 |
| Titel |
Statistical framework for evaluation of climate model simulations by use of climate proxy data from the last millennium – Part 3: Practical considerations, relaxed assumptions, and using tree-ring data to address the amplitude of solar forcing |
| VerfasserIn |
A. Moberg, R. Sundberg, H. Grudd, A. Hind |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1814-9324
|
| Digitales Dokument |
URL |
| Erschienen |
In: Climate of the Past ; 11, no. 3 ; Nr. 11, no. 3 (2015-03-12), S.425-448 |
| Datensatznummer |
250117208
|
| Publikation (Nr.) |
 copernicus.org/cp-11-425-2015.pdf |
|
|
|
|
|
| Zusammenfassung |
| A statistical framework for evaluation of climate model simulations by
comparison with climate observations from instrumental and proxy data (part 1
in this series) is improved by the relaxation of two assumptions. This allows
autocorrelation in the statistical model for simulated internal climate
variability and enables direct comparison of two alternative forced
simulations to test whether one fits the observations significantly better than
the other. The extended framework is applied to a set of simulations driven
with forcings for the pre-industrial period 1000–1849 CE and 15
tree-ring-based temperature proxy series. Simulations run with only one
external forcing (land use, volcanic, small-amplitude solar, or
large-amplitude solar) do not significantly capture the variability in the
tree-ring data – although the simulation with volcanic forcing does so for
some experiment settings. When all forcings are combined (using either the small- or large-amplitude solar forcing), including also
orbital, greenhouse-gas and non-volcanic aerosol forcing, and additionally
used to produce small simulation ensembles starting from slightly different
initial ocean conditions, the resulting simulations are highly capable of
capturing some observed variability. Nevertheless, for some choices in the
experiment design, they are not significantly closer to the observations than
when unforced simulations are used, due to highly variable results between
regions. It is also not possible to tell whether the small-amplitude or
large-amplitude solar forcing causes the multiple-forcing simulations to be
closer to the reconstructed temperature variability. Proxy data from more
regions and of more types, or representing larger regions and complementary
seasons, are apparently needed for more conclusive results from model–data
comparisons in the last millennium. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|