1.4.2. SPO Programs

Table 1.4 is a summary of the measurement programs at SPO during 1996-1997.  Operational highlights are as follows. 

Carbon Cycle 

The Siemens continuous carbon dioxide (CO₂) analyzer ran continuously without significant problems.  During the 1996 winter an intermittent (wandering) output was traced to the Multi-Cool system.  The magnetic stirrer was disabled and the spurious output was eliminated. A new Hewlett Packard data acquisition system was installed when the system was moved to the new building, January 1997.  The use of the Linseis chart recorder ceased in August 1997 due to the lack of paper.  Sample flasks were filled through the analyzer once per week and through a portable Martin and Kitzis Sampler (MAKS) unit twice per month.

Aerosols

The Meteorology Research, Inc. (MRI) four-wavelength nephelometer, the Pollak condensation nucleus counter (CNC), and the Thermo Systems Inc. (TSI) CNC all ran continuously without significant problems.  Discrete observations with the Pollak CNC took place twice daily and compared within historical averages with data from the TSI CNC.

Solar and Terrestrial Radiation

During the austral summer, all Epply pyranometers, pyrgeometers, and the tracking normal incidence phyrheliometer (NIP) ran continuously with minimal problems.  Occasional (24-48 hours) adjustments had to be made to both tracking instruments to align them with the sun.  Discrete observations with the filter wheel NIP took place three times daily during especially clear conditions.  After sunset each March, the short-wave instruments were taken off-line for the winter.

Ozone and Water Vapor

The Dasibi ultraviolet absorption ozone monitor ran continuously without significant problems.  The new computer-based data acquisition system (PC-DAS) was brought on-line in mid-February 1996 and was run concurrently with the CAMS unit.  After 6 weeks of simultaneous operation, the CAMS unit was removed in March.  Minor changes were made to the PC-DAS software to correct some minor errors.

Discrete observations with the Dobson ozone spectrophotometer took place three times daily during the austral summer and again during the winter months when the full moon was at least 5° above the horizon and at least 50% full.  In June 1996 the mercury thermometer was accidentally broken.  Without a spare mercury thermometer, an alcohol thermometer had to be used.  In late October repeated mercury lamp tests were outside acceptable limits.  The Q setting table was adjusted by -0.36.  Weekly mercury lamp tests were performed to verify that the instrument had stabilized.  A new mercury thermometer was installed in November 1996 and the old Q setting table was used again.  With the move into the ARO building Dobson no. 82 was replaced with Dobson no. 80 in January 1997.  Side-by-side observations with the two instruments were conducted for a number of days during the changeover.

The ozonesonde program ran well during the year.  Rubber balloons (1500 g) were launched during the warmer summer months, November–March, while the larger 540 m³ plastic balloons were used in the colder winter months, April–October.  Launches occurred once per week except during the months of stratospheric ozone depletion (August-November) when the schedule was increased to every 3 days and then to every other day.  Periodically, plastic balloons were flown with both CMDL sondes and ASA Meteorological Department sondes.  It is strongly recommended that tandem (dual instrument) launches be undertaken as much as possible during the non-ozone hole season.  Tandem launches save on the helium supply and ASA meteorological balloons.  Balloon launches from the new BIF began in late February 1997.

Nitrous Oxide and Halocarbons

The two Shimadzu Mini-2 electron capture gas chromato-graphs (GC) ran continuously with no significant problems. 

During the MET tower move in November 1996, the GC sampling lines were discovered to be connected to the intakes that were attached to the outside of the aerosol stack.  After the tower was erected at its new location, new sampling lines were spliced to the lines running out to the tower.  These lines (at mid-tower and top-of-tower) were then used as the intakes for the GCs.  These same lines were used after the move into the ARO building; however, they were shortened by about half their length.

A spurious signal appeared on the trailing edge of the CFC-113 trace.  This contamination was traced to the CAL1 cylinder regulator.  CMDL-Boulder was notified and the contamination signal was removed mathematically during analysis. 

There was a noticeable effect on the GC system from room temperature changes in the new ARO building; limiting the use of the double doors to the storage room significantly reduced this problem.  

Meteorology

The meteorology system ran continuously without significant problems.  During the MET tower relocation, all instruments were removed and placed on the roof windward railing of the “old” CAF.  Also during this time, yearly maintenance and calibrations were performed.

Data Acquisition

The use of an automatic file transfer protocol (FTP) process began in December 1996 for sending data to CMDL-Boulder.  The satellite rise times change on a weekly basis.  In previous years this required CMDL South Pole personnel to manually FTP the data back at different times throughout the year.  With the new set-up, the data files are automatically sent when the satellites rise above the horizon.

Cooperative Programs

SIO.  The Scripps Institution of Oceanography (SIO) conducts long-term monitoring of CO₂, ¹³C/¹²C ratio, and N₂O.  Twice per month, three evacuated glass flasks were exposed to ambient air.

Three glass flasks were pressurized with ambient air twice per month for the long-term monitoring of O₂ and N₂.  A new pump unit was brought down in February 1997.  Throughout the 1997 winter the new pump unit was used for the first-of-the month sample and the old unit for the mid-month sample.

DOE.  The Department of Energy (DOE) conducts long-term monitoring of the spatial and temporal distribution of specific and anthropogenic radionuclides in surface air.  The DOE pumps on the first floor of the ARO building required that the intake pipe be extended about 5 m.  The DOE pump ran continuously without problems; filters were replaced each week.

CSIRO.  Commonwealth Scientific and Industrial Research Organization (CSIRO) monitors the long-term ratio of ¹³C/¹²C in atmospheric CO₂ .  Two glass flasks were filled with ambient air every 2 weeks.  There were no problems with this system.

State University of New York (SUNY).  Air-filled cylinders remained on platforms approximately 800 m downwind of the main station for the quantification of the production rate of radiocarbon by galactic cosmic rays.  The cylinders were inspected and cleared of snow once per month.  One of the two support stands was raised in September 1997 due to significant snow drifting.

University of Arizona.  Snow samples were collected to study the snow/atmosphere exchange of H₂O_2.  Surface snow and micropit samples were collected weekly, except during the spring when they were collected twice per week.  Beginning in January 1996, two additional, deeper (30 and 50 mm) samples were collected.  Additionally, snow heights were measured from a “sampling grid” inside the CAS.  A new sampling grid was set up in the new CAS in October 1996.  Concurrent snow-height measurements were made in the old and new grids for about 1 month before sampling began in the new grid.  In October 1997 another sampling grid was set up in the new CAS due to significant snow drifting in the old one.  Concurrent snow-height measurements were again made in both grids. 

TABLE 1.4.  Summary of Measurement Programs at SPO in 1995-1996

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