STRATOSPHERIC AEROSOL EFFECTIVE RADIUS, SURFACE-AREA AND VOLUME ESTIMATED FROM INFRARED MEASUREMENTS
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES 100:D8 (1995) 16507-16518
PROPERTIES OF NORTHERN-HEMISPHERE POLAR STRATOSPHERIC CLOUDS AND VOLCANIC AEROSOL IN 1991/92 FROM UARS ISAMS SATELLITE MEASUREMENTS
J ATMOS SCI 51 (1994) 3019–3026-3019–3026
Abstract:
Observations of polar stratospheric clouds by the Improved Stratospheric and Mesospheric Sounder (ISAMS) experiment on the Upper Atmospheric Research Satellite (UARS) have revealed new details of their global properties and behavior. These include the vertical and horizontal spatial distributions of Arctic and Antarctic polar stratospheric clouds (PSCs) as a function of time and air temperature, their optical thicknesses and estimated densities, their spectral properties, and their inferred composition. In particular, ISAMS spectral data allows different PSC types to be distinguished from each other and from volcanic aerosol by their compositional differences. Northern PSCs during the 1991/92 season are found to be more ephemeral and more compact than reported in previous years and to differ markedly in scale from those in Southern Hemisphere, which cause the Antarctic ozone hole by activating stratospheric chlorine chemistry. There were only two episodes of dense PSC formation in the 1991/92 northern winter, one of which took place in sunlight. The latter correlates well with UARS/Microwave Limb Sounder observations of enhanced chlorine monoxide, but substantial amounts of chlorine monoxide were also reported at times and places with at most very minor PSC activity.PROPERTIES OF NORTHERN-HEMISPHERE POLAR STRATOSPHERIC CLOUDS AND VOLCANIC AEROSOL IN 1991/92 FROM UARS ISAMS SATELLITE MEASUREMENTS
JOURNAL OF THE ATMOSPHERIC SCIENCES 51:20 (1994) 3019-3026
INFRARED-ABSORPTION BY VOLCANIC STRATOSPHERIC AEROSOLS OBSERVED BY ISAMS
GEOPHYS RES LETT 20 (1993) 1283–1286-1283–1286
Abstract:
The Improved Stratospheric and Mesospheric Sounder (ISAMS) aboard the Upper Atmosphere Research Satellite (UARS) senses in 14 wideband channels in the infrared. The absorption by the Mt. Pinatubo aerosol cloud for nine of the channels was averaged over heights from 20 km to 30 km for a 60-degrees latitude band centred on the Equator. The absorption spectrum for sulphuric acid-water aerosols was calculated for wavelengths from 4 mum to 17 mum and investigated as a function of the particle size distribution and the particle composition. The infrared spectrum is shown to be more sensitive to changes in particle composition than to drop size; the ISAMS results are consistent with drops composed of a 59% to 77% solution of sulphuric acid in water.MEASUREMENTS OF THE EVOLUTION OF THE MT-PINATUBO AEROSOL CLOUD BY ISAMS
GEOPHYS RES LETT 20 (1993) 1287–1290-1287–1290