Sentences with phrase «observed trends»

It is therefore neither surprising nor problematic that the simulated and observed trends in global temperature are in good agreement.

Here we show that the unexplained strengthening of the NAO can be fully simulated in a climate model by imposing observed trends in the lower stratosphere.

We indeed gave very conservative projections based on extrapolation of current GRACE observed trends,» Larour told indiaclimatedialogue.net.

His work explores observed trends in heat waves and determining the natural and human components of observed regional climate change in Australia, using both observed and climate model data.

This section assesses the consistencies of these relationships in the observed trends.

[10] Observed trends in precipitation and floods over Europe are in line with these future projections, however their climate change signal is quite complex.

Here we consider briefly some additional studies that examine the spatial structure of observed trends or use more sophisticated time - series analysis techniques to characterise the behaviour of global, hemispheric and zonal mean temperatures.

They found that the observed trends in these indices over the last 40 years are unlikely to have occurred due to natural climate variations and that they are consistent with model simulations of anthropogenic climate change.

When the phase of natural variability is taken into account, the model 15 - year warming trends in CMIP5 projections well estimate the observed trends for all 15 - year periods over the past half - century.

However, the same report also acknowledged that there are «differences between simulated and observed trends over periods as short as 10 to 15 years.»

There are, however, differences between simulated and observed trends over periods as short as 10 to 15 years (e.g., 1998 to 2012).

If it's needed in the models, then the models would fail to reproduce observed trends.

We can debate how robust Kerry's data are, they are quite new and surely there will be further analysis of the observed trends — but I think we can say at this stage that Kerry's data directly contradict your conclusion about the small contribution of climatic trends to the damage.

But one of the papers discussing the observed trends throughout the 20th century [Karl et al. 1984, J. Climate and Appl.

This work highlights that observed trends in midlatitude weather patterns are complex and likely not simply understood in terms of Arctic amplification alone»

Our key assumption is that the observed trends of coastal growth are likely to continue into the future.

Edahiro's observed trends certainly leave high hopes.

«The observed trends may be extrapolated to the coastal seas of the North American Atlantic Ocean and the North, Baltic and Mediterranean Seas, which have received ever - increasing amounts of anthropogenic atmospheric nitrate deposition and river - borne nitrate, comparable to those absorbed by coastal and marginal seas of the northwestern Pacific Ocean.»

Calculations to resolve the anthropogenic component of CO2 are remarkably difficult for the coastal ocean, where the assumptions of the various methods (Sabine and Tanhua 2010) are not met, thereby precluding a direct calculation of the effect of anthropogenic CO2 on observed trends in coastal pH. Calculations based on mixing between an open - ocean end - member displaying the trajectories predicted from OA and the freshwater end - member are also unreliable because pH and the carbon system do not necessarily behave conservatively within the coastal zone and because the freshwater end - member may also shift into the future.

These adjustments result in the observed trends at Kerang being more consistent with other sites in the region.

The observed trends are extremely unlikely (< 5 %) to be caused by internal variability, even if current models were found to strongly underestimate it.

Further, the attempt to portray an disagreement between model and observed trends ignores directly relevant factors by which the IPCC took that discrepancy into account.

«To allow us to attribute an anthropogenic signiture to the observed trends we need to eliminate the natural forcings at work and demonstrate the degree of the anthropogenic vs the natural signal.»

Actually, I think we can use this model - obs comparison to crudely estimate possible magnitude of internal variability by taking the standard deviation of the difference between modelled and observed trends.

In data spanning 1979 to 1999, observed trends are not significantly different from zero or from model projections.

But if researchers run the same model, or an ensemble of models, multiple times and the results diverge from each other or from the observed trends, he cautions, «planners should handle them with kid gloves.

In data spanning 1979 to 2009 the observed trends are significant in some cases but tend to differ significantly from modeled trends.

But the observed trends vary notably depending on the time period being explored, and it is unclear to what extent they reflect internal variability or anthropogenic forcing (e.g., IPCC, 2013; Seager and Naik, 2012).

