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<button class="button is-small is-link">Go</button> </div> </div> </form> </div> </div> <ol class="breathe-horizontal" start="1"> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2001.02808">arXiv:2001.02808</a> <span> [<a href="https://arxiv.org/pdf/2001.02808">pdf</a>, <a href="https://arxiv.org/format/2001.02808">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4357/ab65f0">10.3847/1538-4357/ab65f0 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A Comparison of Flare Forecasting Methods. IV. Evaluating Consecutive-Day Forecasting Patterns </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Park%2C+S">Sung-Hong Park</a>, <a href="/search/astro-ph?searchtype=author&query=Leka%2C+K+D">K. D. Leka</a>, <a href="/search/astro-ph?searchtype=author&query=Kusano%2C+K">Kanya Kusano</a>, <a href="/search/astro-ph?searchtype=author&query=Andries%2C+J">Jesse Andries</a>, <a href="/search/astro-ph?searchtype=author&query=Barnes%2C+G">Graham Barnes</a>, <a href="/search/astro-ph?searchtype=author&query=Bingham%2C+S">Suzy Bingham</a>, <a href="/search/astro-ph?searchtype=author&query=Bloomfield%2C+D+S">D. Shaun Bloomfield</a>, <a href="/search/astro-ph?searchtype=author&query=McCloskey%2C+A+E">Aoife E. McCloskey</a>, <a href="/search/astro-ph?searchtype=author&query=Delouille%2C+V">Veronique Delouille</a>, <a href="/search/astro-ph?searchtype=author&query=Falconer%2C+D">David Falconer</a>, <a href="/search/astro-ph?searchtype=author&query=Gallagher%2C+P+T">Peter T. Gallagher</a>, <a href="/search/astro-ph?searchtype=author&query=Georgoulis%2C+M+K">Manolis K. Georgoulis</a>, <a href="/search/astro-ph?searchtype=author&query=Kubo%2C+Y">Yuki Kubo</a>, <a href="/search/astro-ph?searchtype=author&query=Lee%2C+K">Kangjin Lee</a>, <a href="/search/astro-ph?searchtype=author&query=Lee%2C+S">Sangwoo Lee</a>, <a href="/search/astro-ph?searchtype=author&query=Lobzin%2C+V">Vasily Lobzin</a>, <a href="/search/astro-ph?searchtype=author&query=Mun%2C+J">JunChul Mun</a>, <a href="/search/astro-ph?searchtype=author&query=Murray%2C+S+A">Sophie A. Murray</a>, <a href="/search/astro-ph?searchtype=author&query=Nageem%2C+T+A+M+H">Tarek A. M. Hamad Nageem</a>, <a href="/search/astro-ph?searchtype=author&query=Qahwaji%2C+R">Rami Qahwaji</a>, <a href="/search/astro-ph?searchtype=author&query=Sharpe%2C+M">Michael Sharpe</a>, <a href="/search/astro-ph?searchtype=author&query=Steenburgh%2C+R+A">Rob A. Steenburgh</a>, <a href="/search/astro-ph?searchtype=author&query=Steward%2C+G">Graham Steward</a>, <a href="/search/astro-ph?searchtype=author&query=Terkildsen%2C+M">Michael Terkildsen</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2001.02808v2-abstract-short" style="display: inline;"> A crucial challenge to successful flare prediction is forecasting periods that transition between "flare-quiet" and "flare-active". Building on earlier studies in this series (Barnes et al. 2016; Leka et al. 2019a,b) in which we describe methodology, details, and results of flare forecasting comparison efforts, we focus here on patterns of forecast outcomes (success and failure) over multi-day per… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2001.02808v2-abstract-full').style.display = 'inline'; document.getElementById('2001.02808v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2001.02808v2-abstract-full" style="display: none;"> A crucial challenge to successful flare prediction is forecasting periods that transition between "flare-quiet" and "flare-active". Building on earlier studies in this series (Barnes et al. 2016; Leka et al. 2019a,b) in which we describe methodology, details, and results of flare forecasting comparison efforts, we focus here on patterns of forecast outcomes (success and failure) over multi-day periods. A novel analysis is developed to evaluate forecasting success in the context of catching the first event of flare-active periods, and conversely, of correctly predicting declining flare activity. We demonstrate these evaluation methods graphically and quantitatively as they provide both quick comparative evaluations and options for detailed analysis. For the testing interval 2016-2017, we determine the relative frequency distribution of two-day dichotomous forecast outcomes for three different event histories (i.e., event/event, no-event/event and event/no-event), and use it to highlight performance differences between forecasting methods. A trend is identified across all forecasting methods that a high/low forecast probability on day-1 remains high/low on day-2 even though flaring activity is transitioning. For M-class and larger flares, we find that explicitly including persistence or prior flare history in computing forecasts helps to improve overall forecast performance. It is also found that using magnetic/modern data leads to improvement in catching the first-event/first-no-event transitions. Finally, 15% of major (i.e., M-class or above) flare days over the testing interval were effectively missed due to a lack of observations from instruments away from the Earth-Sun line. