Andrew P. Ingersoll

TL;DR: In this article, the authors show that the fine-tuning of this parameter could be the result of negative feedback in which processes associated with global dust storms raise the threshold and small-scale processes like dust devils, which are active in years between the storms, lower the threshold.

Abstract: Expressions are derived for the potential energy of a fluid whose density depends on three variables: temperature, pressure, and salinity. The thermal expansion coefficient is a function of depth, and the application is to thermobaric convection in the oceans. Energy conservation, with conversion between kinetic and potential energies during adiabatic, inviscid motion, exists for the Boussinesq and anelastic approximations but not for all approximate systems of equations. In the Boussinesq/anelastic system, which is a linearization of the thermodynamic variables, the expressions for potential energy involve thermodynamic potentials for salinity and potential temperature. Thermobaric instability can occur with warm salty water either above or below cold freshwater. In both cases the fluid may be unstable to large perturbations even though it is stable to small perturbations. The energy per mass of this finite-amplitude instability varies as the square of the layer thickness. With a 4-K temperature difference and a 0.6-psu salinity difference across a layer that is 4000 m thick, the stored potential energy is 0.3 m^2 s^−2, which is comparable to the kinetic energy of the major ocean currents. This potential could be released as kinetic energy in a single large event. Thermobaric effects cause parcels moving adiabatically to follow different neutral trajectories. A cold fresh parcel that is less dense than a warm salty parcel near the surface may be more dense at depth. Examples are given in which two isopycnal trajectories cross at one place and differ in depth by 1000 m or more at another.

TL;DR: In one model, the winds are confined to a thin layer at the surface; in another model the winds extend through the fluid depths of each planet as mentioned in this paper. But neither of these models describe the sun's two giant companions.

TL;DR: Porco et al. as discussed by the authors reported on simultaneous ISS images and CIRS thermal maps that confirm that the North Equatorial Belt (NEB) wave shown in the ISS ultraviolet (UV1) and strong methane band (MT3) images is correlated with the thermal wave in the C IRS temperature maps, with low temperatures in the ICIRS maps (upwelling) corresponding to dark regions in the UV1 images (UV absorbing particles) and bright regions in MT3 images (high clouds and haze).

TL;DR: Optical observations of lightning flashes detected on Jupiter by the Juno spacecraft with energies of approximately 105–108 joules, flash durations as short as 5.4 milliseconds and inter-flash separations of tens of milliseconds, with typical terrestrial energies are reported.