CCC group research primarily falls within two topic areas of atmospheric science: Radar & Satellite Meteorology, and Upper Troposphere and Lower Stratosphere (UTLS) studies. Many of the topics that we work on are cross-cutting in that they require and contribute to knowledge in multiple areas. For example, thunderstorms are capable of reaching the tropopause: the boundary between the lowest layer of the atmosphere and that in which we live (the troposphere) and the layer immediately above (the stratosphere). If a storm overshoots the tropopause and extends into the stratosphere, it may lead to transport of air between the two layers (stratosphere-troposphere exchange or STE). STE affects the composition of the UTLS, which in turn leads to changes in the radiation budget and climate. Studying such problems enables the CCC group to broadly impact the atmospheric sciences. Additional details on our research activities and research identity can be found below.
CCC group research is/has been supported by the National Science Foundation (NSF), the National Aeronautics and Space Administration (NASA), and the National Oceanic and Atmospheric Administration (NOAA).
Radar & Satellite Meteorology
Weather radars are able to detect cloud and precipitation particles suspended in the air and their motion toward and away from the radar at fine spatial and temporal resolution. Modern systems that transmit both horizontally and vertically polarized beams (polarimetric or dual-polarization radars), such as the NEXRAD WSR-88D network in the United States, provide information on the size, shape, phase (liquid or ice), and concentration of these particles. As a result, these radar observations enable studies on the physical and dynamical characteristics of storms. On the other hand, satellite observations (especially imagery from geostationary platforms) can be combined with radar to provide broader context in cloudy and cloud-free situations and allow for unique cloud top studies that are not possible from radar. CCC group activities in these areas often focus on:
- Development of three-dimensional large-area, high-resolution mergers (or composites) of volumes from individual NEXRAD WSR-88D radars, which we call GridRad data (GridRad.org). For years 2013-Present, we have been incorporating all available polarimetric variables. For years 2010-Present, some of our products also include several dynamical (kinematic) variables.
- Using GridRad data to study tropopause-overshooting storms and their transport potential.
- Combining GridRad data and high-resolution (≤ 1 min) satellite imagery to study severe and/or tropopause-overshooting storms. An important phenomenon we focus on here is the above-anvil cirrus plume.
- Development of machine learning models to characterize and predict storm types and hazards in vast radar and satellite datasets.
- Validation of numerical model (e.g., WRF) simulations of storms and their characteristics using GridRad data.
- Climatological studies of storms and associated hazards.
UTLS Studies
Because the chemical characteristics of the troposphere and stratosphere are distinct, interactions between the two such as STE can significantly impact the composition of the UTLS and the structure of the tropopause. Moreover, since these interactions involve greenhouse gases, they directly impact the radiation budget and climate. For example, the primary research interest for STE studies is typically the irreversible modification of greenhouse gases such as LS water vapor (troposphere-to-stratosphere transport) or UT ozone (stratosphere-to-troposphere transport). Thunderstorms, though widely studied for their meteorological impacts, are increasingly becoming a focal point of UTLS studies and the CCC group is helping to lead the community in this area. CCC group activities for UTLS research include:
- Observational studies of STE and its impact on UTLS composition and chemistry. Most of our efforts are focused on midlatitude storms using aircraft, satellite, and radar observations.
- Studies of large-scale STE processes using global winds from model analyses to drive a trajectory model.
- Numerical modeling of thunderstorms. These efforts support process- (or mechanism) based studies of STE and evaluation of the quantitative impacts of storms on UTLS composition.
- Tropopause identification, classification, and evolution.
- Development of machine learning models to identify signatures of STE and other processes affecting UTLS composition from large satellite and aircraft datasets.
Previous Collaborative Relationships, Projects and Field Experiments
- NSF In-situ Collaborative Experiment for the Collection of Hail In the Plains (ICECHIP), 2024–Present
- NSF AI Institute for Research on Trustworthy AI in Weather, Climate, and Coastal Oceanography (AI2ES), 2020–2026
- NASA Dynamics and Chemistry of the Summer Stratosphere (DCOTSS), 2019–2025
- NSF Prediction of Rainfall Extremes at Subseasonal to Seasonal Periods (PRES2iP), 2017–2022
- SPARC-Reanalysis Intercomparison Project (S-RIP), 2013–2019
- NSF CONvective TRansport of Active Species in the Tropics (CONTRAST), 2014
- NASA Airborne Tropical TRopopause EXperiment (ATTREX), 2013–2014
- NASA Studies of Emissions and Atmospheric Composition, Clouds, and Climate Coupling by Regional Surveys (SEAC4RS), 2013
- NSF/NASA Deep Convective Clouds & Chemistry experiment (DC3), 2012
- NSF Stratosphere-Troposphere Analyses of Regional Transport 2008 (START08), 2008