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2001.02808v2-abstract-full').style.display = 'none'; document.getElementById('2001.02808v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 January, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 8 January, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">33 pages, 13 figures, accepted for publication in ApJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1907.02909">arXiv:1907.02909</a> <span> [<a href="https://arxiv.org/pdf/1907.02909">pdf</a>, <a href="https://arxiv.org/ps/1907.02909">ps</a>, <a href="https://arxiv.org/format/1907.02909">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Data Analysis, Statistics and Probability">physics.data-an</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Space Physics">physics.space-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4357/ab2e11">10.3847/1538-4357/ab2e11 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A Comparison of Flare Forecasting Methods. III. Systematic Behaviors of Operational Solar Flare Forecasting Systems </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Leka%2C+K+D">K. D. Leka</a>, <a href="/search/astro-ph?searchtype=author&query=Park%2C+S">Sung-Hong Park</a>, <a href="/search/astro-ph?searchtype=author&query=Kusano%2C+K">Kanya Kusano</a>, <a href="/search/astro-ph?searchtype=author&query=Andries%2C+J">Jesse Andries</a>, <a href="/search/astro-ph?searchtype=author&query=Barnes%2C+G">Graham Barnes</a>, <a href="/search/astro-ph?searchtype=author&query=Bingham%2C+S">Suzy Bingham</a>, <a href="/search/astro-ph?searchtype=author&query=Bloomfield%2C+D+S">D. Shaun Bloomfield</a>, <a href="/search/astro-ph?searchtype=author&query=McCloskey%2C+A+E">Aoife E. McCloskey</a>, <a href="/search/astro-ph?searchtype=author&query=Delouille%2C+V">Veronique Delouille</a>, <a href="/search/astro-ph?searchtype=author&query=Falconer%2C+D">David Falconer</a>, <a href="/search/astro-ph?searchtype=author&query=Gallagher%2C+P+T">Peter T. Gallagher</a>, <a href="/search/astro-ph?searchtype=author&query=Georgoulis%2C+M+K">Manolis K. Georgoulis</a>, <a href="/search/astro-ph?searchtype=author&query=Kubo%2C+Y">Yuki Kubo</a>, <a href="/search/astro-ph?searchtype=author&query=Lee%2C+K">Kangjin Lee</a>, <a href="/search/astro-ph?searchtype=author&query=Lee%2C+S">Sangwoo Lee</a>, <a href="/search/astro-ph?searchtype=author&query=Lobzin%2C+V">Vasily Lobzin</a>, <a href="/search/astro-ph?searchtype=author&query=Mun%2C+J">JunChul Mun</a>, <a href="/search/astro-ph?searchtype=author&query=Murray%2C+S+A">Sophie A. Murray</a>, <a href="/search/astro-ph?searchtype=author&query=Nageem%2C+T+A+M+H">Tarek A. M. Hamad Nageem</a>, <a href="/search/astro-ph?searchtype=author&query=Qahwaji%2C+R">Rami Qahwaji</a>, <a href="/search/astro-ph?searchtype=author&query=Sharpe%2C+M">Michael Sharpe</a>, <a href="/search/astro-ph?searchtype=author&query=Steenburgh%2C+R">Rob Steenburgh</a>, <a href="/search/astro-ph?searchtype=author&query=Steward%2C+G">Graham Steward</a>, <a href="/search/astro-ph?searchtype=author&query=Terkildsen%2C+M">Michael Terkildsen</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1907.02909v1-abstract-short" style="display: inline;"> A workshop was recently held at Nagoya University (31 October - 02 November 2017), sponsored by the Center for International Collaborative Research, at the Institute for Space-Earth Environmental Research, Nagoya University, Japan, to quantitatively compare the performance of today's operational solar flare forecasting facilities. Building upon Paper I of this series (Barnes et al. 2016), in Paper… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1907.02909v1-abstract-full').style.display = 'inline'; document.getElementById('1907.02909v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1907.02909v1-abstract-full" style="display: none;"> A workshop was recently held at Nagoya University (31 October - 02 November 2017), sponsored by the Center for International Collaborative Research, at the Institute for