Sentences with phrase «changes over a solar cycle»

The other theme was the discussion of the spectral irradiance changes — specifically by how much the UV changes over a solar cycle are larger in magnitude than the changes in the total irradiance.

Our understanding 48 of the «ion - aerosol clear air» mechanism as a whole relies on a few model investigations that simulate GCR 49 changes over a solar cycle (Kazil et al., 2012; Pierce and Adams, 2009a; Snow - Kropla et al., 2011) or during 50 strong Forbush decreases (Bondo et al., 2010; Snow - Kropla et al., 2011).

The main origin: solar UV maxima and minima are far more pronounced (10 %) than the overall solar energy (1 %) changes over a solar cycle.

The total energy change over a solar cycle is quite small, which has led many to argue that solar variability has little impact on climate.

Not exact matches

They then infer a higher temperature sensitivity to changes in radiance over this cycle and conclude that maybe 0.1 K temperature increase would be possible due to the variation in solar radiance, or about 30 % (if you push it) of the total temperature anomaly over this period.

For example, 2005 is near solar minimum in the 11 year cycle, and radiance now is about 1 - 2 W / m ^ 2 less than a few years ago, which means Pluto and Mars are getting LESS solar radiance on the time scale of the atmosphere and polar cap changes, EVEN IF the radiance averaged over the whole cycle was higher.

«What is generally required [for proving solar forcing of climate change] is a consistent signal over a number of cycles (either the 11 year sunspot cycle or more long term variations), similar effects if the timeseries are split, and sufficient true degrees of freedom that the connection is significant and that it explains a non-negligible fraction of the variance.»

In my opinion, climate behaves in a far from linear way, with loads of factors to take into account, so in most cases it would be very difficult to find climate records react consistently (over several solar cycles / decades / centuries) in the same way to say a solar change (see the Hoyt & Schatten 1998 book).

The solar - cloud connection is quite real (after two satellite measured sun cycles), but can't explain the rather fast and huge changes in radiation balance over the previous period.

This would cause a change of 4.75 degrees K for the 100 % reference change in GCR over the 11 year solar cycle (and a non physical decrease of more than 100 % in cloud cover — are negative high clouds cooling and negative low clouds warming?

This is the case even if there is a change in the mean radiance over decades (between solar cycles) because the year - to - year variation within a cycle is larger than the variation between cycles, and we measured solar radiance in 1999 - 2005.

I noticed that the change in cloud cover from the minimum to maximum of the solar cycle was 2 percent, much less than the 10 % change in CO2, over the period of their study.

I could go through a dozen... examples: the skill associated with solar cycles, changing the ozone in the stratosphere; the skill associated with orbital changes over 6,000 years.

The change in insolation due to orbital changes are significant, of the order of 50 W / m2, or 50 times larger than the change of TSI over the solar cycle.

But as there is little change in the configuration of the continents over the past million years, we may assume that the same changes in terrestrial / solar cycles will have a similar effect on temperature.

But it doesn't make all that much difference to global warming anyway, because the total peak - to - trough change in insolation over a complete solar cycle is only about 1 % anyway.

At the top of atmosphere the the inward radiative flux is about 1360 W / m - 2 in the latest estimate — but changes a little bit over an 11 year solar cycle.

According to their modeling studies, the difference in the amount of incoming solar radiation, in this case, primarily in the ultraviolet (UV) wavelengths, during the minima and maxima of the 11 - yr solar cycle are large enough to produce a characteristic change in the winter circulation pattern of the atmosphere over North America... When the NAO is in its negative phase, more cold air can seep south from the Arctic and impact the lower latitudes of Europe and the eastern U.S., which helps spin up winter storm systems.

«The results also show that ionisation of the atmosphere by cosmic rays accounts for nearly one - third of all particles formed, although small changes in cosmic rays over the solar cycle do not affect aerosols enough to influence today's polluted climate significantly.»

The change in total solar irradiance over recent 11 - year sunspot cycles amounts to < 0.1 %, but greater changes at ultraviolet wavelengths may have substantial impacts on stratospheric ozone concentrations, thereby altering both stratospheric and tropospheric circulation patterns... This model prediction is supported by paleoclimatic proxy reconstructions over the past millennium.

As time and the solar / climactic cycles march on, natural changes ahead might end up putting a - not insignificant dent - in the harvested energy (measured in kwh / yr) of a larger 20MW PV system over a quarter century.

The authors found that consistent with previous research, changes in solar and volcanic activity, land cover, and incoming solar radiation due to the Earth's orbital cycles were the main contributors to the cooling between the MWP and LIA (the years 900 — 1600), and probably also caused the cooling over the full 2,000 - year period.

7.4.5.3 Synthesis Although there is some evidence that ionization from cosmic rays may enhance aerosol nucleation in the free troposphere, there is medium evidence and high agreement that the cosmic ray - ionization mechanism is too weak to influence global concentrations of CCN or their change over the last century or during a solar cycle in any climatically significant way.

