An oceanic general circulation model is used to investigate the annual cycle of the near-surface currents in the eastern equatorial Pacific Ocean; in particular, the causes of the springtime increase of eastward momentum that reverses the westward surface flow and intensifies the Equatorial Undercurrent are examined. A set of process experiments are carried out that isolates effects due to thre...

Long-period oscillations in the period range 2– 30 days, interpreted as planetary wave (PW) signatures, have been analysed using daily mesosphere/lower thermosphere wind measurements near 90 km over Collm (52 N, 15 E) in the time interval 1980–2005. Interannual and interdecadal variability of PW are found. Since the 1990s, a tendency for larger zonal amplitudes compared to meridional ones has b...

With data from 12 coupled models in the 4th Assessment Report of the Intergovernmental Panel on Climate Change (IPCC-AR4), climate under year 2000 greenhouse gas (GHG) + aerosol forcing was compared with climate under pre-industrial conditions. In the tropical Pacific, the warming in the mean sea surface temperatures (SST) was found to have an El Niño-like pattern, while both the equatorial zon...

The response of the Southern Hemisphere (SH), extratropical, atmospheric general circulation to transient, anthropogenic, greenhouse warming is investigated in a coupled climate model. The extratropical circulation response consists of a SH summer half-year poleward shift of the westerly jet and a year-round positive wind anomaly in the stratosphere and the tropical upper troposphere. Along wit...

The known general solution of the system of linearized equations for non-viscous, adiabatic, quasi-hydrostatic flow on an equatorially oriented @-plane is examined in detail for various boundary conditions imposed on the motion. The base state is a space-time invariant zonal current. The particular solutions examined are those in which the meridional wind component is distributed either symmetr...

This SI Appendix is formed by three sections. Section 1 contains a brief discussion of the derivations of the dynamical model and its low-order meridional truncation. The details of boundary conditions, numerical solvers as well as a list of the parameter values are also included. The mathematical formula of the Walker circulation is shown at the end of this section. Section 2 involves the basi...

In this work we solve the set of hydrodynamical equations for accretion disks in the spherical coordinates (r,θ,ϕ) to obtain the explicit structure along θ direction. We study a two-dimensional advective accretion disc in the presence of thermal conduction. We find self-similar solutions for an axisymmetric, rotating, steady, viscous-resistive disk. We show that the global structure of an advec...

The dynamics of Lagrangian particles and tracers in the vicinity of a baroclinically unstable zonal jet are investigated in a simple 2-layer model with an initially quiescent lower layer. Presence of a wave induces a particle drift which is dominated by a Stokes drift rather then the mean Eulerian velocity due to the wave. Stable and unstable waves both have zonal Stokes drift with a similar me...

Abstract Intraseasonal waves in the tropical Atlantic Ocean have been found to carry prominent energy that affects interannual variability of zonal currents. This study investigates transfer and interaction wind-driven intraseasonal using single-layer model experiments. Three sets wind stress forcing at periods around 30 days, 50 days 80 with a realistic horizontal distribution are employed sep...

A majority of positive Indian Ocean dipole (IOD) events in the last 50 years were accompanied by enhanced summer monsoon circulation and above-normal precipitation over central-north India. Given that IODs peak during boreal autumn following the summer monsoon season, this study examines the role of the summer monsoon flow on the Indian Ocean (IO) response using a suite of ocean model experimen...