Slide 1

IMPACT OF OCEAN OBSERVATIONSON HURRICANE IRENE INTENSITY FORECASTSS. Glenn, O. Schofield, J. Kohut, H. Roarty, J. Kerfoot, M. Oliver, H. Seim, G. Seroka, L. Palamara, W. Boicourt, W. Brown, L. Atkinson

1U..

CapeCodCapeHatterasNJMACTVADENYNCRIMDPA10 StatesMiddle AtlanticRegional Association Coastal Ocean Observing System1000 km Cape to Cape

GlidersForecastsL-BandX-BandCODARRegional Association 2004

Regional Coastal Ocean Observing System 20072

Total inches of rainfall032Aug 20-29

First tropical storm to threaten NYC since Hurricane Gloria in 1985Flooding records broken in 26 riversCaused at least 56 deathsDamage nearly $8 billion

Hurricane Irene

39.5N 73W Surface Current Time SeriesTotal Current Near-Inertial CurrentWave & Wind Direction Time SeriesHurricane Irene

Hurricane IreneDirect Wind ForcingInertial Response

Two Gliders Deployed by MARACOOS in Hurricane Irene

RU16 Deployed for EPA. Map bottom dissolved oxygen. Provided data on mixing during storm.

RU23 Deployed for MARACOOS. Map subsurface T/S structure for fisheries. Damaged early - drifter Recovered by fisherman Provided data on inertial currents during storm.

14332910560salinity% oxygentemperature55550055depthdepthdepth8/129/07date260Hurricane Irene

Hurricane Irene

Temp. Vert. Vel. Temp. Vert. Vel. Temp. Vert. Vel. RU16Temp.SectionUpcastDowncast

For Each 2-hour Segment:1) Calculate the Average Temperature Profile2) Calculate the Vertical Velocity Standard Deviation Profile and Smooth Vertically.Pre-IreneDuring IrenePost-IreneTempS.D. w

Time History of Mixing During Irene:Profiles of the Standard Deviation Vertical Velocity Profile Time Progresses from Red to BlueTempS.D. w

Time History of Mixing During Irene:Profiles of the Standard Deviation Vertical Velocity Profile Time Progresses from Red to Blue

Eddy viscosity

LinearLinear * Exponential Decay

Time Series of Derived ParametersGlider RU16NOAA Delaware Bay BuoyThermocline DepthSurface TempMax S.D. wMax S.D. w DepthWind SpeedWave HeightWave PeriodWave Bottom Orbital Velocity

RU-WRF Atmospheric Forecast Model14

27/120028/060028/060029/0600WRF Model Run: SST UpdateWARM (RTG only)COLD Update (AVHRR)Run Comparison

-little change in track (still good!)16Maximum Wind Speed Error (knots)Date/Time (UTC)

NHC Forecast

Warm (RTG only)

Warm (RTG only, OML Model)Cold Update(AVHRR)

27/12005-17.22-17.23-6.1727/1800104.14.25.8828/0000101.39-2.143.9628/06005-1.2-1.04-1.2128/1200152.394.790.528/1800154.973.51-2.6729/0000153.621.93-0.8929/06001010.489.844.52Sum of Squares800457452118RMSE9.437.137.093.61-RMSE much better than NHC forecast, better than Warm RTG only, Warm RTG w/ OML, and comparable to GFS17Wind Speed ErrorDate/Time (UTC)

NHC Forecast

Warm (RTG only)

Warm (RTG only, OML Model)Cold Update(AVHRR)

27/12005-17.22-17.23-6.1727/1800104.14.25.8828/0000101.39-2.143.9628/06005-1.2-1.04-1.2128/1200152.394.790.528/1800154.973.51-2.6729/0000153.621.93-0.8929/06001010.489.844.52Sum of Squares800457452118RMSE9.437.137.093.61

U.S. IOOS interactive observatory network closes a gap in storm science.

Bottom boundary layer mixing is responsible for surface layer cooling.

The cooling occurs rapidly during the peak in the storm waves.

Cooler sea surface temperatures reduce hurricane forecast intensities.

U.S. IOOS could produce better hurricane forecasts now.

Hurricane Irene - U.S. IOOS as it is designed A multi-agency activity.Make Observations > Advance the Science > Improve the Forecasts -RMSE much better than NHC forecast, better than Warm RTG only, Warm RTG w/ OML, and comparable to GFS18