Kelly Ryan (Co-I) and Heather Holbach (Co-I)

Sim Aberson, Joe Cione, Jun Zhang

The goal of this module is to observe the temperature, and humidity, and structure of small features in the eyewalls of very intense tropical cyclones that could increase the amount of energy available for hurricane intensification or cause damaging surface wind at landfall or intense turbulence features impacting flight operations. The structures of these features, especially the temperature and humidity structures, have never been documented.

Jun Zhang (PI) and David Nolan (co-PI, UM)

Tropical cyclone (TC) convection produces gravity waves that propagate both upward and outward. The observational data collected from this module will be analyzed to quantify the characteristics of the gravity waves in mature-stage hurricanes and their relationship with storm intensity and intensity change. These data would also provide valuable information for model evaluation and physics improvement.

Paul Chang (PI), Zorana Jelenak, Joe Sapp (NOAA/NESDIS/STAR): Ricky Roy (Tomorrow.io), Sim Aberson (NOAA/AOML/HRD)

Joseph Cione (Co-PI), Josh Wadler (Co-PI, ERAU), Jun Zhang (Co-PI), Mikal Montgomery (Co-PI), Lev Looney (NOAA/U Miami), Guo Lin, Ron Dobosy (NOAA/ARL-ret), Altug Aksoy, Sim Aberson, Frank Marks, Kelly Ryan, Brittany Dahl, Johna Rudzin-Schwing (MS State), Xiaomin Chen (UAH), George Bryan (NCAR), Josh Alland (NCAR), Rosimar Rios- Berrios (NCAR), Don Lenschow (NCAR), Chris Rozoff (NCAR), Eric Hendricks (NCAR), Falko Judt (NCAR), Jonathan Vigh (NCAR)

This experiment will leverage NOAA’s P-3 aircraft to deploy uncrewed assets into regions of the TC environment that are unsafe for crewed operations. The experimental goals are to improve physical understanding, situational awareness, and ultimately, operational forecasts of TC track and intensity. It is believed that observations from these unique platforms will improve basic understanding and enhance forecaster situational awareness. Detailed analyses of data collected from these small drones also have the potential to improve the physics of computer models that predict changes in storm intensity.

Paul Reasor and John Gamache

This module provides three-dimensional wind analyses derived from two P-3 aircraft equipped with tail-Doppler radar (TDR) and flying simultaneous, perpendicular transects through the hurricane eyewall are compared in an evaluation of the Doppler-radar wind analysis method. Through this evaluation, we seek to gain a better understanding of how to relate radar-derived peak wind speed and other aspects of hurricane wind structure to similar estimates using conventional observations.

Brian Tang (UAlbany), Jun Zhang, Kristen Corbosiero (UAlbany), Rosimar Rios-Berrios (NCAR)

Ventilation occurs when drier and/or cooler environmental air intrudes into a vertically-sheared, tilted tropical cyclone (TC). Ventilation pathways include lateral intrusion (radial ventilation) and downward intrusion (downdraft ventilation) of dry and/or cool air. Both pathways may inhibit intensification. This module aims to collect observational data to study ventilation pathways, validate model simulations of ventilation in TCs, and assess the link between ventilation and intensity changes.

Heather Holbach, John Kaplan, Jun Zhang, Ghassan Alaka, Frank Marks, Lew Gramer, Lev Looney, George Alvey, Forrest Masters (University of Florida), Michael Biggerstaff (University of Oklahoma), David Nolan (University of Miami), Xiaomin Chen (University of Alabama Huntsville), Johna Rudzin (Mississippi State University), John Schroeder (Texas Tech University)

Landfalling tropical cyclones (TCs) often produce a variety of high impact weather over land including tornadoes and damaging winds (particularly gusts) for which there exists limited objective forecast guidance. Thus, our experiment seeks to utilize P-3 aircraft, land-based mobile research team instrumentation, and ocean-based uncrewed surface vehicles to collect data in landfalling TCs to improve both our understanding and capability to predict the dangerous phenomena often associated with these landfalling systems.

Tropical cyclones can either decay (spin down) or transform into powerful extratropical cyclones when they encounter cold water below or high wind shear in the atmosphere. The mechanisms by which tropical cyclones become extratropical is not well forecast by numerical models leading to large errors, especially in impacts downstream of the actual transitioning cyclone. This experiment aims to improve forecasts of these systems.

