Impact of Glider Data Assimilation on the Global Ocean Forecasting System During - PowerPoint Presentation

1. Impact of Glider Data Assimilation on the Global Ocean Forecasting System During the 2018 Hurricane SeasonMaria AristizabalScott GlennTravis Miles Benjamin LaCourPat Hogan MTS Oceans Meeting 2019Roy WatlingtonDoug Wilson (OCOVI)

2. Improve the intensity forecast of the operational hurricane modelshttps://www.emc.ncep.noaa.gov/gc_wmb/vxt/HWRF/index.phpHurricane Michael ForecastMotivation

3. After Hurricane MichaelCategory 5 at landfallStorm surge 7.7 feetTotal cost estimated as $25 billionMexico Beach

4. https://www.emc.ncep.noaa.gov/None of the models forecasted the rapid intensificationOfficial forecast predicted a cat 2 at landfallhttps://www.emc.ncep.noaa.gov/gc_wmb/vxt/HWRF/index.phpOct 8/2018Forecast Guidance for Storm Michael

5. Limitations on Hurricane Intensity ImprovementComputing resources and model resolution (Rotunno et al., 2009)Poor understanding of the atmospheric boundary layer (Nolan et al., 2009; Andreas et al., 2015)Difficulty in modeling the upper ocean response to storm forcing (Yablonsky and Ginis, 2009). ~ 50%~ 15 %NOAA Annual Operational Suite Review

6. Temperature and humidity differences at the air-sea interface control the heat fluxes. SST is a relevant ocean quantityDuring a storm, SST is manly controlled by the storm-induced vertical mixing and the strength of the vertical stratificationPrice 2009Hurricane Francis 2004Upper Ocean Response

7. In the continental shelf, there are other physical processes that control SST during storms: shear-induced vertical mixing due to wind-forced two-layer circulation (Glenn et al 2016), upwelling/downwelling circulation depending on the incident angle of the storm (Miles et al 2017) To capture the upper ocean response in the shelf is critical because the SST at the shelf will determine if a hurricane will intensify or weaken before landfall Hurricane Irene (Glenn et al 2016)On ShoreOff ShoreUpper Ocean Response

8. How to Improve the Modeling of the Upper Ocean Response During a Hurricane on the continental shelf?Improve the subsurface initial conditions in the operational ocean models: right initial vertical stratification, better evolution of the SST during storms , better heat fluxes estimates

9. How to Improve the Modeling of the Upper Ocean Response During a Hurricane on the continental shelf?Improve the subsurface initial conditions in the operational ocean models: right initial vertical stratification, better evolution of the SST during storms , better heat fluxes estimates Ocean Data Assimilation

10. HWRF/HYCOMHMON/HYCOMHWRF/POMWestPacificSouthPacificNorthIndianSouthIndianCentralPacificEastPacificNorth AtlanticHWRF – Hurricane Weather Research Forecasting ModelHYCOM – Hybrid Coordinate Ocean ModelHMON - Hurricanes in a Multi-scale Ocean-coupled Non- hydrostatic modelPOM – Princeton Ocean Model NOAA Hurricane Forecasting Models

11. Kim et al. 2014Forecasting Model: HWRF-HYCOM SystemICGOFS/NCODAICRTOFS – Real Time Ocean Forecasting SystemGFS – Global Forecasting SystemHurricane Coupled Ocean-Atmosphere

12. Navy Coupled Ocean Data Assimilation System (NCODA)Surface DataSatellite SSTSatellite AltimeterIn Situ SSTGOFS/NCODADrifting buoysFixed buoysArgo FloatsGlidersTESACXBTs (only temp.)Global Ocean Forecasting System (GOFS)Subsurface Temperature and Salinity

13. During the 2018 Hurricane SeasonArgo floats mostly occupy the open oceanOne vertical profile every ten days Argo Floats

14. During the 2018 Hurricane SeasonGlider observations are mostly in the shelfTens of profiles per dayArgo Floats

15. Center (DAC) During Hurricane Season 201862 Gliders in the IOOS Glider Data Assembly

16. ng288Seven Navy gliders reporting to the glider DACin the GoM during hurricane MichaelNg288 was at 36 km from the eye of hurricane MichaelHurricane Michael

17. Jason 2CryoSatArgoThe increment is the change made to the model state at the end of the previous assimilation cycleNCODA Temperature Increments

18. IncrementsInsertion WindowIncrementsInsertion WindowThe assimilation of glider data days ahead of Michael corrected the position of the thermoclineIncrementsInsertion WindowHurricane Michael

19. IncrementsInsertion WindowIncrementsInsertion WindowThe modeled SST increased after the passage of Michael: the ocean response is faster than the 1-day assimilation cycleHurricane Michael

20. Nine gliders reporting to the glider DACin the MAB during hurricane FlorenceRamses was at 188 km north from the eye of FlorenceHurricane FlorenceRamses

21. Hurricane FlorenceGOFS 3.1 captures the main features of the cold pool The model fails to produce the extend of the cold pool As a result the model can not produce the drop in temperature during Florence

22. Ongoing collaboration with NCEP to evaluate the coupled atmosphere-ocean hurricane forecasting models 2018100718 ForecastOngoing and Future WorkAssessing the impact of glider data assimilation during the current hurricane seasonDorianAug 20 – Sep 07

23. During hurricane Michael, the assimilation of glider data proved to be critical to improve the pre-storm vertical stratification in GOFS 3.1The length of the assimilation cycle in NCODA needs to be short enough to be able to capture the rapid ocean response during a hurricaneDuring hurricane Florence, GOFS 3.1 did not capture the extend of the cold pool in the MAB. This prevented the model from capturing the evolution of the SSTConclusions

24. SG665 Salinity at DeploymentJul 19Jul 20Jul 21Jul 22Jul 23Jul 24Jul 25Jul 27Large Salinity offset surface to 160 mSalinity Progressively Improves over 1 week period

25. SG665 Mean temperature and Salinity within the mixed layerDorianCold bias in GOFS 3.1 during Dorian0.3 oC0.6

26. DorianSG665 Mixed layer depth26o

27. DorianSG665 Mixed layer depth