Contributions of the solar ultraviolet irradiance to the total solar irradiance during large flares

2006 ◽  
Vol 111 (A10) ◽  
Author(s):  
Thomas N. Woods ◽  
Greg Kopp ◽  
Phillip C. Chamberlin
Keyword(s):  
Solar Irradiance ◽  
Total Solar Irradiance ◽  
Ultraviolet Irradiance ◽  
Solar Ultraviolet

scholarly journals Estimating solar ultraviolet irradiance (290-385 nm) by means of the spectral parametric models: SPCTRAL2 and SMARTS2

2000 ◽  
Vol 18 (11) ◽  
pp. 1382-1389 ◽  
Author(s):  
I. Foyo-Moreno ◽  
J. Vida ◽  
F. J. Olmo ◽  
L. Alados-Arboledas
Keyword(s):  
Solar Irradiance ◽  
Biological Effects ◽  
Stratospheric Ozone ◽  
Radiant Energy ◽  
Parametric Models ◽  
Spectral Irradiance ◽  
Atmospheric Composition ◽  
Relevant Variables ◽  
Ultraviolet Irradiance ◽  
Solar Ultraviolet

Abstract. Since the discovery of the ozone depletion in Antarctic and the globally declining trend of stratospheric ozone concentration, public and scientific concern has been raised in the last decades. A very important consequence of this fact is the increased broadband and spectral UV radiation in the environment and the biological effects and heath risks that may take place in the near future. The absence of widespread measurements of this radiometric flux has lead to the development and use of alternative estimation procedures such as the parametric approaches. Parametric models compute the radiant energy using available atmospheric parameters. Some parametric models compute the global solar irradiance at surface level by addition of its direct beam and diffuse components. In the present work, we have developed a comparison between two cloudless sky parametrization schemes. Both methods provide an estimation of the solar spectral irradiance that can be integrated spectrally within the limits of interest. For this test we have used data recorded in a radiometric station located at Granada (37.180°N, 3.580°W, 660 m a.m.s.l.), an inland location. The database includes hourly values of the relevant variables covering the years 1994-95. The performance of the models has been tested in relation to their predictive capability of global solar irradiance in the UV range (290–385 nm). After our study, it appears that information concerning the aerosol radiative effects is fundamental in order to obtain a good estimation. The original version of SPCTRAL2 provides estimates of the experimental values with negligible mean bias deviation. This suggests not only the appropriateness of the model but also the convenience of the aerosol features fixed in it to Granada conditions. SMARTS2 model offers increased flexibility concerning the selection of different aerosol models included in the code and provides the best results when the selected models are those considered as urban. Although SMARTS2 provide slightly worse results, both models give estimates of solar ultraviolet irradiance with mean bias deviation below 5%, and root mean square deviation close to experimental errors.Key words: Atmospheric composition and structure (transmission and scattering of radiation) - Meteorology and atmospheric dynamics (radiative process)

scholarly journals How Does the Sun’s Spectrum Vary?

2012 ◽  
Vol 25 (7) ◽  
pp. 2555-2560 ◽  
Author(s):  
Judith L. Lean ◽  
Matthew T. DeLand
Keyword(s):  
Solar Activity ◽  
Solar Irradiance ◽  
Solar Spectrum ◽  
Total Solar Irradiance ◽  
Spectral Irradiance ◽  
Model Calculations ◽  
Uv Irradiance ◽  
Infrared Spectral ◽  
Total Irradiance ◽  
Solar Ultraviolet

Abstract Recent observations made by the Spectral Irradiance Monitor (SIM) on the Solar Radiation and Climate Experiment (SORCE) spacecraft suggest that the Sun’s visible and infrared spectral irradiance increased from 2004 to 2008, even as the total solar irradiance measured simultaneously by SORCE’s Total Irradiance Monitor (TIM) decreased. At the same time, solar ultraviolet (UV) irradiance decreased 3–10 times more than expected from prior observations and model calculations of the known effects of sunspot and facular solar features. Analysis of the SIM spectral irradiance observations during the solar minimum epoch of 2008, when solar activity was essentially invariant, exposes trends in the SIM observations relative to both total solar irradiance and solar activity that are unlikely to be solar in origin. The authors suggest that the SIM’s radically different solar variability characterization is a consequence of undetected instrument sensitivity drifts, not true solar spectrum changes. It is thus doubtful that simulations of climate and atmospheric change using SIM measurements are indicative of real terrestrial behavior.

