Sentences with phrase «models and observations since»

A recent study by Cowtan et al. (paper here) suggests that accounting for these biases between the global temperature record and those taken from climate models reduces the divergence in trend between models and observations since 1975 by over a third.

Not exact matches

Covering the period since 1950, the researchers show how the science has leaped ahead thanks to computerisation, mathematical modelling and new technologies of observation.

The model is supported by observations from satellites, ground - based networks that measure ozone - depleting chemicals in the real world, and by observations from two decades of NASA aircraft field campaigns, including the most recent Airborne Tropical Tropopause Experiment (ATTREX) in 2013 and the Atmospheric Tomography (ATom) global atmospheric survey, which has made three deployments since 2016.

Your statement that «Thus it is natural to look at the real world and see whether there is evidence that it behaves in the same way (and it appears to, since model hindcasts of past changes match observations very well)» seems to indicate that you think there will be no changes in ocean circulation or land use trends, nor any subsequent changes in cloud responses thereto or other atmospheric circulation.

Thus it is natural to look at the real world and see whether there is evidence that it behaves in the same way (and it appears to, since model hindcasts of past changes match observations very well).

«We built several models of equal quality from the photometric data, but we favored a model made of two lobes since some of the best adaptive optics observations suggest that the Trojan asteroid has a dual structure,» said Josef Durech, co-author and researcher at the Charles University in Prague.

The researchers combined these observations into a simple model, using only solar energy and waiting time since the previous interglacial, that was able to predict all the interglacial onsets of the last million years, occurring roughly every 100,000 years.

Based on our model, and our observations near greenhouses, it is probable that destructive pathogens have been spilling over into wild bee populations since the collapse of commercial B. occidentalis during the late 1990s, and this has contributed to the ongoing collapse of wild Bombus sensu stricto.

«We use a massive ensemble of the Bern2.5 D climate model of intermediate complexity, driven by bottom - up estimates of historic radiative forcing F, and constrained by a set of observations of the surface warming T since 1850 and heat uptake Q since the 1950s... Between 1850 and 2010, the climate system accumulated a total net forcing energy of 140 x 1022 J with a 5 - 95 % uncertainty range of 95 - 197 x 1022 J, corresponding to an average net radiative forcing of roughly 0.54 (0.36 - 0.76) Wm - 2.»

Since any actual model prediction depends on a collection of hypotheses together, as do the «observation» and the comparison, there are multiple chances for errors to creep in.

But these issues are hard to quantify — both from the observations (since there are few occurrences) and models (which might not be complete / detailed enough to include these effects).

I talked only about the topic of this post, which is: the mismatch betweem model results and observations, and it's implication for model uncertainty (since the mismatch can not be attributed to observation errors).

This has been documented since (at least) the very earliest model papers by Manabe and colleagues and in the observations since at least a 1994 paper by Christy and McNider in Nature.

Even putting aside the OHC data and fingerprinting, there is absolutely no evidence in model simulations (or in prevailing reconstructions of the Holocene), that an unforced climate would exhibit half - century timescale global temperature swings of order ~ 1 C. I don't see a good theoretical reason why this should be the case, but since Judith lives on «planet observations» it should be a pause for thought.

Your statement that «Thus it is natural to look at the real world and see whether there is evidence that it behaves in the same way (and it appears to, since model hindcasts of past changes match observations very well)» seems to indicate that you think there will be no changes in ocean circulation or land use trends, nor any subsequent changes in cloud responses thereto or other atmospheric circulation.

Since (by then) not all models showed more warming aloft than on the surface (which I wouldn't call a strong sign of reliability in the models) the gap between models and observations closed just enough to make both statistically compatible.

Moreover, since observations now appear to track Scenario C — a drastic reduction in GHG — and there appears to have been no such reduction, then again the assumptions underlying the model need to be made explicit and re-assessed.

If only let's say 90 % of the budgets spent on computer modeling had gone on more extensive, more detailed observations since 1979 (the date of that sensitivity of 3 plus or minus 1.5 which seems to have so influenced the modelers and proven so hard for them to improve upon much).

