Characterizing the aerosol atmosphere above the Observatorio del Roque de los Muchachos by analyzing seven years of data taken with an GaAsP HPD-readout, absolutely calibrated elastic LIDAR

TL;DR

This study introduces a new elastic LIDAR system and analyzes seven years of data to characterize aerosol and cloud properties above the Observatorio del Roque de los Muchachos, providing detailed seasonal and altitude-dependent atmospheric insights.

Contribution

The paper presents a novel LIDAR concept with calibration and applies it to long-term atmospheric data, revealing seasonal aerosol and cloud characteristics.

Findings

Aerosol extinction scale heights vary with zenith and azimuth angles.

Seasonal changes observed in cloud base and top altitudes.

LIDAR ratios of clouds show no seasonal variation.

Abstract

We present a new elastic LIDAR concept, based on a bi-axially mounted Nd:YAG laser and a telescope with HPD readout, combined with fast FADC signal digitization and offline pulse analysis. The LIDAR return signals have been extensively quality checked and absolutely calibrated. We analyze seven years of quasi-continuous LIDAR data taken during those nights when the MAGIC telescopes were operating. Characterization of the nocturnal ground layer yields zenith and azimuth angle dependent aerosol extinction scale heights for clear nights. We derive aerosol transmission statistics for light emitted from various altitudes throughout the year and separated by seasons. We find further seasonal dependencies of cloud base and top altitudes, but none for the LIDAR ratios of clouds. Finally, the night sky background light is characterized using the LIDAR photon backgrounds. abstract.txt