Eddy fluxes of CO2 and H2O are measured at two levels (58m and 47m) using tower-mounted closed-path Licor 6262 analyzers and Campbell CSAT3 sonic anemometers. A third Licor gas analyzer measures (a) the CO2/H2O concentration profile (1 of 8 levels every 2 minutes) and (b) the instantaneous integrated canopy storage of CO2/H2O, using a design pulling air simultaneously through 8 inlets (once every 20 minutes). Comprehensive meteorological data (air temperature, PAR, net radiation, etc) are also included. Pressure and temperature of the Licor cells are controlled to 500 torr and 48 degrees C. Eddy licors are automatically zeroed every 2 hours and the profile licor every 20 minutes. All Licors are automatically calibrated with span gases (at 325, 400, and 475 ppm) every 6 hours.
Goddard Earth Sciences Data and Information Services Center
NASA Goddard Space Flight Center
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Xia, Y., K. Mitchell, M. Ek, J. Sheffield, B. Cosgrove, E. Wood, L. Luo, C. Alonge, H. Wei, J. Meng, B. Livneh, D. Lettenmaier, V. Koren, Q. Duan, K. Mo, Y. Fan, and D. Mocko, (2012), Continental-scale water and energy flux analysis and validation for the North American Land Data Assimilation System project phase 2 (NLDAS-2): 1. Intercomparison and application of model products, J. Geophys. Res., 117, D03109, doi:10.1029/2011JD016048.