Atmospheric carbon dioxide at Mauna Loa Observatory: 2. Analysis of the NOAA GMCC data, 1974–1985

Abstract

The first 12 years (1974–1985) of continuous atmospheric CO2 measurements from the NOAA GMCC program at the Mauna Loa Observatory in Hawaii are analyzed. Hourly and daily variations in the concentration of CO2 due to local sources and sinks are described, with subsequent selection of data representing background concentrations. A digital filtering technique using the fast Fourier transform and low‐pass filters was used to smooth the selected data and to separate the seasonal cycle from the long‐term increase in CO2. The amplitude of the seasonal cycle was found to be increasing at a rate of 0.05±0.02 ppm yr−1. The average growth rate of CO2 was 1.42±0.02 ppm yr−1, and the fraction of CO2 remaining in the atmosphere from fossil fuel combustion was 59%. A comparison between the Mauna Loa continuous CO2 data and the CO2 flask sample data from the sea level site at Cape Kumukahi, Hawaii, showed that the amplitude of the seasonal cycle at Cape Kumukahi was 23% larger than at Mauna Loa, with the phase of the cycle at Mauna Loa lagging the cycle at Cape Kumukahi by about 1–2 weeks.

Anthropogenic changes of CO2, CH4, N2O, CFCl3, CF2Cl2, CCl2FCClF2, CHCl3, CH3CCl3, CCl4, SF6 and SF5CF3 mixing ratios in the atmosphere over southern Poland

“…A three-step pro ce dure was applied to se lect the data rep re sent ing back ground con di tions at the sta tion (Necki et al, 2003). Daily mean val ues were fur ther smoothed us ing the rou tine rec om mended by NOAA (CCGvu 4.40; Thoning et al, 1989). For com par i son, the CO 2 trend curve rep re sent ing the re gional ma rine back ground (Mace Head) is also shown (http://www.esrl.noaa.gov/gmd/; GLOBALVIEW-CO2, 2013).…”

“…The an nual means are arith me tic av er ages of the daily mean val ues. The am pli tudes of sea sonal vari a tions were cal cu lated us ing the CCGvu 4.40 rou tine (Thoning et al, 1989) which uses the smoothed CO 2 re cord. The an nual growth rates were cal culated through der i va tion of the trend curve shown in Fig ure 2.…”

“…They were cal cu lated as arithme tic av er ages of in di vid ual mea sure ments. Shown also are trend curves (red) de rived from daily means of these compounds mea sured at the Mace Head sta tion rep re sent ing the re gional ma rine back ground (http://agage.eas.gatech.edu; Fraser et al, 1996;Cunnold et al, 1997;Prinn et al, 2000;O'Doherty et al, 2001;Reimann et al, 2005), cal cu lated us ing the CCGvu 4.40 rou tine (Thoning et al, 1989). Fig ure 5H shows the at mo spheric con cen tra tions of SF 5 CF 3 mea sured in flask sam ples col lected in Kraków and at Kasprowy Wierch.…”

“…To quan tify the av er age load of the lo cal at mo sphere in Kraków with re spect to the halocarbons mea sured, the re cords of their daily mean val ues shown in Fig ure 5A-G have been smoothed us ing the CCGvu 4.40 rou tine (Thoning et al, 1989) and off sets be tween the cal cu lated trend curves for Kraków and Mace Head sta tion were cal cu lated. The an nual mean off sets for the halocarbons mea sured are sum ma rized in Ta ble 5.…”

Robust extraction of baseline signal of atmospheric trace species using local regression

“…Hence, data filtering is often an essential part of the analysis of data from those sites. For example, data filtering was applied for trend estimations (Thoning et al, 1989;Novelli et al, 1998;Schuepbach et al, 2001;Novelli et al, 2003;Zellweger et al, 2009), for evaluation of source regions and corresponding emission estimates Cox et al, 2005;Reimann et al, 2005;Greally et al, 2007), as well as for modeling of long-range transport of trace gases Balzani Lööv et al, 2008).…”