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Atmospheric Research Observatory aro

The Atmospheric Research Observatory (ARO) at the Amundsen-Scott South Pole Station is a National Science Foundation facility used in support of scientific research related to atmospheric phenomena.  ARO is located approximately five hundred meters grid east-northeast of the main station, physically separated and generally upwind of all other station facilities. 

The operational use of ARO for research programs began in early 1997. The majority of space within, on, and in the vicinity of the 3000 square feet, two story ARO building is allocated to a long-term research program carried out by the National Oceanic and Atmospheric Administration's Global Monitoring Division (NOAA/ESRL).  NOAA/ESRL operates a climate Baseline Observatory at ARO to measure long-term trends of important trace gases, aerosols, and solar radiation and to investigate the influence of these gases and aerosols on the Earth's climate.  This observatory was previously located in the old Clean Air Facility (CAF) since removed from the pole, but the ESRL observatory at ARO is still referred to as the CAF.   Some NOAA/ESRL atmospheric measurements date back to the International Geophysical Year (IGY) South Pole expedition of 1957 as shown in Figure 1 for the South Pole CO2 record.  NOAA/ESRL programs also make use of the South Pole Station Balloon Inflation Facility, which is situated downwind of the main station, to launch balloon-borne instrumentation to investigate and monitor stratospheric ozone depletion over the Antarctic interior.   A composite view of some research results form the ESRL programs at South Pole are presented in Figure 2.

The ARO is the blue building at the bottom of the photo.
Photo by Andrew V. Williams, NSF
(Click on image to view full size figure.)

Other current or recent research programs at ARO include:  an ultraviolet spectroradiometer operated by Biospherical Instruments, Inc. for the National Science Foundation, Rayleigh and sodium lidar studies of the atmosphere carried out by the National Aeronautics and Space Administration (NASA) and the University of Illinois, investigations of long-wave radiation processes on the Antarctic plateau carried out by the University of Washington and NASA, and a research program investigating nitrogen chemistry in the Antarctic troposphere headed by the Georgia Institute of Technology and the National Center for Atmospheric Research.

The ARO building is modular in construction with six-inch insulation and 15 insulated bubble windows.  The building design includes rooftop hatches for LIDAR equipment and four thermally heated windows for Dobson measurements.  The ARO has two sets of cargo bay doors, one on each floor, and an outdoor crane system for hauling equipment from the ground level to the second floor.  An NSF support contractor provides equipment transportation as needed.  Currently ARO, like the other outlying science buildings, has no running water or sewage system.

Eclipse over ARO
Lunar eclipse over the ARO.
(Click on image to view full size figure.)

Clean Air Sector

Upwind of ARO lies the Clear Air Sector, or region of dominant wind direction between grid 340 and 110.  Clean air sector winds are generally between 6 to 10 knots but occasionally are In the 30 knots range. Warmer temperatures are recorded near the surface at the ARO during periods of increased wind speed due to warmer air mixing down through the near-surface temperature inversion.  But, wind-chill is the great equalizer on the polar plateau, with wind chills of -100°F to -140°F not uncommon. 

Access to the Clean Air Sector by vehicles and even foot is strictly limited to preserve the integrity of the site.  Aircraft flight paths traversing the sector are discouraged.  A 100 meter vehicle exclusion zone exists downwind and surrounding the building outside of the Clean Air Sector.

Wind rose plots for the years 1980 to 2014. Each plot shows the frequency of wind direction for four categories of wind speeds arriving at the ARO.

First Floor

Click on one of the rooms to view a photo of that room.

GMD Gas & Air Sampling Pump Cabinet Stairs to Second Floor Storage Area Tech Shop Electrical Power Office & Computer Area Outside Deck

Second Floor

Click on one of the rooms to view a photo of that room.

Aerosol & Surface Ozone Dobson & Radiation Room Future Upwind Science Area LIDAR Room Open Office

Figure 1.  The South Pole CO2 record dates back to the International Geophysical Year (IGY)  expedition of 1957, revealing the steady global rise of CO2.
Figure 2.  A composite view of some research results form the ESRL programs at South Pole.