# --------------------------------------------------------------------
# USE OF NOAA GML DATA
# 
# These data are made freely available to the public and the scientific
# community in the belief that their wide dissemination will lead to
# greater understanding and new scientific insights. To ensure that GML
# receives fair credit for their work please include relevant citation
# text in publications. We encourage users to contact the data providers,
# who can provide detailed information about the measurements and
# scientific insight.  In cases where the data are central to a
# publication, coauthorship for data providers may be appropriate.
# 
# 
# 
# Contact:  Xin Lan (xin.lan@noaa.gov)
# 
# File Creation: Fri Apr  5 08:01:55 2024
# 
# 
# --------------------------------------------------------------------
# 
# 
# See gml.noaa.gov/ccgg/trends/ for additional details.
# 
#
# Annual CH4 mole fraction increase (ppb) from Jan 1 through Dec 31.
#
# Uncertainty in the global annual increase is estimated using two
# terms: The first is a bootstrap (resampling) method that varies the
# sites in our network. Each pseudo-network contains the same number of
# sites as our actual NOAA ESRL cooperative global air sampling network,
# but some are repeated and some are excluded. The second term is a
# Monte Carlo method that randomly modifies the data to account for
# measurement uncertainty. In both cases, 100 globally-averaged time
# series are created. Standard deviations of the annual increases are
# calculated, and the two terms (network and analytical) are taken in
# quadrature to give the  reported uncertainties. Please see Dlugokencky
# et al., 1994, JGR, vol. 99, 17021-17043, for a complete discussion.
#
# CH4 expressed as a mole fraction in dry air, nanomol/mol, abbreviated as ppb
#
# NOTE: In general, the data presented for the last year are subject to change,
# depending on recalibration of the reference gas mixtures used, and other quality
# control procedures. Occasionally, earlier years may also change for the same
# reasons.  Usually these changes are minor.
# 
# year     ann inc         unc
  1984       12.86        0.84
  1985       12.29        0.84
  1986       12.90        0.72
  1987       11.37        0.73
  1988       10.74        0.47
  1989       11.18        0.57
  1990        8.69        0.49
  1991       14.03        0.56
  1992        2.40        0.47
  1993        3.85        0.63
  1994        7.23        0.62
  1995        3.85        0.52
  1996        2.49        0.42
  1997        6.37        0.69
  1998       12.10        0.64
  1999        2.39        0.61
  2000       -1.46        0.53
  2001       -0.72        0.45
  2002        3.25        0.56
  2003        4.83        0.60
  2004       -4.86        0.42
  2005        0.34        0.43
  2006        1.90        0.51
  2007        7.86        0.64
  2008        6.51        0.44
  2009        4.71        0.56
  2010        5.22        0.70
  2011        4.86        0.59
  2012        4.99        0.46
  2013        5.69        0.57
  2014       12.75        0.43
  2015       10.05        0.72
  2016        7.05        0.64
  2017        6.89        0.75
  2018        8.70        0.62
  2019        9.67        0.65
  2020       15.16        0.45
  2021       17.95        0.45
  2022       13.11        0.77
  2023       11.05        0.58