Papers on N2O atmospheric concentration

This is a list of papers on the atmospheric concentration of nitrous oxide (N₂O) – one of the more important greenhouse gases. The list is not complete, and will most likely be updated in the future in order to make it more thorough and more representative.

UPDATE (August 15, 2010): Artuso et al. (2010) added.

Modern concentration

Tropospheric halocompounds and nitrous oxide monitored at a remote site in the Mediterranean – Artuso et al. (2010) “Analysis of time series and trends of nitrous oxide (N₂O) and halocompounds weekly monitored at the Mediterranean island of Lampedusa are discussed. Atmospheric N₂O levels showed a linear upward growth rate of 0.78 ppb yr−1 and mixing ratios comparable with Northern Hemisphere global stations.”

Atmospheric nitrous oxide: patterns of global change during recent decades and centuries – Khalil et al. (2002) “Data from weekly global measurements of nitrous oxide from 1981 to the end of 1996 are presented. The results show that there is more N₂O in the northern hemisphere by about 0.7 plus or minus 0.04 ppbv, and the Arctic to Antarctic difference is about 1.2 plus or minus 0.1 ppbv. Concentrations at locations influenced by continental air are higher than at marine sites, showing the existence of large land-based emissions. For the period studied, N₂O increased at an average rate of about 0.6 ppbv/year (AA0.2%/year) although there were periods when the rates were substantially different.”

Variations in atmospheric nitrous oxide observed at Hateruma monitoring station – Tohjima et al. (2000) “In situ measurement of atmospheric nitrous oxide (N₂O) has been carried out at Hateruma monitoring station (lat 24°03′N, long 123°48′E) since March 1996 by the National Institute for Environmental Studies (NIES). A fully automated gas chromatograph equipped with an electron capture detector (ECD) measures the N₂O concentrations at a frequency of 3 air samples per hour. Details of the experimental methods and procedures are presented in this paper. The N₂O concentrations observed from March 1996 to February 1999 increased at an average rate of 0.64 ppb/yr. The observed data also suggest that there is a weak annual cycle of N₂O concentration, increasing in autumn and winter and decreasing in spring and summer, with a peak-to-peak amplitude of at most 0.3 ppb.”

Atmospheric Emissions and Trends of Nitrous Oxide Deduced From 10 Years of ALE–GAGE Data – Prinn et al. (1990) “We present and interpret long-term measurements of the chemically and radiatively important trace gas nitrous oxide (N₂O) obtained during the Atmospheric Lifetime Experiment (ALE) and its successor the Global Atmospheric Gases Experiment (GAGE). The ALE/GAGE data for N₂O comprise over 110,000 individual calibrated real-time air analyses carried out over a 10-year (July 1978–June 1988) time period. These measurements indicate that the average concentration in the northern hemisphere is persistently 0.75 ± 0.16 ppbv higher than in the southern hemisphere and that the global average linear trend in N₂O lies in the range from 0.25 to 0.31% yr−1, with the latter result contingent on certain assumptions about the long-term stability of the calibration gases used in the experiment. … The measured trends and latitudinal distributions are consistent with the hypothesis that stratospheric photodissociation is the major atmospheric sink for N₂O, but they do not support the hypothesis that the temporal N2O increase is caused solely by increases in anthropogenic N₂O emissions associated with fossil fuel combustion. Instead, the cause for the N₂O trend appears to be a combination of a growing tropical source (probably resulting from tropical land disturbance) and a growing northern mid-latitude source (probably resulting from a combination of fertilizer use and fossil fuel combustion).”

Increase and seasonal cycles of nitrous oxide in the earth’s atmosphere – Khalil & Rasmussen (1983) “Based on about nine thousand ground-level measurements at Cape Meares, Oregon (45° N), and Cape Grim, Tasmania (42° S), spanning three years, it is shown that nitrous oxide (N₂O) is increasing at about 0.9 p.p.b. yr−1 (0.6, 1.1) in the northern hemisphere, and at 0.7 p.p.b. yr−1 (±0.2 p.p.b. yr−1) in the southern hemisphere. It is also shown that N₂O concentrations vary with the season. On average, northern hemisphere concentrations are 0.8 p.p.b.v. higher during April, May, and June compared to the rest of the year, and southern hemisphere concentrations are about 0.5 p.p.b.v. lower during March, April, and May compared to the rest of the year. Based on the existing estimates of natural and anthropogenic sources of N₂O, the increase is explained by a sizeable anthropogenically-controlled land-based source. Mass-balance calculations also indicate that a natural land-based source, peaking in spring, would explain the main features of the observed seasonal cycle.”

