A numerical model of isotropic homogeneous turbulence with helical forcing is investigated. The resulting flow, which is essentially the prototype of the α dynamo of mean-field dynamo theory, produces strong dynamo action with an additional large scale field on the scale of the box (at wavenumber k = 1; forcing is at k = 5). This large scale field is nearly force-free and exceeds the equipartit...

The inverse energy cascade in two-dimensional Navier-Stokes turbulence is examined in the quasisteady regime, with small-scale, band-limited forcing at scale kf-1, with particular attention to the influence of forcing Reynolds number Re on the energy distribution at large scales. The strength of the inverse energy cascade, or fraction of energy input that is transferred to larger scales, increa...

Sensitivities of cirrus cloud radiative forcing as well as solar albedo and infrared emittances to ice crystal size spectrum and ice crystal shape were examined using a coupled cloud-radiation model. The singleand bi-modal crystal size distribution were considered and simulated based on field measurements. Optical parameters of ice crystals shaped as hexagonal columns and random Ž . polycrystal...

[1] If mitigation of black carbon (BC) particulate matter is accompanied by a decrease in particle number emissions, and thereby by a decrease in global cloud condensation nuclei (CCN) concentrations, a decrease in global cloud radiative forcing (a reverse “cloud albedo effect”) results. We consider two present‐day mitigation scenarios: 50% reduction of primary black carbon/organic carbon (BC/O...

traditional work on pro-drop languages identified a set of parametric values ‎associated with the availability of null subjects, including the presence of null ‎expletive subjects. in the same vein, but more within the framework of minimalist ‎program, i will discuss while referential subjects may optionally be overt or covert ‎in the persian, expletives are obligatorily null. in this regard, a...

The eeect of axial and azimuthal forcing on the spreading and mixing characteristics in the near eld (x=D < 13) of a cooowing, turbulent (Re > 2000) water jet is studied by means of planar, laser induced uorescence (PLIF) visualizations. Measurements of both the initial spreading rate of the jet and the decay of the concentration along the centerline of the jet show a marked increase in the mix...

We study spatial localization in the real subcritical Ginzburg-Landau equation ut = m0u + Q(x)u + uxx + d|u|u − |u|u with spatially periodic forcing Q(x). When d > 0 and Q ≡ 0 this equation exhibits bistability between the trivial state u = 0 and a homogeneous nontrivial state u = u0 with stationary localized structures which accumulate at the Maxwell pointm0 = −3d/16. When spatial forcing is i...