I want to understand better how it is you decide that GHGs are responsible for a deterministic forced trend when you have this powerful but poorly understood
stochastic noise rocess operating in the background.
Consequently, it is likely that these DTR changes are attributable to
stochastic noise (Laken et al. 2012c).
What you are looking at, David, is more function of
stochastic noise than underlying trend.
In a system such as the climate, we can never include enough variables to describe the actual system on all relevant length scales (e.g. the butterfly effect — MICROSCOPIC perturbations grow exponentially in time to drive the system to completely different states over macroscopic time) so the best that we can often do is model it as a complex nonlinear set of ordinary differential equations with
stochastic noise terms — a generalized Langevin equation or generalized Master equation, as it were — and average behaviors over what one hopes is a spanning set of butterfly - wing perturbations to assess whether or not the resulting system trajectories fill the available phase space uniformly or perhaps are restricted or constrained in some way.
Not exact matches
This was accomplished using a
stochastic climate model based on the concept that ocean temperature variability is a slow dynamical system, a red
noise signal, generated by integrating
stochastic atmospheric forcing, or white
noise71.
Ligand - dependent induction of our synthetic signal transduction system has
stochastic fluctuations or
noise.
Statistically, the low R2 indicates
noise in the system, also apparent as GUS activity without the ligand and
stochastic fluctuation.
Future winter SST forecasts are projected linear trends with an added
stochastic component derived from the empirical
noise.
One possible mechanism for the movement of cells from one state to another would be the combination of
stochastic changes in low - level gene expression or
noise, combined with positive feedback loops.
In essence, technical indicators incorporated into your live charts like volume indicators, trend lines, Fibonacci levels,
stochastic oscillators etc., can block out the market
noise, forming a better picture of the markets and trends that lie ahead.
While
noise is often understood as an obstacle to a signal carrying a message, the phenomenon of
stochastic resonance indicates cases where the presence of white
noise (that is, randomness) actually helps amplify the signal.
In this way, they in fact train their
stochastic engine with significant (if not dominant) low frequency climate signal rather than purely non-climatic
noise and its persistence.»
What I was reminded of though is something along the lines of the hypothesis of a very weak signal /
stochastic - resonance idea, where «
noise» and a very weak «signal» could combine (similar to some of the D - O hypotheses out there).
[Response: Red
noise is produced by a kind of
stochastic process that has more variability at longer time scales than at shorter time scales.
The question about uncertainty is a question about information about processes, whether understood, random variations (known as «
noise» or
stochastic processes), or systematic model shortcomings (biases).
tpinlb, climate models don't «predict» year - specific phenomena arising from
stochastic variation that adds «
noise» to progression of climate states under the influence of persistent forcings.
As Richard Alley has shown in a couple of papers, the ice core data of DO events are entirely consistent with
stochastic resonance — which is not chaos but arises from a simple threshold process («flicking of a switch») in the presence of
noise.
Characteristic of this school is the following quote: But as soon as you add any sort of
noise, your perfect chaotic system becomes a mere
stochastic one over long time periods, and probabilities really do apply.
In fact, it's my experience modeling
stochastic processes and
noise (which are inherently chaotic systems that can not be directly modeled except as probability functions) that informs this next statement: climate models can, and do, model cloud formation.
Most cycles are formed from
noise, ice ages (Nicolis and Nicolis) biological, business cycles (Slutsky) Enso (Zaliaplin and Ghil) there is even a very adept name for it
stochastic resonance eg Benzi.
«train [ing] the
stochastic engine with significant (if not dominant) low frequency climate signal rather than purely non-climatic
noise and its persistence».
Whereas the corresponding precipitation variability can be described as a white
noise stochastic process, power spectra of vertically integrated soil water exhibit significant redness on timescales of years to decades, since the predictability of soil water storage arises mostly from the integration of precipitation variability.
But it is unclear whether or not the 1976 regime shift in North Pacific climate reflects an abrupt change in the extratropical atmosphere - ocean system or simply the random superposition of different climate signals, e.g., similar regime - shifts are reproducible in simple
stochastic models forced by atmospheric
noise and ENSO (Newman et al., 2003).
Obtain future
stochastic projections by extending the trend (e.g. by extrapolation) and adding back random «realisations» of the
noise model («Monte Carlo simulation»).
The current approach that is generally pursued assumes essentially that past climate variability is indistinguishable from a
stochastic red -
noise process (Hasselmann, 1976), whose only regularities are those of periodic external forcing (Mitchell, 1976).
Time series from a wide class of
stochastic processes may be considered to be the output of a linear filter applied to white
noise, but the terminology also applies to processes that are not the result of any filter.
The current approach that is generally pursued assumes essentially that past climate variability is indistinguishable from a
stochastic red -
noise process... Given such a null hypothesis, the official consensus of IPCC (1995) tilts towards a global warming effect of recent trace - gas emissions, which exceeds the cooling effect of anthropogenic aerosol emissions.»
But once you look at the rate of change you start to realise that it's not just random
noise or «
stochastic» variation.
However, ongoing debate and recent studies suggest that
stochastic atmospheric white
noise is the main driver of the pattern.