Sentences with phrase «for ocean heat uptake»

If I understand correctly your estimate and error for ocean heat uptake are for average rate over the period 1880 - 2011, while your estimate of the forcing rate and associated delta T are for 2011.

JK «If I understand correctly your estimate and error for ocean heat uptake are for average rate over the period 1880 - 2011, while your estimate of the forcing rate and associated delta T are for 2011.»

Various groups have analyzed that data and they all come up with about the same answer for ocean heat uptake in the ARGO era, one that is disappointingly small for alarmists.

Let's think about the implications for ocean heat uptake.

Section 8.6 discusses the various feedbacks that operate in the atmosphere - land surface - sea ice system to determine climate sensitivity, and Section 8.3.2 discusses some processes that are important for ocean heat uptake (and hence transient climate response).

If one was to redo those papers, you would choose the efficacies most relevant to their calculations (i.e. the ERF derived values for Otto et al) along with their adjustment for the ocean heat uptake (in our sensitivity test), and conclude that instead of an ECS of 2.0 ºC [likely range 1.4 - 3.2], you'd get 3.0 ºC [likely range 1.8 - 6.2].

Not exact matches

For the change in annual mean surface air temperature in the various cases, the model experiments show the familiar pattern documented in the SAR with a maximum warming in the high latitudes of the Northern Hemisphere and a minimum in the Southern Ocean (due to ocean heat uptakOcean (due to ocean heat uptakocean heat uptake)(2)

For one thing, the fit neglects lags in the system (such as those resulting from ocean heat uptake) and it also neglects changes in albedo and other radiative factors.

Dr Peter Stott, commenting on Gavin's study in the Guardian, http://www.theguardian.com/environment/2015/jun/04/global-warming-hasnt-paused-study-finds says the term slowdown is valid because the past 15 years might have been still hotter were it not for natural variations like deep ocean heat uptake.

The treatment of uncertainty in the ocean's uptake of heat varies, from assuming a fixed value for a model's ocean diffusivity (Andronova and Schlesinger, 2001) to trying to allow for a wide range of ocean mixing parameters (Knutti et al., 2002, 2003) or systematically varying the ocean's effective diffusivity (e.g., Forest et al., 2002, 2006; Frame et al., 2005).

Further, it suggests a clear mechanism for the «efficacies» of both ocean heat uptake and radiative forcing.»

The upper 95th percentile is not well constrained, particularly in studies that account conservatively for uncertainty in, for example, 20th - century radiative forcing and ocean heat uptake.

If I instantly quadruple CO2 in an experiment, I'd expect ocean heat uptake (OHU) to occur pretty uniformly in latitude for the initial few years, but then become pretty localized to the subpolar oceans after, say, year 100.

The authors note that more than 85 % of the global heat uptake (Q) has gone into the oceans, including increasing the heat content of the deeper oceans, although their model only accounts for the upper 700 meters.

His description should be read for details, but the essence of the evidence lies in the observation that ocean heat uptake (OHC) has been increasing during the post-1950 warming.

Since OHC uptake efficiency associated with surface warming is low compared with the rate of radiative restoring (increase in energy loss to space as specified by the climate feedback parameter), an important internal contribution must lead to a loss rather than a gain of ocean heat; thus the observation of OHC increase requires a dominant role for external forcing.

Dr Peter Stott, commenting on Gavin's study in the Guardian, http://www.theguardian.com/environment/2015/jun/04/global-warming-hasnt-paused-study-finds says the term slowdown is valid because the past 15 years might have been still hotter were it not for natural variations like deep ocean heat uptake.

Your attempt to estimate equilibrium climate sensitivity from the 20th C won't work because a) the forcings are not that well known (so the error in your estimate is large), b) the climate is not in equilibrium — you need to account for the uptake of heat in the ocean at least.

... a pronounced strengthening in Pacific trade winds over the past two decades — unprecedented in observations / reanalysis data and not captured by climate models — is sufficient to account for the cooling of the tropical Pacific and a substantial slowdown in surface warming through increased subsurface ocean heat uptake.

