Simulating Properties of “Seasonal” Variability in Solar Activity and Space Weather Impacts

Solar short-term, quasi-annual variability within a decadal sunspot-cycle has recently been observed to strongly correlate with major class solar flares, resulting into quasi-periodic space weather “seasons.” In search for the origin of this quasi-periodic enhanced activity bursts, significant researches are going on. In this article we show, by employing a 3D thin-shell shallow-water type model, that magnetically modified Rossby waves can interact with spot-producing toroidal fields and create certain quasi-periodic spatio-temporal patterns, which plausibly cause a season of enhanced solar activity followed by a relatively quiet period. This is analogous to the Earth’s lower atmosphere, where Rossby waves and jet streams are produced and drive global terrestrial weather. Shallow-water models have been applied to study terrestrial Rossby waves, because their generation layer in the Earth’s lower atmospheric region has a much larger horizontal than vertical scale, one of the model-requirements. In the Sun, though Rossby waves can be generated at various locations, particularly favorable locations are the subadiabatic layers at/near the base of the convection zone where the horizontal scale of the fluid and disturbances in it can be much larger than the vertical scale. However, one important difference with respect to terrestrial waves is that solar Rossby waves are magnetically modified due to presence of strong magnetic fields in the Sun. We consider plausible magnetic field configurations at the base of the convection zone during different phases of the cycle and describe the properties of energetically active Rossby waves generated in our model. We also discuss their influence in causing short-term spatio-temporal variability in solar activity and how this variability could have space weather impacts. An example of a possible space weather impact on the Earth’s radiation belts are presented.

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Optical instrumentation for chromospheric monitoring during solar cycle 25 at Paris and Côte d’Azur observatories

Journal of Space Weather and Space Climate ◽

10.1051/swsc/2020032 ◽

2020 ◽

Vol 10 ◽

pp. 31

Author(s):

Jean-Marie Malherbe ◽

Thierry Corbard ◽

Kevin Dalmasse

Keyword(s):

Solar Activity ◽

Solar Cycle ◽

Space Weather ◽

Coronal Mass Ejections ◽

Calibration Method ◽

Line Profiles ◽

Short Term ◽

Optical Instruments ◽

Dynamic Events

We present the observing program proposed by Paris and Côte d’Azur Observatories for monitoring solar activity during the upcoming cycle 25 and providing near real time images and movies of the chromosphere for space-weather research and applications. Two optical instruments are fully dedicated to this task and we summarize their capabilities. Short-term and fast-cadence observations of the chromosphere will be performed automatically at Calern observatory (Côte d’Azur), where dynamic events, as flare development, Moreton waves, filament instabilities and Coronal Mass Ejections onset, will be tracked. This new set of telescopes will operate in 2021 with narrow bandpass filters selecting Hα and CaII K lines. We present the instrumental design and a simulation of future images. At Meudon, the Spectroheliograph is well adapted to the long-term and low-cadence survey of chromospheric activity by recently improved and optimized spectroscopic means. Surface scans deliver daily (x, y, λ) datacubes of Hα, CaII K and CaII H line profiles. We describe the nature of available data and emphasize the new calibration method of spectra.

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Understanding Space Weather: Part III: The Sun’s Domain

Bulletin of the American Meteorological Society ◽

10.1175/bams-d-16-0204.1 ◽

2017 ◽

Vol 98 (12) ◽

pp. 2593-2602 ◽

Cited By ~ 2

Author(s):

Keith Strong ◽

Nicholeen Viall ◽

Joan Schmelz ◽

Julia Saba

Keyword(s):

Solar Wind ◽

Solar System ◽

Space Weather ◽

Interplanetary Space ◽

The Sun ◽

Intrinsic Variability ◽

Slow Speed ◽

Complex Processes ◽

Solar System Objects ◽

Weather Impacts

Abstract The Sun exports a continuous outflow of plasma into interplanetary space: the solar wind. The solar wind primarily comprises two components: high- and slow-speed flows. These move with velocities ranging from 200 to 800 km s-1 depending on the source of the particular flow. As well as its speed, the density, temperature, and even the composition of the solar wind change. Adding to its intrinsic variability, there are embedded transients resulting from flares and coronal mass ejections that further complicate its dynamics and space weather impacts. The solar wind interacts differently with each of the solar system objects it encounters based on their magnetic and atmospheric properties. Even more complex processes occur as the solar wind encounters the interstellar medium, at the outer boundaries of the Sun’s domain. The solar wind stretches to beyond 100 au (where 1 au ≡ 149 597 870 700 m) from the Sun, which means that Earth is essentially immersed in the very hot solar atmosphere, and that leads to many space weather impacts on life and society. The specific space weather impacts on Earth will be discussed in detail in the next two papers in this series.

