The Cirrus Guide III Data Set

The Cirrus Guide III data set contains
(i) The Cirrus Guide III in-situ data set (Krämer et al., 2020, Krämer et al., 2025):
Cloud and humidity observations in the troposhere, in particular in cirrus clouds, from research aircraft on a flight by flight basis.
The major parameters contained in the data set are: Cloud particle size distributions (PSDs), synchronized
to a logarithmically equidistant size grid, 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.

A description of the instruments, measurement methods and their uncertainties can be found in Krämer et al. (2016) and Krämer et al. (2020).

(ii) The Cirrus Guide data set with simulations of ice particle size distributions (Krämer et al., 2016, Krämer et al., 2025):
Simulations of the development of ice particle size distributions are performed for various conditions
(temperature, updraft, freezimg mechanism, freezing threshold, INP number) using the model MAID.

A description of the model is given in Krämer et al. (2016), Krämer et al. (2025).

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, https://doi.org/10.5194/acp-16-3463-2016, 2016.

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.