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Variability of Calibration Factors for Open-Path CO2/H2O Infrared Gas Analyzer and Its Effect on Long-Term Flux Measurement  

Choi, Tae-jin (Department of Atmospheric Sciences and Global Environment Laboratory, Yonsei University)
Yun, Jin-I. (Department of Ecosystem and Engineering, Kyung Hee University)
Lim, Jong-Hwan (Division of Forest Ecology, Korea Forest Research Institute)
Park, Eun-Woo (National Instrumentation Center for Environmental Management, Seoul National University)
Kim, Joon (Department of Atmospheric Sciences and Global Environment Laboratory, Yonsei University)
Publication Information
Korean Journal of Agricultural and Forest Meteorology / v.4, no.2, 2002 , pp. 103-113 More about this Journal
Abstract
Calibration experiments were executed to document pertinent calibration methods for open-path infrared gas analyzer (OP-2) in field operations and to quantify their performance characteristics in continuous long-term flux measurements. Based on our results, we concluded: (1) flow rate of 2.0 L min$^{-1}$ can be used for calibration instead of the recommended 0.5 L min$^{-1}$ . Such faster flow rate brings the sampled air in the calibration hood at equilibrium within 5 min for $CO_2$ and 10 min for $H_2O$; (2) after reaching equilibrium, two-minute average sampling for related variables per each concentration may be sufficient; (3) use of four concentration is needed to derive the nonlinear calibration equation for water vapor with 1% uncertainty of flux measurement; and (4) the resultant calibration interval for OP-2 for both $CO_2$ and $H_2O$ is approximately one month.
Keywords
long-term flux measurement; open-path infrared gas analyzer; calibration factors;
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  • Reference
1 Auble, D. and T.P. Meyer, 1992: An open path, fast response infrared absorption gas analyzer for $H_2O and CO_2$, Boundary-Layer Meteorology, 59, 243-256.
2 Data design group, 2000: OP-2 Open-Path $CO_2/ H_2O$ Analyser.
3 Licor, 1991: LI610 Portable Dew Point Generator: Instruction Manual.
4 Webb, E.K., G.I. Perman and R. Leuning, 1980: Correction of flux measurements for density effects due to heat and water transfer. Quarterly Journal of Royal Meteorology Society, 106, 85-100.
5 최태진, 김준, 윤진일, 1999: 농림생태계와 대기간의 상호작용 연구를 위한 에디 공분산 방법의 사용에 관하여, 한국농림기상학회지, 1(1), 60-71.
6 Leuning, R. and J. Moncrief, 1990: Eddy covariance $CO_2$ flux measurements using open-path and closed-path $CO_2$ analyzer-Corrections for analyzer water vapor sensitivity and damping of fluctuations in air sampling tubes. Boundary-Layer Meteorology, 53, 63-76.
7 Massman, W.J. and X. Lee, 2002: Eddy covariance flux corrections and uncertainties in long term studies of carbon and energy exchange, Agricultral and Forest Meteorology, in press.
8 홍진규, 김준, 최태진, 윤진일, B. Tanner, 2000: 폐회로 습도계를 이용한 수증기 플럭스 관측시 관의 감쇠 효과에 관하여, 한국농림기상학회지, 2(3), 80-86.
9 Kim, J., W. Kim, C. Cho, B. Lee, D. Lee, E. Park, J. Lee, J. Lim, J. Oh, J. Yun and C. Rho, 2002: KOFLUX: A New Network of Reference Sites for AsiaFlux/FLUXNET and CAMP/CEOP. Proceedings of the 2nd International Workshop on Advanced Flux Network and Flux Evaluation, Jeju, Korea, 9-11 January.
10 박윤호, 김준, 이희춘, 임종환, 권원태, 2000: 증발산 장기관측에 따른 크맆톤 습도계의 흡수 계수의 변화와 이슬점 생성기를 이용한 기기 보정, 한국농림기상학회지, 2(3), 75-79.
11 Kim, J., Y. Harazono, S. Yamamoto, A. Miyata, N. Saigusa and T. Choi, 2001: Flux measurements in a Complex Landscape: How reliable and Consistent Are Fluxes from Single Eddy Covariance Tower? Proceedings of the International Workshop on GAME-AAN/Radiation, Phuket, Thailand, 7-9 March.
12 Kohsiek, W., 2000: Water Vapor Cross-Sensitivity of Open Path $CO_2/ H_2O$ Sensors, Journal of Atmospheric and Oceanic Technology, 17, 299-311.
13 Licor, 2001: LI7500 Open-Path $CO_2/ H_2O$ Analyser: Instruction Manual.