Sentences with phrase «irradiance changes»
The phrase "irradiance changes" means the amount of light or energy that is being received or emitted by a surface, which can vary or fluctuate over time. Full definition
A model of solar irradiance variations is presented which is based on the assumption that solar surface magnetism is responsible for all total irradiance changes on time scales of days to years.
aanda.org
Amplification of the direct solar forcing is conceivable, e.g., through effects on ozone or atmospheric condensation nuclei, but empirical data place a factor of two upper limit on the amplification, with the most likely forcing in the range 100 — 120 % of the directly measured solar irradiance change [64].
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.
This increases the sensitivity to solar irradiance changes just as it increases the sensitivity to longwave (i.e., greenhouse) radiative forcing.
In their calculations, the direct tropo - spheric aerosol effect does not play a large net role, because the moderately absorbing aerosol assumption leads to an offset between its sunlight reflecting and absorbing properties insofar as the top of the atmosphere irradiance change is concerned.
We also use five - member ensembles of simulations with greenhouse gas changes only (GHG), volcanic and solar irradiance changes only (NAT), and aerosol changes only (AER) over the period 1850 — 2010.»
But the bottom line is that solar irradiance changes little over time and we need to look at other mechanisms.
Because of the ocean thermal inertia and decadal irradiance change, the peak warming and cooling effects of solar maximum and minimum are delayed about two years after irradiance extrema.
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).
Amplification of the direct solar forcing is conceivable, e.g., through effects on ozone or atmospheric condensation nuclei, but empirical data place a factor of two upper limit on the amplification, with the most likely forcing in the range 100 — 120 % of the directly measured solar irradiance change [64].
The irradiance changes are assumed to be relatively small and the importance of potential amplifying mechanisms is still a matter of current debate.
But please be sure to understand me — I am not claiming that there is no possibility of solar feedbacks affecting the other «forcings» (in fact we are working on ozone feedbacks quite extensively — though they are affected by the irradiance changes on 11 year timescales, not on 22 - year timescales).
Solar irradiance change has a strong spectral dependence [Lean, 2000], and resulting climate changes may include indirect effects of induced ozone change [RFCR; Haigh, 1999; Shindell et al., 1999a] and conceivably even cosmic ray effects on clouds [Dickinson, 1975].
To understand if climate models are capable of simulating the long - term atmospheric and climate response to solar irradiance changes, we first test their ability to simulate the roughly 11 year solar cycle changes, which have been observed from satellites over the past few decades.
«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.
I have quoted Palle above on the small contribution of solar irradiance changes to climate change.
Simulations where the magnitude of solar irradiance changes is increased yield a mismatch between model results and CO2 data, providing evidence for modest changes in solar irradiance and global mean temperatures over the past millennium and arguing against a significant amplification of the response of global or hemispheric annual mean temperature to solar forcing.
Model minus solar irradiance changes and volcanic aerosols.
10 Heat Storage: Mostly the Oceans 1955 - 1996; Levitus et al. 2001: Science World Ocean = 18.2 x10 22 Joules Atmosphere = 0.7 x10 22 Joules Land Ice = 0.8 x10 22 Joules observed Modeled Model includes forcing from Greenhouse Gases, Sulfate Aerosols Solar irradiance changes, and volcanic aerosols.
The model is based on the assumption that all irradiance changes on time - scales of a day and longer are entirely due to the variations of the surface distribution of the solar magnetic field.
This was on top of any volcanoes and solar irradiance changes that occurred... but it's hard to see anything comparable.
It is intriguing to extrapolate these results to longer term solar irradiance changes, which are roughly two to three times larger than solar cycle variations.
Add this to your list of articles and papers to read regarding sun exposure changes, meaning solar irradiance changes, I presume.
Total solar irradiance changes, though of small magnitude, do appear to affect sea surface temperatures (SSTs), most obviously at latitudes where cloud cover is small and irradiance is abundant, such as the Northern Hemisphere subtropics during summer.