Aerosol and Cloud Experiments in the Eastern North Atlantic (ACE-ENA)

1 June 2017 - 28 February 2018

Lead Scientist: Jian Wang

Observatory: AAF, ENA

With their extensive coverage, low clouds greatly impact global climate, but they are poorly represented in global climate models (GCMs). The response of low clouds to changes in atmospheric greenhouse gases and aerosols remains the major source of uncertainty in climate simulations. The poor representations of low clouds in GCMs are partly due to inadequate observations of their microphysical and macrophysical structures, radiative effects, and the associated aerosol distribution and budget in regions where the aerosol impact is the greatest. The Eastern North Atlantic (ENA) is a region with persistent but diverse subtropical marine boundary layer (MBL) clouds. Their albedo and precipitation are highly susceptible to perturbations in aerosol properties. Boundary layer aerosol in the ENA region is influenced by a variety of sources, leading to strong variations in cloud condensation nuclei (CCN) concentration and aerosol optical properties.

The ARM Climate Research Facility has a fixed ENA atmospheric observatory on Graciosa Island in the Azores, providing invaluable information on MBL aerosol and low clouds. At the same time, the vertical structures and horizontal variabilities of aerosol, trace gases, cloud, drizzle, and atmospheric thermodynamics are critically needed for understanding and quantifying the budget of MBL aerosol, the radiative properties, precipitation efficiency, and life cycle of MBL clouds, and the cloud response to aerosol perturbations. Much of this data can be obtained only through aircraft-based measurements. In addition, the interconnected aerosol and cloud processes are best investigated by a study involving simultaneous in situ aerosol, cloud, and thermodynamics measurements. In situ measurements are also necessary for validating and improving ground-based retrieval algorithms at the ENA site.

The Aerosol and Cloud Experiments in the Eastern North Atlantic (ACE-ENA) field campaign is motivated by the need for comprehensive in situ characterizations of boundary layer structure, and associated vertical distributions and horizontal variabilities of low clouds and aerosol over the Azores. The ARM Aerial Facility (AAF) Gulfstream-159 (G-1) aircraft will be deployed at the ENA site during two intensive operational periods: early summer 2017 (June to July) and winter 2018 (January to February). Deployments during both seasons allow for examination of key aerosol and cloud processes under a variety of representative meteorological and cloud conditions.

The science themes for this project include:

  • the budget of MBL CCN and its seasonal variation
  • effects of aerosol on cloud and precipitation
  • cloud microphysical and macrophysical structures, and entrainment mixing
  • advancing retrievals of turbulence, cloud, and drizzle
  • model evaluation and processes studies.

A key advantage of the deployments is the strong synergy between the measurements on board the G-1 and the routine measurements at the ENA site, including state-of-the-art profiling and scanning radars. The three-dimensional cloud structures provided by the scanning radars will put the detailed in situ measurements into mesoscale and cloud life cycle contexts. On the other hand, high-quality in situ measurements will enable validation and improvements of ground-based retrieval algorithms at the ENA site, leading to high-quality and statistically robust data sets from the routine measurements. The deployments, combined with the routine measurements at the ENA site, will have a long-lasting impact on the research and modeling of low clouds and aerosols in the remote marine environment.

Operational Periods:

--2017.06.01-2017.07.31
--2018.01.01-2018.02.28

Co-Investigators

Eduardo Azevedo Mary Gilles Edward Luke
Christopher Bretherton Anne Jefferson Allison McComiskey
Duli Chand Michael Jensen Fan Mei
J.-Y. Christine Chiu Pavlos Kollias Mark Miller
Xiquan Dong Chongai Kuang Arthur Sedlacek
Jerome Fast Alexander Laskin Raymond Shaw
Andrew Gettelman Ernie Lewis Robert Wood
Steven Ghan Yangang Liu
Scott Giangrande Xiaohong Liu

Campaign Data Sets

IOP Participant Data Source Name Final Data
Fan Mei Fast Cloud Droplet Probe (FCDP) Order Data
Fan Mei High Volume Precipitation Spectrometer Order Data
Fan Mei Meteorology/State/Position Parameters Order Data

