• Former Title: Graduate Research Associate (HART Group)
  • Affiliations: University of Utah, Department of Atmospheric Sciences, Utah Department of Environmental Quality

Past Research Interests

One of the biggest uncertainties that remains with future projections of climate change is how clouds will react to increased anthropogenic emissions and warming temperatures. Currently, my research involves investigating new particle formation (NPF) which has the potential to increase cloud condensation nuclei (CCN). NPF begins when nucleate leads to the formation of a stable nucleus (1-3 nanometers in size) that is more likely to grow than evaporate, and these particles do grow at amazing rates. By extrapolation, these ultrafine particles can grow to CCN size (~ 50 nm) within 1-2 days. This prompts the majority of my research questions:

- Is NPF driving an increase in CCN?
- If clouds form, what is their spatial expanse?
- Do they have a measurable effect on the surface energy budget?

Answering these questions would reveal new information about the hygroscopicity of newly formed particles, which could be used in future model parameterizations. My ultimate goal is to be instrumental in the better prediction of the future of our planet in the age of the anthropocene.

Interest in aerosols and their effect on the atmosphere began in my masters, where I studied the WRF model’s ability to generate fog in northern Utah basins. Through combined effects of topography and surface emission, the Salt Lake and surrounding valleys experience persistent cold air pool or “inversion” events during the winter months. The topographically-trapped airmass can effectively be considered independent of the column above it, and is separated by a layer of statically stable air or a temperature inversion, hence the common colloquialism. This airmass often has colder temperatures, higher stability, and calmer winds than the free troposphere at higher altitudes. Due to the valleys’ lack of available drainage and the high density of the valley airmass, anthropogenic injections of moisture and aerosols are not able to be vertically mixed past terrain height. These persistent cold air pool conditions are also suitable for the development of and sustainability of fog in the valleys. Through extensive sensitivity studies, my research aimed to identify and reduce the uncertainty of fog in model solutions.

  • Catherine is now an employee at the Utah Department of Environmental Quality.
  • Education

    Degree Institution Field
    M.S. University of Utah Atmospheric Sciences
    B.S. University of South Alabama Meteorology


    Chachere, C. N. and Z. Pu (2017), Sensitivity of numerical prediction of fog events to WRF model physical parameterization schemes: A study with MATERHORN Fog-X observations. Pure and Applied Geophysics, submitted.


    Chachere, C. N. and Z. Pu (2016), Connection between cold air pools and mountain valley fog events in Salt Lake City, Pure and Appl. Geophys., 173, 3187, doi:10.1007/s00024-016-1316-x link


    Pu, Z., C. N. Chachere, S. W. Hoch, E. Pardyjak, and I. Gultepe (2016), Numerical prediction of cold season fog events over complex terrain: The performance of the WRF model during MATERHORN-Fog and early evaluation. Pure and Appl. Geophys., 173, 3165, doi:10.1007/s00024-016-1375-z link