Program Overview
The 2019 Hurricane Field Program is a project under the Intensity Forecasting Experiment. This page is organized by the lifecycle stages of the storm from genesis to end stage. On this page you can find detailed descriptions of the overview plan for the season, information about each product, and the data to go along with it.
About the Intensity Forecasting Experiment: Developed in partnership with NOAA’s Environmental Modeling Center and its Hurricane Center, the Intensity Forecast Experiment is intended to improve our understanding and prediction of hurricane intensity change by collecting observations that will aid in the improvement of current operational models and the development of the next-generation operational hurricane model, the Hurricane Weather Research and Forecasting model. Observations also will be collected for NESDIS’ Ocean Winds Experiment in a variety of tropical wind regimes as ‘ground truth’ for remote sensing equipment.
Genesis Stage
Favorable Air Mass Experiment
Investigators
Ghassan Alaka (PI), Jon Zawislak, Jason Dunion, Alan Brammer (CSU/CIRA), Chris Thorncroft (Univ. at Albany-SUNY)Project Goal
To investigate the favorability in both dynamics (e.g., vertical wind shear) and thermodynamics (e.g., moisture) for tropical cyclogenesis in the environment near a pre-tropical depression, especially the downstream environment [IFEX Goals 1, 3].Observational Applications
Observations resulting from this science goal have the potential to improve operational forecasts of tropical cyclone formation by identifying characteristics of the large-scale environment near the disturbance. Aircraft observations may provide more details about the thermodynamic and dynamic vertical structure that cannot be measured by satellites. These observations can be stratified into developing and non-developing categories to determine critical differences that are associated with tropical cyclogenesis. Further, these observations may translate into refinement of satellite-based guidance to better determine whether or not a particular disturbance will develop into a tropical cyclone.Science
Requirements
Pre-genesis disturbances (pre-TDs), including NHC-designated “Invests”
Motivation
The environment near a pre-TD is critical to the favorability for tropical cyclogenesis to occur. The probability of cyclogenesis for a given pre-TD is dependent upon thermodynamics (e.g., moisture) and dynamics (e.g., vertical wind shear) in the adjacent air mass. Increased observations of lower-tropospheric humidity in the near-disturbance environment would shed light upon critical moisture thresholds important (or necessary) for tropical cyclogenesis and would help correct moisture biases in numerical weather prediction models. The downstream environment is most important for cyclogenesis predictions because that is the environment that a pre-TD moves into.
Flight Pattern
Find here a detailed description of intended flight patterns for the experiment.
Pouch Evolution During Genesis
Investigators
Ghassan Alaka (Co-PI), Jon Zawislak (Co-PI), Mark Boothe (Co-PI, Naval Postgraduate School, NPS), Michael Montgomery (Co-PI, NPS), Tim Dunkerton (Co-PI, Northwest Research Associates, NWRA), Blake Rutherford (CoPI, NWRA)Project Goal
To investigate the importance of the pouch, including the shear sheath, which tends to indicate a tropical storm, and its relationship to a low-level circulation and organized deep convection within the pouch [IFEX Goal 3]. In 2019, this experiment has the potential to also be flown collaboratively with the National Science Foundation supported Organization of Tropical East Pacific Convection (OTREC) Experiment.Observational Applications
Observations within this science goal have the potential to improve operational forecasts of tropical cyclone formation by identifying key characteristics of the pouch evolution in developing and non-developing storms. These tendencies can be quantified and incorporated into statistical genesis probabilities issued by the National Hurricane Center. Further impact on genesis forecasts can be made through model evaluation efforts, which have been historically lacking due to the sparse record of in-situ measurements of developing storms [IFEX Goal 1]. Of particular focus is on whether models replicate the location of pouch centers in the low and middle troposphere, and whether they represent well the observed thermodynamic environment encompassing the pouch.Science
Requirements
Pre-genesis disturbances (pre-TDs), including NHC-designated “Invests”
Motivation
A longstanding challenge for hurricane forecasters, theoreticians, and numerical weather forecast systems is to distinguish tropical waves that will develop into hurricanes from tropical waves that will not develop. The Naval Postgraduate School (NPS) Montgomery Research Group (MRG) has been tracking pouches in the Atlantic since 2008 in numerical models. Airborne observations provide much-needed data for analysis of processes critical for TC genesis, as well as an opportunity to compare our much-used numerical models with reality.
Flight Pattern
Find here a detailed description of intended flight patterns for the experiment.
Precipitation Module
Investigators
Jon Zawislak (Co-PI), Ghassan Alaka (Co-PI), and Paul Reasor (Co-PI)Goal
To investigate the precipitation modes (e.g., stratiform or convective precipitation) that are prevalent during the genesis stage, the evolution of key characteristics (e.g., areal coverage and intensity of precipitation), and the response of the potentially developing vortex to the observed precipitation organization [IFEX Goal 3]. In 2019, this experiment has the potential to also be flown collaboratively with the National Science Foundation supported Organization of Tropical East Pacific Convection (OTREC) Experiment. SObservational Applications
Observations within this science goal have the potential to improve operational forecasts of tropical cyclone formation by identifying tendencies in precipitation characteristics in developing and non-developing storms. These tendencies can be quantified and incorporated into statistical genesis probabilities issued by the National Hurricane Center. Further impact on genesis forecasts can be made through model evaluation efforts, which have been historically lacking due to the sparse record of in-situ measurements of developing storms [IFEX Goal 1]. This particular goal will require using (precipitation) tail Doppler radar data to identify whether precipitation biases exist within Hurricane Weather Research and Forecast (HWRF) model forecasts of potentially developing storms, which could subsequently feed back on the modeled (forecasted) vortex evolution.Science
Requirements
Pre-genesis disturbances (pre-TDs), including NHC-designated “Invests”
Motivation
One of the fundamental requirements to achieve a more accurate prediction, and understanding, of tropical cyclogenesis events is an improved knowledge of the precipitation organization and the developing vortex response, in the context of environmental forcing, during the formation process. While true that the favorable environmental conditions for tropical cyclogenesis have been well accepted for decades, those conditions also frequently exist in non-developing disturbances. An understanding of the sequence of events, and thus more informed prediction, of tropical cyclogenesis is still very much constrained by our inability to describe the relative contributions of precipitation organization (e.g., deep convection vs. stratiform rain), in the context of the environmental properties, to the evolution of the developing incipient vortex. Numerical models are a convenient platform to study tropical cyclogenesis events, and are often able to reproduce them, but the processes — particularly the relative roles of various precipitation modes involved — that contribute to genesis have generally been unobserved. Satellites are a convenient tool for identifying precipitation properties, particularly with the availability of the Dual-frequency Precipitation Radar (DPR) on the core satellite of the Global Precipitation Measuring Mission (GPM) and multiple higher resolution passive microwave sensors (AMSR2, GMI, SSMIS), but the vortex itself is not well observed; thus the co-evolution of precipitation and vortex cannot be described using satellites alone. Dedicated aircraft missions (outside of the GRIP-PREDICTIFEX, tri-agency field program effort in 2010) have historically been too few.
