Structure & Intensity Change: Future Directions IWTC VI, Topic 1

Transcription

1 Structure & Intensity Change: Future Directions IWTC VI, Topic 1 Chair: Rob Rogers Rapporteurs Environmental Impacts (J. Evans) Inner Core Impacts (E. Ritchie) Oceanic Impacts (N. Shay) Observational Capabilities (E. Fukada and J. Molinari) Operational Techniques (A. Burton) Subtropical and Hybrid Cyclones (J. Gyakum)

2 Future directions for structure and intensity change research and forecasting I. What are the areas of structure and intensity change research most in need of further attention? II. How can these research advances best be transitioned to operations?

3 I. Recap of research advances since last IWTC Environmental Impacts shear humidity impacts (e.g., SAL) composites of environmental conditions for RI vs. non RI shear impacts on precip distribution TC size, forecast tools for wind radii Inner core Impacts angular momentum convergence above vs. within boundary layer radial location of diabatic heating vs. intensity change vortical hot towers multiple mechanisms proposed for RI competing mechanisms for superintensity secondary eyewall formation hub cloud dynamics eyewall slope/storm size

4 I. Recap of research advances since last IWTC Oceanic Impacts coupled ocean models and realistic temperature and salinity profiles as I.C. s entrainment mixing and impacts on OML, parameterizations OHC vs. SST as controls on lower boundary condition momentum and enthalpy exchange coefficients sea state maturity and sea spray effects multiscale aspects of air sea coupling through OML and ABL processes Observational Capabilities focus on satellite datasets geostationary and microwave primary tools surface wind estimation via SFMR, dropsonde, flight level reduction satellite based scatterometry loss of QuikSCAT big impact, ASCAT filled gap some value of microwave sensors for intensity estimation, center location intensity estimation algorithms (ADT, ARCHER addition of microwave info to ADT, SATCON) structure prediction schemes using satellites secondary eyewall formation emerging use of UAS, including Aerosonde, Global Hawk, Aeroclipper

5 I. Recap of research advances since last IWTC Operational Techniques analysis of TC structure RMW and wind radii use of GEO imagery, low level AMV s to infer wind field size value of microwave imagers inner core structure and environmental impacts structure forecasting much more subjective than intensity forecasting poor cousin of track and intensity statistical/dynamical models continue to show most skill for intensity change, including RI dynamical models high resolution, advanced data assimilation and parameterizations increased emphasis on consensus methods for intensity forecast needed mesoscale ensembles likely best approach for structure and intensity forecast guidance Subtropical and Hybrid Cyclones climatological characteristics of formation of these systems pathways to TC development 6 paths, of which only 40% were strictly nonbaroclinic Intra and inter basin variability of development pathways operational response to STC and hybrid cyclones predictability limits of hybrid systems composite analyses and numerical simulation

6 I. Proposed foci for future research efforts Environmental impacts shear, humidity (e.g., SAL), wind structure forecasting Inner core impacts RI mechanisms (inner core vs. environmental controls), secondary eyewall formation and prediction Oceanic impacts expanded ocean observations and assimilation methods, exchange coefficient (especially landfall), sea spray impacts Observational capabilities continued development of satellite based intensity estimates, unmanned aerial systems (UASs) Operational techniques improving structure analysis and forecasts, continued development of statistical/dynamical intensity guidance, optimal use of numerical models Subtropical and hybrid cyclones pathways to development, universal classification scheme, model performance

7 I. Proposed foci for future research efforts Ventilation impact on peak intensity Theory Diagnostics (Tang and Emanuel 2010) How can this result be incorporated into improved intensity and structure forecasts? Can it be applied to existing statistical/dynamical intensity prediction schemes (e.g., SHIPS)?

8 I. Proposed foci for future research efforts Eyewall mesovortices and impact on inner core structure and intensity Absolute Vorticity Storm relative asymmetric wind wind vectors vectors How can this result be incorporated into improved intensity and structure forecasts? What does this result imply for requirements for operational models (e.g., horizontal resolution)? What demands would this place on observational networks? (Braun et al. 2006; Cram et al. 2007)

9 I. Proposed foci for future research efforts Wind wave coupling and drag coefficient Different formulations of C D vs. 10 m wind C D vs. wave age Good example of transition of research result to modeling community. Enthalpy exchange coefficient dependence on 10 m winds, wave age still not well known. Moon et al. (MWR, 2004) Moon et al. (MWR, 2004) What demands would this place on observational networks? On operational modeling capabilities?