In these experiments the climate sensitivity was 2.7 deg C for a doubling of CO2, the net aerosol forcing from 1940 to 2000 was around -0.7 W / m2 (55 % of the total forcing, -1.27, from 1850 to 2000), and the ocean uptake of heat was well - matched to recent observations.

Further, it suggests a clear mechanism for the «efficacies» of both ocean heat uptake and radiative forcing.»

Abstract:... Here we show that a pronounced strengthening in Pacific trade winds over the past two decades — unprecedented in observations / reanalysis data and not captured by climate models — is sufficient to account for the cooling of the tropical Pacific and a substantial slowdown in surface warming through increased subsurface ocean heat uptake.

If I instantly quadruple CO2 in an experiment, I'd expect ocean heat uptake (OHU) to occur pretty uniformly in latitude for the initial few years, but then become pretty localized to the subpolar oceans after, say, year 100.

Indeed, Jim Hansen used such a diffusive mixing for representing ocean heat uptake in several of his seminal papers.

For example: 1) plants giving off net CO2 in hot conditions (r / t aborbing)-- see: http://www.climateark.org/articles/reader.asp?linkid=46488 2) plants dying out due to heat & drought & wild fires enhanced by GW (reducing or cutting short their uptake of CO2 & releasing CO2 in the process) 3) ocean methane clathrates melting, giving off methane 4) permafrost melting & giving off methane & CO2 5) ice & snow melting, uncovering dark surfaces that absorb more heat 6) the warming slowing the thermohaline ocean conveyor & its up - churning of nutrients — reducing marine plant life & that carbon sink.

For example, there are not sufficient observations of the uptake of heat, particularly into the deep ocean, that would be one of the possible mechanisms to explain this warming hiatus.»

What model have you assumed for the rate of the oceans» heat uptake?

These scaling factors compensate for under - or overestimates of the amplitude of the model response to forcing that may result from factors such as errors in the model's climate sensitivity, ocean heat uptake efficiency or errors in the imposed external forcing.

Ocean warming: «Assessing recent warming using instrumentally homogeneous sea surface temperature records» «Tracking ocean heat uptake during the surface warming hiatus» «A review of global ocean temperature observations: Implications for ocean heat content estimates and climate change» «Unabated planetary warming and its ocean structure since 2006&rOcean warming: «Assessing recent warming using instrumentally homogeneous sea surface temperature records» «Tracking ocean heat uptake during the surface warming hiatus» «A review of global ocean temperature observations: Implications for ocean heat content estimates and climate change» «Unabated planetary warming and its ocean structure since 2006&rocean heat uptake during the surface warming hiatus» «A review of global ocean temperature observations: Implications for ocean heat content estimates and climate change» «Unabated planetary warming and its ocean structure since 2006&rocean temperature observations: Implications for ocean heat content estimates and climate change» «Unabated planetary warming and its ocean structure since 2006&rocean heat content estimates and climate change» «Unabated planetary warming and its ocean structure since 2006&rocean structure since 2006»

Chance that increased GHGs are expected to lead to warming on the scale of the observed warming: this requires estimates of climate sensitivity, ocean heat uptake, etc., but I would think that basic theory suggests that increased GHGs could be responsible for much more than the observed warming.

fanciful — has it ever been proposed that ocean heat uptake during interglacials might be the planets way of preparing for the next ice age, when the oceans give up the heat to preserve continuity of life on the surface — I know, sounds a bit link an intelligent Gaia mythology, but doesn't the notion of synergy suggest the possibility?

The cycle of extra heat uptake by the oceans may be over for at least a decade.

Based on the rather vast uncertainties in aerosol forcing, and the substantial discrepancies between model projections of ocean heat uptake and measured heat uptake (ARGO), it strikes me as bizarre that the IPCC insists on excluding the possibility of quite low sensitivity, when there is a wealth of evidence for fairly low sensitivity.

Using this estimate, the value of needed to produce near zero heat uptake by the oceans is, so internal variability need only contribute about 25 % of the total warming to fully compensate for the heat uptake due to the forced response.

«Assessing recent warming using instrumentally homogeneous sea surface temperature records» «Tracking ocean heat uptake during the surface warming hiatus» «A review of global ocean temperature observations: Implications for ocean heat content estimates and climate change» «Unabated planetary warming and its ocean structure since 2006»

It's not quantitative for several reasons (ocean heat uptake, the dependence of radiative feedbacks on the spatial structure of the SST changes, etc).