Flight Pattern
Find here a detailed description of intended flight patterns for the experiment.
Early Stage
Analysis of Intensity Change Processes Experiment
Investigators
Robert Rogers (Co-PI), Jon Zawislak (Co-PI), Trey Alvey (Co-PI), Jason Dunion (Co-PI), Ghassan Alaka (Co-PI), Heather Holbach (Co-PI), Xiaomin Chen (Co-PI), Josh Wadler (Co-PI, UM/RSMAS)Project Goal
The goal of this experiment is to collect aircraft observations (i.e., tail Doppler radar, lower fuselage radar, dropsonde, flight-level data, Doppler Wind Lidar, and stepped-frequency microwave radiometer) that will allow us to characterize the precipitation and vortex-scale kinematic and thermodynamic structures of tropical cyclones (TCs) experiencing moderate vertical shear. Understanding the reasons behind these structures, particularly greater azimuthal coverage of precipitation and vortex alignment, will contribute toward a greater understanding of the physical processes that govern whether TCs will intensify in this type of environment [IFEX Goal 3].Observational Applications
The data collected during this experiment will be useful for the evaluation of numerical model performance in the challenging forecasting environment of moderate vertical wind shear [IFEX Goal 1]. Radar measurements of reflectivity and vertical velocity, along with flight-level measurements of vertical velocity, can be used for the evaluation of microphysical parameterizations. Dropsonde measurements of low-level kinematic and thermodynamic structures and SFMR measurements of surface wind speed can be used to evaluate the performance of planetary boundary layer parameterizations. Select datasets can be withheld in observing system experiments (OSEs) to assess the impact of them on modeling accurately the TC structure and evolution. Finally, deep tropospheric dropsonde data can be used to assess the ability of geophysical retrievals (e.g., relative humidity) from operational satellites (e.g., instruments on NOAA-20, S-NPP) to accurately represent the characteristics of the environments moderately-sheared storms interact with.Science
Requirements
TD, TS, Category 1
Motivation
While some improvements in operational tropical cyclone (TC) intensity forecasting have been made in recent years (DeMaria et al. 2014), predicting changes in TC intensity (as defined by the 1-min. maximum sustained wind) remains problematic. In particular, the operational prediction of rapid intensification (RI) has proven to be especially difficult (Kaplan et al. 2010). The significant impact of such episodes has prompted the Tropical Prediction Center/National Hurricane Center (TPC/NHC) to declare it as its top forecast priority (Rappaport et al. 2009).
Flight Pattern
Find here a detailed description of intended flight patterns for the experiment.
Convective Burst Structure and Evolution Module
Investigators
Robert Rogers (PI), Jon Zawislak, Trey Alvey, Josh Wadler (UM/RSMAS), Michael Bell (CSU)Project Goal
The objectives are to obtain a quantitative description of the kinematic and thermodynamic structure and evolution of intense convective systems (convective bursts) and the nearby environment to examine their role in TC intensity change [IFEX Goals 1, 3].Observational Applications
The data collected during this experiment will be useful for the evaluation of numerical model performance in capturing the structure and evolution of deep convection, particularly as it evolves in a sheared environment. Radar measurements of reflectivity and vertical velocity, and cloud and precipitation probe measurements of hydrometeor type and size, can be used for the evaluation of microphysical parameterizations. Dropsonde measurements of low-level kinematic and thermodynamic structures and stepped-frequency microwave radiometer measurements of surface wind speed can be used to evaluate the performance of planetary boundary layer parameterizations. Select datasets can be withheld to assess the impact of them on TC structure and evolution in an observing system experiment (OSE) framework.Science
Requirements
TD, TS, Category 1
Motivation
The objectives are to obtain a quantitative description of the kinematic and thermodynamic structure and evolution of intense convective systems (convective bursts) and the nearby environment to examine their role in TC intensity change.
Flight Pattern
Find here a detailed description of intended flight patterns for the experiment.
Doppler Wind LIDAR
Investigators
Lisa Bucci (PI), Kelly Ryan, Jun Zhang, G. David Emmitt (Simpson Weather Associates, Inc.), Sid Wood (Simpson Weather Associates, Inc.)Goal
The goal is to create a more comprehensive 3-D analysis of the wind field within a TC through the addition of DWL observations to existing wind observing platforms [IFEX Goals 1 & 2]. Early-stage TCs often exhibit an asymmetric distribution of rain and the DWL can add wind observations in the precipitation-free regions of a developing storm.Observational Applications
The data collected during the module will be useful for the evaluation of data impact studies which include the DWL wind profiles. The more symmetric distribution of observations could lead to better initial conditions provided to the numerical models. A more accurate representation of the TC structure could generate more reliable intensity forecasts.Science
Requirements
TD, TS, Category 1
Motivation
Collect wind observations on the dry side of a TC with asymmetric precipitation distribution to provide symmetric coverage of its wind field.
