CALIPSO Recordings and Categorization of Atmospheric Aerosols over the Urmia Lake

Fatemeh Ghomashi,Hamid R Khalesifard,D Altausen,J Hofer,S Abdullaev

doi:10.1051/e3sconf/20199901005

Fatemeh Ghomashi, Hamid R Khalesifard + Show 3 more

Open Access

https://doi.org/10.1051/e3sconf/20199901005

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Abstract

The Urmia Lake is suffering from a severe drought scenario that started in recent decades. The lake has lost almost 88% of its surface area in comparison to its value in 1995. This has left a bed of salt around the lake, that has the potential to disperse a significant amount of aerosols (dust and salt) into the atmosphere. We use the recordings of the CALIPSO satellite to investigate the optical parameters of atmospheric aerosols over the Urmia Lake. For this purpose, the aerosol optical depth (AOD) and the particulate depolarization ratio (PDR) at 532 nm have been selected from the whole available recordings of the CALIPSO. To distinguish between the atmospheric particles which are originating from the lake bed and those that are transported from the surrounding sources to the lake area, the PDR has been categorized for two altitude ranges, i.e., from the ground level up to 2 km above the mean sea level (amsl) and above 3 km amsl. Investigating the variations of the PDR at these two altitude ranges, provides information about the type of atmospheric particles at different times of the year. Although it is not easy to distinguish between the transported dust layers and atmospheric particles from the lake bed, it seems that the Urmia Lake is mostly active in the driest times of the year, i.e., June to October. Also, it seems that the particles which are originating from the lake, are mostly dry salt particles, where their corresponding PDR is 0.16 ± 0.05.

Highlights

The Urmia Lake (UL) in Northwest Iran (37.62◦N, 45.41◦E) is one of the most hypersaline lakes in the world [1]
To distinguish between the particles which are originating from the lake bed, transported dust particles and other local atmospheric aerosols, the particulate depolarization ratio (PDR) has been monitored at two different altitude ranges, which are dictated by the orography of the region
We looked at all Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) time series were showing a dust plum in contact with the lake bed subject to the condition that 0.1 < δl < 0.25 to eliminate dust and urban industrial particles

Summary

Introduction

The Urmia Lake (UL) in Northwest Iran (37.62◦N, 45.41◦E) is one of the most hypersaline lakes in the world [1]. To distinguish between the particles which are originating from the lake bed, transported dust particles and other local atmospheric aerosols, the PDR has been monitored at two different altitude ranges, which are dictated by the orography of the region.

Results

Conclusion