ENA Data Sources

Name Full Name Browse Data
ACSM Aerosol Chemical Speciation Monitor Browse Data
AERI Atmospheric Emitted Radiance Interferometer Browse Data
AERINF AERI Noise Filtered Browse Data
AOS Aerosol Observing System Browse Data
AOSMET Meteorological Measurements associated with the Aerosol Observing System Browse Data
CAPS-PMEX Cavity Attenuated Phase Shift Extinction Monitor Browse Data
CCN Cloud Condensation Nuclei Particle Counter Browse Data
CCN-AIR Cloud Condensation Nuclei Particle Counter aboard Aircraft Browse Data
CEIL Ceilometer Browse Data
CMH-AIR Chilled Mirror Hygrometer aboard Aircraft Browse Data
CO-ANALYZER Carbon Monoxide Analyzer Browse Data
CPC Condensation Particle Counter Browse Data
CPC-AIR Condensation Particle Counter aboard Aircraft Browse Data
CSPHOT Cimel Sunphotometer Browse Data
DL Doppler Lidar Browse Data
DLPROF Doppler Lidar Profiles Browse Data
ECMWFDIAG European Centre for Medium Range Weather Forecasts Diagnostic Analyses Browse Data
ECOR Eddy Correlation Flux Measurement System Browse Data
GHG Greenhouse Gas Monitor Browse Data
GNDRAD Ground Radiometers on Stand for Upwelling Radiation Browse Data
GUSTPROBE-AIR Aircraft Gust Probe Browse Data
HK-AIR House Keeping Instruments aboard Aircraft Browse Data
HTDMA Humidified Tandem Differential Mobility Analyzer Browse Data
INLETCVI-AIR Inlet for Counterflow Virtual Impactor aboard Aircraft Browse Data
INLETISOK-AIR Isokinetic Inlet aboard Aircraft Browse Data
INTERPSONDE Interpolated Sonde Browse Data
IRT Infrared Thermometer Browse Data
KASACR Ka-Band Scanning ARM Cloud Radar Browse Data
KAZR Ka ARM Zenith Radar Browse Data
LDIS Laser Disdrometer Browse Data
MAWS Automatic Weather Station Browse Data
MET Surface Meteorological Instrumentation Browse Data
MET-AIR Meteorological Instrumentation aboard Aircraft Browse Data
MFR Multifilter Radiometer Browse Data
MFRSR Multifilter Rotating Shadowband Radiometer Browse Data
MPL Micropulse Lidar Browse Data
MPLCMASK Cloud mask from Micropulse Lidar Browse Data
MWR3C Microwave Radiometer, 3 Channel Browse Data
MWRP Microwave Radiometer Profiler Browse Data
NAV-AIR Navigational Location and Attitude for Aircraft Browse Data
NEPHELOMETER Nephelometer Browse Data
NEPHELOMETER-AIR Nephelometer aboard Aircraft Browse Data
OZONE Ozone Monitor Browse Data
OZONE-AIR Ozone Monitor aboard Aircraft Browse Data
PBLHT Planetary Boundary Layer Height Browse Data
PCASP-AIR Passive Cavity Aerosol Spectrometer aboard Aircraft Browse Data
PSAP Particle Soot Absorption Photometer Browse Data
PSAP-AIR Particle Soot Absorption Photometer aboard Aircraft Browse Data
QCRAD Data Quality Assessment for ARM Radiation Data Browse Data
RADFLUXANAL Radiative Flux Analysis Browse Data
RAIN Rain Gauge Browse Data
RL Raman Lidar Browse Data
RLPROF Raman LIDAR Vertical Profiles Browse Data
RWP Radar Wind Profiler Browse Data
SACRADVVAD SACR Advance Velocity Azimuth Display Browse Data
SEBS Surface Energy Balance System Browse Data
SKYRAD Sky Radiometers on Stand for Downwelling Radiation Browse Data
SONDE Balloon-Borne Sounding System Browse Data
SONDEGRID Gridded Sonde VAP Product Browse Data
TRACEGAS-AIR Trace gas concentrations - airborne Browse Data
TSI Total Sky Imager Browse Data
TWRCAM Tower Camera Browse Data
UHSAS Ultra-High Sensitivity Aerosol Spectrometer Browse Data
VDIS Video Disdrometer Browse Data
VISST Minnis Cloud Products Using Visst Algorithm Browse Data
WB Weighing Bucket Precipitation Gauge Browse Data
WSACR W-band Scanning ARM Cloud Radar Browse Data