Flight Pattern
Find here a detailed description of intended flight patterns for the experiment.
Gravity Waves
Investigators
Jun Zhang (Co-PI), David Nolan (Co-PI, University of Miami)Project Goal
This module aims to collect observations for improving our understanding of the characteristics of gravity waves in early-stage hurricanes. The goal is to quantify how the characteristics of these waves are related to hurricane intensity and intensity change. The observational data collected in this module will also be used to evaluate the hurricane structure in hurricane model simulations [IFEX Goals 1, 3].Observational Applications
Hurricane convection produces gravity waves that propagate both upward and outward. Physics in hurricane forecast models to represent these waves remain to be evaluated and improved for improving track and intensity prediction. The flight-level data collected from this module would provide valuable information for model evaluation and physics improvement. These observational data will be analyzed to quantify the characteristics of the gravity waves in early-stage hurricanes and their relationship with storm intensity and intensity change. Such relationship would assist the operational intensity forecast in the future. Furthermore, the observational data collected from this module would benefit model initialization in hurricane forecast and research models.Science
Requirements
TD, TS, Category 1
Motivation
Internal gravity waves are ubiquitous in the atmosphere and are continuously generated by deep moist convection around the globe. Gravity waves play a critical role in the dynamical adjustment processes that keep the atmosphere close to hydrostatic and geostrophic wind balance, by redistributing localized heating over larger distances. Numerical simulations showed gravity waves radiating from the eyewall region to the outer core in TCs. TC convection produces gravity waves that propagate both upward and outward. This module is designed to observe smaller scale gravity waves, with radial wavelengths of 2 to 20 km, that radiate outward from the TC core with phase speeds of 20 to 30 m s-1 . The goal is to quantify how the characteristics of these waves are tied to TC intensity and intensity change
Flight Pattern
Find here a detailed description of intended flight patterns for the experiment.
Stepped Frequency Microwave Radiometer (Early)
Investigators
Heather Holbach (PI)Project Goal
Improve the wind speed and rain rate estimates obtained by the P-3 and G-IV Stepped Frequency Microwave Radiometers (SFMR). For the P-3 SFMR, we aim to be able to obtain wind speed and rain rate estimates when the aircraft is not flying straight and level. For the G-IV SFMR, we aim to develop algorithm corrections to retrieve wind speed and rain rates from a higher altitude [IFEX Goal 2].Observational Applications
Improved measurements from the SFMR on the P-3 and G-IV have numerous implications for numerical modeling, operational, and research efforts. For numerical models, improved observations of the surface wind speed field will lead to better model initialization and allow for more accurate model evaluations. The operational community will benefit from more accurate surface wind speed observations allowing for improved estimates of tropical cyclone intensity and wind structure. Improvements to these quantities leads to better warnings and preparedness. Finally, SFMR data is used routinely in research studies. Therefore, all of those studies will benefit from improved wind speed and rain rate retrievals leading to more accurate results.Science
Requirements
: TD, TS, Category 1
Motivation
Surface winds in a tropical cyclone are essential for determining its intensity. Currently, the Stepped-Frequency Microwave Radiometer (SFMR) is used for obtaining surface wind measurements at nadir. Due to poor knowledge about sea surface microwave emission at large incidence angles in high wind speed conditions, SFMR winds are only retrieved when the antenna is pointed directly downward from the aircraft during level flight. Understanding the relationship between the SFMR measured brightness temperatures, surface wind speed, wind direction, and the ocean surface wave field at off-nadir incidence angles would allow for the retrieval of wind speed measurements when the aircraft is not flying level. At off-nadir incidence angles the distribution of foam on the ocean surface from breaking waves impacts the SFMR measurements differently than at nadir and is dependent on polarization (Holbach et al. 2018). Therefore, by analyzing the excess brightness temperature at various wind speeds and locations within the tropical cyclone environment at various off-nadir incidence angles, the relationship between the ocean surface characteristics and the SFMR measurements will be quantified as a function of wind direction relative to the SFMR look angle and polarization.
In addition, the proven track record of the P-3 SFMRs for providing surface wind data in tropical cyclones (Uhlhorn et al. 2007, Klotz and Uhlhorn 2014) has motivated the effort to obtain usable wind data from the G-IV SFMR. However, there is no documentation of the G-IV SFMR data and its usefulness under the current specifications of the G-IV flight patterns. To our knowledge no data from the G-IV SFMR has been released or used in any research or operational capacity. This data could potentially provide important information about the tropical cyclone wind radii as well as for mapping the environmental surface winds. The goal of this module is to validate the G-IV SFMR data with reliable, coincident P-3 SFMR data in the full spectrum of wind speeds and rain rates.
Flight Pattern
Find here a detailed description of intended flight patterns for the experiment.
Tail Doppler Radar (Early)
Investigators
Paul Reasor (Co-PI), John Gamache (Co-PI)Goal
The goal of the Early Stage TDR Experiment is to provide real-time quality-controlled airborne Doppler-radar radial velocities, as well as Doppler wind fields in the form of three dimensional Cartesian analyses, and vertical cross-sections of analyzed wind along the inbound and outbound radial flight tracks, to EMC, NHC, and CPHC. This is not a basic science experiment, even though the results can contribute to such studies, particularly composite early tropical-cyclone composites and statistical studies. A new goal is determining whether the three dimensional analyses can provide better information for assimilation than the more raw Doppler radial velocities. Another goal is to begin to test assimilation of TDR radar reflectivity [IFEX Goals 1, 2].Observational Applications
The added value of TDR observation over flight-level data, dropsondes and satellite data continue to be a topic of research. It is expected there is more value in early-stage tropical cyclones than in deep, well-organized systems, particularly in describing the tilt of the center, and the generally greater effect of shear over the system. The HRD HEDAS group is also beginning to evaluate whether including reflectivity and rms-error estimates of both velocity and reflectivity in the superobs can help the assimilation process. The HRD assimilation group will also be evaluating the products from this experiment to compare model runs using radar radial observations with those using three-dimensional wind and reflectivity analyses.Science
Requirements
TD, TS, Category 1
Motivation
This experiment is a response to the requirement listed as Core Doppler Radar in Section 5.4.2.9 of the National Hurricane Operations Plan (NHOP). The goal of that particular mission is to gather airborne-Doppler wind measurements that permit an accurate initialization of the Hurricane Weather Research and Forecasting (HWRF) model, and also provide three dimensional wind analyses for forecasters. 2019 will be the first year that the TDR analyses will be available in AWIPS-II for hurricane forecasters at NHC, CPHC, and any other forecast office that would find the analyses helpful. There is some reason to believe that TDR data are particularly helpful in initializing simulated tropical cyclones that are less organized. The incremental improvement over flight-level data only are greater at this stage, when the tilt of the center with height is often greater than in mature systems, and when the vertical coherence is less.
