Atlantic atmospheric aerosol studies: 2. Compendium of airborne backscatter measurements at 10.6μm

Abstract

The airborne backscatter measurements at 10.6 μm, from the South Atlantic Backscatter Lidar Experiment (SABLE) and the Global Atmospheric Backscatter Lidar Experiment (GABLE) programs over the Atlantic, are gathered together and presented. Plots of backscatter versus altitude are shown for 80 flight sequences. These data comprising about 4×105 measurements from over 180 flight hours is statistically analyzed. The material is distributed in altitude (1 km) and backscatter (half decade) intervals and presented in tabular and histogram form for six principal regions and seasons: South Atlantic summer, South Atlantic winter, far‐North Atlantic spring, mid‐Atlantic spring/summer, and Northeast Atlantic winter and summer. Several features of the results are discussed, including the incidence of low backscatter and drop‐outs and the remarkably high incidence of thin cirrus in the southern tropical winter season. The compendium should provide a climatology of atmospheric backscatter at 10.6 μm for regions of the Atlantic during the relatively clean atmospheric period 1988–1990.

The definition of an atmospheric database for Aeolus

“…For reference aerosol backscatter from two other datasets are included in the figure. The green curve (with the lowest particle backscatter values) is the reference model atmosphere (RMA) median profile as derived by (Vaughan et al, 1995) and used as a reference for many Aeolus related studies e.g. (Marseille et al, 2003), (Stoffelen et al, 2005).…”

“…In a comparative study of lidar aerosol measurements at different wavelengths Vaughan et al (1998) parameterized theÅngström exponent throughÅ(β 0 (z)) = −0.104×ln(β 0 (z)) − 0.62 (see also Marseille et al (2003)) with β 0 the aerosol backscatter at 10.6 µm as obtained from flight campaigns over the North and South Atlantic in 1989, (Vaughan et al, 1995). The corresponding dashed curve in Fig.…”

Sensitivity studies for a space-based methane lidar mission

“…Atmospheric aerosols can increase the measurement uncertainty due to scattering and absorption, as already shown by Ehret et al (2008). To quantify this effect the performance model was run with various representative aerosol backscatter profiles based on comprehensive lidar measurements over the Atlantic Ocean at a wavelength of 10.6 µm by Vaughan et al (1995). The data were roughly scaled to 1.65 µm using an altitude-dependent Angstrom exponent of 1.0 at sea level and 1.8 at 5 km a.s.l.…”

Airborne Instrumentation for Aerosol Measurements

“…Such systems were mainly devoted to wind measurements, but could also deliver very good aerosol data as a byproduct. Vaughan et al (43) ), is similar to a ground-based system, but operates inside a pressurized aircraft and needs an operator during the flight; ALAAM (Airborne Lidar for Automatic Aerosol Monitoring) is an automated mid-power LIDAR, installed in an unpressurized bay of a low altitude aircraft; and finally MULID (Microjoule Lidar) is an fully automatic microjoule LIDAR for balloon-borne stratospheric platforms, which uses a diode-pumped Nd-YAG laser of 1.5 microjoule of energy per pulse at a firing rate of 1 kHz, and seems to be one of the most promising technologies for future low-cost and compact size instrument for spacelike operation.…”