Sentences with phrase «in solar irradiance»

Facts: It's not the sun («According to PMOD at the World Radiation Center there has been no increase in solar irradiance since at least 1978 when satellite observations began.

Thus the spectral composition of solar radiation is crucial in determining atmospheric structure, as well as surface temperature, and it follows that the response of the atmosphere to variations in solar irradiance depends on the spectrum2.

The reduced radiative forcing estimate comes from a re-evaluation of the long - term change in solar irradiance since 1610 (the Maunder Minimum) based upon: a new reconstruction using a model of solar magnetic fl ux variations that does not invoke geomagnetic, cosmogenic or stellar proxies; improved understanding of recent solar variations and their relationship to physical processes; and re-evaluation of the variations of Sunlike stars.

The authors also note that they chose a reconstruction with high variability in solar irradiance, so if anything they may have overestimated the natural contribution to the observed warming.

For the period after 1974,... there is no evidence for any non-magnetic change in the solar irradiance on time scales longer than about a day.»

For example, the minima in solar irradiance combined to the increase in explosive volcanism after the 12th century have been proposed as mechanisms capable of explaining the cooler LIA conditions [55 — 57].

We obtained a large historical solar forcing between the Maunder minimum and the present, as well as a significant increase in solar irradiance in the first half of the twentieth - century.

From the conclusion to his 1997 paper, based essentially on a correlation approach a la Soon (but done correctly in this case): «From examining the data records I conclude: Changes in solar irradiance explain perhaps one - quarter of the increase in temperature during the last century.

At a recent conference, scientists explained how a major atmospheric circulation known as the North Atlantic Oscillation (NAO) was in a negative phase at the onset of the LIA, which amplified the cooling effect of a reduction in solar irradiance and volcanic activity.

While the Southern Hemisphere & Antarctic have been cooling for the past 3 years (Spencer & Christy, 2006) which also coincides with the drop in solar irradiance since 2002.

«Cycles and Trends in Solar Irradiance and Climate.»

That said, the main reason we think that the current warming trend is not natural is because the small increase in solar irradiance from 1975 to current is much less than from the first half of the century.

Earth's Radiative Equilibrium in the Solar Irradiance (PDF), Martin Hertzberg, 01/2009, Energy & Environment, Volume 20, Numbers 1 - 2, pp. 85 - 95

The 12th century episode, also reflected in precipitation and drought extent (13, 25, 43, 44), was particularly severe and persistent and was associated with a peak in solar irradiance and nadir in volcanic activity (4)(Fig. 2A).

I think the view of RC is that the predicted solar changes will make almost no difference in the climate of coming decades because it will make almost no difference in solar irradiance and there is no other credible link between the sun and climate other than the solar irradiance one.

The response of atmospheric CO2 and climate to the reconstructed variability in solar irradiance and radiative forcing by volcanoes over the last millennium is examined by applying a coupled physical — biogeochemical climate model that includes the Lund - Potsdam - Jena dynamic global vegetation model (LPJ - DGVM) and a simplified analogue of a coupled atmosphere — ocean general circulation model.

For example, from the mid-1600s to the early 1700s, there is believed to have been a minimum in solar irradiance, called the Maunder Minimum.

On the other hand, Esper's data appear to be in close agreement with variations in cosmogenic isotopes whose production rates are indicators of variation in solar irradiance, and thus, global temperatures on Earth.

3, Eric, in line: From examining the data records I conclude: Changes in solar irradiance explain perhaps one - quarter of the increase in temperature during the last century.

Given that a CO2 doubling or halving is equivalent to a 2 % change in solar irradiance [66] and the estimate that solar irradiance was approximately 6 % lower 600 Ma at the most recent snowball Earth occurrence [113], figure 7 implies that about 300 ppm CO2 or less was sufficiently small to initiate glaciation at that time.

Over this time frame, there is no evidence for any non-magnetic change in the solar irradiance on time scales longer than about a day.

Climate scientists sometimes refer to the effects of chaos as intrinsic or unforced variability: the unpredictable changes that arise from the dynamic interactions between the oceans and atmosphere rather than being a result of «forcings» such as changes in solar irradiance or greenhouse gases.

This is a very straightforward and easy to understand formula - the larger the change in solar irradiance, the larger the energy imbalance it causes, and thus the larger the radiative forcing.

A common misconception is that the climate sensitivity and temperature change in response to increasing CO2 differs from the sensitivity to other radiative forcings, such as a change in solar irradiance.