AOS Graduate Student Profile
Cynthia A. Randles
Ph. D. Candidate, Princeton University
Address: 201 Forrestal Rd Rm 308
Phone: (609) 452-6500 ext 6984
Email: crandles@ NOSPAM princeton.edu
Ph. D. Candidate, Princeton University
Address: 201 Forrestal Rd Rm 308
Phone: (609) 452-6500 ext 6984
Email: crandles@ NOSPAM princeton.edu
Publications Vita
Research Field
My thesis work has focused on the direct effect of carbonaceous aerosol on climate using a variety of numerical models. For my first study, I used a thermodynamic equilibrium model to predict the hygroscopic growth of aerosol consisting of a mixture of water-soluble organic carbon (WSOC) and sea salt. In my thesis I show that the reduction in hygroscopic growth associated with internally mixing WSOC with sea salt causes significantly less cooling than pure sea salt. Because WSOC have similar effects on sulfate aerosol hygroscopic growth and light extinction, this implies that global climate models (GCMs) that employ external mixtures of these aerosol types may be overestimating the cooling associated with sulfate and sea salt aerosol. In addition, using the GFDL GCM to study the impact of increases in black carbon (BC) aerosol over Asia, I have investigated the sensitivity of the GCM to aerosol extinction optical depth (AOD), an optical measure of the amount of aerosol as relevant for light extinction, and aerosol single scattering albedo (SSA), a measure of aerosol absorption. Using various satellite and in situ observations of AOD and SSA to constrain the model, I have found that at high extinction optical depths strong absorption contributes to an enhancement of the monsoonal circulation and increased precipitation while purely scattering aerosol opposes the monsoonal circulation and decreases precipitation in this region.
Some Recent Publications:
Articles in peer-reviewed publications
Randles, C. A., L. M. Russell, and V. Ramaswamy (2004), Hygroscopic and optical properties of organic sea salt aerosol and consequences for climate forcing, Geophysical Research Letters, 31, L16108, doi:10.1029/2004GL020628.
Manuscripts in preparation or submitted
Randles, C. A. and V. Ramaswamy, Absorbing aerosol over Asia: A Geophysical Fluid Dynamics Laboratory general circulation model sensitivity study of model response to perturbations of aerosol optical depth and aerosol absorption, manuscript in preparation for Journal of Geophysical Research.
Conference presentations and abstracts
Randles, C. A., L. M. Russell, and V. Ramaswamy (2004), Hygroscopic and optical properties of organic sea salt aerosol and consequences for climate forcing, (invited speaker) 2004 American Association for Aerosol Research (AAAR) Conference, October 4-8, Atlanta, Georgia, USA.
Randles, C. A., L. M. Russell, and V. Ramaswamy (2004), Hygroscopic and optical properties of organic sea salt aerosol and consequences for climate forcing, (poster) 8th International Global Atmospheric Chemistry (IGAC) Conference, September 4-9, Christchurch, New Zealand.
Randles, C. A., L. M. Russell, and V. Ramaswamy (2003), Optical properties of internal mixtures of sea salt and organics, (poster) Gordon Research Conference on Solar Radiation and Climate, July 13-18, New London, New Hampshire, USA.
Randles, C. A., L. M. Russell, and V. Ramaswamy (2004), Hygroscopic and optical properties of organic sea salt aerosol and consequences for climate forcing, Geophysical Research Letters, 31, L16108, doi:10.1029/2004GL020628.
Manuscripts in preparation or submitted
Randles, C. A. and V. Ramaswamy, Absorbing aerosol over Asia: A Geophysical Fluid Dynamics Laboratory general circulation model sensitivity study of model response to perturbations of aerosol optical depth and aerosol absorption, manuscript in preparation for Journal of Geophysical Research.
Conference presentations and abstracts
Randles, C. A., L. M. Russell, and V. Ramaswamy (2004), Hygroscopic and optical properties of organic sea salt aerosol and consequences for climate forcing, (invited speaker) 2004 American Association for Aerosol Research (AAAR) Conference, October 4-8, Atlanta, Georgia, USA.
Randles, C. A., L. M. Russell, and V. Ramaswamy (2004), Hygroscopic and optical properties of organic sea salt aerosol and consequences for climate forcing, (poster) 8th International Global Atmospheric Chemistry (IGAC) Conference, September 4-9, Christchurch, New Zealand.
Randles, C. A., L. M. Russell, and V. Ramaswamy (2003), Optical properties of internal mixtures of sea salt and organics, (poster) Gordon Research Conference on Solar Radiation and Climate, July 13-18, New London, New Hampshire, USA.