Space-Earth Environmental Research, Nagoya University, Japan, to quantitatively compare the performance of today's operational solar flare forecasting facilities. Building upon Paper I of this series (Barnes et al. 2016), in Paper II (Leka et al. 2019) we described the participating methods for this latest comparison effort, the evaluation methodology, and presented quantitative comparisons. In this paper we focus on the behavior and performance of the methods when evaluated in the context of broad implementation differences. Acknowledging the short testing interval available and the small number of methods available, we do find that forecast performance: 1) appears to improve by including persistence or prior flare activity, region evolution, and a human "forecaster in the loop"; 2) is hurt by restricting data to disk-center observations; 3) may benefit from long-term statistics, but mostly when then combined with modern data sources and statistical approaches. These trends are arguably weak and must be viewed with numerous caveats, as discussed both here and in Paper II. Following this present work, we present in Paper IV a novel analysis method to evaluate temporal patterns of forecasting errors of both types (i.e., misses and false alarms; Park et al. 2019). Hence, most importantly, with this series of papers we demonstrate the techniques for facilitating comparisons in the interest of establishing performance-positive methodologies. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1907.02909v1-abstract-full').style.display = 'none'; document.getElementById('1907.02909v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 5 July, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">23 pages, 6 figures, accepted for publication in The Astrophysical Journal</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1907.02905">arXiv:1907.02905</a> <span> [<a href="https://arxiv.org/pdf/1907.02905">pdf</a>, <a href="https://arxiv.org/ps/1907.02905">ps</a>, <a href="https://arxiv.org/format/1907.02905">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Data Analysis, Statistics and Probability">physics.data-an</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Space Physics">physics.space-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4365/ab2e12">10.3847/1538-4365/ab2e12 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A Comparison of Flare Forecasting Methods. II. Benchmarks, Metrics and Performance Results for Operational Solar Flare Forecasting Systems </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Leka%2C+K+D">K. D. Leka</a>, <a href="/search/astro-ph?searchtype=author&query=Park%2C+S">Sung-Hong Park</a>, <a href="/search/astro-ph?searchtype=author&query=Kusano%2C+K">Kanya Kusano</a>, <a href="/search/astro-ph?searchtype=author&query=Andries%2C+J">Jesse Andries</a>, <a href="/search/astro-ph?searchtype=author&query=Barnes%2C+G">Graham Barnes</a>, <a href="/search/astro-ph?searchtype=author&query=Bingham%2C+S">Suzy Bingham</a>, <a href="/search/astro-ph?searchtype=author&query=Bloomfield%2C+D+S">D. Shaun Bloomfield</a>, <a href="/search/astro-ph?searchtype=author&query=McCloskey%2C+A+E">Aoife E. McCloskey</a>, <a href="/search/astro-ph?searchtype=author&query=Delouille%2C+V">Veronique Delouille</a>, <a href="/search/astro-ph?searchtype=author&query=Falconer%2C+D">David Falconer</a>, <a href="/search/astro-ph?searchtype=author&query=Gallagher%2C+P+T">Peter T. Gallagher</a>, <a href="/search/astro-ph?searchtype=author&query=Georgoulis%2C+M+K">Manolis K. Georgoulis</a>, <a href="/search/astro-ph?searchtype=author&query=Kubo%2C+Y">Yuki Kubo</a>, <a href="/search/astro-ph?searchtype=author&query=Lee%2C+K">Kangjin Lee</a>, <a href="/search/astro-ph?searchtype=author&query=Lee%2C+S">Sangwoo Lee</a>, <a href="/search/astro-ph?searchtype=author&query=Lobzin%2C+V">Vasily Lobzin</a>, <a href="/search/astro-ph?searchtype=author&query=Mun%2C+J">JunChul Mun</a>, <a href="/search/astro-ph?searchtype=author&query=Murray%2C+S+A">Sophie A. Murray</a>, <a href="/search/astro-ph?searchtype=author&query=Nageem%2C+T+A+M+H">Tarek A. M. Hamad Nageem</a>, <a href="/search/astro-ph?searchtype=author&query=Qahwaji%2C+R">Rami Qahwaji</a>, <a href="/search/astro-ph?searchtype=author&query=Sharpe%2C+M">Michael Sharpe</a>, <a href="/search/astro-ph?searchtype=author&query=Steenburgh%2C+R">Rob Steenburgh</a>, <a href="/search/astro-ph?searchtype=author&query=Steward%2C+G">Graham Steward</a>, <a href="/search/astro-ph?searchtype=author&query=Terkildsen%2C+M">Michael