upper ocean response and feedback to 2002 hurricanes isidore and lili in tandem

Upper Ocean Response and Feedback to 2002 Hurricanes Isidore and Lili in Tandem

Wei ZhaoShuyi S. Chen and Joseph Tenerelli

Rosenstiel School of Marine and Atmospheric ScienceUniversity of Miami

Hurricanes Isidore and Lili (2002) in tandem

Objectives

To examine the upper ocean circulation in response to Hurricanes Isidore and Lili in tandem.

To assess potential feedback to the atmosphere by the complex oceanic features in the Gulf of Mexico.

Ocean Circulation in Gulf of Mexico

William J. Schmitz Jr. (2003)

mean

maximum

minimum

Propagation path

Hybrid Coordinate Ocean Model (HYCOM)

• one-way nested Western Atlantic-Gulf of Mexico-Caribbean Sea regional domain (with data assimilation of SSH and SST prior to hurricane simulations)

• 0.08 degree grid spacing• 22 Vertical layer, 4-6 layers in mixed layer with the

1st layer at 3 meter • MM5 atmospheric forcing, 18 August – 17 October

2002 (Hurricanes Isidore and Lili)

Hurricane Isidore Hurricane Lili

SSHA (satellite)

SST/SSC (HYCOM)

Pre-Isidore

Satellite

SST pre- and post-Isidore

HYCOM

HYCOM

Satellite

SST Cooling post-Isidore

Satellite

SST pre- and post-Lili

HYCOM

HYCOM

Satellite

SST Cooling post-Lili

zTcQ p

Shay and CookHeat Content

pre- and post-Isidore

Satellite

HYCOM

Heat Content before and after Lili

Satellite

HYCOM

Shay and Cook

A B

B: Loop CurrentA: Gulf Common Water

Isidore Lili Isidore Lili

Conclusions

Upper ocean was cooled significantly by the passage of Isidore and, therefore, the heat content loss was much larger during Isidore than Lili.

Loop Current and warm core rings (WCR) continue to provide large amount heat during Lili while the Gulf common water heat content loss was close to zero.

Although satellite observed SST shows a recovery in a few days after each hurricanes, full recovery of upper ocean takes 1-2 weeks, which is largely affected by local circulation.

HYCOM is capable of producing observed fine upper ocean features and responses to hurricanes.