Observations from satellite microwave instruments have a large information content and are known to improve the quality of global analyses of the atmosphere. However, the use of these observations remains far from being optimal. Indeed, only microwave observations, for which the surface contribute the least, are currently assimilated. This restriction is mainly due to remaining uncertainties ab...

Cosmic dust is pervasive within our galaxy and it is reasonable to suspect it is dispersed in various ways throughout the universe. Cosmic dust has emissivity when exposed to electromagnetic energy sources. The emissivity of cosmic dust contributes to cosmic radio noise and concentrations of it alters electromagnetic waves by refraction. Cosmic dust is concentrated in our Sun’s heliosphere and ...

We calculate the reionization history in Cold Dark Matter (CDM) models. The epoch of the end of reionization and the Thomson scattering optical depth to the cosmic microwave background depend on the power spectrum amplitude on small scales and on the ionizing photon emissivity per unit mass in collapsed halos. We calibrate the emissivity to reproduce the measured ionizing background intensity a...

Aims. We recently performed a study of a sample of relaxed, cooling core galaxy clusters with deep Very Large Array observations at 1.4 GHz. We find that in the central regions of A1835, A2029, and Ophiuchus the dominant radio galaxy is surrounded by a diffuse low-brightness radio emission that takes the form of a mini-halo. Here we present the results of the analysis of the extended diffuse ra...

This study examines and validates a technique for spatial enhancement of thermal satellite images for urban heat island analysis, using a nighttime ASTER satellite image. The technique, termed Emissivity Modulation, enhances the spatial resolution while simultaneously correcting the image derived temperatures for emissivity differences of earth surface materials. A classified image derived from...

I review my work with Bruce Draine on dust emissivity at microwave frequencies (3 cm-3 mm). This emissivity explains the recently detected " anomalous " component of the galactic foreground emission. Both small (a < 10 −7 cm) and large grains contribute to this emission. Small grains have electric dipole moments and emit while they rotate; the microwave emission of large grains is mostly due to...

This study compared three broadband emissivity (BBE) datasets from satellite observations. The first is a new global land surface BBE dataset known as the Global Land Surface Satellite (GLASS) BBE. The other two are the North American ASTER Land Surface Emissivity Database (NAALSED) BBE and University of Wisconsin Global Infrared Land Surface Emissivity Database (UWIREMIS) BBE, which were deriv...

Some tenebrionind beetles inhabiting the Namib desert are known for using their body to collect water droplets from wind-blown fogs. We aim to determine whether dew water collection is also possible for desert insects. For this purpose, we investigated the infra-red emissivity, and the wetting and structural properties, of the surface of the elytra of a preserved specimen of Physasterna cribrip...