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The Science of Space Weather: From Bit Flips to Exoplanets

10.5194/egusphere-egu21-6488 ◽

2021 ◽

Author(s):

Janet G Luhmann

Keyword(s):

Solar Wind ◽

Solar Activity ◽

Space Weather ◽

Interplanetary Space ◽

Planetary Science ◽

In Situ Measurements ◽

Space Environment ◽

The Sun ◽

Multiple Imaging

While the term &#8216;space weather&#8217; remains to some synonymous with operational anomalies on spacecraft, communications interruptions, and other practical matters, its broader implications extend across the EGU and beyond. Much of the science underlying space weather has to do with how our star, the Sun, affects the space environment at Earth&#8217;s orbit. We are lucky to be living at a time where information from both remote sensing (especially imaging at visible, x-ray and EUV wavelengths) and in-situ measurements (of plasmas, magnetic fields, and energetic particles) have provided unprecedented pictures of the Sun and knowledge of its extended atmosphere, the solar wind. Building on early forays into interplanetary space and deployments of coronagraphs with the Helios and SMM missions in the 70s and 80s, the Ulysses mission reconnaissance far above the ecliptic and the launch of Yohkoh&#8217;s and SOHO&#8217;s imagers in the 90s, and the long-term &#8216;monitoring&#8217; of both the Sun and the conditions upstream of the Earth on SOHO, WIND and ACE, the STEREO mission opened a floodgate to research focused on solar activity and its heliospheric and terrestrial consequences. Physics-based, often semi-empirical 3D models increasingly came into widespread use for reconstructing and interpreting the multiple imaging perspectives and multipoint in-situ measurements that the twin STEREO spacecraft, combined with Earth-viewpoint assets (including the GONG ground-based network, and as of 2010, SDO magnetographs), provided on a regular basis. These observations and models together transformed perceptions of phenomena ranging from coronal structure to solar wind sources to eruptive phenomena and consequences, and the tools used to study and forecast them. Now Parker Solar Probe and Solar Orbiter are probing details of the still unexplored regions closer to the Sun than Mercury&#8217;s orbit, with the goal of completing that part of the solar/solar wind connection puzzle. And the overall science results from these observations and analysis efforts have not been confined to heliophysics, having especially influenced planetary science and astrophysics. They are seen in recreations of long-past scenarios when our Sun and solar system were evolving, in investigations of solar activity impacts including auroral emissions at the planets, &#160;and in applications to distant planetary systems around other &#8216;Suns&#8217;. That these lofty implications are related to the bit flips and static &#8216;noise&#8217; first identified with &#8216;space weather&#8217;, provides one of the interesting connections, and still ongoing journeys/stories, within EGU&#8217;s research universe.

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Seismic Forecasting of Solar Activity

Highlights of Astronomy ◽

10.1017/s1539299600013800 ◽

2002 ◽

Vol 12 ◽

pp. 378

Author(s):

D.C. Braun ◽

C. Lindsey

Keyword(s):

Solar Activity ◽

Space Weather ◽

Solar Limb ◽

Active Regions ◽

Solar Interior ◽

The Sun ◽

Near Surface ◽

Near Earth Space ◽

Doppler Imager ◽

East Limb

Computational seismic holography, applied to Solar Oscillations Investigation -Michelson Doppler Imager (SOI-MDI) data fromSOHO, has recently given us the first images of an active region on the far side of the Sun(Lindsey & Braun 2000). The advent of phase-coherent seismic imaging is now allowing us quite literally to look into the solar interior from a local perspective, indeed to see through the solar interior acoustically to its far surface. Solar activity is critical to near-Earth space weather. A great deal of effort has been invested towards the prediction of flares and CMEs, based on the formidable presence of active regions on the near solar surface. Active regions can emerge rapidly from beneath the photosphere or appear on the east limb with relatively little warning. Because of this, the ability to anticipate the appearances of active regions will contribute substantially to forecasts of space weather on time scales of more than about a day. In collaboration with Dr. Phil Scherrer and the MDI team at Stanford University we are currently deriving far-side images from the lower resolution “medium-l” SOI-MDI Dopplergrams, which are obtained continuously through the year and arrive at MDI headquarters within 24 hours of their acquisition by theSOHOspacecraft. We are therefore already capable of locating large far-side active regions and predicting their appearance on the east solar limb to within a few hours more than a week in advance. In addition, ground-based networks such as GONG will soon have the capability for “real-time helioseismology”, and will be routinely monitoring the far surface of the Sun, and perhaps beneath the near surface, for emerging solar activity.