Terkildsen</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1907.02905v1-abstract-short" style="display: inline;"> Solar flares are extremely energetic phenomena in our Solar System. Their impulsive, often drastic radiative increases, in particular at short wavelengths, bring immediate impacts that motivate solar physics and space weather research to understand solar flares to the point of being able to forecast them. As data and algorithms improve dramatically, questions must be asked concerning how well the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1907.02905v1-abstract-full').style.display = 'inline'; document.getElementById('1907.02905v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1907.02905v1-abstract-full" style="display: none;"> Solar flares are extremely energetic phenomena in our Solar System. Their impulsive, often drastic radiative increases, in particular at short wavelengths, bring immediate impacts that motivate solar physics and space weather research to understand solar flares to the point of being able to forecast them. As data and algorithms improve dramatically, questions must be asked concerning how well the forecasting performs; crucially, we must ask how to rigorously measure performance in order to critically gauge any improvements. Building upon earlier-developed methodology (Barnes et al, 2016, Paper I), international representatives of regional warning centers and research facilities assembled in 2017 at the Institute for Space-Earth Environmental Research, Nagoya University, Japan to - for the first time - directly compare the performance of operational solar flare forecasting methods. Multiple quantitative evaluation metrics are employed, with focus and discussion on evaluation methodologies given the restrictions of operational forecasting. Numerous methods performed consistently above the "no skill" level, although which method scored top marks is decisively a function of flare event definition and the metric used; there was no single winner. Following in this paper series we ask why the performances differ by examining implementation details (Leka et al. 2019, Paper III), and then we present a novel analysis method to evaluate temporal patterns of forecasting errors in (Park et al. 2019, Paper IV). With these works, this team presents a well-defined and robust methodology for evaluating solar flare forecasting methods in both research and operational frameworks, and today's performance benchmarks against which improvements and new methods may be compared. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1907.02905v1-abstract-full').style.display = 'none'; document.getElementById('1907.02905v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 5 July, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">26 pages, 5 figures, accepted for publication in the Astrophysical Journal Supplement Series</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1904.01133">arXiv:1904.01133</a> <span> [<a href="https://arxiv.org/pdf/1904.01133">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Computer Vision and Pattern Recognition">cs.CV</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.33166/AETiC.2019.02.001">10.33166/AETiC.2019.02.001 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Filling Factors of Sunspots in SODISM Images </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Alasta%2C+A+F">Amro F. Alasta</a>, <a href="/search/astro-ph?searchtype=author&query=Algamudi%2C+A">Abdrazag Algamudi</a>, <a href="/search/astro-ph?searchtype=author&query=Almesrati%2C+F">Fatma Almesrati</a>, <a href="/search/astro-ph?searchtype=author&query=Meftah%2C+M">Mustapha Meftah</a>, <a href="/search/astro-ph?searchtype=author&query=Qahwaji%2C+R">Rami Qahwaji</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1904.01133v1-abstract-short" style="display: inline;"> Received: 1st December 2018; Accepted: 18th February 2019; Published: 1st April 2019 Abstract: The calculated filling factors (FFs) for a feature reflect the fraction of the solar disc covered by that feature, and the assignment of reference synthetic spectra. In this paper, the FFs, specified as a function of radial position on the solar disc, are computed for each image in a tabular form. The fi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1904.01133v1-abstract-full').style.display = 'inline'; document.getElementById('1904.01133v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1904.01133v1-abstract-full" style="display: none;"> Received: 1st December 2018; Accepted: 18th February 2019; Published: 1st April 2019 Abstract: The calculated filling factors (FFs) for a feature reflect the fraction of the solar disc covered by that feature, and the assignment of reference synthetic spectra. In this paper, the FFs, specified as a function of radial position on the solar disc, are computed for each image in a tabular form. The filling factor (FF) is an important parameter and is defined as the fraction of area in a pixel covered with the magnetic field, whereas the rest of the area in the pixel is field-free. However, this does not provide extensive information about the experiments conducted on tens or hundreds of such images. This is the first time that filling factors for SODISM images have been catalogued in tabular formation. This paper presents a new method that provides the means to detect sunspots on full-disk solar images recorded by the Solar Diameter Imager and Surface Mapper (SODISM) on the PICARD satellite. The method is a totally automated detection process that achieves a sunspot recognition rate of 97.6%. The number of sunspots detected by this method strongly agrees with the NOAA catalogue. The sunspot areas calculated by this method have a 99% correlation with SOHO over the same period, and thus help to calculate the filling factor for wavelength (W.L.) 607nm. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1904.01133v1-abstract-full').style.display = 'none'; document.getElementById('1904.01133v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 1 April, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">11 pages, 7 figures, 2 tables This article is an extension of our previous studies investigating the detection of sunspots using SODISM images. The paper presented in August 2018 at the IEEE International Conference on Computing, Electronics and Communications Engineering. http://aetic.theiaer.org/archive/v3/v3n2/p1.html</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Published by International Association of Educators and Researchers (IAER ) Annals of Emerging Technologies in Computing (AETiC) Vol. 3, No. 2, 2019 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1608.06319">arXiv:1608.06319</a> <span> [<a href="https://arxiv.org/pdf/1608.06319">pdf</a>, <a href="https://arxiv.org/ps/1608.06319">ps</a>, <a href="https://arxiv.org/format/1608.06319">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/0004-637X/829/2/89">10.3847/0004-637X/829/2/89 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A Comparison of Flare Forecasting Methods, I: Results from the "All-Clear" Workshop </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Barnes%2C+G">G. Barnes</a>, <a href="/search/astro-ph?searchtype=author&query=Leka%2C+K+D">K. D. Leka</a>, <a href="/search/astro-ph?searchtype=author&query=Schrijver%2C+C+J">C. J. Schrijver</a>, <a href="/search/astro-ph?searchtype=author&query=Colak%2C+T">T. Colak</a>, <a href="/search/astro-ph?searchtype=author&query=Qahwaji%2C+R">R. Qahwaji</a>, <a href="/search/astro-ph?searchtype=author&query=Ashamari%2C+O+W">O. W. Ashamari</a>, <a href="/search/astro-ph?searchtype=author&query=Yuan%2C+Y">Y. Yuan</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+J">J. Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=McAteer%2C+R+T+J">R. T. J. McAteer</a>, <a href="/search/astro-ph?searchtype=author&query=Bloomfield%2C+D+S">D. S. Bloomfield</a>, <a href="/search/astro-ph?searchtype=author&query=Higgins%2C+P+A">P. A. Higgins</a>, <a href="/search/astro-ph?searchtype=author&query=Gallagher%2C+P+T">P. T. Gallagher</a>, <a href="/search/astro-ph?searchtype=author&query=Falconer%2C+D+A">D. A. Falconer</a>, <a href="/search/astro-ph?searchtype=author&query=Georgoulis%2C+M+K">M. K. Georgoulis</a>, <a href="/search/astro-ph?searchtype=author&query=Wheatland%2C+M+S">M. S. Wheatland</a>, <a href="/search/astro-ph?searchtype=author&query=Balch%2C+C">C. Balch</a>, <a href="/search/astro-ph?searchtype=author&query=Dunn%2C+T">T. Dunn</a>, <a href="/search/astro-ph?searchtype=author&query=Wagner%2C+E+L">E. L. Wagner</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1608.06319v1-abstract-short" style="display: inline;"> Solar flares produce radiation which can have an almost immediate effect on the near-Earth environment, making it crucial to forecast flares in order to mitigate their negative effects. The number of published approaches to flare forecasting using photospheric magnetic field observations has proliferated, with varying claims about how well each works. Because of the different analysis techniques a… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1608.06319v1-abstract-full').style.display = 'inline'; document.getElementById('1608.06319v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1608.06319v1-abstract-full" style="display: none;"> Solar flares produce radiation which can have an almost immediate effect on the near-Earth environment, making it crucial to forecast flares in order to mitigate their negative effects. The number of published approaches to flare forecasting using photospheric magnetic field observations has proliferated, with varying claims about how well each works. Because of the different analysis techniques and data sets used, it is essentially impossible to compare the results from the literature. This problem is exacerbated by the low event rates of large solar flares. The challenges of forecasting rare events have long been recognized in the meteorology community, but have yet to be fully acknowledged by the space weather community. During the interagency workshop on "all clear" forecasts held in Boulder, CO in 2009, the performance of a number of existing algorithms was compared on common data sets, specifically line-of-sight magnetic field and continuum intensity images from MDI, with consistent definitions of what constitutes an event. We demonstrate the importance of making such systematic comparisons, and of using standard verification statistics to determine what constitutes a good prediction scheme. When a comparison was made in this fashion, no one method clearly outperformed all others, which may in part be due to the strong correlations among the parameters used by different methods to characterize an active region. For M-class flares and above, the set of methods tends towards a weakly positive skill score (as measured with several distinct metrics), with no participating method proving substantially better than climatological forecasts. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1608.06319v1-abstract-full').style.display = 'none'; document.getElementById('1608.06319v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 22 August, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2016. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in ApJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1505.02036">arXiv:1505.02036</a> <span> [<a href="https://arxiv.org/pdf/1505.02036">pdf</a>, <a href="https://arxiv.org/ps/1505.02036">ps</a>, <a href="https://arxiv.org/format/1505.02036">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> Identification of photospheric activity features from SOHO/MDI data using the ASAP tool </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Ashamari%2C+O">Omar Ashamari</a>, <a href="/search/astro-ph?searchtype=author&query=Qahwaji%2C+R">Rami Qahwaji</a>, <a href="/search/astro-ph?searchtype=author&query=Ipson%2C+S">Stan Ipson</a>, <a href="/search/astro-ph?searchtype=author&query=Scholl%2C+M">Micha Scholl</a>, <a href="/search/astro-ph?searchtype=author&query=Nibouche%2C+O">Omar Nibouche</a>, <a href="/search/astro-ph?searchtype=author&query=Haberreiter%2C+M">Margit Haberreiter</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1505.02036v1-abstract-short" style="display: inline;"> The variation of solar irradiance is one of the natural forcing mechanisms of the terrestrial climate. Hence, the time-dependent solar irradiance is an important input parameter for climate modelling. The solar surface magnetic field is a powerful proxy for solar irradiance reconstruction. The analyses of data obtained with the Michelson Doppler Imager (MDI) on board the SOHO mission are therefore… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1505.02036v1-abstract-full').style.display = 'inline'; document.getElementById('1505.02036v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1505.02036v1-abstract-full" style="display: none;"> The variation of solar irradiance is one of the natural forcing mechanisms of the terrestrial climate. Hence, the time-dependent solar irradiance is an important input parameter for climate modelling. The solar surface magnetic field is a powerful proxy for solar irradiance reconstruction. The analyses of data obtained with the Michelson Doppler Imager (MDI) on board the SOHO mission are therefore useful for the identification of solar surface magnetic features to be used in solar irradiance reconstruction models. However, there is still a need for automated technologies that would enable the identification of solar activity features from large databases. To achieve this we present a series of enhanced segmentation algorithms developed to detect