70 Years of Sunspot Observations at the Kanzelhöhe Observatory: Systematic Study of Parameters Affecting the Derivation of the Relative Sunspot Number

Pötzi, W.; Veronig, Astrid; Temmer, Manuela; Baumgartner, D.; Freislich, H.; Strutzmann, Heinz

doi:10.1007/s11207-016-0857-6

Cited by 17 publications

(16 citation statements)

References 13 publications

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“…This would be a definite (for the X1.5) or an even more considerable (for the X2.0) improvement in determining the flare onset time, would a solar instrumentation measuring routinely LoS magnetic data in the chromosphere. A more comprehensive analysis of Korsós et al (2020a) has shown that, in spite of the apparent limitations of employing PF extrapolations only, the potential lead-time improvement for estimating the flare onset time varies in the interval (2,8) hours if one applies the WG M method to an identified "sunspot" in the height region between ∼800-1000 and ∼1800 km above the photosphere.…”

Section: Optimum Height For Forecastingmentioning

confidence: 99%

The Solar Activity Monitor Network – SAMNet

Erdélyi

Korsós

Huang

et al. 2022

J. Space Weather Space Clim.

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The Solar Activity Magnetic Monitor (SAMM) Network (SAMNet) is a future UK-led international network of ground-based solar telescope stations. SAMNet, at its full capacity, will continuously monitor the Sun’s intensity, magnetic and Doppler velocity fields at multiple heights in the solar atmosphere (from photosphere to upper chromosphere). Each SAMM sentinel will be equipped with a cluster of identical telescopes each with different magneto-optical filter (MOFs) to take observations in K~I, Na~D and Ca~I spectral bands. A subset of SAMM stations will have white-light coronagraphs and emission line coronal spectropolarimeters. The objectives of SAMNet are to provide observational data for the space weather research and forecast. The goal is to achieve an operationally sufficient lead time of e.g. flare warning of 2-8 hours, and provide much sought-after continuous synoptic maps (e.g., LoS magnetic and velocity fields, intensity) of the lower solar atmosphere with a spatial resolution limited only by seeing or diffraction limit, and with a cadence of 10 minutes. The individual SAMM sentinels will be connected into their master HQ hub where data received from all the slave stations will be automatically processed and flare warning issued up to 26 hrs in advance.

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Section: Optimum Height For Forecastingmentioning

confidence: 99%

The Solar Activity Monitor Network – SAMNet

Erdélyi

Korsós

Huang

et al. 2022

J. Space Weather Space Clim.

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“…For the period from January 1945 to December 2004. Temmer et al (2006) derived HSNs from the daily sunspot drawings obtained at Kanzelhöhe Observatory (KSO, Austria;Pötzi et al 2016) 1 and Skalnate Pleso Observatory (Slovakia), and merged them to a common homogeneous data series. 2 The data coverage of daily observations from these two stations is 84% (see also, Rybák et al 2004).…”

Section: Datamentioning

confidence: 99%

Hemispheric sunspot numbers 1874–2020

Veronig

Jain

Podladchikova

et al. 2021

A&A

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Context. Previous studies show significant north-south asymmetries for various features and indicators of solar activity. These findings suggest some decoupling between the two hemispheres over the solar cycle evolution, which is in agreement with dynamo theories. For the most important solar activity index, the sunspot numbers, so far only limited data are available for the two hemispheres independently. Aims. The aim of this study is to create a continuous series of daily and monthly hemispheric sunspot numbers (HSNs) from 1874 to 2020, which will be continuously expanded in the future with the HSNs provided by SILSO. Methods. Based on the available daily measurements of hemispheric sunspot areas from 1874 to 2016 from Greenwich Royal Observatory and National Oceanic and Atmospheric Administration (NOAA), we derive the relative fractions of the northern and southern activity. These fractions are applied to the international sunspot number (ISN) to derive the HSNs. This method and obtained data are validated against published HSNs for the period 1945-2004 and those provided by SILSO for 1992 to 2016. Results. We provide a continuous data series and catalogue of daily, monthly mean, and 13-month smoothed monthly mean HSNs for the time range 1874-2020 -fully covering solar cycles 12 to 24-that are consistent with the newly calibrated ISN (Clette et al. 2014). Validation of the reconstructed HSNs against the direct data available since 1945 reveals a high level of consistency, with Pearson correlation coefficients of r = 0.94 (0.97) for the daily (monthly mean) data. The cumulative hemispheric asymmetries for cycles 12-24 give a mean value of 16%, with no obvious pattern in north-south predominance over the cycle evolution. The strongest asymmetry occurs for cycle no. 19, in which the northern hemisphere shows a cumulated predominance of 42%. The phase shift between the peaks of solar activity in the two hemispheres may be up to 28 months, with a mean absolute value over cycles 12-24 of 16.4 months. The phase shifts reveal an overall asymmetry of the northern hemisphere reaching its cycle maximum earlier (in 10 out of 13 cases), with a mean signed phase shift of −7.6 months. Relating the ISN and HSN peak growth rates during the cycle rise phase with the cycle amplitude reveals higher correlations when considering the two hemispheres individually, with r ≈ 0.9. Conclusions. Our findings provide further evidence that to some degree the solar cycle evolves independently in the two hemispheres, and demonstrate that empirical solar cycle prediction methods can be improved by investigating the solar cycle dynamics in terms of the HSN evolution.

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“…当前(2020年), 我们已经进入太阳活动第25周(1755年极小年为起点的太阳活动周为第1周). [22] )的白光像对比了这两天中黑子数量的多寡, 而日本Hinode卫星的软X射线像则显示了黑子周围活动区辐射的强弱. 需要指出的是, 短期的平静并非只能在太阳活动极小期才能见到, 而短期的活跃也可以发生在太阳活动的衰减期甚至极小期.…”

Section: -2unclassified

Monitoring and research of high-energy solar flare emissions with GECAM

Chen

Xiong

et al. 2020

Sci. Sin.-Phys. Mech. Astron.

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70 Years of Sunspot Observations at the Kanzelhöhe Observatory: Systematic Study of Parameters Affecting the Derivation of the Relative Sunspot Number

Cited by 17 publications

References 13 publications

The Solar Activity Monitor Network – SAMNet

The Solar Activity Monitor Network – SAMNet

Hemispheric sunspot numbers 1874–2020

Monitoring and research of high-energy solar flare emissions with GECAM

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