Sentences with phrase «from volcanic forcing»

You end up with NH ocean being 3C warmer than SH oceans plus «super recovery» from volcanic forcing in the NH, but that is only a fraction of the ocean area.

The two candidates (apart from volcanic forcing) are solar variability and the natural internal variability of the coupled ocean atmosphere system, e.g. the multi-decadal and longer oscillations such as the NAO, PDO, etc..

So the marked early 20th century warming was likely a mixture of recovery from volcanic forcing and accumulated (but masked) greenhouse forcing [the 1880 - 1940 [CO2] rise from ~ 290 — ~ 309 ppm was quite significant (equivalent to nearly 0.3 oC at equilibrium with a mid-range climate sensitivity)-RSB-.

Not exact matches

Researchers from the College of New Jersey and the University of Rochester now know what caused that bend — a dense, underground block of rigid, volcanic rock forced the chain to shift eastward as it was forming millions of years ago.

One just included the effective influence on temperatures from manmade forces (including greenhouse gases and aerosols, which tend to have a cooling effect), while the second included both manmade and natural ones (including volcanic activity and solar radiation).

So ocean temperatures, unlike temperatures on land, are slow to fluctuate from natural forces, such as El Niño / La Niña patterns or volcanic eruptions.

Constraining ECS from the observed responses to individual volcanic eruptions is difficult because the response to short - term volcanic forcing is strongly nonlinear in ECS, yielding only slightly enhanced peak responses and substantially extended response times for very high sensitivities (Frame et al., 2005; Wigley et al., 2005a).

Insights from Antarctica on volcanic forcing during the Common Era.

From the Franklin Institute Science Museum, Earthforce focuses on the forces of Earth that cause movement, such as earthquakes, floods, and volcanic eruptions.

Jakarta, Indonesia (CNN) Authorities have issued the highest - level warning possible after volcanic eruptions from Mount Agung on the Indonesian resort island of Bali forced the closure of the island's main airport and evacuation of thousands of residents living nearby.

A lingering volcanic ash cloud has forced the cancellation of several flights from Bali, keeping thousands of Australians stranded, and all flights to the island from Australia have been cancelled by Virgin, Qantas and Jetstar.

A product of erosion and volcanic forces, the views from in amongst these knobbly pillars extend over the town of Graaff - Reinet and the plains of the Camdeboo.

Arif, who is also the chairman of INACA, further explained that this achievement came when the airline industry is facing huge challenges, from a sluggish economy to a number of «force majeures» or natural disasters, such as volcanic eruptions and haze.

Hundreds of passengers are facing travel disruption after a volcanic eruption in Indonesia sent ash clouds over the region, forcing airlines to cancel flights to and from Northern Australia.

The forcing from 1900 to mid-century was mostly natural... mostly solar, a bit of lack - of - volcanic, maybe some black carbon in the arctic.

Maybe someone would like to generate some examples using a basic red - noise process overlaid with a climate signal (for instance from solar or volcanic forcing histories) and then compute the auto - correlations?

Almost equal contribution from human forcings, natural forcings (mainly recovery from large volcanic eruptions from 1883 to 1912), oceanic cycles, and uncorrected SST measurement errors for this period.

Earlier periods, say 1850 going back to the 1500s or so, have reasonable coverage from paleo - proxy data, and only have solar and volcanic forcing.

The large volcanic forcing signal basically obliterates the far smaller solar forcing signal, which can not be isolated in the presence of noise and other forcings from this reconstruction, yielding the spurious apparent negative response to solar irradiance.

Maybe a dumb question BUT since the «hockey stick» shows up in the sunspot curves in 20 above, in the Solanski 2002 Jeffreys lecture solar irradiance curves, in Be-10 curves etc etc, indicating a driving solar forcing for the hockey stick, then why doesn't it show up in the GCM models for natural only (see Is modelling science http://www.realclimate.org/index.php?p=100) Surely the volcanic forcings from one 1991 volcano can't dominate the sun?

Thus this period is not ideal for assessing the magnitude of natural changes (both intrinsic and forced by natural processes like solar variability or volcanic eruptions) since there is likely a contamination from human - related causes.

A submarine landslide might release a Gigaton of carbon as methane (Archer, 2007), but the radiative effect of that would be small, about equal in magnitude (but opposite in sign) to the radiative forcing from a volcanic eruption.

One key metric in this debate is the spatial pattern of cooling which may provide a «fingerprint» of the underlying climate change, whether that was externally forced (from solar or volcanic activity) or was part of an intrinsic mode of variability.

Vertical and horizontal forces operate on the below sea level grounded ice sheet from tides, ocean currents, thermal expansion and volcanic and other geological -LRB-?)

The MM was also a time of enhanced volcanic activity, and the cooling from this was probably comparable with the cooling due to solar effects (an exact attribution is impossible given the uncertainties in both forcings).

First, for changing just CO2 forcing (or CH4, etc, or for a non-GHE forcing, such as a change in incident solar radiation, volcanic aerosols, etc.), there will be other GHE radiative «forcings» (feedbacks, though in the context of measuring their radiative effect, they can be described as having radiative forcings of x W / m2 per change in surface T), such as water vapor feedback, LW cloud feedback, and also, because GHE depends on the vertical temperature distribution, the lapse rate feedback (this generally refers to the tropospheric lapse rate, though changes in the position of the tropopause and changes in the stratospheric temperature could also be considered lapse - rate feedbacks for forcing at TOA; forcing at the tropopause with stratospheric adjustment takes some of that into account; sensitivity to forcing at the tropopause with stratospheric adjustment will generally be different from sensitivity to forcing without stratospheric adjustment and both will generally be different from forcing at TOA before stratospheric adjustment; forcing at TOA after stratospehric adjustment is identical to forcing at the tropopause after stratospheric adjustment).