CHAOS focuses on the coordination of a diverse suite of innovative observing platforms (i.e., autonomous, uncrewed, expendable) and conventional ones (e.g., aircraft) to support:

-Targeted coordinated observations of the air-sea transition zone to improve the understanding of air-sea interactions, including the ocean’s response and recovery to tropical cyclone (TC) forcing, and for improved prediction and modeling of TC intensification changes.

-Coordinated atmospheric and oceanic observations with sustained monitoring of key ocean features of the Gulf of Mexico, tropical Atlantic, and/or the Caribbean Sea – e.g., Loop Current, Gulf Stream, eddies and rings, and freshwater barrier layers from the Mississippi & Amazon-Orinoco River Plumes

Jun Zhang (PI), Nick Shay (co-PI, UM), Sue Chen (co-PI, NRL), Benjamin Jaimes (UM), Elizabeth Sanabia (USNA), Joseph Cione, Joshua Wadler (ERAU), Rick Lumpkin (AOML), Gregory Foltz (AOML), Lev Looney (AOML/UM), Guo Lin (CIMAS), Cheyenne Stienbarger (GOMO), James Doyle (NRL), James Cummings (NRL), Luca Centurioni (Scripps), Theresa Paluszkiewicz (OOC, LLC), Martha Schonau (Scripps), Steven Jayne (WHOI), Michael Bell (CSU), David Richter (UND), Johna Rudzin (MSU), Brian Tang (SUNY Albany)

Physical representation of how the atmosphere and ocean interact in numerical forecast models of tropical cyclones (TCs) have not been fully evaluated against observations. Near collocated and simultaneous measurements of the ocean and the atmosphere just above the ocean surface, the energy exchanges that occur between them, and how they change over time have been less understood due to lack of substantial close coordination across a wide array of ocean and atmosphere observing platforms. This experiment will provide a unique opportunity to evaluate how well coupled forecast models represent these lowest regions of storms. The new type of observations that are collected should help improve the model initialization and inform how coupled forecast models represent interactions between the ocean and atmosphere in hurricanes.

Jun Zhang (PI), Jason Dunion (co-PI), Joseph Cione, Joshua Wadler (ERAU), Robert Rogers, Frank Marks, Andrew Hazelton, Jonathan Zawislak, Guo Lin, Kwun Yip Fung, George Alvey, Gregory Foltz, Cheyenne Stienbarger (GOMO), Daniel Stern (NRL), James Doyle (NRL), Sue Chen (NRL), Yi Jin (NRL), Nick Shay (UM), Benjamin Jaimes (UM), Elizabeth Sanabia (USNA), Ping Zhu (FIU), Xiaomin Chen (UAH), Brian Tang (SUNY Albany), Robert Fovell (SUNY Albany), Zhien Wang (SBU), Michael Bell (CSU), Ralph Foster (UW), George Bryan (NCAR), David Richter (UND)

The atmospheric boundary layer is a crucial region of a tropical cyclone (TC), because it is the area of the storm in direct contact with the ocean moisture and heat sources which power the storm. This module aims to collect observational data to improve our understanding of physical processes in the boundary layer that control the TC intensity change. This data can be used to evaluate and improve the performance of TC forecast models such as the Hurricane Analysis and Forecast System (HAFS).

Philippe Papin, Lisa Bucci, Eric Blake, Brad Reinhart (NHC/NWS/NOAA), Jason Dunion (HRD/NOAA), Jim Doyle (NRL), Victoria Pizzini (University of Miami)

This experiment seeks to use aircraft observations to better validate high-resolution surface wind speed measurements becoming more frequently available with Synthetic Aperture Radar (SAR) polar orbiting passes. This will be accomplished by coordinating NOAA P-3 flights to occur simultaneously with an orbiting SAR pass near a TC or other ocean environments deemed research relevant to sample the wind and wave interface near the surface.

Brittany Dahl (co-PI), Jason Dunion (co-PI), Rob Rogers (co-PI), Trey Alvey, William Blackwell (MIT, Lincoln Laboratory), Patrick Duran (NASA MSFC SPoRT)

This experiment is designed to calibrate and validate temperature, moisture, and precipitation measurements obtained from the new TROPICS satellites. These profiles will be compared to NOAA P-3 and NOAA G-IV aircraft observations, whose flight patterns will be coordinated in space and time with overpasses from the satellite.