The discrepancy is likely accounted for by excessive ocean heat uptake at low latitudes in our model, a problem related to the model's slow surface response time (Fig. 4) that may be caused by excessive small - scale ocean mixing.

And finally, we account carefully for the impact of uncertainties in forcing, ocean heat uptake and surface temperature on the determination of climate sensitivity.

I got a most probable value of 1.55 C / doubling, a 17 % to 83 % range of 1.41 C to 3.27 C / doubling, and a 5 % to 95 % range of 1.18 C to 6.2 C / doubling... not far from your values (but I assumed a little higher total heat accumulation, including deep ocean uptake equal to 10 % of the 0 - 2000M value, and some additonal heat for ice melt and land mass warming).

The notion that over the longer timescales, forced responses dominated (at least for the second half of the past century) is reinforced by data on Ocean Heat Uptake since 1955.

I tell you what I would do for temperature, which is to analyze the heat equation and evaluate how much the ocean would uptake assuming there is an uncertainty in the effective diffusivity and a smearing of the stimulating thermal interface.

Even if you assume a low value for the variables of SO2 cooling and the rate of heat uptake by the deep ocean.

The point to be made regarding that paper is similar to the one I made above: there is evidence that internal variability (to the extent it can be equated with the AMO) has affected the rate at which anthropogenic forcing has warmed the surface, but most of the warming must have been forced, with the observed positive ocean heat uptake data excluding more than a very minor role for internal variability in the warming itself with very high confidence.

There is a wide spread among the models for the thermal expansion commitment at constant composition due partly to climate sensitivity, and partly to differences in the parametrization of vertical mixing affecting ocean heat uptake (e.g., Weaver and Wiebe, 1999).

frankclimate: It is my understanding that the TOA imbalance average over decade is measured using ocean heat uptake and is 0.7 W / m2 for the ARGO period.

To explain such a pause, an increase in ocean heat uptake below the superficial ocean layer2, 3 has been proposed to overcompensate for the Earth's heat storage.

Using 1981 - 2011 ocean heat data (again for 0 - 2000m, from Levitus et al, 2012), rather than the last 10 years, to compute the trend would have reduced the recent - period OHU estimate, scaling up as before to allow for heat uptake in the deeper ocean and elsewhere, by 0.08 W / m.

The recent transient warming (combined with ocean heat uptake and our knowledge of climate forcings) points towards a «moderate» value for the equilibrium sensitivity, and this is consistent with what we know from other analyses.

The ocean heat uptake efficiency (W m — 2 °C — 1), discussed in Chapter 10, may be roughly estimated as F2x x (TCR — 1 — ECS — 1), where F2x is the radiative forcing for doubled atmospheric CO2 concentration (see Supplementary Material, Table 8.

9.3.1 Global Mean Response 9.3.1.1 1 % / yr CO2 increase (CMIP2) experiments 9.3.1.2 Projections of future climate from forcing scenario experiments (IS92a) 9.3.1.3 Marker scenario experiments (SRES) 9.3.2 Patterns of Future Climate Change 9.3.2.1 Summary 9.3.3 Range of Temperature Response to SRES Emission Scenarios 9.3.3.1 Implications for temperature of stabilisation of greenhouse gases 9.3.4 Factors that Contribute to the Response 9.3.4.1 Climate sensitivity 9.3.4.2 The role of climate sensitivity and ocean heat uptake 9.3.4.3 Thermohaline circulation changes 9.3.4.4 Time - scales of response 9.3.5 Changes in Variability 9.3.5.1 Intra-seasonal variability 9.3.5.2 Interannual variability 9.3.5.3 Decadal and longer time - scale variability 9.3.5.4 Summary 9.3.6 Changes of Extreme Events 9.3.6.1 Temperature 9.3.6.2 Precipitation and convection 9.3.6.3 Extra-tropical storms 9.3.6.4 Tropical cyclones 9.3.6.5 Commentary on changes in extremes of weather and climate 9.3.6.6 Conclusions