The Fengyun-3E/Joint Total Solar Irradiance Absolute Radiometer: Instrument Design, Characterization, and Calibration

Solar Physics ◽  
2021 ◽  
Vol 296 (3) ◽  
Author(s):  
Baoqi Song ◽  
Xin Ye ◽  
Wolfgang Finsterle ◽  
Manfred Gyo ◽  
Matthias Gander ◽  
...  
Keyword(s):  
Solar Irradiance ◽  
Total Solar Irradiance ◽  
Instrument Design

Long-term variations in total solar irradiance

Solar Physics ◽  
1994 ◽  
Vol 152 (1) ◽  
pp. 13-21 ◽  
Author(s):  
Judit M. Pap ◽  
Richard C. Willson ◽  
Claus Fr�hlich ◽  
Richard F. Donnelly ◽  
Larry Puga
Keyword(s):  
Solar Irradiance ◽  
Total Solar Irradiance ◽  
Long Term Variations

Solar ultraviolet irradiance observed from southern Argentina: September 1990 to March 1991

1993 ◽  
Vol 98 (D5) ◽  
pp. 8891-8897 ◽  
Author(s):  
J. E. Frederick ◽  
P. F. Soulen ◽  
S. B. Diaz ◽  
I. Smolskaia ◽  
C. R. Booth ◽  
...  
Keyword(s):  
Ultraviolet Irradiance ◽  
Solar Ultraviolet

scholarly journals Stellar activity, differential rotation, and exoplanets

2010 ◽  
Vol 6 (S273) ◽  
pp. 89-95 ◽  
Author(s):  
A. F. Lanza
Keyword(s):  
Time Series ◽  
Differential Rotation ◽  
Solar Irradiance ◽  
Giant Planet ◽  
Total Solar Irradiance ◽  
Short Term ◽  
Stellar Activity ◽  
Transiting Planets ◽  
Spot Model ◽  
Spot Activity

AbstractThe photospheric spot activity of some of the stars with transiting planets discovered by the CoRoT space experiment is reviewed. Their out-of-transit light modulations are fitted by a spot model previously tested with the total solar irradiance variations. This approach allows us to study the longitude distribution of the spotted area and its variations versus time during the five months of a typical CoRoT time series. The migration of the spots in longitude provides a lower limit for the surface differential rotation, while the variation of the total spotted area can be used to search for short-term cycles akin the solar Rieger cycles. The possible impact of a close-in giant planet on stellar activity is also discussed.

Total Solar Irradiance Trend During Solar Cycles 21 and 22

Science ◽  
1997 ◽  
Vol 277 (5334) ◽  
pp. 1963-1965 ◽  
Author(s):  
Richard C. Willson
Keyword(s):  
Solar Irradiance ◽  
Total Solar Irradiance ◽  
Solar Cycles

Data Fusion of Total Solar Irradiance Composite Time Series Using 40 years of Satellite Measurements: First Results 

2021 ◽  
Author(s):  
Jean-Philippe Montillet ◽  
Wolfgang Finsterle ◽  
Werner Schmutz ◽  
Margit Haberreiter ◽  
Rok Sikonja
Keyword(s):  
Time Series ◽  
Data Fusion ◽  
Solar Irradiance ◽  
Total Solar Irradiance ◽  
Maunder Minimum ◽  
The Sun ◽  
Climate Reconstructions ◽  
The Earth ◽  
First Results ◽  
The Difference

<p><span>Since the late 70’s, successive satellite missions have been monitoring the sun’s activity, recording total solar irradiance observations. These measurements are important to estimate the Earth’s energy imbalance, </span><span>i.e. the difference of energy absorbed and emitted by our planet. Climate modelers need the solar forcing time series in their models in order to study the influence of the Sun on the Earth’s climate. With this amount of TSI data, solar irradiance reconstruction models  can be better validated which can also improve studies looking at past climate reconstructions (e.g., Maunder minimum). V</span><span>arious algorithms have been proposed in the last decade to merge the various TSI measurements over the 40 years of recording period. We have developed a new statistical algorithm based on data fusion.  The stochastic noise processes of the measurements are modeled via a dual kernel including white and coloured noise.  We show our first results and compare it with previous releases (PMOD,ACRIM, ... ). </span></p>

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