Nina Črnivec is a postdoctoral research scientist at Columbia University's Center for Climate Systems Research and NASA Goddard Institute for Space Studies, studying cloud feedbacks and climate sensitivity. She holds a PhD from Ludwig Maximilian University of Munich, where she investigated the three-dimensional interaction between clouds and radiative transfer to improve its representation in weather and climate models. Her research interests also include tropical cyclone dynamics.
The proficient representation of cloud-radiation interaction in weather and climate models remains a challenge in the atmospheric science community. We investigate the three-dimensional interaction between atmospheric radiation and highly-resolved heterogeneous cloud structures in order to improve its parameterization in regional and global models. We first quantify the radiative bias at the scale of regional models arising from poor representation of unresolved clouds and neglected horizontal photon flow. We subsequently address the issues related to misrepresentation of cloud horizontal inhomogeneity in coarse-resolution global models. This subject is tackled with the Tripleclouds radiation scheme, the fundamental feature of which is the inclusion of the optically thicker and thinner cloud fraction. We explore the potential of the Tripleclouds method for various cloud types, including case studies of shallow cumulus, stratocumulus, cirrus and cumulonimbus. We assess the validity of the global cloud variability estimate as well as more sophisticated parameterizations, optimizing the treatment of overcast and extremely heterogeneous cloudiness. We demonstrate that the optimal Tripleclouds configuration minimizing the radiative bias essentially depends on cloud type, which supports the use of cloud regime dependent methodologies in next-generation atmospheric models.
Arranged date for the seminar talk Nov 28, 2022 at 14:15
Place: BCCR seminar room 4020, Jahnebakken 5, Bergen