University of Colorado at Boulder University of Colorado CU Home Search A to Z Index Map
Laboratory for Atmospheric and Space Physics


Experimental Investigations of Tropospheric and Stratospheric Phenomena

(2022) For many years I have been involved in using NASA aircraft to address various issues in stratospheric and tropospheric science. In the past these studies have dealt with volcanic clouds, stratospheric ozone loss, stratospheric transport processes, searching for evidence of heterogeneous chemistry in the troposphere, as well as investigating the formation and radiative properties of cirrus clouds and the sensitivity of cirrus clouds to emissions from aircraft. I was the Co-project scientist for CRYSTAL/FACE in 2002. This project was aimed at understanding the role of deep convection in forming high altitude cirrus, and their role in influencing the energy budget of Earth. Six research aircraft made numerous flights from Key West, Fla. I was the Co-Mission Scientist for NASA’s Tropical Composition, Clouds and Climate Coupling Experiment which took place in Costa Rica in July and Aug. 2007 to help validate Aura and the A-Train satellites, and to learn more about tropical clouds and stratosphere-troposphere exchange. I was Co-Project Scientist for the ATTREX field missions using the NASA Global Hawk to investigate water vapor in the upper troposphere and how it enters the stratosphere. I was the Campaign Leader for SEAC4RS, a mission to investigate how air pollution over Southeast U.S. may be lofted by deep convective clouds and then enter the stratosphere. This mission used the NASA DC-8, ER-2 and a SPEC Inc. Learjet for 2 months in 2013. Currently we are working with NCAR/NASA on a GV &WB57 mission to investigate outflow from the Asian Monsoon.  Flights are planned from South Korea in 2022 summer.

Planetary Atmospheres and Exobiology

(2022) The focus of this work is to understand the clouds and climates of the terrestrial planets. Presently Eric Wolf is the PI on an effort to understand the origins of river valleys on Mars and whether clouds might have provided the greenhouse warming.  Brian and Eric are also working on a project with the University of Chicago to understand the role of clouds on exoplanets.  Brian and former graduate student Victoria Hartwick are working on the feasibility of using wind energy for Martian spacecraft.

Aerosols and Clouds Above the Tropopause

(2022) This work has two facets – investigations of stratospheric aerosols and studies of polar stratospheric and mesospheric clouds. We have constructed a numerical model of stratospheric volcanic aerosols over the past two decades. The model was initially one-dimensional, approximating Earth as a vertical column of air. As computational tools have improved we expanded, and now have developed a fully three-dimensional global model by combining our microphysical model with the NCAR WACCM/CAM dynamical models so that detailed predictions can be made. These calculations aid in the analysis of remote sensing information, as well as being useful to studies of stratospheric ozone loss and to studies of climate change. Research Associate Yunqian Zhu, who graduated in 2015, built a model for polar stratospheric clouds, to improve our ability to simulate stratospheric ozone. Charles Bardeen now at NCAR coupled our aerosol code, CARMA, with the NCAR Community Earth System Model and has used the code to simulate noctilucent clouds, micrometeorites, and cirrus clouds. Peter Colarco, now at Goddard has linked CARMA to the GEOS-5 model and uses it for volcanic clouds. Presently, Parker Case is working with the Goddard version of the model, and Margot Clyne is collaborating with Yunqian Zhu on the NCAR version of the code to study volcanic clouds. We have a large study, supported by  the Open Philanthropy Project, to investigate the influence of smoke generated by fires in nuclear conflict on the environment and humans.  Four CU faculty are involved in this project along with researchers as NCAR, Rutgers, Columbia and other locations.

Tropospheric Clouds, Aerosols, and Radiative Transfer

(2018) Numerical simulations of the interactions between tropospheric aerosols and clouds are being conducted. One goal is to determine if the indirect effects of aerosols on clouds is a significant feature of Earth’s climate system. Another goal is to simulate the life cycle of tropospheric aerosols and clouds in detail. The eventual goal is to be able to model tropospheric aerosols, marine boundary layer clouds and cirrus clouds including three-dimensional dynamics, atmospheric chemistry, and detailed microphysics. Pengfei Yu, who graduated in 2015, constructed a complete model for aerosols in the troposphere and stratosphere. He has applied the model to understand the origins of the Asian Tropopause Aerosol Layer, smoke in the RIM fire, and organic aerosols. His model is currently being put on the trunk of the NSF/DOE CESM model to serve as an alternative to the modal aerosol there.  Yunqian Zhu and graduate student Lu Wang are working to improve the aerosol/cloud interaction in the NCAR CESM model by adding a CARMA based liquid cloud model.  Charles Bardeen has already added an ice cloud model to CESM.