Sentences with phrase «changes in solar»

Ice ages do not end due to changes in solar activity, they end due to changes in Earth's orbit and axial tilt that result in increases in solar insolation.

Changes in solar activity are simply not at all the same thing as orbital - induced changes in solar insolation.

There's been a 60 % reduction in aerosol optical depth across Europe since 1986, and that appears to have lead to an increase in surface short - wave solar radiation (not due to changes in solar output!).

However, those forcings weren't operative during the transition from ice age to interglacial; in order to explain the amplification necessary (rate and magnitude) for the small slow changes in solar influence due to Milankovic cycles to result in the rapid (compared to the descent into an ice age) transition to an interglacial, CO2 sensitivity must be higher.

Thus solar activity has associated positive feedback when more active and negative feedback when less active, dramatically magnifying Earth's thermal response to changes in solar activity and explaining how fractions of Wm - 2 change in direct solar radiation translate to many Wm - 2 effect between positive and negative phases of relative solar activity.

In fact, there is no ENSO Adjusted Warming at all.These natural ENSO impacts involve both changes in solar activity and the 1977 Pacific Shift.

The only direct real - world inputs to these models, in a climate change simulation context, are changes in atmospheric chemistry and composition (such as increasing greenhouse gases, or changing volcanic aerosols) and changes in solar radiation.

The changes in the rate of outgoing energy flow caused by changes in solar surface turbulence may be small but they appear to be enough to affect the air circulation systems and thereby influence the overall global energy budget disproportionately to the tiny variations in solar power intensity.

The great thing is that, since we can make good estimates of the changes in solar radiation, changes in the Earth's albedo due to melting ice, and changes in atmospheric CO2 concentration during the ice ages, scientists can directly calculate the sensitivity of the climate to changes in the atmospheric CO2 concentration.

For the purpose of my NCM I'm only referring to expansion caused by changes in solar activity.

That doesn't mean he's correct that atmospheric expansion caused by changes in solar activity is the primary positive feedback that drives climate change.

As they stand at present the models 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.

I have now realised that the global albedo changes necessary and the changes in solar energy input to the oceans can be explained by the latitudinal shifts (beyond normal seasonal variation) of all the air circulation systems and in particular the net latitudinal positions of the three main cloud bands namely the two generated by the mid latitude jet streams plus the Inter Tropical Convergence Zone (ITCZ).

Dr. Theodore Landscheidt identified a mechanism that may explain changes in the solar variables that are linked with changes in Earth's climate: Interactions of the Sun with the orbital motions of the four largest planets accelerate and decelerate the Sun in a wobbling and jerky orbit about the center of mass of the solar system.

Warming proponents often say there is no mechanism whereby small changes in solar activity can be scaled up to the apparently large changes in atmospheric temperature.

The unusually high level of 20thC solar activity («highest in several thousand years»: Solanki, 2004) is shown graphically, but solar forcing is restricted to the measurable changes in solar irradiance alone.

My Hot Water Bottle Effect shows how any apparently minor changes in solar activity can be supplemented or offset to match the observed changes in global temperature trend during the latter half of the 20th Century.

Direct solar irradiance is very likely not the only mechanism by which the changes in solar activity influence our climate.

The origin of a slowly varying irradiance component may derive from changes in the solar faculae and / or in the background solar radiation from solar quiet regions.

Before humans, changes in climate resulted entirely from natural causes such as changes in Earth's orbit, changes in solar activity, or volcanic eruptions.

It was recently speculated that long term changes in the solar interior due to planetary gravitational perturbations may produce gradual multi-decadal and secular irradiance changes (e.g.: Abreu et al. 2012; Charbonneau 2013; Scafetta 2012b, c; Scafetta and Willson 2013a, b, c).

«Third, in a period when ocean basins were similar to modern, ice age climate sensitivity to pCO2 changes is underestimated by climate models even when long term changes in solar forcing and ice sheet size and distribution are taken into account, implying that internal positive feedbacks are stronger than previously thought.»

It also requires the added assumption that long - term changes in solar total radiation can exceed by two and a half times what has been observed in recent measurements from space.

