Observational Capabilities for Satellite Cal/Val Field Campaigns. In: Singh, U.N., Tzeremes, G., Refaat, T.F., Ribes Pleguezuelo, P. (eds), Space-based Lidar Remote Sensing Techniques and Emerging Technologies. LIDAR 2023. Springer Aerospace Technology. Springer, Cham. https://doi.org/10.1007/978-3-031-53618-2_21

D’Amico, G., Amodeo, A., Baars, H., Binietoglou, I., Freudenthaler, V., Mattis, I., Wandinger, U., & Pappalardo, G. (2015). EARLINET single calculus chain - overview on methodology and strategy. Atmospheric Measurement Techniques, 8, 4891–4916. https://doi.org/10.5194/amt-8-4891-2015

Engelmann, R., Kanitz, T., Baars, H., Althausen, D., Skupin, A., Wandinger, U., Komppula, M., Stachlewska, I. S., Amiridis, V., Marinou, E., Mattis, I., Linne, H., & Ansmann, A. (2016). The automated multiwavelength Raman polarization and water-vapor lidar PollyXT: the neXT generation. Atmospheric Measurement Techniques, 9, 1767–1784. https://doi.org/10.5194/amt-9-1767-2016

Wang, D., Stachlewska, I.S., Delanoë., J., Ene, D., Song, X., Schüttemeyer, D. 2020, Spatio-temporal discrimination of molecular, aerosol and cloud scattering and polarization using a combination of a Raman lidar, Doppler cloud radar and microwave radiometer. Optics Express, 28, 20117–20134.

ATTENTION:

We offer free access to this dataset. The user is however, encouraged to share the information on the data use with the Remote Sensing Laboratory by sending an e-mail to rslab@fuw.edu.pl.

In the case this dataset is used for a scientific communication (publication, conference contribution, thesis), we would like to kindly ask for considering to acknowledge data provision by adding the following statement in Acknowledgments: "We acknowledge the data originators M. Karasewicz, A. Tomczak, E.A. Ugboma, Ł. Janicka, P. Poczta, A. Hafiz, Z. Rykowska, P. Mishra, R. Fortuna, D.M. Szczepanik and I.S. Stachlewska for quality-assurance, evaluation, and provision of data sets of the Remote Sensing Laboratory at the Faculty of Physics of the University of Warsaw, Poland."