Atmospheric CO/sub 2/ concentrations Mauna Loa Observatory, Hawaii 1958-1983

Technical Report · Sat Sep 01 04:00:00 EDT 1984

OSTI ID:6944267

Keeling, C D

Carbon dioxide concentrations have been obtained throughout the sampling period using a nondispersive, dual detector, infrared gas analyzer. Air samples are obtained via air intakes at the top of 7m towers. Four of these towers exist, along with a 27m tower. The highest intake along with one of the lower intakes take four samples per hour. Air is sampled from one intake for 10 minutes, then from the second for 10 minutes, and then from a reference gas for 10 minutes. The intakes are actually maintained continuously, but are shunted when not being analyzed by the infrared gas analyzer. The air flow registers a voltage on the analyzer which then records the concentrations on a strip chart recorder. Two intakes are used to detect possible contamination. A sign of contamination, whether ambient or instrument, is evidenced by significant differences in CO/sub 2/ concentrations between the two paired intakes. Efforts to calibrate equipment, reduce the possibility of contamination, and to adjust data to represent uncontaminated, true conditions have been done and updated throughout the course of the project. Calibration of the gas analyzer by standardized CO/sub 2/-in-nitrogen reference gases is done twice daily. Flask samples are taken twice monthly to give a comparison to the data recorded using the infrared gas analyzer. Data is scrutinized daily for possible contamination and archived and magnetic tape for possible further scrutiny and adjustment. Daily, monthly, and annual averages are computed for the Mauna Loa data after deletion of con taminated samples and readjustment. These averages have shown a steady rise in the annual average concentration, from 316 ppmv in 1959 to 342 ppmv in 1983.

• Research Organization: California Univ., San Diego, La Jolla (USA)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6944267
• Report Number(s): NDP-001
• Country of Publication: United States
• Language: English

Related Subjects

500200* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
AIR POLLUTION
AIR POLLUTION MONITORING
AIR SAMPLERS
ANNUAL VARIATIONS
CALIBRATION
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CHALCOGENIDES
DAILY VARIATIONS
ECOLOGICAL CONCENTRATION
EQUIPMENT
FEDERAL REGION IX
HAWAII
MONTHLY VARIATIONS
NORTH AMERICA
OXIDES
OXYGEN COMPOUNDS
POLLUTION
SAMPLERS
USA
VARIATIONS