The Impact of Cumulus Parameterization Schemes on the Convective Transport of Biomass Burning Emissions Using WRF-Chem

• Other Authors: Taylor, Zackary Bryan (authoraut), Fuelberg, Henry (professor directing thesis), Liu, Guosheng (committee member), Misra, Vasubandhu (committee member), Department of Earth, Ocean and Atmospheric Sciences (degree granting department), Florida State University (degree granting institution)
• Format: Text
• Language: English
• Published: Florida State University
• Subjects: Oceanography; Atmospheric sciences; Meteorology; Arctic; Human health
• Online Access: http://purl.flvc.org/fsu/fd/FSU_migr_etd-1643; http://fsu.digital.flvc.org/islandora/object/fsu%3A176145/datastream/TN/view/Impact%20of%20Cumulus%20Parameterization%20Schemes%20on%20the%20Convective%20Transport%20of%20Biomass%20Burning%20Emissions%20Using%20WRF-Chem.jpg

Anthropogenic and biomass burning emissions impact atmospheric chemistry and many other natural processes that affect air quality and human health. Biomass burning emissions released in the boundary layer can be quickly lofted to the free troposphere by deep convection. Accurately simulating this process in chemical transport models (CTMs) will improve our understanding of the link between local pollution sources and global scale transport. This study investigated the convective transport of biomass burning emissions during the summer phase of NASA's Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) campaign using the Weather Research and Forecasting (WRF) model with chemistry (WRF-Chem). Three cumulus parameterization schemes were tested to identify which performs best: Kain-Fritsch (KF), Betts-Miller-Janjic (BMJ), and Grell-Devenyi (GD). To test the cumulus parameterizations, simulated meteorological parameters were quantitatively compared against point observations, and daily precipitation fields were compared against the Global Precipitation Climatology Project (GPCP) dataset using the Method for Object-Based Diagnostic Evaluation (MODE), an object-based verification tool. CO vertical mass fluxes were evaluated at various altitudes and times during the simulation period. Daily averaged total column CO and mixing ratios at three altitudes were quantitatively compared against daily averaged values from the Atmospheric InfraRed Sounder (AIRS) using MODE. Results show that the choice of cumulus parameterization is critical when simulating the convective transport of biomass burning emissions using WRF-Chem. Although spatial differences are not great at most individual times, they accumulate over time leading to large magnitude differences in precipitation, upward CO mass flux, and long-range CO plume transport. The KF cumulus parameterization scheme vertically transports more CO than the BMJ and GD schemes, and outperforms the other schemes when compared to GPCP and AIRS dataset. In situations similar to this study, not using KF cumulus parameterization may underestimate the convective transport of CO and subsequently its long-range transport. The current results demonstrate that the choice of a cumulus parameterization scheme in a CTM can affect many aspects of its output. A Thesis Submitted to the Department of Earth, Ocean, and Atmospheric Science in Partial Fulfillment of the Requirements for the Degree of Master of Science. Spring Semester, 2011. March 10, 2011. Numerical weather prediction, Cumulus parameterization, Pollution transport, Forecast verification Includes bibliographical references. Henry Fuelberg, Professor Directing Thesis; Guosheng Liu, Committee Member; Vasubandhu Misra, Committee Member.