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Project: “Leveraging Multiple Observational Datasets to Advance Understanding and Simulation of Convection Lifecycles”

Funding Agency: NASA

Team: Gregory Elsaesser (NASA GISS, PI), Kathleen Schiro (UVA, Co-I), Remy Roca (CNRS, Collaborator), Thomas Fiolleau (CNRS, Collaborator), Piyush Garg (Argonne National Lab, Collaborator), Bill Irion (JPL, Collaborator), Christopher Barnet (STC, Collaborator)

Program: The Science of TASNPP and JPSS Series Satellites

Deep convective systems produce expansive high cloud shields that have large impacts on global radiation budgets. Their heavily raining regions and overall long durations combine to yield substantial rainfall accumulation across many locations, with the majority of rainfall in the tropics being attributed to such systems. Global climate models, in order to provide reliable projections of 21st century climate and rainfall extremes, must accurately simulate the spectrum of cloud feedbacks and hydrological processes associated with deep convective systems, which requires accurate simulation of convective initiation, evolution and termination as well as cloud area production as a function of their lifecycle. Preliminary work, largely informed by Aqua/AIRS retrievals, suggests that increased moisture in the lower-middle troposphere favors system occurrence (and enhanced rainfall), with lifecycle characteristics (e.g., system sizes, duration) being strongly impacted by lower-troposphere stability. Composite preliminary work suggests varying timescales for moistening and stabilization (as short as 1-hr, to as long as 6-12 hours), with regional differences noted. We hypothesize some regional differences may be the result of evaluating system-environment characteristics independent of lifecycle stage, since moving convective systems statistically cross some locations at systematically different lifecycle stages than others. All results suggest a more process-oriented “convective-systems” scale approach that entails investigating the cloud, rainfall, and environmental characteristics as a function of convective system lifecycle stages.

To this end, we propose a project to improve our understanding of convective system lifecycles, where convective system lifecycle stages are provided by a Geostationary Infrared (IR) system tracking database, environmental thermodynamic data are provided by multiple satellites (Aqua, Suomi-NPP, JPSS-1 [a.k.a. NOAA-20]), and supplementary observations of the lower-troposphere are provided by RapidScat cold pool retrievals and in situ (e.g., buoys) observational sources. We initially focus on the entirety of the tropical (30S-30N) oceanic domain, where convective diurnal cycles are less pronounced and controls on convective lifecycles are not well understood, yet GCM rainfall, convection, and cloud biases are still pervasive.

Hypotheses are posed and a framework is laid out for testing the relationship between convective system longevity, system sizes, and the timescale for thermodynamic stabilization of the lower-troposphere. We propose a unique leveraging of time-lagged sampling of temperature and water vapor profiles from Aqua, SNPP and JPSS-1 to assess short term changes in the environment driven by convection as part of understanding the large-scale vs local control on environments surrounding convection and timescales for stabilization. This process-oriented analysis has a potential feedback onto the sounder retrieval community that aims to understand how quickly changing environments affect validation efforts using radiosondes launched at times lagged relative to satellite overpass times. We extend aspects of our work to land environments in order to make more expansive conclusions about convective system duration, size and the environment.

The mapping of Level 2 sounder data to system cloud shields and lifecycle stages allows for a novel process-oriented analysis aiming to understand convective system sizes which closely tie to anvil cloud area sizes, an important endeavor considering the role of anvil cloud area in high cloud feedbacks (Sherwood et al., 2020). Our results overall will inform the development of improved convective system size representation in climate models, an effort PI Elsaesser is involved in with the NASA-GISS climate model parameterization team.

Project: “Using Polarimetric signatures of GNSS signals for the remote sensing characterization of the vertical structures of heavy precipitation and water vapor in clouds”

Funding Agency: NASA

Team: Manuel de la Torre Juarez (JPL, PI), Kathleen Schiro (UVA, Co-I), Joe Turk (JPL, Co-I), Kuo-Nung Wang (JPL, Co-I), Estel Cardellach (ICE-CSIC, Co-I), Chi Ao (JPL, Collaborator), Ramon Padulles (ICE-CSIC, Collaborator)

Program: Global Navigation Satellite System Research (NNH19ZDA001N-GNSS)

Organized convective systems are responsible for a majority of tropical precipitation. However, the feedbacks, mechanisms, and interactions between convection and its environment permitting the organization of convection are poorly understood. The propagation of the circularly polarized GNSS signal through the atmosphere has been shown recently to be altered by precipitating hydrometeors. Theoretical analyses, radio occultation (RO) from space, and mountain top experiments have shown the potential to characterize the vertical structure of heavy precipitation. When combined with the coincident more standard RO products of water vapor, temperature, and neutral stability to convection inside thick clouds, Polarimetric RO (PRO) can clarify the role of the vertical distributions of water vapor, temperature and associated buoyancy in controlling the transition to heavy precipitation. This work focuses on the observations simultaneously of the heights at which the transition to heavy precipitation occurs and the thermodynamic conditions associated with this transition. 

The role of the University of Virginia team in their collaboration with the Jet Propulsion Laboratory team, is to define science requirements that guide the priorities of the GNSS PRO retrieval products. 

To that effect the U of Virginia team’s work will carry out analyses linking variability in the thermodynamic structure of the troposphere to precipitation intensity, deep convection onset, and the convective lifecycle by:

-Collocating GNSS and GNSS PRO retrievals with TRMM/GPM radar data and mesoscale convective tracking databases (which use IR geostationary imagery and IMERG precipitation)

-Preparing composites of Thermodynamic profiles derived from GNSS retrievals as a function of the convective lifecycle over both continental and oceanic regimes in the tropics.