Flight Pattern
Find here a detailed description of intended flight patterns for the experiment.
Mature Stage
Environmental Interaction Tropical Cyclone in Shear
Investigators
Paul Reasor (PI), Xiaomin Chen, Jason Dunion, John Kaplan, Rob Rogers, Jon Zawislak, Jun Zhang, Michael Riemer (Johannes Gutenberg-Universität)Goal
Collect observations targeted at better understanding the response of mature hurricanes to changes in vertical wind shear, the variation in speed and direction with height of the winds surrounding a storm [IFEX Goals 1, 3].Observational Applications
It is presently unclear whether the physical parameterizations (e.g., microphysical and boundary layer) in hurricane forecast models properly represent the pathways for shear-induced intensity change. The targeting of boundary layer thermodynamic structure in particular would provide a unique data set for model evaluation as the TC transitions from axially symmetric structure to a shear-disrupted asymmetric structure. Additionally, the thorough sampling of near-core thermodynamic and kinematic structure of the storm environment should provide better initialization of the flow most closely responsible for interacting with the TC to produce structure and intensity change.Science
Requirements
Categories 2-5
Motivation
Although most TCs in HRD’s data archive experience some degree of vertical wind shear (VWS), the timing of flights with respect to the shear evolution and the spatial sampling of kinematic and thermodynamic variables have not always been carried out in an optimal way for testing hypotheses regarding shear-induced modifications of TC structure and their impact on intensity change (see below). This objective will sample the TC at distinct phases of its interaction with VWS and measure kinematic and thermodynamic fields with the azimuthal and radial coverage necessary to test existing hypotheses.
Flight Pattern
Find here a detailed description of intended flight patterns for the experiment.
Eyewall Mixing
Investigators
Sim Aberson (PI)Project Goal
Eyewall miso- and meso-scale vortices are ubiquitous in very intense (category-4 and category-5) tropical cyclones. However, we have never fully sampled their kinematic nor thermodynamic structures, nor do we know the importance of these features on intensity changes within tropical cyclones, if any. The goal of this experiment is to gain greater understanding of the structure of these features and their ultimate impact on intensity changes [IFEX Goals 1, 3].Observational Applications
The observational data obtained will be transmitted in real-time for incorporation in operational analyses of intensity as they will provide high-resolution measurements of near-surface winds independent of the SFMR. The data will be analyzed to gain understanding of the three-dimensional kinematic and thermodynamic structures of these features. Large eddy simulations of other high-resolution numerical models will be verified to see if similar structures are produced. The data will also be assimilated into very high-resolution numerical models to test their impact on forecasts.Science
Requirements
Categories 2–5
Motivation
Eyewall miso- and mesovortices have been hypothesized to mix high-entropy air from the eye into the eyewall, thus increasing the amount of energy available to the hurricane. They may also produce very high wind-speed signatures at the surface leading to small regions of extreme damage at landfall.
Flight Pattern
Find here a detailed description of intended flight patterns for the experiment.
Gravity Waves (Mature)
Investigators
Jun Zhang (Co-PI) and David Nolan (Co-PI, University of Miami)Goal
This module aims to collect observations for improve our understanding of the characteristics of gravity waves in hurricanes, that radiate outward from the hurricane core. The goal is to quantify how the characteristics of these waves are related to hurricane intensity and intensity change. The observational data collected in this module will also be used to evaluate the hurricane structure in hurricane model simulations [IFEX Goals 1, 3].Observational Applications
Hurricane convection produces gravity waves that propagate both upward and outward. Physics in hurricane forecast models to represent these waves remain to be evaluated and improved for improving track and intensity prediction. The flight-level data collected from this module would provide valuable information for model evaluation and physics improvement. These observational data will be analyzed to quantify the characteristics of the gravity waves in hurricanes. The relationship between the gravity wave properties and hurricane intensity will be derived using these observational data, which would assist the operational intensity forecast in the future. Furthermore, these data would be useful for model initialization purpose in hurricane forecast and research models.Science
Requirements
Categories 2-5
Motivation
Internal gravity waves are ubiquitous in the atmosphere and are continuously generated by deep moist convection around the globe. Gravity waves play a critical role in the dynamical adjustment processes that keep the atmosphere close to hydrostatic and geostrophic wind balance, by redistributing localized heating over larger distances. Numerical simulations showed gravity waves radiating from the eyewall region to the outer core in TCs. TC convection produces gravity waves that propagate both upward and outward. This module is designed to observe smaller scale gravity waves, with radial wavelengths of 2 to 20 km, that radiate outward from the TC core with phase speeds of 20 to 30 m s-1 . The goal is to quantify how the characteristics of these waves are tied to TC intensity and intensity change.
Flight Pattern
Find here a detailed description of intended flight patterns for the experiment.
