Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 5.668 IF 5.668
  • IF 5-year value: 6.201 IF 5-year
    6.201
  • CiteScore value: 6.13 CiteScore
    6.13
  • SNIP value: 1.633 SNIP 1.633
  • IPP value: 5.91 IPP 5.91
  • SJR value: 2.938 SJR 2.938
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 174 Scimago H
    index 174
  • h5-index value: 87 h5-index 87
Volume 16, issue 23
Atmos. Chem. Phys., 16, 14925–14936, 2016
https://doi.org/10.5194/acp-16-14925-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
Atmos. Chem. Phys., 16, 14925–14936, 2016
https://doi.org/10.5194/acp-16-14925-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.

Research article 02 Dec 2016

Research article | 02 Dec 2016

Revisiting the steering principal of tropical cyclone motion in a numerical experiment

Liguang Wu1,2 and Xiaoyu Chen1 Liguang Wu and Xiaoyu Chen
  • 1Key Laboratory of Meteorological Disaster, Ministry of Education (KLME), Pacific Typhoon Research Center (PTRC), Nanjing University of Information Science & Technology, Nanjing, China
  • 2State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing, China

Abstract. The steering principle of tropical cyclone motion has been applied to tropical cyclone forecasting and research for nearly 100 years. Two fundamental questions remain unanswered. One is why the steering flow plays a dominant role in tropical cyclone motion, and the other is when tropical cyclone motion deviates considerably from the steering. A high-resolution numerical experiment was conducted with the tropical cyclone in a typical large-scale monsoon trough over the western North Pacific. The simulated tropical cyclone experiences two eyewall replacement processes.

Based on the potential vorticity tendency (PVT) diagnostics, this study demonstrates that the conventional steering, which is calculated over a certain radius from the tropical cyclone center in the horizontal and a deep pressure layer in the vertical, plays a dominant role in tropical cyclone motion since the contributions from other processes are largely cancelled out due to the coherent structure of tropical cyclone circulation. Resulting from the asymmetric dynamics of the tropical cyclone inner core, the trochoidal motion around the mean tropical cyclone track cannot be accounted for by the conventional steering. The instantaneous tropical cyclone motion can considerably deviate from the conventional steering that approximately accounts for the combined effect of the contribution of the advection of the symmetric potential vorticity component by the asymmetric flow and the contribution from the advection of the wave-number-one potential vorticity component by the symmetric flow.

Publications Copernicus
Download
Short summary
The study shows that the conventional steering calculated over a certain radius from the tropical cyclone center in the horizontal and a deep pressure layer in the vertical is not literally the steering or the advection of the symmetric potential vorticity component associated with a tropical cyclone by the asymmetric flow. The trochoidal motion around the mean tropical cyclone track cannot be accounted for by the effect of the conventional steering.
The study shows that the conventional steering calculated over a certain radius from the...
Citation