Take solar vs. GHGs: 1.5 W / m2 solar change (TOA) over a solar cycle has a large effect in the stratosphere: During a solar cycle, the largest change is in the short waves: 10 % more during high solar activity: that affects ozone building, the temperature in the stratosphere and increases the polewards flow in the stratosphere.

As Don Easterbrook and others note, hardly a significant length in temperatures that can cycle over hundreds and even thousands of years, caused by either solar input changes or circulations within the oceans.

They concluded that with a bit of help from changes in solar output and natural climatic cycles such as the El Nino Southern Oscillation (ENSO), the growth in the volume of aerosols being pumped up power station chimneys was probably enough to block the warming effect of rising greenhouse gas emissions over the period 1998 - 2008.

They are mainly derived from the Shaviv reference (provided in the link above) that concludes that the solar signal is amplified as indicated by the magnitude of changes in ocean heat content (and other less direct measures) over the course of the 11 year solar cycle.

Long - term trends and changes (longer than solar cycle) can partly be caused by long - term changes of trend drivers of solar / space weather origin like geomagnetic activity, which in terms of the aa - index was increasing over almost the whole 20th century (e.g., Mursula & Martini 2006), even though now it is low.

«Over the 11 - year solar cycle, small changes in the total solar irradiance (TSI) give rise to small variations in the global energy budget.

This is achieved through the study of three independent records, the net heat flux into the oceans over 5 decades, the sea - level change rate based on tide gauge records over the 20th century, and the sea - surface temperature variations... We find that the total radiative forcing associated with solar cycles variations is about 5 to 7 times larger than just those associated with the TSI variations, thus implying the necessary existence of an amplification mechanism, although without pointing to which one.

Whether there be radiative gases, biosphere changes, volcanic events, ocean cycles, solar cycles, albedo variations or asteroid strikes the same mechanism restores balance over time.

I think they show that both cycles are underlain by a longer, larger cycle giving a background rising trend over the period for which the solar changes from 1600 to date would be a primary candidate.

Changes in the meridional circulation over longer periods can explain some of the more dramatic variations of the ampltude of the solar cycle [see e.g. http://arxiv.org/abs/1101.4342].

Modelling studies from both Pierce & Adams (2009) and Kazil et al. (2012) concluded that global cloud condensation nuclei (CCN) would not be sensitive to changes in the ion - induced nucleation rate over a solar cycle.

The Intergovernmental Panel on Climate Change estimates a median of 48 gram CO2 - equivalent / kWh for building solar panels, over the complete life cycle.

Changes in the CR flux during large FD events are of the same order of magnitude as changes experienced over the decadal solar cycle, but occur over a period of several days (Čalogović et al.Changes in the CR flux during large FD events are of the same order of magnitude as changes experienced over the decadal solar cycle, but occur over a period of several days (Čalogović et al.changes experienced over the decadal solar cycle, but occur over a period of several days (Čalogović et al. 2010).

Over a solar cycle, the amount of output changes by about + / - 0.5 W / m2, or less than 0.1 %.

Based on these results, we conclude that (1) the sensitivity changes of the PMO6V radiometers within VIRGO during the first two years have very likely not been correctly evaluated; and that (2) the TSI variations over cycle 23 and the change in the TSI levels between the minima in 1996 and 2008 are consistent with the solar surface magnetism mechanism.

Similar conclusions were reached by Agee et al. (2012), who examined ISCCP data over the recent solar minimum (between solar cycles 23 and 24), during which time high levels of CR were recorded, and yet no corresponding cloud changes were observed to suggest a connection to solar activity.

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.

The report which contains statements like this: «Although there is some evidence that ionization from cosmic rays may enhance aerosol nucleation in the free troposphere, there is medium evidence and high agreement that the cosmic ray - ionization mechanism is too weak to influence global concentrations of CCN or their change over the last century or during a solar cycle in any climatically significant way.

The forcing from changes in total solar irradiance alone does not seem to account for these observations, implying the existence of this unknown amplifying mechanism.The cosmic ray - ionization mechanism is too weak to influence global concentrations of CCN or their change over the last century or during a solar cycle in any climatically significant way.

«there is medium evidence and high agreement that the cosmic ray - ionization mechanism is too weak to influence global concentrations of CCN or their change over the last century or during a solar cycle in any climatically significant way.

I came to think of solar radiation as being the ultimate (and only) external forcing of the climate system, which, except for the orbital seasonal changes and the 11 - year sunspot cycle, has been essentially constant over the past several decades of precision solar irradiance monitoring.

SSTs however have been influenced by other forcings, such as greenhouse gases, over the last few decades, and these transient changes will obviously affect the solar cycle influence.