Sentences with phrase «estimated time constant»

One approach to forecasting the natural long - term climate trend is to estimate the time constants of response necessary to explain the observed phase relationships between orbital variation and climatic change, and then to use those time constants in the exponential - response model.

Not exact matches

But it doesn't take a new homeowner long to discover just how large that premium can be in money and time: the constant outlays on maintenance and repairs (at least 1 % of the purchase price per year, experts estimate, and as much as 4 %), the chores and DIY projects that eat up weekends, the pressure to keep up with the ever - gentrifying Joneses.

The problem is that when physicists estimate how much energy is contained within those fields and particles, they come up with a number — called the cosmological constant — that is insanely large, 10120 times greater than what we observe.

To account for changes in observation times, the RSS group used a number of different approaches and models to try and estimate what the temperature would have been if the measurement time remained constant.

Wyoming plaintiffs have returned to court six times and have so far doubled Wyoming's per - pupil spending, elevating it from $ 5,971 in 1996 — 97 to an estimated $ 12,422 for 2006 — 07 Beginning teacher salaries, for those with master's degrees, rose in constant dollars from $ 24,402 in 1997 to $ 32,451 in 2004, a 33 percent increase.

The two assumptions we take issue with are that past performance of factor tilts and smart beta strategies is the best estimate of their future performance, and that factors and smart beta strategies have constant risk premia (value - add) over time.

The mean temperature is therefore an estimate of the global mean plus an unknown constant, presumed constant in time.

Any station that is not very rural will suffer from a heat island effect, which may be constant over time but means the station does not give an unbiased estimate of the mean temperature for the area it is supposed to represent.

As we discussed at the time, those results were used to conclude that the Earth System Sensitivity (the total response to a doubling of CO2 after the short and long - term feedbacks have kicked in) was around 9ºC — much larger than any previous estimate (which is ~ 4.5 ºC)-- and inferred that the committed climate change with constant concentrations was 3 - 7ºC (again much larger than any other estimate — most are around 0.5 - 1ºC).

The short answer is: if the «planet GISSII» has a big time constant, and you increase the «forcing» linearly (or just in any monotonically increasing function of time), you'll tend to under - estimate sensitivity by fitting lines near «time = 0», or using much model data near time = 0.

I agree the lag does not appear to be constant, and does vary, and may not explain everything, however, someone earlier dismissed the lag between temperature and CO2 as irrelevant, so I made some simple calculations, and surprised myself, in that (possibly) co-incidentally the lag of roughly 800 years + / - 200 (my own estimate), matched the time between the MWP and the start of Industrialisation, where CO2 levels are said to start rising, of course it's a very rough estimate.

The IPCC's estimate of the sink rate (and total atmospheric CO2) implies a time constant of 8 years.

Since even the IPCC estimates this constant at ~ 8 years (corresponding to a half - life of 5 years), this means that if humankind had been emitting at the current rate of 8GTC / yr for the last century we still would only be responsible for ~ 30ppm of the 100ppm increase over that time.

Gloor et al (2010)-LRB--RRB- estimate a half life of ~ 30 years for CO2, and find an exponential decay model with unvarying time constant fits the data.

Therefore, estimating equilibrium climate sensitivity based on measurements of a climate that's out of equilibrium requires making some significant assumptions, for example that feedbacks will remain constant over time.

To the contrary: the later estimates of the residence time show a small increase, as the throughput remained quite constant in an increasing CO2 level of the atmosphere.

In a paper, «Heat Capacity, Time Constant, and Sensitivity of Earth's Climate System» soon to be published in the Journal of Geophysical Research (and discussed briefly at RealClimate a few weeks back), Stephen Schwartz of Brookhaven National Laboratory estimates climate sensitivity using observed 20th - century data on ocean heat content and global surface temperature.

As similar results were obtained with various subsets of the data (first and second halves of the time series; data for Northern and Southern Hemispheres, Figure 6) and for the de-seasonalized monthly data, Figure 7, this estimate of the time constant would appear to be robust.

And what, you wonder, are the estimated values of the time constant from the temperature time series?

The utilities were assumed to remain constant over time, with missing values imputed using predictive mean matching and complete cases only to generate estimates of the cost per QALY gained from FLNP over 5 and 10 - year time horizons, based on linear extrapolation of effect over time.

Relaxing the assumption that benefits remain constant over time and assuming that the effect diminishes to zero by the end of the time period considered results in an estimated cost per QALY of # 56 885 for the 5 - year duration (probability cost - effective at # 20 000 = 30 %) and # 29 664 for the 10 - year time horizon (probability at the # 20 000 threshold = 44 %; table 8).