Tropical Cloud Observation

Group Leader: Lutz Hirsch

The overarching objective of the "Tropical Cloud Observation" group is to advance the understanding of tropical cloud regimes, foremost shallow cumulus convection such as that which characterizes the winter trade winds of the Atlantic. Therefore the group develops, maintains, and deploys instrumentation to explore of the role of water vapor, clouds and the aerosol in the climate system. Increasingly however the group is also interested in the interplay between shallow convective cloud regimes and regions of deeper convection. Broad questions or issues that motivate this interest range from a desire to better quantify how clouds set the planetary albedo and affect Earth’s climate sensitivity, how clouds influence larger-scale circulations and their possible changes with warming, and how clouds mediate aerosol forcing of the climate system.

The group has a strong infrastructural component, supported by four permanent positions, that is related to the ongoing development and maintenance of the Barbados Cloud Observatory, the configuration and use of the airborne research platform HALO, and to a lesser extent support for shipboard research aligned with the groups’ broader goals.

Over the coming two years the main focus of the group will be to prepare for the EUREC4A field campaign. Here effort will mostly be focused on HALO, but an expansion of the measurements at the BCO and support for a ship-based component to EUREC4A, not to mention overall coordination among institutes is also something the group is responsible for.

Scientifically the groups’ focus is centered around a number of more specific questions or topics that are each addressed by a member of the group:

  • How well can we measure cumulus mass fluxes out of the boundary layer, and the extent to which this varies with large-scale conditions? (Markus Klingebiel)
  • Understanding and constraining the shallow cumulus cloud feedback (Hauke Schulz)
  • How does the large scale environment influence the cloudiness in the tropical region? (Geet George)

 

In addition the group has an important obligation to characterize the measurements, not unlike is done for model releases. Here papers describing the performance of the BCO and HALO radars (Lutz Hirsch), and the Raman lidar system of the BCO (Ilya Serikov) are also priorities for the coming two years.