A set of atmospheric general circulation model (AGCM) experiments under idealized conditions is performed to investigate atmospheric response to surface boundary forcing by tropical sea surface temperature (SST), extratropical land-sea contrast, and large-scale orography. Stationary eddies forced by the extratropical land-sea distribution are strongest in the high latitudes, where their amplitu...

We investigate the historical variation of the wintertime Pacific marine sector meridional atmospheric circulation, using simple diagnostics calculated from a statistical analysis of 140 years of surface wind data. Intensity of the wintertime expression of the Hadley circulation, as expressed by a wind divergence index, varies interannually and secularly. In agreement with previous studies, int...

The probability density on a height-meridional plane of negative refractive index squared f (nk<0) is introduced as a new analysis tool to investigate the climatology of the propagation conditions of stationary planetary waves based on NCEP/NCAR reanalysis data for 44 Northern Hemisphere boreal winters (1958–2002). This analysis addresses the control of the atmospheric state on planetary wave p...

Cyanobacteria are among the most diverse prokaryotic phyla, with morphotypes ranging from unicellular to multicellular filamentous forms, including those able to terminally (i.e., irreversibly) differentiate in form and function. It has been suggested that cyanobacteria raised oxygen levels in the atmosphere around 2.45-2.32 billion y ago during the Great Oxidation Event (GOE), hence dramatical...

Using almost all the compute nodes on the K computer, we evaluated the performance of the Nonhydrostatic Icosahedral Atmospheric Model (NICAM), a weather/climate application for a high-resolution global atmospheric simulation study. First, based on profiling results, we improved single node performance using six dynamical and two physical kernel programs extracted from the application, resultin...

A theoretical model for the edge image waviness effect is developed for the ground-to-ground imaging scheme and validated by use of IR imagery data collected at the White Sands Missile Range. It is shown that angle-of-arrival (AA) angular anisoplanatism causes the phenomenon of edge image waviness and that the AA correlation scale, not the isoplanatic angle, characterizes the edge image wavines...

An advancement of the unstructured-mesh finite-volume MPDATA (Multidimensional Positive Definite Advection Transport Algorithm) is presented that formulates the error-compensative pseudo-velocity of the scheme to rely only on face-normal advective fluxes to the dual cells, in contrast to the full vector employed in previous implementations. This is essentially achieved by expressing the tempora...

Fluctuations of the refractive index associated with atmospheric turbulence affect the propagation of electromagnetic and acoustic waves in the atmosphere. In the reported study, the effects of turbulence on wave propagation in the atmospheric convective boundary layer (CBL) are considered in terms of the second-order refractive index structure function and related to its structure-function par...

Laser (lidars) used from satellites and space stations for measurement of atmospheric properties may represent an ocular hazard to people on the surface of the earth. The risk of an eye injury depends on a range of parameters such as the energy per pulse, wavelength, beam divergence, space craft orbit, atmospheric conditions, properties of telescopes and other viewing aids, and the viewing beha...

Two El Niño flavors have been defined based on whether warm sea surface temperature (SST) anomalies are located in the central or eastern tropical Pacific (CP or EP). This study further characterizes the impacts on atmospheric circulation in the high latitudes of the Southern Hemisphere associated with these types of El Niño events though a series of numerical simulations using the National Cen...