Award Abstract # 1917693
Collaborative Research: Observing and Understanding Planetary Boundary Layer (PBL) Heterogeneities and Their Impacts on Tornadic Storms during VORTEX-SE 2018 Field Experiment

NSF Org: AGS
Division of Atmospheric and Geospace Sciences
Recipient: THE REGENTS OF THE UNIVERSITY OF COLORADO
Initial Amendment Date: July 30, 2019
Latest Amendment Date: July 30, 2019
Award Number: 1917693
Award Instrument: Standard Grant
Program Manager: Yu Gu
ygu@nsf.gov
 (703)292-8796
AGS
 Division of Atmospheric and Geospace Sciences
GEO
 Directorate for Geosciences
Start Date: August 1, 2019
End Date: July 31, 2024 (Estimated)
Total Intended Award Amount: $325,810.00
Total Awarded Amount to Date: $325,810.00
Funds Obligated to Date: FY 2019 = $325,810.00
History of Investigator:
  • Zhien Wang (Principal Investigator)
    zhien.wang@stonybrook.edu
Recipient Sponsored Research Office: University of Colorado at Boulder
3100 MARINE ST
Boulder
CO  US  80309-0001
(303)492-6221
Sponsor Congressional District: 02
Primary Place of Performance: University of Colorado at Boulder
3665 Discovery Dr.
Boulder
CO  US  80303-7819
Primary Place of Performance
Congressional District:
02
Unique Entity Identifier (UEI): SPVKK1RC2MZ3
Parent UEI:
NSF Program(s): Physical & Dynamic Meteorology
Primary Program Source: 01001920DB NSF RESEARCH & RELATED ACTIVIT
Program Reference Code(s):
Program Element Code(s): 152500
Award Agency Code: 4900
Fund Agency Code: 4900
Assistance Listing Number(s): 47.050

ABSTRACT

High-impact weather phenomena such as high winds, hail, and heavy rainfall have huge socio-economic impacts. However, forecast for severe high-impact weather events, especially tornadoes, remains challenging. Historically, tornado research has been concentrated in the Great Plains while the Southeastern U.S. commonly experiences devastating tornadoes as well. Significant differences in environmental conditions over the two regions and frequent occurrence of tornadoes at night in the Southeast (SE) pose challenges to observing and understanding the formation and development of tornadoes in the SE. The Verification of the Origins of Rotation in Tornadoes Experiment - Southeast (VORTEX-SE) is a research program designed to understand how environments in the SE affect the formation, intensity, structure, and path of tornadoes in this region. During the VORTEX-SE field campaign in 2018, unprecedented advanced measurements from an airplane flying around tornadoes have been collected. Such observations cannot be done easily on the ground with hilly forest terrain. The study will utilize the unique observations and advanced computer models to understand airflow structures of tornadic storms and special environments for their formation. New knowledge gained from the research will contribute to improvement of tornado forecasting across the U.S. This project will provide support and training to graduate students in atmospheric measurement technologies, data analysis, and computer modeling and prepare them to become future scientists in severe weather research and prediction.

The research team will conduct observational data analysis and advanced data assimilation that integrate observations and atmospheric prediction models. The unprecedented observation includes an advanced downward-pointing Compact Raman Lidar (CRL), a horizontally scanning lower fuselage (LF) radar, and dual Tail Doppler Radars (TDRs) onboard of a NOAA P-3 aircraft. The CRL is capable of measuring high-spatial and temporal resolution of water vapor, temperature, and aerosol profiles in the atmospheric boundary layer upstream of moving storms. Together with the P-3's in-situ measurements and the LF and TDR radar observations, unprecedented characterization of tornadic environments is expected. In addition, tornado-resolving numerical simulations will be performed, and variational, and ensemble-based data analysis and assimilation techniques will be applied. The primary goals of the project include: (1) characterization of spatial heterogeneities and temporal evolution of the PBL around convective storms in the VORTEX-SE domain with CRL measurements; (2) analysis and understanding of the impact of PBL heterogeneities on tornadic storms by synthesizing P-3 and other available observations; (3) identification and understanding of key physical processes involved in the tornadic storms through model simulations with advanced data assimilation methods. The synergy of airborne radar and lidar data with high-resolution model simulations will help pave the way for potentially transformative future process-oriented field experiments.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