The day - by - day, month - by - month, year - by - year, etc. sequencing of values, however, will not correspond to observations, since climate models solve a «boundary value problem» and are not constrained to reproduce the timing of natural climate variability (e.g., El Niño - Southern Oscillation) in the observational record.

Since, without free parameters, and parameterizations calibrated (or fudged, if you like) to match observed data (such as it is), models (the principle means of attribution) are unable to replicate real world observations, then the statement above is obvious patent nonsense.

Since then there are a number of papers published on why the warming was statistically insignificant including a recent one by Richardson et al. 2016 which tries to explain that the models were projecting a global tas (temperature air surface) but the actual observations are a combination of tas (land) and SST oceans, meaning projected warming shouldn't be as much as projected.

Since models indicate and observations appear to also indicate an increase in precipitation, perhaps they should be arguing for more CO2 release in order to provide more freshwater to the continents.

««Climate model simulations that consider only natural solar variability and volcanic aerosols since 1750 — omitting observed increases in greenhouse gases — are able to fit the observations of global temperatures only up until about 1950.»

However, there is not compelling evidence that anthropogenic CO2 was sufficient to influence Earth's temperatures prior to 1950, i.e. «Climate model simulations that consider only natural solar variability and volcanic aerosols since 1750 — omitting observed increases in greenhouse gases — are able to fit the observations of global temperatures only up until about 1950.»

«We use a massive ensemble of the Bern2.5 D climate model of intermediate complexity, driven by bottom - up estimates of historic radiative forcing F, and constrained by a set of observations of the surface warming T since 1850 and heat uptake Q since the 1950s... Between 1850 and 2010, the climate system accumulated a total net forcing energy of 140 x 1022 J with a 5 - 95 % uncertainty range of 95 - 197 x 1022 J, corresponding to an average net radiative forcing of roughly 0.54 (0.36 - 0.76) Wm - 2.»

«In the case of the Arctic we have high confidence in observations since 1979, from models (see Section 9.4.3 and from simulations comparing with and without anthropogenic forcing), and from physical understanding of the dominant processes; taking these three factors together it is very likely that anthropogenic forcing has contributed to the observed decreases in Arctic sea ice since 1979.»

There have been many studies aiming to test this hypothesis since AR4, 50 which fall in two categories: i) studies that seek to establish a causal relationship between cosmic rays and 51 aerosols / clouds by looking at correlations between the two quantities on timescales of days to decades, and 52 ii) studies that test through observations or modelling one of the physical mechanisms that have been put 53 forward.

There have been many studies aiming to test this hypothesis since AR4, which fall in two categories: i) studies that seek to establish a causal relationship between cosmic rays and aerosols / clouds by looking at correlations between the two quantities on timescales of days to decades, and studies that test through observations or modeling one of the physical mechanisms that have been put forward.

Observations and model simulations show that the Antarctic ozone hole caused much of the observed southward shift of the Southern Hemisphere middle latitude jet in the troposphere during summer since 1980.

Since all climate models agree (possibly because of tuning) about the combined WV+LR feedback through clear skies (globally at least), the differences between models arises and between models and observations (globally at least) comes from OLR from cloudy skies.

---------------------------------- Bastos et al., 2017 http://iopscience.iop.org/article/10.1088/1748-9326/aa67b5/meta The sustained increasing vegetation activity trend (greening) in the Northern Hemisphere (NH) has been a prominent feature in satellite observations since the 1980s and is consistently simulated by models.

We identify human and natural contributions to the observed IPWP changes since the 1950s by comparing observations with climate model simulations using an optimal fingerprinting technique.

Since the projections are based on the models simulations that indicate approximately 0.2 C per decade, the error in the models in the Antarctic and tropics appear to be higher than observation, and the trend in the tropics since 1994 is only 0.04 C per decade, it appears likely that H I will be falsiSince the projections are based on the models simulations that indicate approximately 0.2 C per decade, the error in the models in the Antarctic and tropics appear to be higher than observation, and the trend in the tropics since 1994 is only 0.04 C per decade, it appears likely that H I will be falsisince 1994 is only 0.04 C per decade, it appears likely that H I will be falsified.

