Cirrus Cloud Properties as Seen by the CALIPSO Satellite and ECHAM-HAM Global Climate Model

• DOI: 10.1175/jcli-d-16-0608.1
• Publication Date: 2017-11-30T20:00:37Z
• Authors: B. Gasparini; A. Meyer; D. Neubauer; S. Münch; U. Lohmann
• Keywords: Cirrus; Ice nucleus; Liquid water content

Cirrus clouds impact the planetary energy balance and upper-tropospheric water vapor transport are therefore relevant for climate. In this study cirrus at temperatures colder than −40°C simulated by ECHAM–Hamburg Aerosol Module (ECHAM-HAM) general circulation model compared to Cloud–Aerosol Lidar Infrared Pathfinder Satellite Observations ( CALIPSO) satellite data. The captures cloud cover pattern reproduces observed median ice content within a factor of 2, while extinction is overestimated about 3 as revealed temperature-dependent frequency histograms. Two distinct types found: in situ–formed dominating −55°C liquid-origin warmer −55°C. latter form anvils deep convective or glaciation mixed-phase clouds, leading high crystal number concentrations. They associated with coefficients up 1 km −1 0.1 g m −3 , respectively, smaller content. nucleated either heterogeneously homogeneously. homogeneous crystals similar cirrus, which On contrary, appear However, aggregation depositional growth smooth differences between several formation mechanisms, making attribution specific nucleation mechanism challenging.