10 I. Proposed foci for future research efforts Genesis pathways with a focus on TCs that form in conjunction with extratropical precursors developers non developers How can this result be incorporated into improved intensity and structure forecasts? How can these results be quantified for forecaster use? What demands would this place on observational networks? from Galarneau

11 I. Proposed foci for future research efforts How best to incorporate new observing platforms? new spaceborne platforms (e.g., Megha Tropiques, GPM Core) new airborne platforms (e.g., UAS) OSSE s, OSE s How best to promote modeling advances that incorporate new research results? data assimilation/vortex initialization techniques (3DVar, 4DVar, EnKF, hybrid, bogussing) model evaluation/physical parameterization development improved use of ensemble techniques

12 I. How best to incorporate new observing platforms? Unmanned Aerial Systems (UASs) Aeroclipper Could this observing platform be practically used for improved operational forecasts? Relative tangential and radial wind recorded by the Aeroclipper 1 (circles, 30 Jan utc 31 Jan 2310 utc ) and 2 (squares, 30 Jan utc ) as they converged into Dora. The radius of the polar graph represents the separating distance from Dora s centre (log scale) and the angle represents the position of the Aeroclipper in regard to Dora s motion (zero angle corresponds to Dora s track). The black crosses indicate the eyewall crossings. From: The Aeroclipper, a new device to explore convective systems and cyclones, J.P. Duvel at al. BAMS Jan 2009 Relative trajectories of tropical cyclone DORA (green) and of the two Aeroclippers that were captured within the storm s eye during the period 29 January 12 utc to 6 February 00 utc 2007 superimposed to the IR Meteosat 7 image of 3 February at 03 utc. What would be the impact on other observational networks?

13 I. How best to promote modeling advances that incorporate new research results? Impact of horizontal resolution on three dimensional vortex structure Tangential wind (m/s) airborne Doppler composite Tangential wind (m/s) 9 km HWRFx Tangential wind (m/s) 3 km HWRFx How can this result be incorporated into improved intensity and structure forecasts? normalized radius Vertical wind (m/s) airborne Doppler composite Vertical wind (m/s) 9 km HWRFx Vertical wind (m/s) 3 km HWRFx How to quantify importance of horizontal resolution vs. other model parameters? What demands would this place on operational modeling resources? normalized radius Ensemble vs. deterministic?

14 II. How best to transition research results into operations? How well do existing research efforts map onto operational priorities? NHC/JTWC Operational Priorities top priority Intensity change/ri improved observations, guidance on guidance high priorities track, genesis medium priority rainfall, wind structure forecasts, seasonal forecasts lower priority 14

15 II. How well do existing research efforts map onto operational priorities? Research Efforts 15

16 II. How well do existing research efforts map onto operational priorities? Distribution of Research Activities Combined Man Years vs. Detailed Research Intensity / Structure Track Genesis QPF Surge Model Development Observations [Seasonal]

17 II. How well do existing research efforts map onto operational priorities? Combined Man Years Mapped to NHC Priorities TC Research Roughly Aligned with Operational Priorities Intensity & Structure: ~ 35% HFIP Intensity Intensity Change Change Stat Aids Observations Observations Storm Surge Fcst Efficiency Genesis Genesis Track Fcst QPF Model Res vs Ensembles Size/Structure Size/Structure Wind Analysis Radar/Sat. Data Seasonal Progs SST Gradients

18 II. Proposed foci for future transition efforts Transition to operations Perform compilation of operational needs Conduct mapping of research activities onto needs Establish review and funding mechanisms for research activities tied into operations (e.g., JHT, HFIP)

19 I. Proposed foci for future research efforts Eyewall slope vs. various parameter s from multiple Doppler passes How can this result be incorporated into improved intensity and structure forecasts? What does this result imply for model initialization? What demands would this place on observational networks? Stern and Nolan (JAS, 2009)

20 How best to transition research results into operations? mechanisms for transition JHT (U.S.) HFIP (U.S.) WG/TCR (U.S.) how can improved understanding be transitioned to improved forecasting? improvement of dynamical models development/improvement of statistical/dynamical models e.g., SHIPS, RI index, wind radii CLIPER statistical methods pattern recognition for forecasters examples RMW slope baroclinic pathways to genesis momentum/enthalpy exchange coefficients and wave age

21 How to transition research results? NOAA Joint Hurricane Testbed (JHT) Mission To transfer more rapidly and smoothly new technology, research results, and observational advances of the United States Weather Research (USWRP), its sponsoring agencies, the academic community and other groups into improved tropical cyclone analysis and prediction at operational centers. Process Principal Investigators apply for funding through NOAA A seven member Steering Committee rates all proposals Funded projects are tested during one or two hurricane seasons in conjunction with NHC/ Environmental Modeling Center points of contact At the project s end, each are evaluated by NHC/EMC staff Implementation of successful projects are then carried out by NHC/EMC staff/pis Since first year in 2001, 62 projects supported, 50 completed, 35 transitioned to operations Factors Considered in NHC Decisions on Operational Implementation Forecast or Analysis Benefit Efficiency Compatibility Sustainability

22 How to transition research results? Goals Improve Forecast Accuracy Hurricane impact areas (track) 50% in 10 years Severity (intensity) 50% in 10 years Storm surge impact locations and severity Extend forecast reliability out to 7 days Quantify, bound and reduce forecast uncertainty to enable risk management decisions Accomplish this through Improved models Improved observations Improved understanding