Ocean Winds
Investigators
Paul Chang (NOAA/NESDIS/STAR), Zorana Jelenak (NOAA/NESDIS/STAR), Joe Sapp (NOAA/NESDIS/STAR)Goal
Improve our understanding of microwave scatterometer retrievals of the ocean surface wind field and to evaluate new remote sensing techniques/technologies. [IFEX Goal 2].Observational Applications
A primary application is to calibrate and validate satellite ocean wind products in extreme conditions found tropical and extratropical storms in support of the NWS marine analysis, warning and forecast mission. This experiment also tests of new remote sensing technologies for possible future satellite missions (risk reduction). The data collected can also be utilized to advance our understanding of broader scientific questions such as:- Rain processes in tropical cyclones and severe storms: the coincident dual-polarized, dual frequency, dual-incidence measurements would enable us to improve our understanding of precipitation processes in these moderate to extreme rainfall rate events.
- Atmospheric boundary layer (ABL) wind fields: the conical scanning sampling geometry and the Doppler capabilities of this system provide a unique source of measurements from which the ABL winds can be derived. The raw data system will enable us to use spectral techniques to retrieve the wind field all the way down to the surface.
- Analysis of boundary layer rolls: linearly organized coherent structures are prevalent in tropical cyclone boundary layers, consisting of an overturning “roll” circulation in the plane roughly perpendicular to the mean flow direction. IWRAP has been shown to resolve the kilometer-scale roll features, and the vast quantity of data this instrument has already collected offers a unique opportunity to study them.
- Drag coefficient, Cd: extending the range of wind speeds for which the drag coefficient is known is of paramount importance to further our understanding of the coupling between the wind and surface waves under strong wind forcing, and has many important implications for hurricane and climate modeling. The new raw data capability, which allows us to retrieve wind profiles closer to the ocean surface, can also be exploited to derive drag coefficients by extrapolating the derived wind profiles down to 0 m altitude.
Science
Requirements
Categories 2-5
Motivation
This effort aims to improve our understanding of microwave scatterometer retrievals of the ocean surface wind field and to evaluate new remote sensing techniques/technologies. The NOAA/NESDIS/Center for Satellite Applications and Research in conjunction with the University of Massachusetts (UMASS) Microwave Remote Sensing Laboratory, the NOAA/AOML/Hurricane Research Division, and the NOAA/OMAO/Aircraft Operations Center have been conducting flight experiments during hurricane season for the past several years. The Ocean Winds experiment is part of an ongoing field program whose goal is to further our understanding of microwave scatterometer and radiometer retrievals of the ocean surface winds in high wind speed conditions and in the presence of rain for all wind speeds. This knowledge is used to help improve and interpret operational wind retrievals from current and future satellite-based sensors. The hurricane environment provides the adverse atmospheric and ocean surface conditions required.
Flight Pattern
Find here a detailed description of intended flight patterns for the experiment.
Secondary Eyewall Formation
Investigators
Rob Rogers (PI), Hui Christophersen, Michael Fischer, Anthony Didlake (PSU)Goal
The goal of this module is to sample the TC inner core convection and environment when secondary eyewall formation (SEF) appears likely to occur or has already occurred within the storm. The module will provide critical observations for improving the understanding of the dynamic and physical processes of SEFs and eyewall replacement cycles, which have impacts on storm intensity and structure [IFEX Goals 1, 3].Observational Applications
The data collected during this module will be useful for the evaluation of numerical model performance during secondary eyewall formation [IFEX Goal 1]. Radar measurements of reflectivity and vertical velocity, along with flight-level measurements of vertical velocity, can be used for the evaluation of microphysical parameterizations. Dropsonde measurements of low-level kinematic and thermodynamic structures and SFMR measurements of surface wind speed can be used to evaluate the performance of planetary boundary layer parameterizations. Select datasets can be withheld in observing system experiments (OSEs) to assess the impact of them on modeling accurately the TC structure and evolution.Science
Requirements
Categories 2-5
Motivation
Secondary eyewall formation (SEF) and eyewall replacement cycles (ERCs) frequently occur during the mature phase of the tropical cyclone (TC) lifecycle. These processes typically result in a halting of the intensification of a TC, and occasionally lead to a temporary weakening as the secondary eyewall becomes the dominant eyewall (Sitkowski et al., 2011). Additionally, they typically coincide with a significant broadening of the wind field, increasing the total kinetic energy of the storm and thus the risks from widespread wind damage and storm surge. Statistical analysis of a 10-year (1997-2007) dataset shows that 77% of major hurricanes (120 knots or higher) in the Atlantic Ocean, 56% in the eastern Pacific, 81% in the western Pacific, and 50% in the Southern Hemisphere underwent at least one ERC (Hawkins and Helveston, 2008). Despite the relative frequency of their occurrence, operational forecasting of SEF/ERCs remains a great challenge, partly since there is no consensus on the mechanisms responsible for SEF or ERC.
Flight Pattern
Find here a detailed description of intended flight patterns for the experiment.
Stepped Frequency Microwave Radiometer
Investigators
Heather Holbach (PI)Project Goal
Improve the wind speed and rain rate estimates obtained by the P-3 and G-IV SteppedFrequency Microwave Radiometers (SFMR). For the P-3 SFMR, we aim to be able to obtain wind speed and rain rate estimates when the aircraft is not flying straight and level. For the G-IV SFMR, we aim to develop algorithm corrections to retrieve wind speed and rain rates from a higher altitude [IFEX Goal 2].Observational Applications
Improved measurements from the SFMR on the P-3 and G-IV have numerous implications for numerical modeling, operational, and research efforts. For numerical models, improved observations of the surface wind speed field will lead to better model initialization and allow for more accurate model evaluations. The operational community will benefit from more accurate surface wind speed observations allowing for improved estimates of tropical cyclone intensity and wind structure. Improvements to these quantities leads to better warnings and preparedness. Finally, SFMR data is used routinely in research studies. Therefore, all of those studies will benefit from improved wind speed and rain rate retrievals leading to more accurate results.Science
Requirements
Categories 2–5
Motivation
Surface winds in a tropical cyclone are essential for determining its intensity. Over the past several hurricane seasons, surface wind speed measurements from the SteppedFrequency Microwave Radiometer (SFMR), dropsondes, and surface adjusted flight-level winds in major hurricanes have not been consistent. By obtaining better collocated SFMR, dropsonde, and flight-level measurements in major hurricanes we will be able to determine what the cause of the inconsistency is. Better colocations of the SFMR and dropsondes will lead to improved calibration of the SFMR algorithm for high wind speeds by removing spatial colocation errors related to dropsonde drift.
