Advertent and inadvertent effects of anthropogenic aerosols on clouds and climate

Aerosol-cloud-climate interactions have been identified as key contributors to the current uncertainty in projections of future climate. This problem has been identified as one of the major puzzles driving scientific research today, and tackling it as a s ingle investigator is a daunting task. Such a monumental challenge calls for collaborative science along the lines of what will be initiated through the proposed research visit. The specific research questions that will be addressed during the visit are i) To what extent has human activity influenced ice clouds (cirrus) in the upper troposphere, and thereby perturbed Earth's energy budget? ii) Can cirrus clouds be intentionally modified in order to counteract some of the warming caused by increasing leve ls of greenhouse gases in the atmosphere? These research questions will be addressed by combining a global climate model (GCM) with sophisticated modules describing the atmospheric lifecycles of aerosols and cirrus cloud microphysics. Some of the modules that will be implemented in the GCM have been developed over decades by the Oslo aerosol-climate group, and the visit will therefore simplify the setup of a suitable modeling tool. The outcome of this research has potential for publications in high-impa ct journals, and results will also prove useful to the upcoming assessment report by the Intergovernmental for Climate Change (IPCC AR5). Beyond the specific research that will be carried out during the visit, the outcome of a successful research visit wi ll be a lasting collaboration between the aerosol-cloud-climate groups in Oslo and at Yale University. The hope is also that by being visible and active within the Oslo research group, Professor Storelvmo can become one of few female role models in this f ield for women at early stages in their career.