U.S. Department of Energy Office of Biological and Environmental Research

BER Research Highlights

Aerosol Variability and Synoptic-Scale Processes over the Northeast Pacific
Published: May 01, 2015
Posted: May 12, 2015

ARM aerosol measurements on board a ship during a marine campaign in the northeast Pacific Ocean. [Image courtesy ARM Climate Research Facility]

Subtropical marine boundary layer clouds play a significant role in cloud-climate feedbacks due to their warm temperatures and high reflectivity; small changes in cloud cover or droplet size resulting from changes in meteorology or interactions with aerosol particles can lead to large changes in the energy budgets of these clouds.  During its first marine deployment, the second Atmospheric Radiation Measurement (ARM) Mobile Facility (AMF-2) was installed on a container ship that made 36 transects between the port of Los Angeles, CA, and Honolulu, HI, to provide detailed observations of the meteorological variables and aerosol, cloud, and surface radiation properties in this region. The campaign provided one of the most comprehensive datasets available in this important marine boundary layer cloud region.

Scientists funded by the Department of Energy’s Atmospheric System Research (ASR) program combined the ARM in situ observations of aerosol concentrations with satellite retrievals and numerical model meteorological outputs to understand how the atmospheric circulation regulates the synoptic and monthly variations in aerosol concentration over a vast area of the northeast Pacific. Analysis of monthly observations of cloud condensation nuclei (CCN) reveal an annual cycle with peaks during spring and summer. The seasonal variation mostly occurs within 30° of the California coast, whereas monthly variations near Hawaii are modest. The analysis suggests that the annual cycle in CCN is consistent with a wind-transport mechanism associated with large-scale circulations and the California low-level jet, rather than with seasonal changes in precipitation. The study also examined the sensitivity of cloud properties to aerosol number concentration, and results support emerging new evidence from aircraft observations indicating that the aerosol-cloud interaction in low subtropical clouds is substantially stronger than that inferred from previous ground-based and satellite observations and from climate models.

Reference: Painemal, D., P. Minnis, and M. Nordeen. 2015. “Aerosol Variability, Synoptic-Scale Processes, and Their Link to the Cloud Microphysics over the Northeast Pacific During MAGIC,” Journal of Geophysical Research-Atmospheres, DOI: 10.1002/2015JD023175. (Reference link)

Contact: Sally McFarlane, SC-23.1, (301) 903-0943, Shaima Nasiri, SC-23.1, 301-903-0207
Topic Areas:

  • Research Area: Atmospheric System Research
  • Facility: DOE ARM User Facility

Division: SC-23.1 Climate and Environmental Sciences Division, BER


BER supports basic research and scientific user facilities to advance DOE missions in energy and environment. More about BER

Recent Highlights

Aug 24, 2019
New Approach for Studying How Microbes Influence Their Environment
A diverse group of scientists suggests a common framework and targeting of known microbial processes [more...]

Aug 08, 2019
Nutrient-Hungry Peatland Microbes Reduce Carbon Loss Under Warmer Conditions
Enzyme production in peatlands reduces carbon lost to respiration under future high temperatures. [more...]

Aug 05, 2019
Amazon Forest Response to CO2 Fertilization Dependent on Plant Phosphorus Acquisition
AmazonFACE Model Intercomparison. The Science Plant growth is dependent on the availabi [more...]

Jul 29, 2019
A Slippery Slope: Soil Carbon Destabilization
Carbon gain or loss depends on the balance between competing biological, chemical, and physical reac [more...]

Jul 15, 2019
Field Evaluation of Gas Analyzers for Measuring Ecosystem Fluxes
How gas analyzer type and correction method impact measured fluxes. The Science A side- [more...]

List all highlights (possible long download time)