ALBERT

Description: This dataset contains the processed and raw data collected with the Backscatter Cloud Probe with Polarization Detection during the HALO-AC³ campaign in March and April 2022 with the Polar 6 Aircraft out of Longyearbyen, Svalbard. The dataset contains two kinds of data. Data to which no inversion procedure has been applied and data to which the inversion procedure has been applied. The inversion procedure is applied to account for an uneven intensity of the laser beam across the sample area and resulting undersizing effects. The inversion procedure has been discussed in Lucke et al. (2023) (doi.org/10.4271/2023-01-1485) and Beswick et al. (2014) (doi.org/10.5194/amt-7-1443-2014). All quantities which carry the suffix inv are based on the inverted data, all other properties are not. It should be noted, that the necessity of the inversion procedure remains unclear (see the previously mentioned publications). The inversion procedure could only be applied when more than 2000 particles were present over a 5 second interval. When this was not the case, the inverted data are 9999.999. The inverted data are therefore also computed from a 5s rolling average. The measurements of the BCPD are likely severely influenced by inertial separation effects, due to the proximity of the BCPD sample area to the fuselage (approx. 3cm). When ice particles are present, shattering occurs on the fuselage and artificially increases the ice number concentration. The number of ice and liquid particles listed in this data set can be useful for assessing the presence of ice and liquid particles. To estimate the number of liquid and ice particles more than 100 particles are required over a 5s interval. When this is not the case, the data are 9999.999. The number of ice and liquid particles were computed as rolling averages over 5s intervals. The sample area in case no inversion procedure is applied is 0.273 square millimeters.

Description: During the HALO-(AC)³ field campaign in spring 2022, the Basler BT-67 research aircraft Polar 6, based in Spitzbergen (78.24 N, 15.49 E), was equipped with an advanced in situ cloud payload by the DLR. This payload contained a combination of cloud instruments, including the Cloud Droplet Probe (CDP), the Cloud Imaging Probe (CIP), and the Precipitation Imaging Probe (PIP). The published data contain the particle size distributions measured by each particle measurement system. The respective instruments operate in different size ranges, and by combining their data, an additional data set is calculated that covers cloud particles in the size range from 2.8 µm to 6400 µm. Microphysical cloud properties such as cloud particle number concentration, liquid water content, ice water content, and effective diameter are derived from the given particle size distributions. The in situ cloud measurements focused on low and mid-level clouds in the Fram Strait, over the sea ice and the open ocean. The measurement campaign is embedded in the Transregional Collaborative Research Centre TR 172 (ArctiC Amplification: Climate Relevant Atmospheric and SurfaCe Processes, and Feedback Mechanisms (AC)³).

Description: Liquid water content and total water content from the Nevzorov probe, collected during the HALO-AC³ campaign out of Longyearbyen, Svalbard in April 2022. The dataset contains measurements from the three collector sensors of the Nevzorov probe. These are the cylindrical LWC sensor, the 8 mm TWC cone and the 12 mm TWC cone (for a description of the probe see doi:10.1175/1520-0426(1998)015〈1495:TNAHWL〉2.0.CO;2, doi:10.5194/egusphere-2022-647 ). Furthermore, corrected LWC and TWC values are contained in the dataset. These values are best estimates of LWC and TWC. They are computed by solving a system of equations and they consider collection efficiencies, the different latent heats of water and ice and the sensitivity of the LWC sensor to ice particles. For a description of the computation see Lucke et al. (2023) (doi:10.4271/2023-01-1485). However, for this data, the 12 mm cone was not included in the computation, as its data were deemed to be too unreliable in conditions where droplet diameters are low. NaNs are represented as 9999.999 in the dataset. The dataset only contains research flight 8 - 13. For the previous flights a problem with the probe existed and no data was recorded.