Greg McFarquhar                                                               University of Illinois


Graduate Student Henian Zhang leads a weather briefing for the NAMMA Science Team at the Operations Center in the Cape Verde Islands. The NAMMA Science and Operations team poses for a picture in front of the NASA DC-8 in the Cape Verde Islands. A photo taken by Henian Zhang from the DC-8 as it transits over the west coast of Africa during NAMMA.
NAMMA: The NASA African Monsoon Multidisciplinary Analysis campaign was based out of the Cape Verde Islands during August and September of 2006. The goal of the campaign was to study the influence of the Saharan Aerosol Layer (SAL) on the genesis and evolution of tropical cyclones. During NAMMA, the NASA DC-8 sampled a tropical depression, a tropical storm, two African easterly waves that developed into tropical depressions and three African easterly waves that did not.
Uof Illinois Role and Interests: Graduate student Henian Zhang spent the entire NAMMA time period in the Cape Verde Islands working as part of the forecast team. Her role in NAMMA motivated her Ph.D. study, where she examined the role of dust in the SAL acting as cloud condensation nuclei (CCN) on the evolution of tropical cyclones using idealized simulations conducted with the CSU RAMS model. Graduate student Amanda Dooley used data obtained from the in-situ probes during NAMMA to investigate whether ice crystal size distributions vary depending upon the conditions under which they are measured (e.g., depending upon temperature, vertical velocity and whether they were obtained in tropical storms, depressions, or developing vs. non-developing waves). Graduate student Richard Maliawco will continue similar investigations starting in the fall of 2009.

Publications arising from NAMMA:

Wisdom, A., and G.M. McFarquhar, 2008: Ice microphysics observations in tropical cyclones from CAMEX-4 and NAMMA. 28th Conf. Hurricanes Tropical Meteor., American Meteorological Society, May, Orlando, FL. Available from http://ams.

 Zhang, H., G. McFarquhar, S. Saleeby and W.R. Cotton, 2007: Impacts of Saharan Dust as CCN on the evolution of an idealized tropical cyclone. Geophys. Res. Lett., 34, L14812, doi:10.1029/2007GL029876.

Zhang, H., G. M. McFarquhar, W.R. Cotton and Y. Deng, 2009: Direct and indirect impacts of Saharan dust acting as cloud condensation nuclei on tropical cyclone eyewall development. Geophys. Res. Lett., 36, L05802, doi:10.1029/2009GL037276.

Thesis arising from NAMMA:

Dooley, Amanda L., “Ice microphysics observations in tropical cyclones from NAMMA”, M.S. thesis, 2008

Zhang, Henian, “Impacts of Saharan dust as CCN on the evolution of an idealized tropical cyclone”, Ph.D. thesis, 2008.