Historic concentration

Glacial–interglacial and millennial-scale variations in the atmospheric nitrous oxide concentration during the last 800,000 years – Schilt et al. (2010) “We present records of atmospheric nitrous oxide obtained from the ice cores of the European Project for Ice Coring in Antarctica (EPICA) Dome C and Dronning Maud Land sites shedding light on the concentration of this greenhouse gas on glacial–interglacial and millennial time scales. The extended EPICA Dome C record covers now all interglacials of the last 800,000 years and reveals nitrous oxide variations in concert with climate. Highest mean interglacial nitrous oxide concentrations of 280 parts per billion by volume are observed during the interglacial corresponding to Marine Isotope Stage 11 around 400,000 years before present, at the same time when carbon dioxide and methane reach maximum mean interglacial concentrations. The temperature reconstruction at Dome C indicates colder interglacials between 800,000 and 440,000 years before present compared to the interglacials of the last 440,000 years. In contrast to carbon dioxide and methane, which both respond with lower concentrations at lower temperatures, nitrous oxide shows mean interglacial concentrations of 4–19 parts per billion by volume higher than the preindustrial Holocene value during the interglacials corresponding to Marine Isotope Stage 9–19. At the end of most interglacials, nitrous oxide remains substantially longer on interglacial levels than methane. Nevertheless, nitrous oxide shows millennial-scale variations at the same time as methane throughout the last 800,000 years. We suggest that these millennial-scale variations have been driven by a similar mechanism as the Dansgaard/Oeschger events known from the last glacial. Our data lead to the hypothesis that emissions from the low latitudes drive past variations of the atmospheric nitrous oxide concentration.” [Full text]

Law Dome CO₂, CH₄ and N₂O ice core records extended to 2000 years BP – MacFarling Meure et al. (2006) “New measurements of atmospheric greenhouse gas concentrations in ice from Law Dome, Antarctica reproduce published Law Dome CO₂ and CH₄ records, extend them back to 2000 years BP, and include N₂O. … Major increases in CO₂, CH₄ and N₂O concentrations during the past 200 years followed a period of relative stability beforehand. Decadal variations during the industrial period include the stabilization of CO₂ and slowing of CH₄ and N₂O growth in the 1940s and 1950s. Variations of up to 10 ppm CO₂, 40 ppb CH₄ and 10 ppb N₂O occurred throughout the preindustrial period.”

Atmospheric Methane and Nitrous Oxide of the Late Pleistocene from Antarctic Ice Cores – Spahni et al. (2005) “The European Project for Ice Coring in Antarctica Dome C ice core enables us to extend existing records of atmospheric methane (CH₄) and nitrous oxide (N₂O) back to 650,000 years before the present. … In contrast, the N₂O record shows maximum concentrations of 278 ± 7 ppbv, slightly higher than early Holocene values.” [supplementary information]

Ice Core Records of Atmospheric N₂O Covering the Last 106,000 Years – Sowers et al. (2003) “Here, we present a 106,000-year record of atmospheric nitrous oxide (N₂O) along with corresponding isotopic records spanning the last 30,000 years, which together suggest minimal changes in the ratio of marine to terrestrial N₂O production. During the last glacial termination, both marine and oceanic N₂O emissions increased by 40 ± 8%. We speculate that our records do not support those hypotheses that invoke enhanced export production to explain low carbon dioxide values during glacial periods.