PUBLICATIONS PRODUCED AS A RESULT OF THIS RESEARCH

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Hosek, Michael J. and Ziegler, Conrad L. and Biggerstaff, Michael I. and Murphy, Todd A. and Wang, Zhien "Relation between Baroclinity, Horizontal Vorticity, and Mesocyclone Evolution in the 67 April 2018 Monroe, Louisiana, Tornadic Supercell during VORTEX-SE" Monthly Weather Review , v.151 , 2023 https://doi.org/10.1175/MWR-D-22-0313.1 Citation Details
Lin, Guo and Grasmick, Coltin and Geerts, Bart and Wang, Zhien and Deng, Min "Convection initiation and bore formation following the collision of mesoscale boundaries over a developing stable boundary layer: a case study from PECAN" Monthly Weather Review , 2021 https://doi.org/10.1175/MWR-D-20-0282.1 Citation Details
Lin, Guo and Wang, Zhien and Chu, Yufei and Ziegler, Conrad L. and Hu, XiaoMing and Xue, Ming and Geerts, Bart and Paleri, Sreenath and Desai, Ankur R. and Yang, Kang and Deng, Min and DeGraw, Jonathan "Airborne Measurements of ScaleDependent Latent Heat Flux Impacted by Water Vapor and Vertical Velocity Over Heterogeneous Land Surfaces During the CHEESEHEAD19 Campaign" Journal of Geophysical Research: Atmospheres , v.129 , 2024 https://doi.org/10.1029/2023JD039586 Citation Details
Lin, Guo and Wang, Zhien and Ziegler, Conrad and Hu, Xiao-Ming and Xue, Ming and Geerts, Bart and Chu, Yufei "A Comparison of Convective Storm Inflow Moisture Variability between the Great Plains and the Southeastern United States Using Multiplatform Field Campaign Observations" Journal of Atmospheric and Oceanic Technology , v.40 , 2023 https://doi.org/10.1175/JTECH-D-22-0037.1 Citation Details

PROJECT OUTCOMES REPORT

Disclaimer

This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.

The Verification of the Origins of Rotation in Tornadoes Experiment - Southeast (VORTEX-SE) is a research program designed to understand how environmental factors characteristic of the southeastern United States (US) affect the formation, intensity, structure, and path of tornadoes in this region. Due to the complex terrain in the region, airborne observations are critical to documenting the planetary boundary layer (PBL) structures and evolution and their interactions with tornadic storms. During VORTEX-SE (2018), a Compact Raman lidar (CRL) was successfully deployed on one of the NOAA P-3 aircraft out of Huntsville, AL, from 1 March to 13 April 2018. The CRL observed fine-scale water vapor, temperature, and aerosol structures within the PBL around storms over complex terrain when P-3 flew in the inflow region, following storm movements. A comprehensive, unique dataset was collected that would allow unprecedented characterization and understanding of PBL inhomogeneities and their impacts on tornadic storm dynamics and evolutions. In this project, a team with special expertise in instrumentation, field data collection, numerical analyses, and simulations from the University of Colorado, Boulder (CU), and the University of Oklahoma (OU) was formed to study the above problems by taking full advantage of this unique data set. 

The outcomes of CU's effort are summarized here:

  1. CRL water vapor, temperature, and aerosol/cloud profiles were validated, quality-controlled, and archived. Furthermore, we developed a collocated CRL and P-3 tail Doppler radars (TDRs) data set to characterize storm inflow properties and fine-scale 3-D storm dynamical structures to track storm evolution, archived at NCAR for others to use.
  2. We documented fast water vapor variations in convective storm inflow, which is not possible with traditional observations.  The observed rapid PBL water vapor variations (at a time scale of ~5 minutes) can lead to perturbations in convective available potential energy over 1000 J kg-1, representing significant perturbations for storms to intensify or decay. Collocated storm intensity based on ground-based radar or TDR measurements confirmed that changing storm inflow leads to expected storm intensity changes. This highlights the importance of models to capture inflow water vapor reliably to improve storm intensity forecasts.
  3. Observations revealed that the surface contributes more to low-atmospheric water vapor in the US Southeastern than in the Great Plains. Therefore, heterogeneous surfaces in the US Southeast could lead to large local water vapor variations impacting storm evolutions in the region. 
  4. Our results provide important guidance on improving tornadic storm forecasts and warnings in the Southeast to save lives and minimize economic loss. In the Southeast, future models need to capture better low-atmospheric water vapor distributions impacted by heterogeneous surfaces and storm-environment interactions.
  5. This project graduates one PH. D. and published three journal papers. 

 


Last Modified: 08/13/2024
Modified by: Zhien Wang

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