Absolute solar ultraviolet intensities and their variations with solar activity. I - The wavelength region 1750-2100 A

Proxy reconstruction of ultraviolet-B irradiance at the Earth’s surface, and its relationship with solar activity and ozone thickness

The Holocene ◽

10.1177/0959683619875798 ◽

2019 ◽

Vol 30 (1) ◽

pp. 155-161 ◽

Cited By ~ 3

Author(s):

Phillip E Jardine ◽

Wesley T Fraser ◽

William D Gosling ◽

C Neil Roberts ◽

Warren J Eastwood ◽

...

Keyword(s):

Solar Activity ◽

Positive Relationship ◽

Pollen Grains ◽

Ultraviolet B ◽

Uv Irradiance ◽

Solar Uv ◽

Long Timescales ◽

Biotic Stressor ◽

Solar Ultraviolet

Solar ultraviolet-B (UV-B) irradiance that reaches the Earth’s surface acts as a biotic stressor and has the potential to modify ecological and environmental functioning. The challenges of reconstructing ultraviolent (UV) irradiance prior to the satellite era mean that there is uncertainty over long-term surface UV-B patterns, especially in relation to variations in solar activity over centennial and millennial timescales. Here, we reconstruct surface UV-B irradiance over the last 650 years using a novel UV-B proxy based on the chemical signature of pollen grains. We demonstrate a statistically significant positive relationship between the abundance of UV-B absorbing compounds in Pinus pollen and modelled solar UV-B irradiance. These results show that trends in surface UV-B follow the overall solar activity pattern over centennial timescales, and that variations in solar output are the dominant control on surface level UV-B flux, rather than solar modulated changes in ozone thickness. The Pinus biochemical response demonstrated here confirms the potential for solar activity driven surface UV-B variations to impact upon terrestrial biotas and environments over long timescales.

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A high precision Solar Ultraviolet Spectral Irradiance Monitor for the wavelength region 120?400 nm

Solar Physics ◽

10.1007/bf00154535 ◽

1981 ◽

Vol 74 (2) ◽

pp. 521-530 ◽

Cited By ~ 11

Author(s):

M. E. VanHoosier ◽

J.-D. F. Bartoe ◽

G. E. Brueckner ◽

D. K. Prinz ◽

J. W. Cook

Keyword(s):

High Precision ◽

Wavelength Region ◽

Spectral Irradiance ◽

Solar Ultraviolet

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CALIBRATION AND METEOROLOGICAL CHARACTERISTICS OF EQUIPMENT FOR SATELLITE MONITORING OF GEOEFFECTIVE SOLAR ULTRAVIOLET RADIATION

Meteorologiya i Gidrologiya ◽

10.52002/0130-2906-2021-10-116-122 ◽

2021 ◽

pp. 116-122

Author(s):

A. A. NUSINOV ◽

◽

P. S. ZAVERTKIN ◽

D. V. IVLYUSHKIN ◽

YU. M., KACHANOVSKII ◽

...

Keyword(s):

Solar Activity ◽

Ultraviolet Radiation ◽

Satellite Monitoring ◽

Semiconductor Detectors ◽

Solar Ultraviolet Radiation ◽

Lyman Alpha ◽

Radiation Spectra ◽

High Level ◽

Different Levels ◽

Solar Ultraviolet

The results are considered of calibration of semiconductor detectors of the VUSS-E spectro- photometer intended for monitoring the solar ultraviolet radiation flux in the Lyman-alpha line (L, 121.6 nm) on Roshydromet geostationary satellites. The calibration was carried out at the Kosmos metrological station at the Siberian International Center for Synchrotron Radiation in the channel of the VEPP-4 relativistic electron storage ring. The contribution P to the VUSS-E signal from the L line and from the spectral region above ~122 nm is calculated using the model ultraviolet radiation spectra. It is shown that the value of P can vary greatly for different sensors and different levels of solar activity: P ~ 30-60% at a low level and P ~ 50-70% at a high level of solar activity. This result indicates a need to calibrate all channels of each flight instrument and to take into account the dependence of the contribution P to the VUSS-E signal from the L line on the level of solar activity when monitoring space weather.