Flight Pattern
Find here a detailed description of intended flight patterns for the experiment.
Tail Doppler Radar
Investigators
Paul Reasor (Co-PI), John Gamache (Co-PI)Goal
The goal of the Early Stage TDR Experiment is to provide real-time quality-controlled airborne Doppler-radar radial velocities, as well as Doppler wind fields in the form of three dimensional Cartesian analyses, and vertical cross-sections of analyzed wind along the inbound and outbound radial flight tracks, to EMC, NHC, and CPHC. This is not a basic science experiment, even though the results can contribute to such studies, particularly composite early tropical-cyclone composites and statistical studies. A new goal is determining whether the three dimensional analyses can provide better information for assimilation than the more raw Doppler radial velocities. Another goal is to begin to test assimilation of TDR radar reflectivity [IFEX Goals 1, 2].Observational Applications
The added value of TDR observation over flight-level data, dropsondes and satellite data continue to be a topic of research. It is expected there is more value in early-stage tropical cyclones than in deep, well-organized systems, particularly in describing the tilt of the center, and the generally greater effect of shear over the system. The HRD HEDAS group is also beginning to evaluate whether including reflectivity and rms-error estimates of both velocity and reflectivity in the superobs can help the assimilation process. The HRD assimilation group will also be evaluating the products from this experiment to compare model runs using radar radial observations with those using three-dimensional wind and reflectivity analyses.Science
Requirements
Categories 2-5
Motivation
This experiment is a response to the requirement listed as Core Doppler Radar in Section 5.4.2.9 of the National Hurricane Operations Plan (NHOP). The goal of that particular mission is to gather airborne-Doppler wind measurements that permit an accurate initialization of the Hurricane Weather Research and Forecasting (HWRF) model, and also provide three dimensional wind analyses for forecasters. 2019 will be the first year that the TDR analyses will be available in AWIPS-II for hurricane forecasters at NHC, CPHC, and any other forecast office that would find the analyses helpful. This particular experiment, though a required one because of operations, also provides numerous cases for developing composite and statistical studies of hurricanes.
Flight Pattern
Find here a detailed description of intended flight patterns for the experiment.
Tropical Cyclone Diurnal Cycle
Investigators
Jason Dunion (Co-PI), Morgan O’Neill (Co-PI), Daniel Chavas (Purdue Univ.)Goal
Collect observations targeted at better understanding how the tropical cyclone (TC) diurnal cycle affects hurricane intensity and structure and the environment surrounding the storm. This experiment will also investigate how the TC diurnal cycle impacts day-night oscillations of winds in the lower and middle levels (inflow and outflow) and the upper-level cirrus canopy (outflow) of these storms [IFEX Goals 1, 3].Observational Applications
Although the TC diurnal cycle may be a fundamental TC process, it is unclear how it is fully represented in numerical models. Data that is collected will focus on observing day-night oscillations temperature, moisture, radial winds, and precipitation in the hurricane environment that can provide better initialization of these various components of storm structure. GPS dropsonde observations will be quality controlled and transmitted to the GTS in real-time for assimilation in to numerical models and TDR data will be transmitted to NOAA EMC in real-time. The observations that are collected during this experiment will be used to evaluate the robustness of the operational coupled model forecast system to represent the TC diurnal cycle.Science
Requirements
Categories 2-5
Motivation
The objectives are to obtain quantitative information of the 3-dimensional kinematic and thermodynamic structure and evolution of TC diurnal pulses/waves and examine their effect on TC structure, intensity and the environment surrounding the storm. The TC diurnal cycle may additionally manifest as a substantial midlevel radial return flow underneath the primary TC outflow region during daytime, causing a temporary two-celled overturning circulation. This oscillatory return flow temporarily converges subsiding TC air back toward the storm core at mid-levels, increasing mid-level ventilation. The TC diurnal cycle and associated TC diurnal pulses/waves may be an important and fundamental TC process.
Flight Pattern
Find here a detailed description of intended flight patterns for the experiment.
End Stage
Extratropical Transition
Investigators
Sim Aberson (PI)Goal
More than half of all tropical cyclones in the Atlantic undergo extratropical transition, the process by which they change from a warm-core entity to a potentially large, powerful, and axisymmetric cyclone in the middle and northern latitudes. The transformation can also lead to large impacts both upstream and downstream of the tropical cyclone itself. The processes by which the transformation occurs is poorly understood and, more importantly, poorly forecast, as are the harmful impacts. The goal of this experiment is to gain greater understanding of the extratropical transition process with the ultimate goal of improving forecasts of these potentially high-impact events (IFEX Goals 1, 2, 3].Visit the Extratropical Transition Project Page to see an overview of Extratropical Transition.
Observational Applications
The observational data obtained will be incorporated into operational numerical weather prediction systems to test their impact on improving forecasts of track, intensity, and structure. It will also be assimilated into high-resolution models to test sophisticated data-assimilation techniques, and, with model forecasts, to do case studies. The data will also be used to verify forecast models at the observation time. The ultimate application is to improve forecasts of these potentially high-impact weather events.Science
Requirements
TC making landfall, undergoing rapid weakening, or extratropical transition
Motivation
The poleward movement of a TC initiates complex interactions with the midlatitude environment frequently leading to sharp declines in hemispheric predictive skill. In the Atlantic basin, such interactions frequently result in upstream cyclone development leading to high-impact weather events in the U. S. and Canada, as well as downstream ridge development associated with the TC outflow and the excitation of Rossby waves leading to downstream cyclone development. Such events have been shown to be precursors to extreme events in Europe, the Middle East, and may have led to subsequent TC development in the Pacific and Atlantic basins as the waves progress downstream. During this time, the TC structure begins changing rapidly: the symmetric distributions of winds, clouds, and precipitation concentrated about a mature TC circulation center develop asymmetries that expand. Frontal systems frequently develop, leading to heavy precipitation events, especially along the warm front well ahead of the TC. The asymmetric expansion of areas of high wind speeds and heavy precipitation may cause severe impacts over land without the TC center making landfall. The poleward movement of a TC also may produce large surface wave fields due to the high wind speeds and increased translation speed of the TC that results in a trapped-fetch phenomenon.