Indeed, this was found to be true for any of several different published volcanic forcing series for the past millennium, regardless of the precise geometric scaling used to estimate radiative forcing from volcanic optical depth, and regardless of the precise climate sensitivity assumed.

Recently I have been looking at the climate models collected in the CMIP3 archive which have been analysed and assessed in IPCC and it is very interesting to see how the forced changes — i.e. the changes driven the external factors such as greenhouse gases, tropospheric aerosols, solar forcing and stratospheric volcanic aerosols drive the forced response in the models (which you can see by averaging out several simulations of the same model with the same forcing)-- differ from the internal variability, such as associated with variations of the North Atlantic and the ENSO etc, which you can see by looking at individual realisations of a particular model and how it differs from the ensemble mean.

For ENSO I used the MEI index, for volcanic forcing I used data from Ammann et al. 2003, GRL 30, 1657.

You write:» For the period from the Maunder minimum to a century later though (which is the period we looked at), there are no obvious discrepencies between the solar + volcanic forced changes and the reconstructions.»

Therefore by the same logic, B scenario temperatures should have come close to those of A from ~ 2003 onwards, and until the next volcanic forcing.

For instance, the warming that began in the early 20th century (1925 - 1944) is consistent with natural variability of the climate system (including a generalized lack of significant volcanic activity, which has a cooling effect), solar forcing, and initial forcing from greenhouse gases.

Crowley and Unterman have the currently most complete reconstruction of Volcanic forcing by hemisphere (and tropics) from 800 AD.

The IPCC has failed to convincingly explain the pause in terms of external radiative forcing from greenhouse gases, aerosols, solar or volcanic forcing; this leaves natural internal variability as the predominant candidate to explain the pause.

The short - term cooling imparted by volcanic aerosols is clearly non-anthropogenic, but these forcings are reasonably well known from relevant observational data.

Was this also a conspiracy of clouds and oceans or just the expected forcing change from GHGs that far exceeds any of the solar and volcanic trends that you seem to accept?

Results from wavelet analysis and SEA reveal significant periodicities near the solar DeVries frequency in the volcanic and residual «volcano free» contributions during the LIA, making a clear separation of the solar and volcanic forcing signals difficult.

«We use 1280 years of control simulation, with constant preindustrial forcings including constant specified CO2, and a five - member ensemble of historical simulations from 1850 — 2005 including prescribed historical greenhouse gas concentrations, SO2 and other aerosol - precursor emissions, land use changes, solar irradiance changes, tropospheric and stratospheric ozone changes, and volcanic aerosol (ALL), following the recommended CMIP5 specifications.

Previous large natural oscillations are important to examine: however, 1) our data isn't as good with regards to external forcings or to historical temperatures, making attribution more difficult, 2) to the extent that we have solar and volcanic data, and paleoclimate temperature records, they are indeed fairly consistent with each other within their respective uncertainties, and 3) most mechanisms of internal variability would have different fingerprints: eg, shifting of warmth from the oceans to the atmosphere (but we see warming in both), or simultaneous warming of the troposphere and stratosphere, or shifts in global temperature associated with major ocean current shifts which for the most part haven't been seen.

The models currently assume a generally static global energy budget with relatively little internal system variability so that measurable changes in the various input and output components can only occur from external forcing agents such as changes in the CO2 content of the air caused by human emissions or perhaps temporary after effects from volcanic eruptions, meteorite strikes or significant changes in solar power output.

Here it is important to separate internal natural variability, which is basically ocean circulations from natural variability in the forcing, such as solar and volcanic effects.

Taking out ENSO from a climate regression is different from taking out volcanic aerosols, because we don't know if ENSO is itself a forcing, an endogenous response to forcings, a temporally varying exogenous shift in the response of the climate to forcings, or what.

As far as the original post goes, if you simply look at calculated forcings from known sources (Volcanic Aerosol, Solar Irradience and Greenhouse gases) you can replicate the last 150 years of temperature records surprisingly well; take any of these factors out and you can not.

MarkB (March 29, 2014 at 2:00 pm) «The rise from 1900 to the 40s is principally CO2 and solar forcing of similar magnitudes during a period of minimal volcanic activity.»

The rise from 1900 to the 40s is principally CO2 and solar forcing of similar magnitudes during a period of minimal volcanic activity.

«Here, it is sufficient to note that many of the 20CEN / A1B simulations neglect negative forcings arising from stratospheric ozone depletion, volcanic dust, and indirect aerosol effects on clouds... It is likely that omission of these negative forcings contributes to the positive bias in the model average TLT trends in Figure 6F.

«The solar and volcanic forcings we use are derived from reconstructions based on proxy data and are therefore also subject to considerable uncertainties, although recent explosive volcanic eruptions are likely to have cooled climate, and independent records of solar activity levels inferred from the cosmogenic isotope 10Be (43) and geomagnetic records (44) provide support to reconstructions (22, 45) that show generally increasing solar activity during the 20th century (12).»

Led by Dr. James E. Hansen from 1981 to 2013, research at GISS emphasized a broad study of global change, which is an interdisciplinary initiative addressing natural and man - made changes in our environment that occur on various time scales — from one - time forcings such as volcanic explosions, to seasonal / annual effects such as El Niño, and on up to the millennia of ice ages — and that affect the habitability of our planet.

We are due for cooling, but I do not see how cooling of the second half of the 20th century would have followed from the volcanic and solar forcings.

And, in fact, from what we understand about the possible volcanic and solar forcings involved (and the latter is somewhat limited by ambiguities in the record before the satellite era), there is no reason to expect that the natural trend would have been for rising temperatures in the second half of the 20th century.