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Short-term variation of the Earth's rotation and the solar activity

Symposium - International Astronomical Union ◽

10.1017/s0074180900119722 ◽

1988 ◽

Vol 128 ◽

pp. 353-358 ◽

Cited By ~ 1

Author(s):

D. Djurovic ◽

P. Paquet

Keyword(s):

Spectral Analysis ◽

Angular Momentum ◽

Solar Activity ◽

Earth Rotation ◽

Cyclic Variation ◽

The Sun ◽

Physical Processes ◽

Short Term ◽

The Earth ◽

Term Variation

In 1980, Feissel et al. identified a quasi–cyclic variation of 55 days in the irregularities of the Earth Rotation (ER) later detected in the Atmospheric Angular Momentum (AAM) (Langley et al., 1981). The purpose of this work is to analyse whether the causes of this cycle could lie in the physical processes of the Sun. The Wolf Numbers (WN) are used as parameters of the solar activity. Their spectral analysis over the period 1967–1985 shows such a component at 51 days. Analysis of three other periods, among which is the MERIT campaign, confirms it as well as during low or increasing solar activity periods.

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The Sun Service KRIM - diagnostic complex of solar activity

ITM Web of Conferences ◽

10.1051/itmconf/20193015003 ◽

2019 ◽

Vol 30 ◽

pp. 15003

Author(s):

Alexander Volvach ◽

Olga Gopasyuk ◽

Inna Yakubovskaya

Keyword(s):

Solar Activity ◽

Correlation Coefficients ◽

The Sun ◽

Radio Telescopes ◽

Short Term ◽

X Ray ◽

Daily Monitoring ◽

The Earth ◽

Term Forecast ◽

Diagnostic Complex

The radio astronomical diagnostic complex of solar activity, created on the basis of the radio telescope RT-22 and three small radiotelescopes united in the Sun Service KRIM located in coordinates longitude 33° 59' 30" latitude 44° 23' 52", conducts simultaneous observations in the wavelength range from 8 mm to 1.2 m in the monitoring mode and alerts. The Sun Service KRIM registered a series of strong outbreaks in the Sun in September 2017, when it was at a minimum of its activity. The information obtained by radio telescopes correlates well with data from other terrestrial and satellite observatories such as RSTN and GOES. Correlation coefficients are calculated and scattering diagrams for X-ray class flares X9.3 and X2.2 are constructed. The information from the radio telescopes of the Sun Service KRIM allows them to be used for daily monitoring of solar activity, further processing of data obtained in the course of scientific research, short-term forecast of space weather and analysis of its infuence on the Earth.

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The Venus Climate Database

10.5194/egusphere-egu21-5515 ◽

2021 ◽

Author(s):

Sebastien Lebonnois ◽

Ehouarn Millour ◽

Antoine Martinez ◽

Thomas Pierron ◽

Aymeric Spiga ◽

...

Keyword(s):

Solar Activity ◽

Climate Model ◽

State Of The Art ◽

Global Climate ◽

Global Climate Model ◽

The Sun ◽

Short Term ◽

Extreme Uv

We have over the years developed a state of the art Venus Global Climate Model (GCM, Lebonnois et al. 2016; Gilli et al. 2017; Garate-Lopez & Lebonnois 2018). With funding from ESA in the context of the preparation of the possible upcoming EnVision mission, we have, in the footsteps of what has been done for Mars with the Mars Climate Database (), built a Venus Climate Database (VCD) based on GCM outputs.The VCD dataset and software overall enable users to:- extract atmospheric quantities (temperature, pressure, winds, density, &#8230;) from the surface to the exobase (~250km) over a climatological Venusian day.- to better bracket reality, several scenarios are provided, in order to reflect the possible range of solar activity (Extreme UV input from the Sun) which strongly affects the thermosphere (above ~150km), as well as a realistic range of UV albedo cloud top.- in addition to a baseline climatology, the VCD software provides statistics (internal short term and day-to-day variability) along with means to add perturbations to represent Venusian weather.At EGU we will present the VCD and its features, emphasizing how it can be useful for scientific users wanting to compare with their models or analyze observations, and for engineers planning future missions.

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