on the multi-intensity changes of hurricane earl (2010) daniel nelson, jung hoon shin, and da-lin...
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On the Multi-Intensity Changes of Hurricane Earl (2010)
Daniel Nelson, Jung Hoon Shin, and Da-Lin Zhang
Department of Atmospheric and Oceanic ScienceUniversity of Maryland, College Park
Our studies of NASA’s “old” Storms• Cecelski, S., and D.-L. Zhang, 2013: Genesis of Hurricane Julia (2010) within an African
Easterly wave: Low-level vortices and upper-level warming. J. Atmos. Sci., 70, 3799-3817.
• Cecelski, S., D.-L. Zhang, and T. Miyoshi, 2014: Genesis of Hurricane Julia (2010) within an African Easterly wave: Developing and non-developing members from WRF-LETKF ensemble forecasts. J. Atmos. Sci., 71, 2763-2781.
• Cecelski, S., and D.-L. Zhang, 2014: Genesis of Hurricane Julia (2010) within an African easterly wave: Sensitivity analysis of WRF-LETKF ensemble forecasts. J. Atmos. Sci., 71, 3180-3201.
• Cecelski, S., and D.-L. Zhang, 2015: Genesis of Hurricane Julia (2010) within an African easterly wave: Sensitivity to ice microphysics. Submitted to J. Appl. Meteor. Climatol.
• Zhu, L., D.-L. Zhang, S. F. Cecelski, and X. Shen, 2015: Genesis of Tropical Storm Debby (2006) within an African Easterly wave: Roles of the bottom-up and midlevel pouch processes. J. Atmos. Sci., in press.
NASA - HS3 Workshop
Previous studies of Hurricane Earl (2010)• Rogers et al. (2015) studied multiscale structure and evolution
during RI using data from aircraft missions flown into the storm;
• Chen and Gopalakrishan (2015) modeled the asymmetric RI using the HWRF system with the finest resolution of 3 km;
• Stevenson et al. (2015) examined the relationship between an inner-core lightning outbreak and the subsequent RI;
• Shay and Uhlhorn (2015) calculated enthalpy and momentum fluxes in relation to intensity change and underlying upper-ocean thermal structure during Earl’s RI stage.
NASA - HS3 Workshop
The purposes of this study
• Examine the multiple intensity and structural changes, including RI and an eyewall replacement cycle;
• Explore the mechanisms by which SEF occurred and the modeling sensitivity to SEF; and
• Study the structural changes of upper outflows during RI of Earl and their roles.
This work will be conducted using the WRF-ARW with the finest grid size of 1.333 km.
NASA - HS3 Workshop
Nested-grid domains 45/15/5/1.667-km resolutions 45-km domain: 210 x 15015-km domain: 319 x 3195-km domain: 301 x 301
1.667-km domain: 271 x 271Vertical grids 50 levels with higher resolution in the lowest 300 hPa
and the model top at 30-hPaPlanetary Boundary layer The YSU scheme
Cumulus parameterization The Betts-Miller scheme for 45/15/5-km domains.No Cumulus scheme for 1.667-km domain.
Cloud microphysics The Thompson scheme
Radiation parameterization: The RRTM longwave scheme, and the Dudhia shortwave schemeInitialization time: 0000 UTC 28 August 2010 with the NCEP re-analysis
Model configuration
NASA - HS3 Workshop
NASA - HS3 Workshop
Time series of the model-simulated (PWRF, VWRF) and the observed (POBS, VOBS) maximum surface wind (m s-1) and minimum sea-level pressure (hPa)
Time series of the 1000 by 1000 km area-averaged 200-850 hPa vertical wind shear and shear direction.
NASA - HS3 Workshop
NASA - HS3 Workshop
Tangential winds as a function of time and radius (every 5 m s-1), superimposed with the radar reflectivity (dBZ), at z = 3 km
NASA - HS3 Workshop
Summary and conclusions
• The WRF-ARW reproduces reasonably well the multiple intensity and structural changes, especially the eyewall replacement cycle, but with a large track error.
• Results show changes in SSTs, VWS, upper-level flows and environmental moistures during the multiple intensity and structural change period, indicating possible roles of these parameters in affecting the storm intensity and structural changes.