research interests
* prognostic simulation of fire occurrence and burned area (see recent work)
* land model (lm3) simulations of biomass burning emissions (see recent work)
* role of fires in the carbon cycle (see recent work)
* physical, chemical, and optical properties of atmospheric aerosols (see Magi, 2009)
* atmospheric model (am2p14, am3) physical representation of aerosol properties (see Magi et al., 2009)
* evaluation of model output compared to satellite, ground-based, and in situ measurements (see Magi et al., 2009; Donner et al., 2010)
recent work
a project i am working on is how to simulate global fire occurrence at a climate model spatial resolution. this is in collaboration with elena shevliakova, steve pacala, sergey malyshev, and jeremy lichtstein. our basic question is: can a fire simulation reproduce the nasa modis observations of global fire patterns seen in the figure below? the simple answer is yes. most of my recent research questions and hypotheses are evolving from that answer.
| Figure above shows the mean annual (2000-2009) number of fires that occur (units of fires/gridcell/year on the colorbar). Note that although nearly 75% of fires every year occur in the tropics, emissions of carbon per kg fuel burned are higher for trees than grasses. Boreal and mid-latitude fires are therefore important to understand. Also note that net sources of carbon to the atmosphere from fires are mainly from deforestation in the tropics, but that carbon emissions from boreal fires can easily be transported to the Arctic where impacts are more pronounced. [The figure was created by me, but is based on terra modis thermal anomaly data product, available from 2000-present. The data I used was the monthly temporal resolution, 0.5 x 0.5 degrees (about 50 km x 50 km) gridded product.] |
recent refereed publications
a full list available on my CV [PDF]Donner, L. J., B. L. Wyman, R. S. Hemler, L. W. Horowitz, Y. Ming, M. Zhao, J-C. Golaz, P. Ginoux, S-J. Lin, M. D. Schwarzkopf, ..., B. I. Magi, et al., The Dynamical Core, Physical Parameterizations, and Basic Simulation Characteristics of the Atmospheric Component of the GFDL Global Coupled Model CM3, submitted in July 2010 to J. Climate.
Magi, B.I. (2009), Chemical apportionment of southern African aerosol mass and optical depth, Atmos. Chem. Phys., 9, 7643-7655 [html, PDF]
Figure 5 from Magi (2009) shows the apportionment of
(a) scattering and (b) absorption at a wavelength of 550nm in tropical
southern Africa. Shown are the median percent contributions (and
interquartile range) of organic matter (OM), black carbon (BC), ammonium
nitrate (AN), and ammonium sulfate (AS).
| Figure based on discussions by Magi et al. (2009) showing mean monthly aerosol optical depth (AOD) at 550 nm from satellite data products (Terra MODIS, Aqua MODIS, and MISR) in black (gray is range of means), GFDL AM2 (red), and GFDL AM2 with higher biomass burning emissions (blue) for two regions in Southern Hemisphere Africa. AOD is on the y-axis, months are on the x-axis. The biomass burning season peaks around August-October, and you can see that is where the discrepancies (red vs. black) are most pronounced. With ~40% increase in biomass burning emissions, which is well within the range suggested by emissions uncertainty, the model-satellite discrepancies (blue vs. black) improve. |
Magi, B.I., Q. Fu, and J. Redemann (2007), A methodology to retrieve self-consistent aerosol optical properties using common aircraft measurements, J. Geophys. Res., 112, D24S12, doi:10.1029/2006JD008312. [PDF]
Magi, B.I., P.V. Hobbs, T.W. Kirchstetter, T. Novakov, D.A. Hegg, S. Gao, J. Redemann, and B. Schmid (2005), Aerosol Properties and Chemical Apportionment of Aerosol Optical Depth at Locations off the United States East Coast in July and August 2001, J. Atmos. Sci., 62(4), 919-933, doi:10.1175/JAS3263.1. [PDF]
Magi, B.I., P.V. Hobbs, B. Schmid, and J. Redemann (2003), Vertical profiles of light scattering, light absorption, and single scattering albedo during the dry, biomass burning season in southern Africa and comparisons of in situ and remote sensing measurements of aerosol optical depths, J. Geophys. Res., 108(D13), 8504, doi:10.1029/2002JD002361. [PDF]
Gao, S., D.A. Hegg, P.V. Hobbs, T.W. Kirchstetter, B.I. Magi, and M. Sadilek (2003), Water-soluble organic components in aerosols associated with savanna fires in southern Africa: Identification, evolution, and distribution, J. Geophys. Res., 108(D13), 8491, doi:10.1029/2002JD002324. [PDF]
