Table 1. Column and Profile Observation Sites and the CO2 Seasonal Cycle Amplitude Comparison With Model Simulations Site Name (Code) Location Altitude Range Above Surface, m Mean Scale Factor A of the 12 Modelsa,b Phase Shift T of 12 Models, days Scale Factor A for the Mean Response of the 12 Models RMS in Fitting the Mean Response of the 12 Models, ppm Poker Flats, AK (PFA) 65.07degreesN, 147.29degreesW 1500-7500 1.20+/-0.11 -16.8+/-4.5 1.21 0.71 Zotino, Russia (ZOT) 60.75degreesN, 89.38degreesE 500-3500 1.44+/-0.21 -18.4+/-2.8 1.42 1.70 Estevan Point, Canada (ESP) 49.38degreesN, 126.55degreesW 500-5500 1.20+/-0.12 -16.0+/-3.2 1.20 0.54 Orleans, France (ORL) 47.80degreesN, 2.50degreesE 500-3500 1.39+/-0.18 -19.6+/-3.1 1.38 0.43 Park Falls, WI (LEF) 45.93degreesN, 90.27degreesW Total column 1.34+/-0.14 -7.3+/-4.0 1.34 0.43 Harvard Forest, MA (HFM) 42.54degreesN, 72.17degreesW 500-7500 1.38+/-0.09 -16.0+/-2.7 1.38 0.67 Carr, CO (CAR) 40.90degreesN, 104.80degreesW 1500-6500 1.20+/-0.11 -7.6+/-7.3 1.21 0.56 Kitt Peak, AZ c (KTP) 31.90degreesN, 111.60degreesW Total column 1.11+/-0.07 15.3+/-4.6 1.12 0.56 Mean 1.28 -14.5+/-5.0 d 1.28 0.70 Mean of 35 surface sites e in 30degreesN~70degreesN 1.12 -11.9+/-9.8 1.11 1.07 a For LEF and KTP, total CO2 columns were simulated for the comparison. For the aircraft sites, only partial columns with measurements were simulated. The scale factor A and phase shift T here are described by equation (1). b The names of the models are CSU.gurney, GISS.prather, GISS.prather2, GISS.prather3, JMA-CDTM.maki, MATCH.bruhwiler, MATCH.chen, MATCH.law, RPN.yuen, SKYHI.fan, TM3.heimann, GCTM.baker. For more detail refer to TransCom website (http://www.purdue.edu/transcom/) and Gurney et al. [2003]. c The Kitt Peak observations were taken from Jan 1979 to Mar 1995, for more detail refer to Yang et al. [2002]. d Excluding Kitt Peak due to different observation time period. e These surface sites are part of the Globalview-CO2 (2006) network, for a detailed list see auxiliary material.