Spatially coordinated airborne data and complementary products for aerosol, gas, cloud, and meteorological studies: the NASA ACTIVATE dataset

Abstract

Abstract. The NASA Aerosol Cloud meTeorology Interactions oVer the western ATlantic Experiment (ACTIVATE) produced a unique dataset for research into aerosol–cloud–meteorology interactions, with applications extending from process-based studies to multi-scale model intercomparison and improvement as well as to remote-sensing algorithm assessments and advancements. ACTIVATE used two NASA Langley Research Center aircraft, a HU-25 Falcon and King Air, to conduct systematic and spatially coordinated flights over the northwest Atlantic Ocean, resulting in 162 joint flights and 17 other single-aircraft flights between 2020 and 2022 across all seasons. Data cover 574 and 592 cumulative flights hours for the HU-25 Falcon and King Air, respectively. The HU-25 Falcon conducted profiling at different level legs below, in, and just above boundary layer clouds (< 3 km) and obtained in situ measurements of trace gases, aerosol particles, clouds, and atmospheric state parameters. Under cloud-free conditions, the HU-25 Falcon similarly conducted profiling at different level legs within and immediately above the boundary layer. The King Air (the high-flying aircraft) flew at approximately ∼ 9 km and conducted remote sensing with a lidar and polarimeter while also launching dropsondes (785 in total). Collectively, simultaneous data from both aircraft help to characterize the same vertical column of the atmosphere. In addition to individual instrument files, data from the HU-25 Falcon aircraft are combined into “merge files” on the publicly available data archive that are created at different time resolutions of interest (e.g., 1, 5, 10, 15, 30, 60 s, or matching an individual data product's start and stop times). This paper describes the ACTIVATE flight strategy, instrument and complementary dataset products, data access and usage details, and data application notes. The data are publicly accessible through https://doi.org/10.5067/SUBORBITAL/ACTIVATE/DATA001 (ACTIVATE Science Team, 2020).

Process Modeling of Aerosol‐Cloud Interaction in Summertime Precipitating Shallow Cumulus Over the Western North Atlantic

“…This makes it more challenging for LES to simulate these clouds than the well‐defined cold‐air outbreak clouds observed over the WNAO region. The ACTIVATE campaign employed a dual‐aircraft strategy to provide spatially coordinated measurements of meteorology states, trace gases, aerosol, and cloud properties (Sorooshian et al., 2019, 2023). The high‐flying (∼9 km in altitude) King Air measures meteorology states using dropsonde (X.‐Y.…”

“…We refer to Sorooshian et al. (2023) for a complete list of instruments deployed during the ACTIVATE campaign.…”

A machine learning paradigm for necessary observations to reduce uncertainties in aerosol climate forcing

“…To train the ML algorithms to predict ABS and CCN, we used HSRL-2 data from four airborne measurement campaigns, collocated with accurate in situ observations of the aerosol observables to be predicted. The airborne measurement campaigns were conducted in the continental US 24 , over the Southeast Atlantic Ocean 25 , near the Philippines 26 , and off the US Atlantic coast 27 , capturing a wide range of aerosol types and environmental conditions (Figure 1). For our study, we used lidar data that was spatially collocated with in situ observations within horizontal distances of 1,100 m and vertical distances of 45 m, and coincident within 30 minutes.…”

Tropospheric aerosols over the western North Atlantic Ocean during the winter and summer campaigns of ACTIVATE 2020: Life cycle, transport, and distribution

“…The FLEXPART model (Stohl et al, 1998) is used to identify the origin of air masses associated with high HSRL-2 aerosol extinction during an event of the long-range transport of a western U.S. fire plume. ACTIVATE aircraft data and FLEXPART model output are described in detail by Sorooshian et al (2023) and available at: https://doi.org/10.5067/SUBORBITAL/ACTIVATE/DATA001. CSN, IMPROVE, and NADP.…”