Flight Pattern
Find here a detailed description of intended flight patterns for the experiment.
Tropical Cyclones at Landfall
Investigators
Ghassan Alaka (Co-PI), Heather Holbach (Co-PI), John Kaplan, Peter Dodge, Jun Zhang, Frank MarksGoal
This experiment is designed to employ the P-3 aircraft to collect thermodynamic and kinematic observations in landfalling tropical cyclones to aid in achieving three goals: 1) To better understand the mechanisms that modulate a TC’s potential for producing tornadoes. [IFEX Goals 1, 3] 2) To investigate the factors that control both the magnitude of the wind gusts and rate of decay of the sustained wind both at and after landfall. [IFEX Goals 1, 3] 3) To reduce the uncertainty in SFMR wind speed estimates in coastal regions. [IFEX Goal 2].Observational Applications
The kinematic and thermodynamic data collected during this experiment will be useful both for real-time model initialization and analysis as well as post-storm validation purposes as the airborne Doppler, dropsonde, and SFMR data will each be transmitted in real-time and made available via public web sites after the completion of each flight. The comprehensive nature of the above datasets will allow researchers to perform various model sensitivity experiments to evaluate the forecast accuracy produced utilizing various model configurations as well to validate the accuracy of the pre and post landfall storm structure that is forecasted by a given model.Science
Requirements
Tropical Cyclone making landfall, undergoing rapid weakening, or extratropical transition
Motivation
The TC lifecycle often ends when it makes landfall and decays as it moves inland. During a landfall threat in the US, an average of 300 n mi (550 km) of coastline is placed under a hurricane warning, which costs approximately $1 million per n mi. The size of the warned area depends on the forecast track, extent of hurricane- and tropical storm-force winds, and evacuation lead-times. Research has helped reduce uncertainties in track forecasts, so the goal here is to improve the accuracy of the surface wind analyses and forecasts near and after landfall to allow for optimization of warning areas and reduction in preparations costs. In addition, forecasts of decay after landfall and of severe weather in the TC are required to adequately warn populations away from the coastline. Forecasts of severe weather, particularly tornadoes, embedded within a landfalling TC is particularly difficult.
Flight Pattern
Find here a detailed description of intended flight patterns for the experiment.
Satellite Validation
ADM-Aeolus
Investigators
Jason Dunion (Co-PI), Lidia Cucurull (Co-PI), Mike Hardesty (Co-PI, University of Colorado – NOAA/CIRES)Goal
Coordinate P-3 Orion and G-IV under-flights of the ADM-Aeolus satellite that will provide opportunities to calibrate and validate the satellite-based wind and aerosol observations against the remote sensing and in situ observations that will be collected by the NOAA aircraft [IFEX Goals 1 and 2].Observational Applications
The data collected during this experiment will be useful for validating ADM-Aeolus 3-dimensional wind and aerosol profiles. Remote sensing aircraft data that will be collected includes Doppler Wind Lidar (DWL) wind profiles (P-3 Orion), Tail Doppler Radar (TDR) wind profiles (P-3 Orion and G-IV), and DWL aerosol profiles (P-3 Orion). In situ data observations will include GPS dropsondes deployed from both the P-3 Orion and G-IV. The aircraft data will also be valuable for evaluating numerical model performance in environments such as TCs and the Saharan Air Layer. For more on the Saharan Air Layer, visit the Saharan Air Layer Page.Science
Requirements
No requirements: flown at any stage of the TC lifecycle
Motivation
ADM-Aeolus represents the first satellite mission to measure profiles of Earth’s wind globally and can also be used to detect atmospheric aerosols (Flamant et al. 2008). The validation and evaluation efforts proposed in this module are motivated by several factors: 1) ADM-Aeolus can provide 2,400 atmospheric wind profiles globally per day and can provide data in traditionally data sparse regions of the globe; 2) although the radius of tropical storm force winds (R34) is an important component of the TC forecast process, determining these winds in the periphery of TCs can be difficult in data sparse regions. ADM-Aeolus can provide valuable wind observations to help forecasters determine R34; 3) the Saharan Air Layer (SAL) has been shown to suppress TC formation and intensification in the Atlantic. ADM-Aeolus can detect the SAL’s suspended mineral dust and 600-800 hPa (z~4.4-2.1 km) mid-level easterly jet and can be used to help assess SAL-TC interactions.
Flight Pattern
Find here a detailed description of intended flight patterns for the experiment.
