Towards Early Detection of Tropospheric Aerosol Layers Using Monitoring with Ceilometer, Photometer, and Air Mass Trajectories

Abstract

A near-real-time automatic detection system, based on the synergy of continuous measurements taken by a ceilometer and a photometer, has been implemented in order to detect lofted atmospheric aerosol layers and estimate the aerosol load. When heavy-loaded conditions are detected (defined by a significant deviation of the optical properties from a 10-year climatology), obtained for aerosol layers above 2500 m, an automatic alert is sent to scientists of the Romanian Lidar Network (ROLINET) to further monitor the event. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) back-trajectory calculations are used to establish the possible pollution source. The aerosol transport events are considered to be major when various optical properties provided by the photometer are found outside the climatological values. The aerosol types over the three years for all the events identified revealed that the contribution to the pollution was 31%, 9%, and 60% from marine, dust, and continental types. Considering only the ‘outside climatology limits’ events, the respective contribution was 15%, 12%, and 73% for marine, dust, and continental types, respectively.

Developing an Australian dust early warning system

“…Of the operational systems, 6 were models and 2 were sensor networks. The 2 operational sensor networks were published in 2021 (Hahm and Yoon 2021) and 2022 (Adam et al 2022), while operational model systems span from 2008 onwards.…”

“…This system can alert for 3 types of dust storms (severe, short-term and small-scale, long-term and large-scale) dependent on the spatial/temporal sensitivity of the sensor network and/or satellite. Adam et al (2022) integrated sensor networks consisting of ceilometers, sun photometer and AERONET with HYSPLIT back trajectory modelling and aerosol optical depth data. Ceilometers detect other aerosols such as smoke, fog and anthropogenic particulates that require careful quality control to ensure accuracy in the early warning system.…”

“…The study identified several negatives of the system including availability of AERONET data, the ceilometer only detecting aerosols up to a certain height, spatial availability of sun photometer data, need of internet access and errors in running the HYSPLIT model (Adam et al 2022).…”