-Comparing characteristics of the thermodynamic environment preceding convection organization to study the associations between variability in moisture vertical structure and favorability of organization/clustering. 

-Studying the variability of the thermodynamic structure of the atmosphere in response to deep convection, as deep convection-environment interactions are two-way interactions.

-Proposing retrieval product priorities based on the results of the science analyses described above.

-Training students in this area of research. 

-Reporting the results each 6 months to JPL and at scientific meetings, conferences, or refereed publications.

-These convection-environment interactions underpin variability in tropical weather and climate across scales and are critical to our improved understanding and modeling of the global climate system.


Project: “P2PE Proposal – Climate Science: Bridging Global and Community Scales

Internal Grant (UVA)

Status: Current

Our vision is to dramatically advance the University of Virginia as a world leader in climate change analysis and solutions research. We propose an initiative focused on bridging global-scale climate dynamics with community-scale processes and systems to guide decision-making for equitable climate resilience and sustainability outcomes. This is a critical knowledge gap in creating actionable solutions to climate change, and one in which UVA is uniquely poised to become a preeminent leader given existing faculty particularly in Environmental Sciences, Engineering, Data Science, the Biocomplexity Institute, the Equity Center, with coordination through and recent investments in the Environmental Resilience Institute (ERI) and cluster hires in environmental resilience. We will 1) strengthen our capacity in understanding and projecting climate dynamics and impacts at scales that matter for communities (i.e. regional/local and years/decades), 2) use these enhanced projections in combination with local- scale data (e.g. real-time environmental sensing) to improve regional and global scale quantification of energy/carbon dynamics, and 3) drive actionable natural and engineered solutions to climate change (e.g. land use changes, infrastructure, decarbonization). The capacity this initiative will support is critical for answering urgent societally-relevant questions, such as how do planners in coastal Virginia use climate models to inform adaptation of their infrastructure over the coming decades; or how are national targets for decarbonization are impacted by regional constraints on land use and equity?

We propose a 5-year initiative that includes three components: 1) an end-to-end data and model support infrastructure to bridge the computational gap between global climate dynamics and community-scale impacts and action; 2) a pipeline of Postdoctoral Fellows, specifically targeting traditionally underrepresented groups in STEM, to support the development of this modeling work; and 3) three faculty positions (Assistant Professors) in cross-scale modeling (e.g., artificial intelligence and machine learning, physics-based), decision support (e.g., agent-based modeling), and geospatial analysis (e.g, data acquisition and integration). The model support infrastructure will be coordinated by a proposed staff member who will help co-create the architecture of the model integration and data structure along with the participants. The postdoctoral fellows are critical to seed methodological and application advances using the capacity made possible by this effort, bridging us from prominence to preeminence in the field of climate science. The postdocs will collaborate with faculty and graduate students to strengthen our pan-University network, and accelerate research productivity at the forefront of climate science and action. They will be trained to transition to faculty positions at UVA or elsewhere, thereby enhancing diversity nationally among the next generation of faculty addressing climate change. The appointment of three faculty members at UVA and additional enhancements in data personnel and infrastructure capacity will ensure sustainability of this initiative. The targeted research objectives of this initiative, the critical mass of postdoctoral fellows, the appointment of new faculty, and the enhancement of data processing capacity will elevate UVA from prominence to preeminence in climate resilience and sustainability. This initiative is aligned with UVA’s Environmental Resilience and Sustainability priority of the 2030 Strategic Plan; addresses climate equity, which aligns with the Democracy priority in the Plan; and supports the Plan’s goal of enhancing diversity, equity, and inclusion. We also envision major benefits through partnership with our local community and the State.

Project: “Linkage Between Deep Convection, Large-scale Circulation and Low Cloud Feedback”

Funding Agency: NOAA

Role: Collaborator

Status: Current

Project: “The Role of Deep Convection and Large-scale Circulation in Driving Model Spread in Low Cloud Feedback and Equilibrium Climate Sensitivity

Funding Agency: DOE RGMA

Role: Collaborator

Status: Current


Project: “Thermodynamic and Non-thermodynamic Controls on Deep Convection in ARM Observations”

Funding Agency: DOE ASR

Team: Fiaz Ahmed (UCLA, PI), Kathleen Schiro (UVA, Co-PI), David Neelin (UCLA, Co-PI), Rong Fu (UCLA, Co-I), Scott Giangrande (BNL, Collaborator), Shaocheng Xie (LLNL, Collaborator)

Project: “Building an interdisciplinary and interagency collaboration between DOE BER and the University of Virginia”

Funding Agency: DOE

Team: Xi Yang (Principal Investigator), Lawrence Band (Co-Investigator), Stephan De Wekker (Co-Investigator), Howard Epstein (Co-Investigator), Kevin Grise (Co-Investigator), Ajay B. Limaye (Co-Investigator), Stephen Macko (Co-Investigator), Todd Scanlon (Co-Investigator), Kathleen Schiro (Co-Investigator), Lauren M. Simkins (Co-Investigator)

Project: “Collaborative Research: Characterizing interactions between tropical deep convection and the environment using a buoyancy framework”

Funding Agency: NSF

Team: Kathleen Schiro (PI), Fiaz Ahmed (Co-PI), Brandon Wolding (Co-PI), Angel Adames-Corraliza (Co-PI)

Project: “Collaborative Research: Decomposing the Links Between Clouds and Large-Scale Circulations”

Funding Agency: NSF

Team: Levi Silvers (Stony Brook University, PI), Kathleen Schiro (UVA, Co-PI), Kevin Reed (Stony Brook University, Co-I)

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