[71] Se the books of Robert Tisdale http://bobtisdale.wordpress.com/ for many analyses of the ocean surface temperatures continuously observed by satellites since 1982 and extensive comparisons of model outputs with observations

The results open the possibility that recent climate sensitivity estimates from global observations and [intermediate complexity models] are systematically considerably lower or higher than the truth, since they are typically based on the same realization of climate variability.»

CAMS has been up and running since the summer of 2015 and combines models and observations to monitor and forecast atmospheric pollution and greenhouse gases.

Since the scaling factor used is based purely on simulations by CMIP5 models, rather than on observations, the estimate is only valid if those simulations realistically reproduce the spatiotemporal pattern of actual warming for both SST and near - surface air temperature (tas), and changes in sea - ice cover.

«The assessment is supported additionally by a complementary analysis in which the parameters of an Earth System Model of Intermediate Complexity (EMIC) were constrained using observations of near - surface temperature and ocean heat content, as well as prior information on the magnitudes of forcings, and which concluded that GHGs have caused 0.6 °C to 1.1 °C (5 to 95 % uncertainty) warming since the mid-20th century (Huber and Knutti, 2011); an analysis by Wigley and Santer (2013), who used an energy balance model and RF and climate sensitivity estimates from AR4, and they concluded that there was about a 93 % chance that GHGs caused a warming greater than observed over the 1950 — 2005 period; and earlier detection and attribution studies assessed in the AR4 (Hegerl et al., 2007b).&rModel of Intermediate Complexity (EMIC) were constrained using observations of near - surface temperature and ocean heat content, as well as prior information on the magnitudes of forcings, and which concluded that GHGs have caused 0.6 °C to 1.1 °C (5 to 95 % uncertainty) warming since the mid-20th century (Huber and Knutti, 2011); an analysis by Wigley and Santer (2013), who used an energy balance model and RF and climate sensitivity estimates from AR4, and they concluded that there was about a 93 % chance that GHGs caused a warming greater than observed over the 1950 — 2005 period; and earlier detection and attribution studies assessed in the AR4 (Hegerl et al., 2007b).&rmodel and RF and climate sensitivity estimates from AR4, and they concluded that there was about a 93 % chance that GHGs caused a warming greater than observed over the 1950 — 2005 period; and earlier detection and attribution studies assessed in the AR4 (Hegerl et al., 2007b).»

Curry's evidence to support that assertion boiled down to arguing of a supposed «lack of warming since 1998», discrepancies between models and observations during that time, a lower climate sensitivity range in the 2014 than the 2007 IPCC report, and the fact that Antarctic sea ice extent has increased.

C / decade and the simulated ensemble mean over the models, calculated from the grid boxes of the models where observations exist (which is flawed in my opinion, since excluding of mostly the high latitudes from the model data may emphasize a warm bias in lower latitudes in the models making them appear warmer than they are, but a possible cold bias of the global observations data set is not excluded in this way) had a trend of 0.3 deg.

The authors claim an «inconsistency» between observations and models, since the surface temperature data (HadCRUT4) had a trend of 0.14 deg.

If you are trying to test the hypothesis that climate models have not predicted the pause since 1998, then you should be comparing trends between models and observations, rather than seeing if the observed temperature anomalies lie within a broad envelope of climate model simulations.

Since ocean temperature anomalies in the canonical Niño 3.4 region are now above 2 C — which are record values for the calendar month and not too far from their highest values ever observed at any time of year — current observations in the real world suggests that the models are very much on track.

If Spencer had aligned models and observations properly he could not have made the (false) assertion that more than 95 % of the models had over-forecasted the observed warming trend since 1979.

Ocean observations and simulations from GFDL Earth System Model (ESM2G) show that the recent decline in Atlantic major hurricane frequency since 2005 is consistent with a weakening of AMOC

Longer - term temperature and CO2 observations since 1850 show that the rate of warming has been less than half that projected by the climate models, spawning postulations of «missing energy hidden in the pipeline» to rationalize the dilemma.

Fleming, K. & Lambeck, K. Constraints on the Greenland Ice Sheet since the Last Glacial Maximum from sea - level observations and glacial - rebound models.

From your link: «Using satellite altimetry observations and a large suite of climate models, we conclude that observed estimates of 0 — 700 dbar global ocean warming since 1970 are likely biased low.»