Convective-cloud Urban Boundary-layer Experiment (CUBE) is an NSF funded field campaign and part of the DOE’ Tracking Aerosol Convective cloud Experiment (TRACER). The primary goal is to study the impact of urbanization on convective cloud processes in coastal environments. The project will explore how various coastal urban processes – urban heat islands, sea breeze, anthropogenic heat, and pollution – impact cloud processes. The project uses ground-based point and remote sensing measurements to characterize the coastal urban boundary layer properties. The project will advance current numerical models to better predict coastal urban environments.
Motivation & Objective – Here we plan to investigate how urban land-atmosphere processes influence convective initiation, cloud formation, and dissipation. We will take advantage of the planned DOE’ TRACER study in the Houston Metropolitan area, which will focus on aerosol-convective cloud interactions in a coastal sub-tropical environment. DOE has committed the Atmospheric Research Measurement (ARM) mobile facility, which will include state of the art instrumentation to analyze cloud microphysics and boundary layer structure, and we will provide additional instrument platforms to this study. Our proposed contribution will primarily investigate the influence of urban forcing on convective clouds and storms. We will instrument the Houston Metro area with multiple flux towers and ground-based remote sensing instruments to characterize urban boundary layer processes. We will also use a trace gas monitoring network to quantify anthropogenic contributions. Airborne measurements using a National Center for Atmospheric Research (NCAR) airplane (PI-P. Kollias) will be conducted to understand atmospheric variability along the ocean-urban-rural interfaces. In addition to the observation campaign, we plan to carry out a suite of numerical experiments to quantify the influence of various urban scale processes on convective clouds and storms. Our primary hypothesis is that the unique urban microclimate comprised of a strong advection (rural-urban, coastal-urban), significant production of mechanical as well as buoyant turbulent kinetic energy, and considerable aerosol sources will strongly influence convective initiation, cloud formation, and precipitation intensity and distribution.
The planned field and numerical studies will help us understand how various urban processes, such as landcover land use changes, anthropogenic heat, and aerosols, contribute and interact with convective clouds and their resulting storms- whether they aid or hinder their formation, strengthening, and dissipation. The observations will capture the dynamics and inherent feedbacks between clouds, storms, and urbanization. It will significantly improve various aspects of urban climate modeling related to convective clouds and thunderstorms, including but not restricted to, the urban radiation balance, boundary layer development, and urban land surface schemes. It will also improve microphysics modeling in the urban context. Specific objectives of the proposed project include:
- To understand how key urban boundary layer processes impact convective cloud formation.
- To investigate the impact of urbanization on storm formation, movement, and dissipation.
- To investigate the feedback of convective clouds in urban atmospheric and surface energy processes.
The proposed research agenda will be coupled to a strong education and mentoring framework, in which we plan to engage post-doctoral fellows, as well as graduate and undergraduate students. The work will lead to the development of new material for courses in the field of urban climate, convective clouds, and extreme weather events. Outcomes from the project will be disseminated to the scientific community and various public stakeholders.
Students – Omar Addasi, Gabriel Rios, Harold Gamarro, Aaron Tyler, Kemia Cleveland, Timothy Osazuwa
PostDoc – Dr. Kalimur Rahman
PI- Prof. Prathap Ramamurthy, Co-PI – Prof. Jorge Gonzalez, Co-PI- Prof. Fred Moshary