NESDIS JPSS
Investigators
Jason Dunion (Co-PI), Jon Zawislak (Co-PI), Michael Folmer (Co-PI), Chris Barnet (Co-PI), Rebekah Esmaili (Co-PI), Nadia Smith (Co-PI)Goal
Use GPS dropsondes launched from the NOAA G-IV jet to validate 3-dimensional temperature and moisture profiles produced from the NOAA-20 and Suomi-NPP polar orbiting satellites. The skill of these atmospheric profiles, created using the NOAA Unique Combined Atmospheric Processing System (NUCAPS) algorithm will be assessed using GPS dropsonde data and will also be used to evaluate analyses from the GFS and FV3-GFS models [IFEX Goals 1, 2, 3].Observational Applications
The data collected during this experiment will be useful for validating NUCAPS thermodynamic profiles produced from the CrIS (infrared) and ATMS (microwave) instruments flying onboard the NOAA-20 and Suomi-NPP polar orbiting satellites, as well as atmospheric stability indices derived from those profiles. The aircraft data will be valuable for evaluating numerical model performance in challenging environments with high temperature and moisture gradients and areas of high static stability (e.g., the Saharan Air Layer and dry air intrusions wrapping around tropical disturbances (e.g., African easterly waves, invests, and TCs).Science
Requirements
No requirements: flown at any stage of the TC lifecycle
Motivation
NUCAPS atmospheric soundings (temperature and moisture) produced from the NOAA-20 and Suomi-NPP polar orbiting satellites provide global coverage and have been extensively validated using ground-based and ship-launched rawinsondes (Nalli et al. 2013). However, the performance of NUCAPS in tropical environments with strong horizontal and vertical gradients in temperature and moisture [e.g., the Saharan Air Layer and the environments of tropical disturbances (e.g., African easterly waves (AEWs), invests, and TCs] has not been extensively assessed. The validation (NUCAPS) and evaluation (forecast models) efforts proposed in this experiment are motivated by two factors: 1) NUCAPS can provide thousands of atmospheric soundings in the environments of TCs globally; and 2) thermodynamics can be an important factor governing the intensity and structure of AEWs, invests, and TCs.
Flight Pattern
Find here a detailed description of intended flight patterns for the experiment.
Other Projects
Ocean Survey
Investigators
Jun Zhang (Co-PI), Nick Shay (Co-PI), Rick Lumpkin (NOAA/AOML/PhOD), George Halliwell (NOAA/AOML/PhOD), Elizabeth Sanabia (USNA), and Benjamin Jaimes (U. Miami/RSMAS)Goal
Collect observations targeted at better understanding the response of hurricanes to changes in underlying ocean conditions. The observational data collected in this experiment will be used to evaluate and improve hurricane model physics related to air-sea interaction [IFEX Goals 1, 3].Observational Applications
Physical parameterizations related to air-sea coupling in hurricane forecast models remain to be evaluated and improved to improve track and intensity prediction. The ocean and near-surface atmosphere observations from this experiment would provide a unique data set for model evaluation and physics improvement. The upper ocean kinematic and thermodynamic structure, as well as surface fluxes can be assessed in the hurricane prediction models by comparing to the observations collected in this experiment. The observational data can also be analyzed to derive new physics for the coupled hurricane model. Furthermore, the observational data collected in this experiment can also be used for model initialization purpose to improve the representation of the ocean and near-surface structure. Furthermore, detailed sampling of the kinematic and thermodynamic and structure of the ocean before the storm and in storm should provide better initialization of the ocean model used in the coupled hurricane modeling system.Science
Requirements
Categories 1–5
Motivation
Understanding physical processes associated with hurricane intensity and structure change is important for improve hurricane forecast through advanced numerical weather production models. Recent improvement in flux parameterizations has led to significant advancement in the accuracy of hurricane simulations and forecasts. These parameterizations, however, were based on a relatively small number of direct flux measurements. The overriding goal of these studies is to make additional flux measurements under a sufficiently wide range of conditions to improve flux parameterizations. In addition to flux observations, this Ocean Survey Experiment aims to measure the two-dimensional sea surface temperature cooling, air temperature, humidity, and wind fields beneath the storm and thereby deduce the effect of the ocean cooling on ocean enthalpy flux to the storm. To deduce the mechanisms and entrainment rates (shear-induced) of ocean cooling, the three-dimensional temperature, salinity and velocity structure of the ocean beneath the storm and thereby will also be measured. These observations will be used to assess the accuracy of the oceanic component of the coupled hurricane modeling system.
Flight Pattern
Find here a detailed description of intended flight patterns for the experiment.
Synoptic Flow
Investigators
Jason Dunion (Co-PI), Sim Aberson (Co-PI), Kelly Ryan, Jason Sippel, Rob Rogers, Ryan Torn (SUNY Albany), Eric Blake (NWS/NHC), Mike Brennan (NWS/NHC), Chris Landsea (NWS/TAFB)Goal
Investigate new sampling strategies for optimizing the use of aircraft observations to improve model forecasts of tropical cyclone track, intensity, and structure [IFEX Goal 1].Observational Applications
NHC’s Synoptic Surveillance missions were flown from 1998 until 2006 in collaboration with HRD’s hurricane field program; it was transitioned to operations at NOAA’s National Hurricane Center and Aircraft Operations Center in 2007. Since that time, definition of flight tracks has relied on the same targeting techniques developed over a decade ago. The new Synoptic Flow Experiment will target the collection of GPS dropsondes and tail Doppler radar (TDR) data using more advanced ensemble-based targeting techniques that optimize aircraft sampling of the TC environment. These targeted observations will be used to evaluate the impact of new adaptive sampling strategies on the operational coupled model forecast system’s forecasts of TC track, intensity, and structure. GPS dropsonde observations will be quality controlled and transmitted to the GTS in real-time for assimilation in to numerical models and TDR data will be transmitted to NOAA EMC in real-time.Science
Requirements
No requirements: flown at any stage of the TC lifecycle
Motivation
Operational G-IV Synoptic Surveillance missions have resulted in average GFS track-forecast improvements of 5–10% and statistically significant intensity improvements through 72 h (Aberson 2010). However, the basic G-IV flight-track design and observational sampling strategies have remained largely unchanged for the past decade while the model, ensemble and data-assimilation systems have been upgraded considerably. The Synoptic Flow Experiment is designed to investigate new strategies for optimizing the use of aircraft observations to improve numerical forecasts of TC track, intensity, and structure.
Flight Pattern
Find here a detailed description of intended flight patterns for the experiment.
Appendices
The P-3 Aircraft
Operational Flight Map
Primary Atlantic operating bases and ranges (assuming ~2-h on-station time) for the P-3.
The G-IV Aircraft
Operational Flight Map
Primary Atlantic operating bases and ranges (assuming ~2-h on-station time) for the G-IV
