Cloud aerosol interactions in liquid boundary-
The most fundamental and complex problems in climate and weather research today are our poor understandings of the basic properties of clouds and our inability to determine quantitatively the many effects cloud processes have on weather and climate. Current climate models indicate that Earth's average surface temperature will warm from 1.5 to 4.5°C by 2100 due to increases in greenhouse gases, with the large uncertainty attributed to different treatments of clouds in climate models. Winter weather significantly impacts the transportation and power industries, schools and businesses, and severe thunderstorms can cause significant damage and flooding. Improved quantitative precipitation forecasts require a greater understanding of how cloud processes and the related energy release affect the structure and dynamics of storms. Research within Prof. McFarquhar’s group addresses the overarching theme of clouds and their relation to climate and weather using a combination of field observations, satellite retrievals and numerical modeling studies. Prof. McFarquhar's work at Illinois aims at making fundamental advances in our understanding of cloud properties and processes, and improving our ability to represent clouds in weather and climate models.
Current projects are advancing our understanding of 1) the microphysical structure of snow bands in winter cyclones; 2) the properties of tropical clouds generated by deep convection; 3) the operating characteristics of probes measuring cloud properties; 4) the transmission of radiation through the cloudy atmosphere; 5) the representation of clouds in climate and weather models; 6) the dependence of arctic cloud properties on aerosol properties; 7) the impact of cloud and aerosol processes on hurricane evolution; and 8) the dependence of fair weather cumuli properties on land-surface and aerosol characteristics. Funding is received from the National Science Foundation (NSF), the Department of Energy (DOE), and the National Aeronautics and Space Administration (NASA) for this research. In the past few years, Prof. McFarquhar’s group have participated in field projects in Darwin Australia (tropical cirrus), Barrow Alaska (arctic mixed-phase clouds), Ponca City Oklahoma (fair weather cumuli and cirrus), Peoria Illinois (winter storms), Boulder Colorado (performance of cloud probes), and have plans to conduct future experiments in Salina Kansas (mesoscale convective systems), Cayenne French Guiana (clouds with high ice contents), Namibia Africa (aerosol-cloud interactions) and the Olympic Mountains (orographic precipitation). Data collected during these projects are being linked with numerical models having a variety of temporal and spatial scales, including cloud resolving, mesoscale and general circulation models.