Tropical Cyclone Eye Morphology and Extratropical-Cyclone-Forced Mountain Lee Waves on SAR Imagery

2017 ◽  
pp. 373-398
Author(s):  
Qing Xu ◽  
Xiaofeng Li ◽  
Shaowu Bao ◽  
Guosheng Zhang
Keyword(s):  
Tropical Cyclone ◽  
Extratropical Cyclone ◽  
Eye Morphology ◽  
Lee Waves ◽  
Sar Imagery

Tropical Cyclone Winds and Inflow Angle Asymmetry from SAR Imagery

2021 ◽  
Author(s):  
Guosheng Zhang ◽  
Xiaofeng Li ◽  
William Perrie ◽  
Jun A. Zhang
Keyword(s):  
Tropical Cyclone ◽  
Sar Imagery

scholarly journals The Contribution of Ex–Tropical Cyclone Gert (1999) toward the Weakening of a Midlatitude Cyclogenesis Event

2008 ◽  
Vol 136 (6) ◽  
pp. 2091-2111 ◽  
Author(s):  
Anna Agustí-Panareda
Keyword(s):  
Tropical Cyclone ◽  
Vertical Velocity ◽  
Initial Conditions ◽  
Negative Impact ◽  
Positive Impact ◽  
Extratropical Cyclone ◽  
Synoptic Scale ◽  
Extratropical Transition ◽  
Peak Intensity ◽  
The Impact

Abstract Tropical Cyclone Gert (1999) experienced an extratropical transition while it merged with an extratropical cyclone upstream. The upstream extratropical cyclone had started to intensify before it merged with the transitioning tropical cyclone, and it continued intensifying afterward (12 hPa in 12 h, according to the Met Office analysis). The question addressed in this paper is the following: what was the impact of the transitioning tropical cyclone on this intensification of the upstream extratropical cyclone? Until now, in the literature, tropical cyclones that experience extratropical transition have been found to have either no impact or a positive impact on the development of extratropical cyclogenesis events. The positive impact involves either a triggering of the development of the extratropical cyclone or simply a contribution to its deepening. However, the case studied here proves to have a negative impact on the developing extratropical cyclone upstream by diminishing its intensification. Forecasts are performed with and without the tropical cyclone in the initial conditions. They show that when Gert is not present in the initial conditions, the peak intensity of the cyclone upstream occurs 9 h earlier and it is 10 hPa deeper than when Gert is present. Thus, Gert acts to weaken the development by contributing to the filling of the extratropical surface low upstream. Quasigeostropic (QG) diagnostics show that the negative impact on the extratropical development is linked to the fact that the transitioning tropical cyclone interacts with a warm front inducing a negative QG vertical velocity over the developing extratropical low upstream. This interpretation is consistent with other contrasting cases in which the transitioning tropical cyclone interacts with a cold front and induces a positive QG vertical velocity over the developing low upstream, thus enhancing its development. The results are also in agreement with idealized experiments in the literature that are aimed at studying the predictability of extratropical storms. These idealized experiments yielded similar results using synoptic-scale and mesoscale vortices as perturbations on warm and cold fronts.

Simulations of the Extratropical Transition of Tropical Cyclones: Phasing between the Upper-Level Trough and Tropical Cyclones

2007 ◽  
Vol 135 (3) ◽  
pp. 862-876 ◽  
Author(s):  
Elizabeth A. Ritchie ◽  
Russell L. Elsberry
Keyword(s):  
Tropical Cyclone ◽  
Tropical Cyclones ◽  
Critical Factor ◽  
Complex Problem ◽  
Initial Position ◽  
Extratropical Cyclone ◽  
Extratropical Transition ◽  
Subtropical Anticyclone ◽  
Temperature And Precipitation ◽  
The Impact

Abstract Whether the tropical cyclone remnants will become a significant extratropical cyclone during the reintensification stage of extratropical transition is a complex problem because of the uncertainty in the tropical cyclone, the midlatitude circulation, the subtropical anticyclone, and the nonlinear interactions among these systems. In a previous study, the authors simulated the impact of the strength of the midlatitude circulation trough without changing its phasing with the tropical cyclone. In this study, the impact of phasing is simulated by fixing the initial position and amplitude of the midlatitude trough and varying the initial position of the tropical cyclone. The peak intensity of the extratropical cyclone following the extratropical transition is strongly dependent on the phasing, which leads to different degrees of interaction with the midlatitude baroclinic zone. Many aspects of the simulated circulation, temperature, and precipitation fields appear quite realistic for the reintensifying and dissipating cases. Threshold values of various parameters in quadrants near and far from the tropical cyclone are extracted that discriminate well between reintensifiers and dissipators. The selection and distribution of threshold parameters are consistent with the Petterssen type-B conceptual model for extratropical cyclone development. Thus, these simulations suggest that phasing between the tropical cyclone and the midlatitude trough is a critical factor in predicting the reintensification stage of extratropical transition.

SAR Observation and Numerical Simulation of Mountain Lee Waves Near Kuril Islands Forced by an Extratropical Cyclone

2016 ◽  
Vol 54 (12) ◽  
pp. 7157-7165 ◽  
Author(s):  
Qing Xu ◽  
Xiaofeng Li ◽  
Shaowu Bao ◽  
Leonard J. Pietrafesa
Keyword(s):  
Numerical Simulation ◽  
Kuril Islands ◽  
Extratropical Cyclone ◽  
Lee Waves

scholarly journals Wind direction retrieval of tropical cyclone from SAR imagery using improved local gradient method

2020 ◽  
Vol 569 ◽  
pp. 012055
Author(s):  
Yan Wang ◽  
Gang Zheng ◽  
Lizhang Zhou ◽  
Zhou Qiu ◽  
Xiaohui Li ◽  
...  
Keyword(s):  
Tropical Cyclone ◽  
Gradient Method ◽  
Wind Direction ◽  
Sar Imagery ◽  
Local Gradient

The Unusual Behavior and Precipitation Pattern Associated with Tropical Storm Ignacio (1997)

2012 ◽  
Vol 140 (10) ◽  
pp. 3347-3360 ◽  
Author(s):  
Kimberly M. Wood ◽  
Elizabeth A. Ritchie
Keyword(s):  
United States ◽  
Tropical Cyclone ◽  
North Pacific ◽  
Tropical Storm ◽  
Extratropical Cyclone ◽  
Precipitation Pattern ◽  
Northern Coast ◽  
Southwestern United States ◽  
Unusual Behavior ◽  
Pressure System

Abstract A case study of eastern North Pacific Tropical Storm Ignacio (1997), which brought rainfall to the southwestern United States as a tropical cyclone and to the northwestern United States as an extratropical cyclone, is presented. This tropical cyclone formed from a region of disturbed weather, rather than a tropical wave, outside the typical eastern North Pacific genesis region and intensified into a tropical storm coincident with the passage of an upper-tropospheric trough. Moisture transported from Ignacio along an outflow jet associated with the trough resulted in precipitation in Mexico and the southwestern United States. As Ignacio moved north and away from the trough, this tropical cyclone weakened and eventually underwent extratropical transition over the open ocean, in contrast to climatological eastern North Pacific tropical cyclone behavior. Ignacio then strengthened as an extratropical cyclone due to favorable baroclinic conditions and the passage of another upper-tropospheric trough before making landfall on the northern coast of California, bringing rain to the northwestern United States. Ignacio’s remnant moisture eventually merged into a slow-moving midlatitude low pressure system that developed after interacting with the extratropical remnant of Hurricane Guillermo.

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