3D Structure of Saharan Dust Transport Towards Europe as Seen by CALIPSO

Eleni Marinou,Prodromos Zanis,Emmanouil Proestakis,Ioannis Binietoglou,Alexandra Tsekeri,Ulla Wandinger,Vassilis Amiridis,Panos Kokkalis,Albert Ansmann,Stavros Solomos,Michael Kottas,Stelios Kazadzis

doi:10.1051/epjconf/201611918007

Abstract

We present a 3D multi-year monthly mean climatology of Saharan dust advection over Europe using an area-optimized pure dust CALIPSO product. The product has been developed by applying EARLINET-measured dust lidar ratios and depolarization-based dust discrimination methods and it is shown to have a very good agreement in terms of AOD when compared to AERONET over Europe/North Africa and MODIS over Mediterranean. The processing of such purely observational data reveals the certain seasonal patterns of dust transportation towards Europe and the Atlantic Ocean. The physical and optical properties of the dust layer are identified for several areas near the Saharan sources, over the Mediterranean and over continental Europe.

Highlights

CALIPSO is capable of providing a multi-year, robust 4D dust climatology, a task that cannot be achieved by passive sensors, especially over bright surfaces like deserts
Limitations on retrieval performance using CALIPSO exist, especially regarding the classification of dust and its mixtures based on the approximate particle depolarization ratio and the retrieval of the dust extinction that is based on the Lidar Ratio (LR) assumption
From the CALIPSO dust product we provide here a climatology for the domain between 20 and 60 in latitude and between -20 and 30 in longitude which includes Europe and North Africa and where we believe that the EARLINET-derived LR value of 58 sr can be applied

Summary

Introduction

CALIPSO is capable of providing a multi-year, robust 4D dust climatology, a task that cannot be achieved by passive sensors, especially over bright surfaces like deserts. Amiridis et al (2013) [1] demonstrated a method for the retrieval of pure dust extinction from CALIPSO based on a depolarization-based separation of pure dust backscatter fraction in dusty mixtures (Tesche et al, 2009) and the application of a regionally uniform LR for calculating dust extinction. This LR value (equal to 58 sr) has been taken from climatological values derived by long-term EARLINET measurements.

Methods

Results

Conclusion