The Cirrus Guide II In-situ Aircraft Data Set

The Cirrus Guide II in-situ data set (see Krämer et al., 2016, 2020) contains cloud and trace gas observations in the UTLS (Upper Troposphere / Lower Stratosphere) from research aircraft on a flight by flight basis. The major parameters contained in the data set are: Total water content (TWC = ice for temperatures T < -38C, liquid or ice or a mixture between -38C - 0C, liquid for T > 0C), cloud particle number concentration N_cloud (physical state as for TWC), mean mass radius R_cloud, in-cloud as well as the clear sky relative humidity with respect to ice (RH_ice) and clear sky water vapor volume mixing ratios of H2O and O_3. Further, meteorological variables are included in the data set: Time, Temperature, potential Temperature, Pressure, Altitude, Latitude, Longitude, Latitude, vertical velocity. The complete in situ data set comprises 24 field campaigns described by Krämer et al. (2016) and Krämer et al. (2020). Note that there is a corrected data base available here; please find the description in the corresponding tar-file (M. Krämer, 2025). Krämer, M., Rolf, C., Spelten, N., Afchine, A., Fahey, D., Jensen, E., Khaykin, S., Kuhn, T., Lawson, P., Lykov, A., Pan, L. L., Riese, M., Rollins, A., Stroh, F., Thornberry, T., Wolf, V., Woods, S., Spichtinger, P., Quaas, J., and Sourdeval, O.: A Microphysics Guide to Cirrus – Part II: Climatologies of Clouds and Humidity from Observations, Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-40, in press, 2020. Krämer, M., Rolf, C., Luebke, A., Afchine, A., Spelten, N., Costa, A., Meyer, J., Zöger, M., Smith, J., Herman, R. L., Buchholz, B., Ebert, V., Baumgardner, D., Borrmann, S., Klingebiel, M., and Avallone, L.: A Microphysics Guide to Cirrus Clouds – Part 1: Cirrus types, Atmos. Chem. Phys., 16, 3463–3483, 2016.