search form

search form
North Slope of Alaska (NSA) 
Date of Last update : 2014.08.03 Rivision Request
1 2 3 4 5 6 7
Sandia National Laboratories, Bldg. 823, 1515 Eubank Blvd., SE, Albuquerque, NM 87123-0734 USA
Coordinating Country
United States
Hosting Organisations
ARM Climate Research Facility
Contact Person
Dr. Mark Ivey (, +1-(505) 284-9092)
RI Category
Atmospheric Measurement Facilities
atmosphere, climate, cloud, radiation
The U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility established climate research sites on the North Slope of Alaska (NSA), to provide data about cloud and radiative processes in cold environments and high latitudes. It is widely believed the polar regions are more affected by changing climate associated with global warming than any other area in the world. Comprehensive measurements from ARM?s state-of-the-art instrument systems at these sites will help scientists improve the understanding of high-latitude cloud and radiation processes, and their representation in global climate models.

NSA Sites
(1) Barrow - Known as the top of the world, ARM?s Barrow research site has been operating continuously since 1997. The site is located at the northernmost point in the United States - 320 miles north of the Arctic Circle and a mile south of the Arctic Ocean. Many of the same instruments used at warmer ARM sites have been hardened to withstand temperatrures that drop well below negative 40 degrees to operate at the Barrow site.

(2) Atqasuk - Located approximately 70 miles south of Barrow, the Atqasuk facility began collecting data in 1999. At this inland Arctic tundra site completed its primary science mission when it collected and archived a 10-year data set. For field campaigns or stand-alone measurements, scientists may request to use this facility through the normal ARM proposal process. All data collected from Atqasuk are available in the ARM Data Archive.

(3) Oliktok - Located approximately 164 miles southeast of the ARM site in Barrow, Oliktok is the location of an extended ARM Mobile Facility deployment. In addition to the standard ARM ground-based instruments, ARM plants to equip unmanned aerial systems and tethered balloons with various sensors to obtain measurements of clouds, atmospheric conditions, sea ice, and heat exchange. The Federal Aviation Administration is considering supplementary airspace options that would allow additional atmospheric sampling to be conducted offshore of Oliktok, heading several hundred miles towards the North Pole. This provides a unique opportunity to couple atmospheric measurements with ground-based observations. Additional flights between Oliktok and Barrow using manned aircraft will further supplement this data set.
Application Area
Scientific obejctives for the NSA/AAO site are provided below:
(1) Provide the comprehensive data sets necessary to develop and test continually improved algorithms for GCMs to describe radiative transfer and cloud processes at high latitudes;

(2) Specifically focus on development of algorithms to describe:
- radiative transfer within both the clear and cloudy atmosphere, especially at low temperatures;
- physical and optical behavior of water (ice) and land surfaces, both bare and snow-covered, especially during transitions from winter to summer and back;
- physical and optical behavior of ice and mixed phase clouds.

(3) Temporal Priorities (issues to be pursued first, second, etc.):
- Infrared radiative transfer under cloudless skies for very cold, dry conditions. This issue pertains to both high latitudes and high altitudes (Instantaneous Radiative Flux (IRF) experiment).
- Influence of stratus clouds on solar radiative transfer near the surface. Start with liquid water clouds; next go to ice clouds; attack mixed phase clouds last (in order of increasing measurement challenges). This issue pertains to the influence of stratus clouds, and to high altitude ice (cirrus) clouds worldwide (IRF experiment).
- Influence of stratus clouds on infrared radiative transfer near the surface. Start with liquid water clouds; next go to ice clouds; address mixed phase clouds last. This issue has the same broad applicability as number 2 above.
- Solar radiative transfer to the surface under cloudless skies (IRF experiment).
- Interactions of surface albedo and related optical and physical factors with surface heating (SOM: Surface Optical Model experiments).
- Local factors affecting the formation and properties of stratus clouds (Cloud Behavior (CB) experiments; horizontal measurement scale, few km; eg. coastal, open lead, snow cover edge, lake and other discontinuity effects).
- Stratus cloud formation and evolution processes on GCM grid cell scales (Cloud Behavior/Single Column Model (CB/SCM) experiments).

Note that the temporal priorities are based in part upon the breadth of the instrumentation resources required to address each issue. Issues with higher temporal priorities can be addressed earlier in the NSA/AAO site development. Lower temporal priorities cannot be addressed until much more of the site instrumentation suite is in place and operating. Nevertheless, progress on each one of these issues is critical to the achievement of the NSA/AAO scientific objectives, and to the achievement of the overall goal of more accurate global and regional future climate predictions.

1. Instrumentation and Data

Continuous data from NSA allow scientists to refine global climate change models and parameterizations for this climatically important region. Instrument systems at NSA include solar and infrared broadband radiometric instruments, a Fourier transform infrared radiometer, and about two dozen indiidual instruments, including cloud lidars and radars, a radar wind profiler, a radiosonde system, a sky imager, and a microwave radiometer.

Through the American Recovery and Reinvestment Act of 2009, ARM enchanced all its sites with new and upgraded instruments. Routine observations from new scanning radars greatly expanded the NSA site's ability to detect and quantify the structure, spatial distribution, and evolution of Arctic clouds and precipitation. Other new instruments close a gap in observations of surface boundary conditions and allow for characterization of the physical properties of clouds over Barrow, particularly those associated with mixed-phase clouds composed of both liquid and ice. New capabilities at NSA include:

- three new dual-frequency scanning cloud radars that provide three-dimensional information about cloud properties, including reflectivity and precipitation;

- an eddy correlation (ECOR) flux measurement system and complementary surface energy balance system (SEBS);

- high spectral resolution lidar for calibrated measurements of aerosol optical depth, backscatter, cross section, and depolarization; and

- a launching system for automated release of weather balloons, carrying radiosondes to measure temperature, humidity, and wind speed.

2. User Information

Researchers can use NSA's facilities and data in a number of ways:

- Access data gathered during normal operations or field campaigns through the ARM Data Archive (

- Propose and conduct a field campaign (


- Make an in-person or virtual visit to the NSA site (

For more information, contact:

Mark Ivey

NSA Site Manager

Phone: (505) 284-9092


Jeffrey Zirzow

NSA Site Technical Operations Manager

Affiliation: Sandia National Laboratories

P.O. Box 5800, MS 0734

Albuquerque, NM 87185-0734

Phone: (505) 284-4446

Fax: (505) 844-0116