DATE RESOURCES and Measurement
Nitrous Oxide (N2O) hemispheric and global monthly means used from the NOAA/ESRL halocarbons program. A combined data set is used from two or more measurement programs. Weighted averages of monthly mean data are combined, interpolated, and smoothed for each sampling location. Hemispheric and global means are estimated by cosine weighting by latitude. (Combined Nitrous Oxide data from the NOAA/ESRL Global Monitoring Division)
Nitrous Oxide (N2O) data for the current year (2019) is from in situ samples analyzed on a gas chromatograph located at Mauna Loa (MLO), Hawaii as part of the NOAA/ESRL halocarbons in situ program. This data should be considered preliminary and will be replaced with official averaged data at the end of this year (2019).
Dr. James Elkins (NOAA), Dr. Ed Dlugokencky (NOAA), Dr. Bradley Hall (NOAA), Dr. Geoff Dutton (NOAA), Dr. David Nanc, Dr. Debra Mondeel (NOAA)
2000 years ago -
Law Dome ice core (DSS, DE08 and DE08-
Etheridge, D.M., L.P. Steele, R.L. Langenfelds, R.J. Francey, J.-
Etheridge, D.M., L.P. Steele, R.J. Francey, and R.L. Langenfelds. 1998. Atmospheric methane between 1000 A.D. and present: evidence of anthropogenic emissions and climatic variability. Journal of Geophysical Research, 103, 15979-
MacFarling Meure, C., D. Etheridge, C. Trudinger, P. Steele, R. Langenfelds, T. van Ommen, A. Smith, and J. Elkins. 2006. The Law Dome CO2, CH4 and N2O Ice Core Records Extended to 2000 years BP. Geophysical Research Letters, Vol. 33, No. 14, L14810 10.1029/2006GL026152
800,000 years ago -
Changes in past atmospheric nitrous oxide concentrations can be determined by measuring the composition of air trapped in ice cores from Antarctica. So far, the Antarctic Vostok and EPICA Dome C ice cores have provided a composite record of atmospheric nitrous oxide levels over the past 800,000 years.
MIS 7.5 to 11 and MIS 17 to 19: Schilt, A., M. Baumgartner, T. Blunier, J. Schwander, R. Spahni, H. Fischer, T.F. Stocker. 2010. Glacial-
A powerful greenhouse gas produced by soil cultivation practices, especially the use of commercial and organic fertilizers, fossil fuel combustion, nitric acid production, and biomass burning.
Nitrogen oxides (esp. NO2)
NOx, especially nitrogen dioxide, are emitted from high temperature combustion. They can be seen as the brown haze dome above or plume downwind of cities. Nitrogen dioxide is a reddish brown toxic gas ….
Air pollution is one of the major environ-