Lidar Observations of Arctic Aerosols and Clouds in the Free Troposphere for More than Fifteen Months over Svalbard

Abstract:

The information on spatial distributions and microphysical properties of aerosols and clouds is crucial for the studies on their direct and indirect impacts on Arctic climate. Observations of tropospheric aerosols and clouds by Mie/depolarization lidar have been made for more than a year at Ny-Ålesund (79^◌N, 12^◌E) since March 2014 by using a pulsed Nd:YAG laser and its wavelengths of 1064 nm and 532 nm. The backscattering coefficients at these two wavelengths, and depolarization ratio at 532nm of aerosols and clouds are obtained by the lidar observations. Figures show the results of aerosols for more than a year. Fig. 1 shows the mean backscattering coefficient of aerosols (BSC) at 532 nm, and Fig. 2 shows mean particle depolarization ratio of aerosols (PDR) at 532 nm in 1 km intervals (0.4 km for the lowest height interval) to 5 km in altitude since March 2014 to May 2015. There is a maximum in backscattering coefficient at spring as indicated by previous studies on Arctic aerosols. In addition, there is another maximum at autumn in depolarization ratio and in color ratio, or the ratio of BSC at 1064 nm to BSC at 532 nm.