High-resolution Holocene N₂O ice core record and its relationship with CH₄ and CO₂ – Flückiger et al. (2002) “Little is known, however, about possible N₂O variations during the more stable climate of the present interglacial (Holocene) spanning the last 11 thousand years. Here we fill this gap with a high-resolution N₂O record measured along the European Project for Ice Coring in Antarctica (EPICA) Dome C Antarctic ice core. On the same ice we obtained high-resolution methane and carbon dioxide records. This provides the unique opportunity to compare variations of the three most important greenhouse gases (after water vapor) without any uncertainty in their relative timing. The CO₂ and CH₄ records are in good agreement with previous measurements on other ice cores. The N₂O concentration started to decrease in the early Holocene and reached minimum values around 8 ka (<260 ppbv) before a slow increase to its preindustrial concentration of ~265 ppbv." [Full text]

Variations in Atmospheric N₂O Concentration During Abrupt Climatic Changes – Flückiger et al. (1999) “Records measured along two ice cores from Summit in Central Greenland provide information about variations in atmospheric N₂O concentration in the past. The record covering the past millennium reduces the uncertainty regarding the preindustrial concentration. Records covering the last glacial-interglacial transition and a fast climatic change during the last ice age show that the N₂O concentration changed in parallel with fast temperature variations in the Northern Hemisphere.”

Increase in the atmospheric nitrous oxide concentration during the last 250 years – Machida et al. (1995) “In order to estimate the concentrations of atmospheric nitrous oxide (N₂O) during the last 250 years, air samples were extracted from an Antarctic ice core, H15, using a dry extraction system and were then analyzed with a precision of ±2 ppbv. The results obtained were clearly less scattered and much tighter than those of the previous studies. Our data showed that the concentrations of atmospheric N₂O in the 18th century were about 276 ppbv on average. It was also obvious that the N₂O concentration began to increase in the mid‐19th century and reached approximately 293 ppbv around 1965, the trend of the concentration increase correlating quite well with the direct atmospheric measurements at the South Pole. Such an increase in the atmospheric N₂O concentration is thought to be of anthropogenic origin.”

Ice-age atmospheric concentration of nitrous oxide from an Antarctic ice core – Leuenberger & Siegenthaler (1992) “Here we report results from Antarctic ice cores, showing that the atmospheric N₂O concentration was about 30% lower during the Last Glacial Maximum than during the Holocene epoch. Our data also show that present-day N₂O concentrations are unprecedented in the past 45 kyr, and hence provide evidence that recent increases in atmospheric N₂O are of anthropogenic origin.”

Nitrous oxide in the Earth’s atmosphere – Badr & Probert (1992) “Nitrous oxide (N₂O) is an important atmospheric trace gas. Changes in the concentration of N2O in the atmosphere have evoked considerable interest because of its role in (i) regulating stratospheric ozone levels, and (ii) contributing to the atmospheric greenhouse phenomenon. The global concentration of N₂O in the atmosphere has been rising since the start of the Industrial Revolution, before which the concentration was almost constant at about 280–290 ppbv. In AD 1990, it reached about 310 ppbv and is rising at a rate of 0·5–1·1 ppbv (i.e. 0·2–0·3%) per year. In this paper, the history of N₂O in the Earth’s atmosphere, together with its latitudinal and altitudinal distributions, and seasonal oscillations, are described.”

N₂O measurements of air extracted from antarctic ice cores: Implication on atmospheric N₂O back to the last glacial-interglacial transition – Zardini et al. (1989) “A method has been developed for determining the N₂O concentrations of air bubbles trapped in ice cores. The air is removed by cutting ice samples of about 45 cm3 with a rotating knife, under pure nitrogen. About 2 cm³ of the gas extracted from the ice is analyzed. The N₂O concentrations are measured by gas chromatography, using electron capture detection with a detection limit of approximately 1 ppbv. The accuracy of the analysis is lower than 6%. This method has been used to analyze 34 Antarctic ice samples. Twelve air samples are from the D57 core and date approximately from AD 1600 and 1900. Data indicate a concentration of about 270 ppbv approximately 400 years ago, and of about 293 ppbv for the beginning of the 20th Century. The other samples have been taken from the Dome C core and date back to the time period extending from the Holocene to the Last Glacial Maximum. The results obtained for the Holocene period are in very good agreement with the concentrations measured for the pre-industrial time from the D57 core and indicate that, during the Holocene period, atmospheric N₂O mixing ratios may have remained fairly constant. The value observed during the last climatic transition suggest a slight increase in the N₂O concentrations when the climate was warming up.”

Nitrous oxide: trends and global mass balance over the last 3000 years – Khalil & Rasmussen (1988)