Influences of sea surface temperature in the tropical Pacific and Indian Oceans on tropical cyclone genesis over the western North Pacific in May

2017 ◽  
Vol 51 (5-6) ◽  
pp. 1915-1926 ◽  
Author(s):  
Jingliang Huangfu ◽  
Wen Chen ◽  
Tianjiao Ma ◽  
Ronghui Huang
Keyword(s):  
Tropical Cyclone ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
North Pacific ◽  
Western North Pacific ◽  
Tropical Pacific ◽  
Sea Surface ◽  
Tropical Cyclone Genesis ◽  
Cyclone Genesis ◽  
The Tropical Pacific

scholarly journals Environmental Factors Affecting Tropical Cyclone Power Dissipation

2007 ◽  
Vol 20 (22) ◽  
pp. 5497-5509 ◽  
Author(s):  
Kerry Emanuel
Keyword(s):  
Tropical Cyclone ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Time Scales ◽  
North Pacific ◽  
Wind Shear ◽  
Western North Pacific ◽  
Vertical Wind Shear ◽  
Sea Surface ◽  
Strongly Correlated

Abstract Revised estimates of kinetic energy production by tropical cyclones in the Atlantic and western North Pacific are presented. These show considerable variability on interannual-to-multidecadal time scales. In the Atlantic, variability on time scales of a few years and more is strongly correlated with tropical Atlantic sea surface temperature, while in the western North Pacific, this correlation, while still present, is considerably weaker. Using a combination of basic theory and empirical statistical analysis, it is shown that much of the variability in both ocean basins can be explained by variations in potential intensity, low-level vorticity, and vertical wind shear. Potential intensity variations are in turn factored into components related to variations in net surface radiation, thermodynamic efficiency, and average surface wind speed. In the Atlantic, potential intensity, low-level vorticity, and vertical wind shear strongly covary and are also highly correlated with sea surface temperature, at least during the period in which reanalysis products are considered reliable. In the Pacific, the three factors are not strongly correlated. The relative contributions of the three factors are quantified, and implications for future trends and variability of tropical cyclone activity are discussed.

scholarly journals Evaluating the Evidence of a Global Sea Surface Temperature Threshold for Tropical Cyclone Genesis

2017 ◽  
Vol 30 (22) ◽  
pp. 9133-9145 ◽  
Author(s):  
Cécile L. Defforge ◽  
Timothy M. Merlis
Keyword(s):  
Tropical Cyclone ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Sea Surface ◽  
Tropical Cyclone Genesis ◽  
Temperature Threshold ◽  
Global Threshold ◽  
The Difference ◽  
Thermodynamic Variables ◽  
Cyclone Genesis

Recent studies have reaffirmed a global threshold sea surface temperature (SST) of 26°C for tropical cyclone (TC) genesis. However, it is well understood that other thermodynamic variables influence TC genesis and that high SST in isolation is not a sufficient criterion for genesis. Here, a basin-by-basin analysis of the SST distributions in the five most active ocean basins is performed, which shows that there is no global SST threshold for TC genesis. The distributions of genesis SST show substantial variations between basins. Furthermore, analysis of the conditional probability of genesis for a given TC season main development region SST suggests that the SST bounds for TC genesis are largely determined by the climatological bounds of the basin and that the SST values within this environmental range have similar probabilities of genesis. The distribution of relative SST (the difference between local and tropical mean) and tropical cyclone potential intensity at TC genesis are more distinct from those of the TC season environment, consistent with their utility in TC genesis indices.

scholarly journals Response of Tropical Cyclone Tracks to Sea Surface Temperature in the Western North Pacific

2016 ◽  
Vol 29 (5) ◽  
pp. 1955-1975 ◽  
Author(s):  
Kotaro Katsube ◽  
Masaru Inatsu
Keyword(s):  
Tropical Cyclone ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
North Pacific ◽  
Linear Response ◽  
Western North Pacific ◽  
Lower Troposphere ◽  
Cyclonic Circulation ◽  
Sea Surface ◽  
The West

Abstract A set of short-term experiments using a regional atmospheric model (RAM) were carried out to investigate the response of tropical cyclone (TC) tracks to sea surface temperature (SST) in the western North Pacific. For 10 selected TC cases occurring during 2002–07, a warm and a cold run are performed with 2 and −2 K added to the SSTs uniformly over the model domain, respectively. The cases can be classified into three groups in terms of recurvature: recurved tracks in the warm and cold runs, a recurved track in the warm run and a nonrecurved track in the cold run, and nonrecurved tracks in both runs. Commonly the warm run produced northward movement of the TC faster than the cold run. The rapid northward migration can be mainly explained by the result that cyclonic circulation to the west of the TC is found in the steering flow in the warm run and it is not in the cold run. The beta effect is also activated under the warm SST environment. For the typical TC cases, a linear baroclinic model experiment is performed to examine how the cyclonic circulation is intensified in the warm run. The stationary linear response to diabatic heating obtained from the RAM experiment reveals that the intensified TC by the warm SST excites the cyclonic circulation in the lower troposphere to the west of the forcing position. The vorticity and thermodynamic equation analysis shows the detailed mechanism. The time scale of the linear response and the teleconnection are also discussed.

scholarly journals The Influence of Large-Scale Environment on the Extremely Active Tropical Cyclone Activity in November 2019 over the Western North Pacific

Atmosphere ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 501
Author(s):  
Mengying Shi ◽  
Sulei Wang ◽  
Xiaoxu Qi ◽  
Haikun Zhao ◽  
Yu Shu
Keyword(s):  
Tropical Cyclone ◽  
Environmental Factors ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
North Pacific ◽  
Western North Pacific ◽  
Large Scale ◽  
Vertical Wind Shear ◽  
Sea Surface ◽  
Formation Mechanisms

In November 2019, tropical cyclone (TC) frequency over the western North Pacific reached its record high. In this study, the possible causes and formation mechanisms of that record high TC frequency are investigated by analyzing the effect of large-scale environmental factors. A comparison between the extremely active TC years and extremely inactive TC years is performed to show the importance of the large-scale environment. The contributions of several dynamic and thermodynamic environmental factors are examined on the basis of two genesis potential indexes and the box difference index that can measure the relative contributions of large-scale environmental factors to the change in TC genesis frequency. Results indicate that dynamical factors played a more important role in TC genesis in November 2019 than thermodynamic factors. The main contributions were from enhanced low-level vorticity and strong upward motion accompanied by positive anomalies in local sea surface temperature, while the minor contribution was from changes in vertical wind shear. Changes in these large-scale environmental factors are possibly related to sea surface temperature anomalies over the Pacific (e.g., strong Pacific meridional mode).

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