Not exact matches
Now scientists
from Kyoto University and UC San Diego have discovered that this phenomenon occurred when the warming phase — «interdecadal
variability mode» —
of both the Pacific and Atlantic Oceans coincided.
While
variability in the age
of disease onset and incomplete pedigree information preclude us
from drawing any definitive conclusions about the
mode of inheritance, the available data is most consistent with an autosomal recessive pattern.
Patterns
of variability that don't match the predicted fingerprints
from the examined drivers (the «residuals») can be large — especially on short - time scales, and look in most cases like the
modes of internal
variability that we've been used to; ENSO / PDO, the North Atlantic multidecadal oscillation etc..
One key metric in this debate is the spatial pattern
of cooling which may provide a «fingerprint»
of the underlying climate change, whether that was externally forced (
from solar or volcanic activity) or was part
of an intrinsic
mode of variability.
And given the inherent unpredictability
of the internal
modes of climate
variability — as distinct
from the external control imposed by the external drivers
of climate, which themselves are also uncertain — such attribution statements will always be subject to uncertainty and therefore probabilistic.
The CO2 flux
variability from the longest inversion correlates with the Southern Annular
Mode (SAM), an index
of the dominant
mode of atmospheric
variability in the Southern Ocean.
The NAO is the dominant
mode of winter climate
variability in the North Atlantic region ranging
from central North America to Europe and much into Northern Asia.
They constructed a numerical network model
from 4 observed ocean and climate indices — ENSO, PDO, the North Atlantic Oscillation (NAO) and the Pacific Northwest Anomaly (PNA)-- thus capturing most
of the major
modes of climate
variability in the period 1900 — 2000.
A new study reconstructs a century - long South Atlantic Meridional Overturning Circulation index,
from 1870 to present, finding it is highly correlated to the observational - based SAMOC time series and the Interdecadal Pacific Oscillation is the leading
mode of variability.
The North Atlantic Oscillation (NAO), the dominant
mode of atmospheric circulation
variability over the North Atlantic / European sector, is a leading governor
of wintertime climate fluctuations in Europe, the Mediterranean, parts
of the Middle East and eastern North America over a wide range
of time scales
from intra-seasonal to multi-decadal (e.g., Hurrell 1995; Hurrell et al. 2003).
«The authors write that North Pacific Decadal
Variability (NPDV) «is a key component in predictability studies
of both regional and global climate change,»... they emphasize that given the links between both the PDO and the NPGO with global climate, the accurate characterization and the degree
of predictability
of these two
modes in coupled climate models is an important «open question in climate dynamics» that needs to be addressed... report that model - derived «temporal and spatial statistics
of the North Pacific Ocean
modes exhibit significant discrepancies
from observations in their twentieth - century climate... conclude that «for implications on future climate change, the coupled climate models show no consensus on projected future changes in frequency
of either the first or second leading pattern
of North Pacific SST anomalies,» and they say that «the lack
of a consensus in changes in either
mode also affects confidence in projected changes in the overlying atmospheric circulation.»»
Moreover, 370 years
of tropical cyclone data
from the Lesser Antilles (the eastern Caribbean island chain that bisects the main development region for landfalling U.S. hurricanes) show no long - term trend in either power or frequency but a 50 - to 70 - year wave pattern associated with the Atlantic Multidecadal Oscillation, a
mode of natural climate
variability.
Removing the influence
of two major
modes of natural internal
variability (the Arctic Oscillation and Pacific Decadal Oscillation)
from observations further improves attribution results, reducing the model - observation discrepancy in cold extremes.
From the paper: Over the whole globe, the dominant spatial
mode of variability in OHC in the upper 300 m [as shown by the first empirical orthogonal function (EOF), which explains the most variance], occurs mainly in the tropical Pacific and has the structure
of ENSO
variability (Fig. 4, A and B).
The researchers
from ETH Zurich found that the differences could be related to the
modes of climate
variability in the Pacific and Atlantic.
Some examples
from energy balance model calculations indicate that: (1) solar
variability has a near - global response, with the amplitude
of response slightly larger over land; (2) volcanism has a proportionately larger amplitude
of response over land than over ocean; and (3) the most oft - cited
mode of internal
variability, changes in the North Atlantic thermohaline circulation, has a hemispheric asymmetry in response.
These range
from simple averaging
of regional data and scaling
of the resulting series so that its mean and standard deviation match those
of the observed record over some period
of overlap (Jones et al., 1998; Crowley and Lowery, 2000), to complex climate field reconstruction, where large - scale
modes of spatial climate
variability are linked to patterns
of variability in the proxy network via a multivariate transfer function that explicitly provides estimates
of the spatio - temporal changes in past temperatures, and
from which large - scale average temperature changes are derived by averaging the climate estimates across the required region (Mann et al., 1998; Rutherford et al., 2003, 2005).
This is very different
from standard climate modelling where no attempt is made to synchronise
modes of internal
variability with the real world.
My favorite quote
from that paper is: «Because ENSO is the dominant
mode of climate
variability at interannual time scales, the lack
of consistency in the model predictions
of the response
of ENSO to global warming currently limits our confidence in using these predictions to address adaptive societal concerns, such as regional impacts or extremes (Joseph and Nigam 2006; Power et al. 2006).»