News
Annual Advisory Committee Review (July 16-17, 2009)
PNNL's Aerosol Climate Initiative scientists welcome the annual Advisory Committee for the annual review on July 16-17, 2009. Review committee members represent universities, government and scientific organizations, and synergistic organizations within PNNL with an expertise in aerosol and climate science and related fields. Committee members will review progress in the three focus areas, planned work, and potential opportunities for transitioning from internal investments to programmatic funding.
Dr. John Shilling, who joined PNNL September 9, 2008, is a scientist in the Atmospheric Chemistry and Meteorology group specializing in aerosol research. He was a post-doctoral associate at Harvard University before joining PNNL. For the Aerosol Climate Initiative, he will be leading a task to build a new dual-sided, temperature-controlled continuous-flow environmental chamber to study secondary organic aerosol formation, evolution, and its ability to act as IN and CCN. Data derived from experiments using the chamber will be used for model validation and directly incorporated into climate models developed by PNNL.
Philip Rasch joins the team (November 2008)
Dr. Philip Rasch joined PNNL last month as the Laboratory's first-ever Chief Scientist for Climate Science. Dr. Rasch comes to us from the prestigious National Center for Atmospheric Research in Boulder, Colorado, where he also served as Chief Scientist for Climate Science. Dr. Rasch brings leadership to PNNL's climate science research portfolio and strategy, with a focus on working with PNNL leaders to establish, implement, and advise on PNNL's role in advancing climate science research and work toward enabling the Nation to predict climate change and its impacts. For PNNL's Aerosol Climate Initiative, he will connect lab and field work to modeling to improve understanding of climate change. More . . .
Scientists Seek and Destroy Algorithm Errors
Drs. Mikhail Ovtchinnikov and Richard Easter have identified and reduced previously unrecognized errors in atmospheric computer models, enabling detailed cloud-model simulations that are much more accurate. The team found the errors in complex mathematical formulas known as advection algorithms, which are important parts of all atmospheric models that analyze aerosol and cloud interactions. Until now, the magnitude of this problem had not been realized and documented. More . . .
Steve Ghan: Initiative Leader of the ACI
(November 2008). Dr. Steven Ghan
took on a new role as Leader of the ACI in the fall of 2008. He's responsible for setting the science vision, guiding the selection of new projects, making sure the research is integrated to achieve the initiative's objectives, and leading the transition to programmatic funding. Steve is highly recognized for his expertise in developing, evaluating, and applying parameterizations for climate models, including aerosol interactions with clouds. He holds a Ph.D. in Meteorology from the Massachusetts Institute of Technology.
Hanna Herich Visits PNNL for Measurements and Instrumentation Focus Area
(December 2007)
Hanna Herich, a Ph.D. student at the ETH Zurich (Swiss Federal Institute of Technology), visited PNNL on December 2-8. The purpose of the visit was to work with Dr. Dan Cziczo on a collaborative paper using a novel combination of a Humidified Tandem Differential Mobility Analyzer (HTDMA) and a single particle mass spectrometer to analyze the chemical composition and growth of aerosols. The paper will describe the technique and measurements made at an urban site (Zurich, Switzerland) and a remote location (the Jungfraujoch High Alpine Research Station). Hanna gave a seminar on this work, entitled "Aerosol Chemical Composition as a Function of the Hygroscopic Growth: Results from Urban, Remote and Polar Field Sites" on December 6th.
During her visit, Hanna toured labs in the Environmental Molecular Sciences Laboratory used by Drs. Alexander Laskin and Alla Zelenyuk, who are world leaders in the field of coupled hygroscopic growth and mass spectrometry and electron microscopy, respectively. Their input will be incorporated into the manuscript she is working on, which will include scientists at both the ETH and PNNL. Based on this productive visit to PNNL, Hanna will return for collaborative experiments and data reduction during the summer of 2008 to continue progress on the Measurements and Instrumentation Focus Area.
Dan Cziczo joins the team (October 2007)
Dr. Dan Cziczo joins PNNL this month to lead the Measurement and Instrument Focus Area, as well as to work on the project, "Understanding Ice Formation in the Atmosphere." Dan comes to us from the Institute for Atmospheric and Climate Science, in Zurich, Switzerland, where he was an instructor in cloud microphysics. Prior to that, he was an adjunct professor at the University of Colorado, and a teaching assistant at the University of Chicago, where he received his PhD. Dan has extensive research experience from projects for both NOAA and NASA.
Alexander Khain Visits PNNL for Cloud Resolving Model Project (August 2007)
Dr. Alexander Khain, from Hebrew University in Jerusalem, Israel, visited PNNL on August 10-22, to discuss various components of the Cloud Resolving Model Project. During his visit, Khain met with Drs. Mikhail Ovtchinnikov, Jiwen Fan, and Jennifer Comstock to assist in the incorporation of his Spectral Bin Model into the cloud resolving model called System for Atmospheric Modeling (SAM). The Spectral Bin Model includes size resolved cloud condensation nuclei (aerosol), water drops, ice crystals, snow, and graupel. Incorporating this information into SAM will help scientists study aerosol indirect effects.
The team also discussed potential model upgrades (such as new collision and melting schemes), and potential case studies for testing the upgraded model. They are currently focusing their simulations on deep convection and Arctic stratocumulus. They also discussed the use of an instrument simulator. To this end, Khain provided the team with computer algorithms for computing microwave scattering properties, which are useful in simulating microwave radiances such as measured by a microwave radiometer.
Khain also gave a seminar titled "Effects of aerosols on precipitation as follows from simulations with spectral (bin) microphysics models" on August 15. Khain's primary research interests are aerosol effects on precipitation, hail formation, collision processes, and the utility of polarization radar in model evaluation. Because these interests overlap the goals of the Cloud Resolving Model Project, the group plans to collaborate with Dr. Khain on some of these topics.
Fast and Gustafson Introduce Aerosol Model Testbed at 8th Weather Research and Forecast Model Workshop (June 2007)
As part of the Initiative's outreach and collaborative activities, Drs. Jerome Fast and William Gustafson attended the 8th WRF Workshop that included participating in the Atmospheric Chemistry Working Group meeting, giving presentations on applying PNNL's version of WRF-chem and presentations as part of the WRF-chem mini-tutorial, and discussing the concept of the AMT with managers of WRF's Development Testbed Center (DTC). One of the presentations was a description of the AMT and positive feedback was received from representatives of the WRF Program Planning Board, NOAA, and the DTC. Follow-up conversations with these interested parties are planned for later this summer.
Jiwen Fan Hired to Support Cloud Resolving Model (June 2007)
In June, Dr. Jiwen Fan joined PNNL to work on the Cloud Resolving Model project with Drs. Mikhail Ovtchinnikov and Jennifer Comstock. Jiwen recently received her Ph.D. in Atmospheric Science from Texas A&M. Mikhail will provide scientific guidance to Jiwen as she works on coupling a new cloud microphysics scheme to the cloud-resolving model to create a tool for studying indirect aerosol effects.
Four Projects launched following selection by LDRD review committee (February 2007)
Following an LDRD review of six project proposals, four were approved for funding and the projects were initiated. Information on these projects is available from the R&D Focus Areas webpage for this initiative.