Sentences with phrase «numbers of proxy series»

The reconstruction all the way back to the year 1400 used 22 proxy data series, although some of the 22 were combinations of larger numbers of proxy series by a method known as «principal components analysis» (hereafter called «PCA» — see here).

Not exact matches

Questions: Is scaling everything to a normal sd before averaging valid in proxy production, or do people weight each given regional series by the number of trees in that series before averaging?

«However, a number of issues specific to the modeling situation could arise in this context, including: how realistically the AOGCM is able to reproduce the real world patterns of variability and how they respond to various forcings7; the magnitude of forcings and the sensitivity of the model that determine the magnitude of temperature fluctuations; and the extent to which the model was sampled with the same richness of information that is contained in the proxy records (not only temperature records, but series that correlate well with the primary patterns of variability including, for example, precipitation in particular seasons.»

Mann includes at this site a large number of temperature proxy data series.

Because North America was so heavily represented in the proxy dataset, Mann choose to use PCA to reduce the number of series so as not to overweight NA in the resulting reconstruction.

«Alternatively, the number of proxies can be lowered through a threshold screening process (Mannet al., 2008) whereby each proxy sequence is correlated with its closest local temperature series and only those proxies whose correlation exceeds a given threshold are retained for model building.

I suspect that the Lasso is picking a very small number of the best proxies, and picking a slightly larger number of noise series.

Of the other two reconstructions, one (Jones et al., 1998) was based on a much smaller number of proxies, whereas the other (Briffa et al., 2001) was based solely on tree ring density series from an expansive area of the extratropics, but reached back only to AD 140Of the other two reconstructions, one (Jones et al., 1998) was based on a much smaller number of proxies, whereas the other (Briffa et al., 2001) was based solely on tree ring density series from an expansive area of the extratropics, but reached back only to AD 140of proxies, whereas the other (Briffa et al., 2001) was based solely on tree ring density series from an expansive area of the extratropics, but reached back only to AD 140of the extratropics, but reached back only to AD 1400.