What is the fine-grained topic of the following text: The North Dakota Thunderstorm Project (NDTP) was a multi-agency cooperative research program designed to examine a number of facets of thunderstorm characteristics and evolution, including transport and dispersion, entrainment, cloud-ice initiation, storm structure, atmospheric chemistry, and electrification. Only return the topic.
The North Dakota Thunderstorm Project (NDTP) and its research on thunderstorm characteristics and evolution