It seems likely that changes in solar radiation, linked to long - term variations in solar activity, may have been the dominant climate driver in the period between about AD 1600 and 1850.

Climate model simulations indicate that changes in solar radiation a few times larger than those confirmed in the eleven - year cycle, and persisting over multi-decadal time scales, would directly affect the surface temperature.

Traditionally, climate - model projections have only accounted for external forcings, such as man - made greenhouse gases, past volcanic eruptions and projected changes in solar output.

Long - term changes in solar irradiance were suspected as early as the mid-nineteenth century (Smyth 1855).

DAvid, «How could anyone have done so, without knowing what ENSOs (especially) would happen in the next 15 - 20 years, the volcanic eruptions, changes in solar variability, etc?»

On the other hand, climate models using up - to - date solar forcings don't show noticeably lower temperatures in the past decade, and that data runs counter to the idea that longer - term changes in the solar cycle are playing a major role in the pause.

Recent changes in solar outputs and the global mean surface temperature.

How could anyone have done so, without knowing what ENSOs (especially) would happen in the next 15 - 20 years, the volcanic eruptions, changes in solar variability, etc?

The model included a more comprehensive set of natural and human - made climate forcings than previous studies, including changes in solar radiation, volcanic particles, human - made greenhouse gases, fine particles such as soot, the effect of the particles on clouds and land use.

How do you expect climate models to predict a short interval (20 yrs) without knowing the ENSOs that will occur, the volcanic eruptions, changes in solar variability, etc, in that time period, which can be significant in the short - term but not in the long - term?

Nor do these simulations yet include potential effects of changes in the solar spectrum, including the more variable UV.

The authors «show that the index commonly used for quantifying long - term changes in solar activity, the sunspot number, accounts for only one part of solar activity and using this index leads to the underestimation of the role of solar activity in the global warming in the recent decades.

It could be that the climate system is more sensitive than we think to changes in solar energy, as opposed to greenhouse gas increases.

If greater changes in solar radiation occur — as seems probable based on what is known of climate and solar activity in the past — the Sun needs to be considered in long - term climate projections.

Estimates of Northern hemisphere surface temperatures from 1610 to 1800 — during part of the so - called Little Ice Age — correlate well with a reconstruction of changes in solar total radiation — around the time of the Maunder Minimum (Fig. 2c).

As such, they may provide a powerful demonstration of the impacts of changes in solar radiation on the climate system.

The good news is that a lot of people are starting to look at this issue more seriously and searching for ways to project more accurately expected changes in solar forcing.

David Appell: How could anyone have done so, without knowing what ENSOs (especially) would happen in the next 15 - 20 years, the volcanic eruptions, changes in solar variability, etc?

PA, The situation you describe in control system theory, doesn't seem to apply to the reaction to the earth's climate in response to changes in solar irradiation.

The short temporal scales of FD events give these studies the benefit of being able to separate out specific changes in solar parameters.

The changes in the solar magnetic field impacting the Earth at polar regions cause changes in surface pressure.

So in the hypothesis we are looking for changes in solar UV in the Hale Cycle.

«Once again about global warming and solar activity We show that the index commonly used for quantifying long - term changes in solar activity, the sunspot number, accounts for only one part of solar activity and using this index leads to the underestimation of the role of solar activity in the global warming in the recent decades.

Temperature changes over time can be affected by various factors, including changes in Solar Radiation (SR) and in the Radiative Forcing (RF) attributable to rising atmospheric concentrations of anthropogenic greenhouse gases.

The study of solar cycles and their climatic effect is hampered by a very short observational record (~ 400 years), an inadequate understanding of the physical causes that might produce centennial to millennial changes in solar activity, and an inadequate knowledge of how such changes produce their climatic effect.

By the way, water is the only molecule in the upper atmosphere of significant quantity to radiate the balance of IR beyond the minor CO2 radiation plus the IR window radiation and as such is the primary earth cooling agent (including cloud reflection) and thus is a negative feedback to any actual changes in solar input energy.

The climatic system / oceanic system are driven by the sun, therefore it stands to reason any changes in solar output (variations) will have an effect on these two systems which in turn will have an effect on the climate.