The Airborne Cloud–Aerosol Transport System: Overview and Description of the Instrument and Retrieval Algorithms

Abstract

The Airborne Cloud–Aerosol Transport System (ACATS) is a Doppler wind lidar system that has recently been developed for atmospheric science capabilities at the NASA Goddard Space Flight Center (GSFC). ACATS is also a high-spectral-resolution lidar (HSRL), uniquely capable of directly resolving backscatter and extinction properties of a particle from a high-altitude aircraft. Thus, ACATS simultaneously measures optical properties and motion of cloud and aerosol layers. ACATS has flown on the NASA ER-2 during test flights over California in June 2012 and science flights during the Wallops Airborne Vegetation Experiment (WAVE) in September 2012. This paper provides an overview of the ACATS method and instrument design, describes the ACATS HSRL retrieval algorithms for cloud and aerosol properties, and demonstrates the data products that will be derived from the ACATS data using initial results from the WAVE project. The HSRL retrieval algorithms developed for ACATS have direct application to future spaceborne missions, such as the Cloud–Aerosol Transport System (CATS) to be installed on the International Space Station (ISS). Furthermore, the direct extinction and particle wind velocity retrieved from the ACATS data can be used for science applications such as dust or smoke transport and convective outflow in anvil cirrus clouds.

EARLINET evaluation of the CATS Level 2 aerosol backscatter coefficient product

“…The authors showed that both CATS and CALIOP profiles and CF agree well on both the vertical patterns and values at 01:30 and 13:30 LT, over both land and ocean, with minor differences of the order of 2 %-7 % throughout all cloud profiles. Finally, CATS depolarization measurements, which are critical in the processing algorithms of aerosol-subtype classification, were investigated in the case of desert dust, smoke from biomass burning, and cirrus clouds (Yorks et al, 2016) and were found to be consistent and in good agreement with depolarization measurements from previous studies and historical datasets implementing CPL (Yorks et al, 2011) and CALIOP (Liu et al, 2015).…”

“…Developed at NASA's Goddard Space Flight Center, CATS is based on the Cloud Physics Lidar (CPL;McGill et al, 2002) and the Airborne Cloud-Aerosol Transport System (ACATS; Yorks et al, 2014), designed to operate aboard the high-altitude NASA ER-2 aircraft. CATS operated as a scientific payload aboard the Japanese Experiment Module -Exposed Facility (JEM-EF), utilizing the International Space Station (ISS) as a space science platform (Yorks et al, 2016). Starting from 10 February 2015, CATS provided aerosol and cloud profile observations along the ISS flight track for more than 33 months, until 30 October 2017, when the system suffered an unrecoverable fault.…”

Satellite inference of water vapor and aerosol-above-cloud combined effect on radiative budget and cloud top processes in the Southeast Atlantic Ocean

“…Transport System (CATS) (Yorks et al, 2014), shows that the CALIOP algorithm probably overestimates the base of the aerosol layer by 500 m (Rajapakshe et al, 2017). Deaconu et al (2017) showed that the CALIOP operational algorithm underestimates the AOT above clouds with a factor of 2 to 4 depending on the aerosol type, when compared to other methods dedicated for aerosol above cloud retrievals -the POLDER polarisation method (Waquet et al, 2009) and the CALIOP depolarisation ratio method DRM (Deaconu et al, 2017;Hu et al, 2007).…”

Modification of Local Urban Aerosol Properties by Long-Range Transport of Biomass Burning Aerosol

“…Satellite-based active remote sensing performed with NASA's Cloud Aerosol Transport System (CATS) is also used. The CATS, installed on-board the International Space Station (ISS) at the Japanese Experimental Module-Exposed Facility (JEM-EF), provided near real-time, continuous and height-resolved information on the vertical structure of aerosols and clouds along the ISS orbit track for the period between 10 February 2015 and 29 September 2017 [46]. Since CATS utilizes the ISS as a platform, the remote sensors were bound to orbit the Earth from an altitude of approximately 405 km and 51-degree inclination.…”