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A High Precision Solar Ultraviolet Spectral Irradiance Monitor for the Wavelength Region 120–400 nm

Physics of Solar Variations ◽

10.1007/978-94-010-9633-1_46 ◽

1981 ◽

pp. 521-530

Author(s):

M. E. Vanhoosier ◽

J.-D. F. Bartoe ◽

G. E. Brueckner ◽

D. K. Prinz ◽

J. W. Cook

Keyword(s):

High Precision ◽

Wavelength Region ◽

Spectral Irradiance ◽

Solar Ultraviolet

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Solar Coronal Fe XVII X-Ray Line Ratios

International Astronomical Union Colloquium ◽

10.1017/s0252921100085535 ◽

1984 ◽

Vol 86 ◽

pp. 137-140

Author(s):

H.R. Rugge ◽

D.L. McKenzie

Keyword(s):

Solar Activity ◽

Solar Flares ◽

Accurate Determination ◽

Wavelength Region ◽

Emission Lines ◽

Crystal Spectrometer ◽

X Ray ◽

Counting Statistics ◽

Solar Coronal

The SOLEX bragg crystal spectrometer experiment on the P78-1 satellite (Landecker, McKenzie and Rugge, 1979) has been used to determine accurate flux ratios of several strong solar Fe XVII x-ray emission lines in the ~ 15 to ~ 17 Å wavelength region. The ratios chosen were selected because the lines used permitted an accurate determination of the ratios both from the aspect of counting statistics as well as the lack of interference from other lines of comparable strength. Observations for a variety of conditions of solar activity, ranging from quiet conditions to large solar flares, are presented. For these observations intensity variations of a factor of about 60 were observed for the Fe XVII lines. Variations of a factor of almost 800 were observed for the Fe XVIII line at 14.2 Å. The observed ratios of the Fe XVII lines are compared to the theories of Loulergue and Nussbaumer (1975) and Smith, Raymond, Mann and Cowan (1984).

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How Does the Sun’s Spectrum Vary?

Journal of Climate ◽

10.1175/jcli-d-11-00571.1 ◽

2012 ◽

Vol 25 (7) ◽

pp. 2555-2560 ◽

Cited By ~ 60

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.

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Influence of Magnetic Fields on Solar Hydrodynamics: Experimental Results

International Astronomical Union Colloquium ◽

10.1017/s025292110005329x ◽

1977 ◽

Vol 36 ◽

pp. 143-180 ◽

Cited By ~ 10

Author(s):

J.O. Stenflo

Keyword(s):

Solar Activity ◽

Energy Balance ◽

Magnetic Fields ◽

Solar Atmosphere ◽

General Problem ◽

Solar Rotation ◽

Active Regions ◽

Physical Conditions ◽

Dynamic Phenomena

It is well-known that solar activity is basically caused by the Interaction of magnetic fields with convection and solar rotation, resulting in a great variety of dynamic phenomena, like flares, surges, sunspots, prominences, etc. Many conferences have been devoted to solar activity, including the role of magnetic fields. Similar attention has not been paid to the role of magnetic fields for the overall dynamics and energy balance of the solar atmosphere, related to the general problem of chromospheric and coronal heating. To penetrate this problem we have to focus our attention more on the physical conditions in the ‘quiet’ regions than on the conspicuous phenomena in active regions.

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Prominences and Solar Activity

International Astronomical Union Colloquium ◽

10.1017/s0252921100065817 ◽

1979 ◽

Vol 44 ◽

pp. 357-372

Author(s):

Z. Švestka

Keyword(s):

Solar Activity ◽

Solar Cycle ◽

List Type ◽

Type Number ◽

Flare Loops ◽

Filament Activation

The following subjects were discussed:(1)Filament activation(2)Post-flare loops.(3)Surges and sprays.(4)Coronal transients.(5)Disk vs. limb observations.(6)Solar cycle variations of prominence occurrence.(7)Active prominences patrol service.Of all these items, (1) and (2) were discussed in most detail and we also pay most attention to them in this report. Items (3) and (4) did not bring anything new when compared with the earlier invited presentations given by RUST and ZIRIN and therefore, we omit them.

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