Tropical Cyclone Heat Potential (TCHP) from the NCMRWF NEMO  based global ocean analysis and forecast system

Abstract Crosnier, L., Drévillon, M., Ramos Buarque, S., and Soulat, F. 2008. Three ocean state indices implemented in the Mercator-Ocean operational suite. – ICES Journal of Marine Science, 65: 1504–1507. We present three indices for the state of the ocean, all computed using the Mercator-Ocean analyses and ocean forecast system: an upwelling index based on sea surface temperature (SST), the tropical cyclone heat potential, showing the thermal energy available in the ocean to enhance or decrease the power of cyclones, and the Indian Ocean dipole mode index based on SST. Such indices are updated on a weekly or monthly basis.

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Effects of ocean eddies on the tropical storm Roanu intensity in the Bay of Bengal

PLoS ONE ◽

10.1371/journal.pone.0247521 ◽

2021 ◽

Vol 16 (3) ◽

pp. e0247521

Author(s):

Yujun Liu ◽

Haibin LÜ ◽

Honghua Zhang ◽

Yusheng Cui ◽

Xueting Xing

Keyword(s):

Tropical Cyclone ◽

Bay Of Bengal ◽

Tropical Storm ◽

The West ◽

Initial Development ◽

Ocean Eddies ◽

Tropical Cyclone Heat Potential ◽

Warm Eddy ◽

Heat Potential ◽

Cold Eddy

A tropical storm (TS) Roanu occurred in northern Sri Lanka in 2016, which transported northwards along the west coast of the Bay of Bengal (BoB). During the development of the TS, ocean eddies on its track had an important effect on the intensity of Roanu. The dynamic mechanism was investigated with multisource reanalysis and Argo float data in this study. The results show that ocean eddies were the main reason why Roanu first enhanced, weakened, and then enhanced again. Warm eddy W1 supports the initial development of the TS, cold eddy C1 weakens Roanu, and warm eddy W2 continues to support Roanu. On May 19, 2016, the maximum average latent heat flux over W1 was 260.85 w/m2, while that of C1 was only 200.71 w/m2. After the passage of Roanu, the tropical cyclone heat potential (TCHP) of eddies significantly decreased. The TCHP of W1, W2, C1 and C2 decreased by 20.95 kJ/cm2, 11.07 kJ/cm2, 29.82 kJ/cm2, 9.31 kJ/cm2, respectively. The mixed layer of warm eddies deepened much more than that of cold eddies, supporting Roanu development. In addition, changes in potential vorticity (PV) values caused by the disturbance of eddies may also reflect changes in the TS intensity. This study offers new insights on the influence of ocean eddies in regulating the development of tropical cyclone (TC) in the BoB.

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Western North Pacific Tropical Cyclone Characteristics Stratified by Genesis Environment

Monthly Weather Review ◽

10.1175/mwr-d-17-0110.1 ◽

2018 ◽

Vol 146 (2) ◽

pp. 435-446 ◽

Cited By ~ 9

Author(s):

Hironori Fudeyasu ◽

Ryuji Yoshida

Keyword(s):

Tropical Cyclone ◽

North Pacific ◽

Western North Pacific ◽

Convective Available Potential Energy ◽

The Philippines ◽

Vertical Shear ◽

Occurrence Rate ◽

Tropical Cyclone Heat Potential ◽

Heat Potential ◽

Confluence Region

Abstract The characteristics of tropical cyclones (TCs) in the summer and autumn seasons over the western North Pacific that are associated with different environmental factors that influence TC genesis (TCG) were studied. The authors objectively categorized factors into the five TCG factors classified by Ritchie and Holland: monsoon shear line (SL), monsoon confluence region (CR), monsoon gyre (GY), easterly wave (EW), and the Rossby wave energy dispersion from a preexisting TC (PTC). The GY-TCs tended to develop slowly, and the highest rates of occurrence of rapid intensification (RI) were found for the CR-TCs, whereas the GY-TCs rarely experienced RI. The average storm size of the GY-TCs at the time of formation was the largest of the averages among the TC types, while the EW- and PTC-TCs were smaller, although these differences disappeared at the mature time. There were no significant differences in the sea surface temperature (SST) beneath the TCs, but the tropical cyclone heat potential (TCHP) of the PTC-TCs was higher. The PTC-TCs tended to develop as intense TCs and exhibited favorable environmental characteristics, such as high TCHP, high convective available potential energy, and weak vertical shear. The occurrence rate of the PTC-TCs that made landfall in the Philippines was higher than the averages of the other TC types, whereas those of the EW-TCs (PTC-TCs) that made landfall in Japan (China) were lower. These results provide important information for use in disaster prevention.

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