Sentences with phrase «hindcast periods»

Well, the focus was on a 20y forecast, since that is the amount of data we now have for validation, but yes, we tried a range of different hindcast periods for fitting the trend and for averaging for the sake of persistence - up to 30y, IIRC.

Their «cooling forecasts» have not passed a the test for their hindcast period.

This is both for the current average climate statistics and the CHANGES of these statistics over the hindcast period of time.

They seem proud of a predicted - to - observed correlation, over their hindcast period 1996 - 2009, of 0.63 («significantly different from zero at the 95 % confidence level»).

This looks very much like the fit has been tightly constrained during the hindcast period, the model is being pushed during this period.

My guess is that during the hindcast period the model is artificially forced, and then in forcasting it relaxes.

If you're calculating the trend from the end of the hindcast period the 1999 - > 2000 change shouldn't be omitted.

Not exact matches

Some studies have attempted to estimate the statistical relationship between temperature and global sea level seen in the period for which tide gauge records exist (the last 2 - 3 centuries) and then, using geological reconstructions of past temperature changes, extrapolate backward («hindcast») past sea - level changes.

You are right that already their prediction (or better to call it hindcast) for the 1994 - 2004 period was too cold.

Surely the hindcast of the models should show periods of time where the climate signal is moving away, up and down, from the climate and weather signal?

Their simulation for 2000 - 2010 period was initialised with 2000 temperatures from the real world, not from a previous hindcast.

If the model is as good at forecasting as hindcasting, then the populations of (model - hindcast) and (model - forecast), for the same time period around day zero should be the same.

If we hindcast a couple thousand years do they get the Little Ice Age and Medieval Warm Periods right?

Finally, I reiterate my request for you and Jason to present papers that document a skill of the multi-decadal (Type 4) regional climate models to predict (in hindcast) the observed CHANGES in climate statistics over this time period.

doi: 10.1007 / s00382 -012-1313-4 who report quite limited predictive skill in two regions of the oceans on the decadal time period, but no regional skill elsewhere, when they conclude that «A 4 - model 12 - member ensemble of 10 - yr hindcasts has been analysed for skill in SST, 2m temperature and precipitation.

The fallacy of hindcasting: If I could hindcast the market for the period 1900 - 1970, would you be confident I could forecast the market for 1970 - 2010?

These should be traced in at least two directions: in the very structure and core hypotheses of GCMs and the related modelling practices, and in the agreement of model results in past periods with reality (hindcasting or retrodiction).»

Hindcasting to the Roman Warm Period, say 200BC - 0AD, it gives a temperature 3.3 to 3.7 deg C cooler than today.

Also, in preparation for our simulations, we made model hindcasts for a range of climate sensitivities and forced by the estimated total radiative forcing anomaly for the period AD 1765 — 2012 (Fig.

The toy models that can't tell us when the interglacial period is going to end, or even grossly hindcast the glaciation cycle, can tell us within a degree or two what the addition of a small amount of trace greenhouse is going to do.

Nic, considering the first part of your comment, let's write the response of a model over the hindcast and forecast periods as something like (A + e, B + d) where A and B are the forced response over the two intervals (which depends on the parameter choices) and e and d are gaussian deviates due to internal variability (which depends on random initial conditions).

Hindcasts even as short as back to 1900 perform very poorly in reproducing the early 20th c. warming and that is a period where the contentious AGW was not significant.

When comparing climate hindcasts to observed land and ocean data (Figure 3), the early 1940's is the only period where observed data lie above model predictions.

The DePreSys hindcast starting from June 1985 correctly predicted a rapid warming during the transition from the weak La Niña of 1985 to the El Niño of 1986 1987 and correctly predicted the warming trend throughout the period until the eruption of Mount Pinatubo.