The Influence of Thermocline Topography on the Oceanic Response to Fluctuating Winds: A Case Study in the Tropical North Pacific

2001 ◽  
pp. 119-124
Author(s):  
Antonietta Capotondi ◽  
M. A. Alexander
Keyword(s):  
North Pacific ◽  
Oceanic Response

Tropical Cyclogenesis Associated with Kelvin Waves and the Madden–Julian Oscillation

2011 ◽  
Vol 139 (9) ◽  
pp. 2723-2734 ◽  
Author(s):  
Carl J. Schreck ◽  
John Molinari
Keyword(s):  
Tropical Cyclone ◽  
Tropical Cyclones ◽  
North Pacific ◽  
Western North Pacific ◽  
Diabatic Heating ◽  
Kelvin Waves ◽  
Tropical Cyclogenesis ◽  
Madden Julian Oscillation ◽  
Convective Envelope

The Madden–Julian oscillation (MJO) influences tropical cyclone formation around the globe. Convectively coupled Kelvin waves are often embedded within the MJO, but their role in tropical cyclogenesis remains uncertain. This case study identifies the influences of the MJO and a series of Kelvin waves on the formation of two tropical cyclones. Typhoons Rammasun and Chataan developed in the western North Pacific on 28 June 2002. Two weeks earlier, conditions had been unfavorable for tropical cyclogenesis because of uniform trade easterlies and a lack of organized convection. The easterlies gave way to equatorial westerlies as the convective envelope of the Madden–Julian oscillation moved into the region. A series of three Kelvin waves modulated the development of the westerlies. Cyclonic potential vorticity (PV) developed in a strip between the growing equatorial westerlies and the persistent trade easterlies farther poleward. Rammasun and Chataan emerged from the apparent breakdown of this strip. The cyclonic PV developed in association with diabatic heating from both the MJO and the Kelvin waves. The tropical cyclones also developed during the largest superposition of equatorial westerlies from the MJO and the Kelvin waves. This chain of events suggests that the MJO and the Kelvin waves each played a role in the development of Rammasun and Chataan.

scholarly journals A Case Study of Downstream Baroclinic Development over the North Pacific Ocean. Part I: Dynamical Impacts

2006 ◽  
Vol 134 (5) ◽  
pp. 1534-1548 ◽  
Author(s):  
Richard E. Danielson ◽  
John R. Gyakum ◽  
David N. Straub
Keyword(s):  
North Pacific ◽  
Initial Conditions ◽  
North Pacific Ocean ◽  
The North ◽  
Potential Vorticity Inversion ◽  
Surface Cyclone ◽  
Upper Level ◽  
The Impact ◽  
The North Pacific

Abstract The impact of eddy energy growth and radiation from a western North Pacific cyclone on the intensity of an eastern North Pacific cyclone a few days later is examined. Associated with the western cyclone is an upstream ridge and trough couplet, initially over Siberia on 8 March 1977. The amplitude of this couplet is perturbed in 5-day numerical simulations of the two marine cyclones. Balanced initial conditions are created by potential vorticity inversion. The magnitude of the upper-level couplet governs much of the subsequent growth of eddy energy in the western cyclone as well as the propagation of eddy energy between the two cyclones. This culminates in measurable changes in the maximum intensity of the eastern surface cyclone. The broader question of the sensitivity of this cyclone to upstream perturbations is also briefly addressed.

scholarly journals A Case Study of Downstream Baroclinic Development over the North Pacific Ocean. Part II: Diagnoses of Eddy Energy and Wave Activity

2006 ◽  
Vol 134 (5) ◽  
pp. 1549-1567 ◽  
Author(s):  
Richard E. Danielson ◽  
John R. Gyakum ◽  
David N. Straub
Keyword(s):  
Group Velocity ◽  
North Pacific ◽  
North Pacific Ocean ◽  
Wave Activity ◽  
The North ◽  
Initial Evolution ◽  
Activity Center ◽  
The North Pacific ◽  
Made In

Abstract The sequential development of a western, and then an eastern, North Pacific cyclone is examined in terms of eddy energy and a phase-independent wave activity. Based on the propagation of both a contiguous wave activity center and eddy energy, the development of the western cyclone appears to influence its downstream neighbor. A quantitative comparison of these two diagnoses is made in terms of group velocity, and only minor differences are found during much of the initial evolution. It is only once the tropopause undulations lose their wavelike appearance (at which point, application of the group-velocity concept itself becomes quite tenuous) that the downstream propagation of eddy energy seems faster than that of wave activity. Conventional methods of tracking this wave packet are also briefly discussed.

Sign in / Sign up

Export Citation Format

Share Document