Sentences with phrase «irradiance variability in»
Harder, J. W., Fontenla, J. M., Pilewskie, P., Richard, E. C. & Woods, T. N. Trends in solar spectral irradiance variability in the visible and infrared.
http://www.nature.com/ Not exact matches
The solar UV irradiance from the thermosphere of Saturn and the solar wind are the most probable sources to account for the long - term variability of the electron radiation belts (Roussos et al. 2014), suggesting that external drivers play indeed an important role in Saturn's magnetospheric dynamics.
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.
«Even for a reconstruction with high variability in total irradiance, solar forcing contributed only about 0.07 °C (0.03 - 0.13 °C) to the warming since 1950.»
Typhoon variability was likely modulated further by the state of the East Asia summer monsoon (EASM) pattern, associated with variation in the magnitude of solar irradiance.
As examples of work in this category, I would mention Judith Lean's tireless efforts on relating luminosity to sunspot number, the work of Bard and colleagues on developing isotopic solar proxies like 10Be, Shindell's work on response to solar ultraviolet variability, and the work of Foukal et al on factors governing solar irradiance variations.
Jo's scientific interests include radiative transfer in the atmosphere, climate modelling, radiative forcing of climate change and the influence of solar irradiance variability on climate.
Thus it appears that, provided further satellite cloud data confirms the cosmic ray flux low cloud seeding hypothesis, and no other factors were involved over the past 150 years (e.g., variability of other cloud layers) then there is a potential for solar activity induced changes in cloudiness and irradiance to account for a significant part of the global warming experienced during the 20th century, with the possible exception of the last two decades.
This is in contrast to externally forced variability in global mean surface temperature which arises due to changes in atmospheric greenhouse gasses, aerosols, solar irradiance, ect.
If Northern Hemisphere temperatures have been in an overall cooling trend for two millennia due to «orbital forcing» (i.e. reduced solar irradiance), then the burden of proof becomes greater on those who attribute the warmth of recent decades to solar variability rather than rising greenhouse gas concentrations.
The field has long been plagued by the lack of an acceptable physical mechanism by which solar variability can affect climate, but the discovery of variability in the Sun's total irradiance (the solar «constant» of meteorology) by spacecraft instruments has pointed to a direct mechanism.
Research suggests that solar variability accounts for up to 68 % of the increase in earths temperatures with strong association between solar sunspots / irradiance and global temperature fluctuations.
-LSB-...] With the increase in irradiance and a decline in explosive volcanism in the early 20th century, global temperatures might then have returned to an unperturbed level similar to that of the MQP [Medieval Quiet Period], but the rapid rise in anthropogenic greenhouse gases propelled temperatures well beyond that level, as positive anthropogenic radiative forcing overwhelmed natural variability (Myhre et al., 2013).»
«The forcings for ECHO - G are selected in advance by (1) choosing the strength and time series of solar irradiance variability; (2) choosing the strength and time series of volcanic aerosol variability and converting this to a surrogate time series of solar irradiance reductions, which are then added to (1); and (3) choosing the time series of greenhouse gas concentrations.
«From what I can tell, the list was compiled mostly from reviewed scientific articles in which authors proposed or identified various sources of natural variability in climate; in my case solar irradiance and cosmic ray flux.
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.
Global solar irradiance reconstruction [48 — 50] and ice - core based sulfate (SO4) influx in the Northern Hemisphere [51] from volcanic activity (a); mean annual temperature (MAT) reconstructions for the Northern Hemisphere [52], North America [29], and the American Southwest * expressed as anomalies based on 1961 — 1990 temperature averages (b); changes in ENSO - related variability based on El Junco diatom record [41], oxygen isotopes records from Palmyra [42], and the unified ENSO proxy [UEP; 23](c); changes in PDSI variability for the American Southwest (d), and changes in winter precipitation variability as simulated by CESM model ensembles 2 to 5 [43].
The 11 - year averaging period minimizes the effect of variability due to the 10 — 12 year periodicity of solar irradiance as well as irregular El Niño / La Niña warming / cooling in the tropical Pacific Ocean.
The choice of the model for the minimum state of the Sun is a crucial point in our technique because it defines the amplitude of the reconstructed solar irradiance variability.
The prominent, readily observable active regions on the Sun also contribute to the variability in irradiance.
The contrast between different brightness components of the quiet Sun is especially high in the UV, which results in a large historical variability of the UV spectral irradiance.
Natural Variability Doesn't Account for Observed Temperature Increase In it's press release announcement, NASA points out that while there are other factors than greenhouse gases contributing to the amount of warming observed — changes in the sun's irradiance, oscillations of sea surface temperatures in the tropics, changes in aerosol levels in the atmosphere — these factors are not sufficient to account for the temperature increases observed since 188In it's press release announcement, NASA points out that while there are other factors than greenhouse gases contributing to the amount of warming observed — changes in the sun's irradiance, oscillations of sea surface temperatures in the tropics, changes in aerosol levels in the atmosphere — these factors are not sufficient to account for the temperature increases observed since 188in the sun's irradiance, oscillations of sea surface temperatures in the tropics, changes in aerosol levels in the atmosphere — these factors are not sufficient to account for the temperature increases observed since 188in the tropics, changes in aerosol levels in the atmosphere — these factors are not sufficient to account for the temperature increases observed since 188in aerosol levels in the atmosphere — these factors are not sufficient to account for the temperature increases observed since 188in the atmosphere — these factors are not sufficient to account for the temperature increases observed since 1880.
Interdecadal 20th century temperature deviations, such as the accelerated observed 1910 — 1940 warming that has been attributed to an unverifiable increase in solar irradiance (4, 7, 19, 20), appear to instead be due to natural variability.
One more: «Interdecadal 20th century temperature deviations, such as the accelerated observed 1910 — 1940 warming that has been attributed to an unverifiable increase in solar irradiance (4, 7, 19, 20), appear to instead be due to natural variability.
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.
«Even for a reconstruction with high variability in total irradiance, solar forcing contributed only about 0.07 °C (0.03 - 0.13 °C) to the warming since 1950.»
DePreSys (18) takes into account the observed state of the atmosphere and ocean in order to predict internal variability, together with plausible changes in anthropogenic sources of greenhouse gases and aerosol concentrations (19) and projected changes in solar irradiance and volcanic aerosol (20).