Aerosol and cloud chemistry during the ACE-ENA campaign
Authors
Maria Anna Anna Zawadowicz — Brookhaven National Laboratory
Jian Wang — Washington University in St. Louis
Robert Wood — University of Washington
Mikhail S. Pekour — Pacific Northwest National Laboratory
Jiumeng Liu — Pacific Northwest National Laboratory
Kaitlyn Suski — Pacific Northwest National Laboratory
John E Shilling — Pacific Northwest National Laboratory
Category
ARM field campaigns – Results from recent ARM field campaigns
Description
The Aerosol and Cloud Experiment in the Eastern North Atlantic (ACE-ENA) investigated properties of aerosols and subtropical marine boundary layer clouds in the Eastern North Atlantic. Low subtropical marine clouds are highly susceptible to perturbations in aerosol properties, have a large effect on Earth’s radiative budget, but are poorly represented in global climate models. The campaign consisted of two intensive operation periods (June-July, 2017 and January-February, 2018). The DOE’s G-1 aircraft was deployed in a series of research flights in the vicinity of the ARM ENA atmospheric observatory on Graciosa Island in the Azores. An Aerodyne HR-ToF Aerosol Mass Spectrometer (AMS) and an Ionicon Proton-Transfer-Reaction Mass Spectrometer (PTR-MS) were deployed aboard the aircraft, characterizing chemistry of non-refractory aerosol and trace gases, respectively. The AMS sampled alternatively through an isokinetic or a counter-flow virtual impactor inlet, providing insights into chemical composition of general aerosol population and cloud droplet residuals. This presentation will consist of an overview of trace gases, aerosol and cloud chemistry during ACE-ENA. The Eastern North Atlantic region was found to be very clean, with average aerosol loadings <1 μg/m3, as reported by AMS. The aerosol chemistry was found to be primarily driven by sulfate. Particulate methane sulfonic acid (MSA), a well-known secondary biogenic marine species was detected, along with its gas-phase precursor, dimethyl sulfide (DMS).