Observed trends in the middle latitude jetstreams and annular modes are not robust across all months (IPCC, 2007c).

And it points at natural causes as the main drivers of the observed trends in both hemispheres.

Firstly, that the statistical distribution of the observed 15 - year global temperature trends since 1880 isn't distinguishable from the distribution of 15 - year global temperature trends derived from an ensemble of model simulations, and, secondly, whether simulated global temperature trends over 15 years since 1950 lie in the same tail of the statistical distribution as the observed 15 - year temperature trends or whether the simulated and observed trends lie in opposite tails of the distribution largely depends on whether the simulated and observed ENSO variablity over the 15 - year periods are in phase or out of phase by chance.

There is not enough evidence at present to suggest high confidence in observed trends in dryness due to lack of direct observations, some geographical inconsistencies in the trends, and some dependencies of inferred trends on the index choice.

A thinking person might ask: If 4.5 C per doubling is possible, why have observed trends been so much less?

And with an interactive climate model including the stratosphere and both composition changes reproduces the vertical structure and seasonality of observed trends.

This figure indicates that the observed trends are most influenced by trends in the third PC.

We compared the balloon trends weighted by the lower troposphere satellite temperature weighting functions to the near - surface observed trends for global and tropical data.

While Zhang et al. (2007) concluded globally that they had detected an anthropogenic influence on the overall latitudinal patterns of precipitation trends (that is, the climate model trends were of the same sign as the observed trends), in the latitude band that includes the majority of the United States population a mismatch between model projections and precipitation trends was found (Figure 1).

Monte Carlo experiments employing FARIMA models indicate that trend tests which fail to consider LTP greatly overstate the statistical significance of observed trends when LTP is present.

the agreement between the simulated and observed global temperature is often used as a supporting argument in the model evaluation process, and certainly as a visual demonstration of consistency between the theoretical understanding of the climate system, its implementation in general circulation climate model models (GCMs) and the observed trends [IPCC, 2007, Fig.

Finally, the researchers examined collections of model simulations with and without human emissions factored in to understand to what degree human emissions were responsible for a given impact, by comparing these simulations against observed trends.

The left - hand panel of Figure 1 (below) illustrates the observed trends over the period 1900 — 2012 for weather observing stations in the contiguous United States located west of longitude 116 ° W — this includes all of Washington and Oregon, most of California, and parts of Idaho and Nevada.

Trenberth also admitted that the climate models have major shortcomings because «they do not consider many things like the recovery of the ozone layer, for instance, or observed trends in forcing agents.

Looking at their Table 3, only 2 out of 22 CMIP3 climate models have significant explanatory power for the spatial pattern of warming trends over land, and the rest have no significant explanatory power or are even anticorrelated with the observed trends.

While the observed trends may be «consistent with» the NCA authors» «expected changes due to human activities,» in actuality they are, in fact, not caused by human activities.

Findings from the 2013 NCA include new analyses of the observed trends and projected future climate changes.

In general, the observed trends fall within the simulated range of trends, with better consistency for the longer period.

Figure 1: Observed trends (days per decade) for 1951 to 2003 in the number of extreme cold and warm days and nights per year.

Second, a series of mildly explosive volcanoes, which increased stratospheric particles, likely had more of a cooling effect than previously recognized.35, 36,37 Third, the high incidence of La Niña events in the last 15 years has played a role in the observed trends.29, 38 Recent analyses13 suggest that more of the increase in heat energy during this period has been transferred to the deep ocean than previously.

Increased understanding of uncertainties in radiosonde and satellite records makes assessment of causes of observed trends in the upper troposphere less confident than an assessment of overall atmospheric temperature changes.

The Intergovernmental Panel on Climate Change reported in its most recent scientific assessment that «[n] o robust trends in annual numbers of tropical storms, hurricanes, and major hurricanes... have been identified over the past 100 years in the North Atlantic basin,» and that there are «no significant observed trends in global tropical cyclone frequency.»