and calculate the area coverages of specific magnetic features from MDI intensitygrams and magnetograms. These algorithms are part of the Automated Solar Activity Prediction (ASAP) tool. The segmentation algorithms allow us to identify the areas on the solar disk covered by magnetic elements inside and outside boundaries of active regions. Depending on their contrast properties, magnetic features within an active region boundary are classified as sunspot umbra and penumbra, or faculae. Outside an active region boundary magnetic elements are identified as network. We present the detailed steps involved in the segmentation process and provide the area coverages of the segmented MDI intensitygrams and magnetograms. The feature segmentation has been carried out on daily intensitygrams and magnetograms from April 21, 1996 to April 11, 2011. This offers an exciting opportunity to undertake further investigations that benefit from solar features segmentations, such as solar irradiance reconstruction, which we plan to investigate in the future. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1505.02036v1-abstract-full').style.display = 'none'; document.getElementById('1505.02036v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 8 May, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2015. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1109.0473">arXiv:1109.0473</a> <span> [<a href="https://arxiv.org/pdf/1109.0473">pdf</a>, <a href="https://arxiv.org/ps/1109.0473">ps</a>, <a href="https://arxiv.org/format/1109.0473">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> A Multi-Wavelength Analysis of Active Regions and Sunspots by Comparison of Automated Detection Algorithms </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Verbeeck%2C+C">Cis Verbeeck</a>, <a href="/search/astro-ph?searchtype=author&query=Higgins%2C+P+A">Paul A. Higgins</a>, <a href="/search/astro-ph?searchtype=author&query=Colak%2C+T">Tufan Colak</a>, <a href="/search/astro-ph?searchtype=author&query=Watson%2C+F+T">Fraser T. Watson</a>, <a href="/search/astro-ph?searchtype=author&query=Delouille%2C+V">Veronique Delouille</a>, <a href="/search/astro-ph?searchtype=author&query=Mampaey%2C+B">Benjamin Mampaey</a>, <a href="/search/astro-ph?searchtype=author&query=Qahwaji%2C+R">Rami Qahwaji</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1109.0473v1-abstract-short" style="display: inline;"> Since the Solar Dynamics Observatory (SDO) began recording ~ 1 TB of data per day, there has been an increased need to automatically extract features and events for further analysis. Here we compare the overall detection performance, correlations between extracted properties, and usability for feature tracking of four solar feature-detection algorithms: the Solar Monitor Active Region Tracker (SMA… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1109.0473v1-abstract-full').style.display = 'inline'; document.getElementById('1109.0473v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1109.0473v1-abstract-full" style="display: none;"> Since the Solar Dynamics Observatory (SDO) began recording ~ 1 TB of data per day, there has been an increased need to automatically extract features and events for further analysis. Here we compare the overall detection performance, correlations between extracted properties, and usability for feature tracking of four solar feature-detection algorithms: the Solar Monitor Active Region Tracker (SMART) detects active regions in line-of-sight magnetograms; the Automated Solar Activity Prediction code (ASAP) detects sunspots and pores in white-light continuum images; the Sunspot Tracking And Recognition Algorithm (STARA) detects sunspots in white-light continuum images; the Spatial Possibilistic Clustering Algorithm (SPoCA) automatically segments solar EUV images into active regions (AR), coronal holes (CH) and quiet Sun (QS). One month of data from the SOHO/MDI and SOHO/EIT instruments during 12 May - 23 June 2003 is analysed. The overall detection performance of each algorithm is benchmarked against National Oceanic and Atmospheric Administration (NOAA) and Solar Influences Data Analysis Centre (SIDC) catalogues using various feature properties such as total sunspot area, which shows good agreement, and the number of features detected, which shows poor agreement. Principal Component Analysis indicates a clear distinction between photospheric properties, which are highly correlated to the first component and account for 52.86% of variability in the data set, and coronal properties, which are moderately correlated to both the first and second principal components. Finally, case studies of NOAA 10377 and 10365 are conducted to determine algorithm stability for tracking the evolution of individual features. We find that magnetic flux and total sunspot area are the best indicators of active-region emergence. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1109.0473v1-abstract-full').style.display = 'none'; document.getElementById('1109.0473v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 2 September, 2011; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2011. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">30 pages, 18 figures. Accepted for publication in Solar Physics topical issue : Solar Image Processing in the Petabyte Era</span> </p> </li> </ol> <div class="is-hidden-tablet">  <span class="help" style="display: inline-block;"><a href="https://github.com/arXiv/arxiv-search/releases">Search v0.5.6 released 2020-02-24</a>  </span> </div> </div> </main> <footer> <div class="columns is-desktop" role="navigation" aria-label="Secondary">  <div class="column"> <div class="columns"> <div class="column"> <ul class="nav-spaced"> <li><a href="https://info.arxiv.org/about">About</a></li> <li><a href="https://info.arxiv.org/help">Help</a></li> </ul> </div> <div class="column"> <ul class="nav-spaced"> <li> <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" class="icon filter-black" role="presentation"><title>contact arXiv</title><desc>Click here to contact arXiv</desc><path d="M502.3 190.8c3.9-3.1 9.7-.2 9.7 4.7V400c0 26.5-21.5 48-48 48H48c-26.5 0-48-21.5-48-48V195.6c0-5 5.7-7.8 9.7-4.7 22.4 17.4 52.1 39.5 154.1 113.6 21.1 15.4 56.7 47.8 92.2 47.6 35.7.3 72-32.8 92.3-47.6 102-74.1 131.6-96.3 154-113.7zM256 320c23.2.4 56.6-29.2 73.4-41.4 132.7-96.3 142.8-104.7 173.4-128.7 5.8-4.5 9.2-11.5 9.2-18.9v-19c0-26.5-21.5-48-48-48H48C21.5 64 0 85.5 0 112v19c0 7.4 3.4 14.3 9.2 18.9 30.6 23.9 40.7 32.4 173.4 128.7 16.8 12.2 50.2 41.8 73.4 41.4z"/></svg> <a href="https://info.arxiv.org/help/contact.html"> Contact</a> </li> <li> <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" class="icon filter-black" role="presentation"><title>subscribe to arXiv mailings</title><desc>Click here to subscribe</desc><path d="M476 3.2L12.5 270.6c-18.1 10.4-15.8 35.6 2.2 43.2L121 358.4l287.3-253.2c5.5-4.9 13.3 2.6 8.6 8.3L176 407v80.5c0 23.6 28.5 32.9 42.5 15.8L282 426l124.6 52.2c14.2 6 30.4-2.9 33-18.2l72-432C515 7.8 493.3-6.8 476 3.2z"/></svg> <a href="https://info.arxiv.org/help/subscribe"> Subscribe</a> </li> </ul> </div> </div> </div>   <div class="column"> <div class="columns"> <div class="column"> <ul class="nav-spaced"> <li><a href="https://info.arxiv.org/help/license/index.html">Copyright</a></li> <li><a href="https://info.arxiv.org/help/policies/privacy_policy.html">Privacy Policy</a></li> </ul> </div> <div class="column sorry-app-links"> <ul class="nav-spaced"> <li><a href="https://info.arxiv.org/help/web_accessibility.html">Web Accessibility Assistance</a></li> <li> <p class="help"> <a class="a11y-main-link" href="https://status.arxiv.org" target="_blank">arXiv Operational Status <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 256 512" class="icon filter-dark_grey" role="presentation"><path d="M224.3 273l-136 136c-9.4 9.4-24.6 9.4-33.9 0l-22.6-22.6c-9.4-9.4-9.4-24.6 0-33.9l96.4-96.4-96.4-96.4c-9.4-9.4-9.4-24.6 0-33.9L54.3 103c9.4-9.4 24.6-9.4 33.9 0l136 136c9.5 9.4 9.5 24.6.1 34z"/></svg></a><br> Get status notifications via <a class="is-link" href="https://subscribe.sorryapp.com/24846f03/email/new" target="_blank"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" class="icon filter-black" role="presentation"><path d="M502.3 190.8c3.9-3.1 9.7-.2 9.7 4.7V400c0 26.5-21.5 48-48 48H48c-26.5 0-48-21.5-48-48V195.6c0-5 5.7-7.8 9.7-4.7 22.4 17.4 52.1 39.5 154.1 113.6 21.1 15.4 56.7 47.8 92.2 47.6 35.7.3 72-32.8 92.3-47.6 102-74.1 131.6-96.3 154-113.7zM256 320c23.2.4 56.6-29.2 73.4-41.4 132.7-96.3 142.8-104.7 173.4-128.7 5.8-4.5 9.2-11.5 9.2-18.9v-19c0-26.5-21.5-48-48-48H48C21.5 64 0 85.5 0 112v19c0 7.4 3.4 14.3 9.2 18.9 30.6 23.9 40.7 32.4 173.4 128.7 16.8 12.2 50.2 41.8 73.4 41.4z"/></svg>email</a> or <a class="is-link" href="https://subscribe.sorryapp.com/24846f03/slack/new" target="_blank"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 448 512" class="icon filter-black" role="presentation"><path d="M94.12 315.1c0 25.9-21.16 47.06-47.06 47.06S0 341 0 315.1c0-25.9 21.16-47.06 47.06-47.06h47.06v47.06zm23.72 0c0-25.9 21.16-47.06 47.06-47.06s47.06 21.16 47.06 47.06v117.84c0 25.9-21.16 47.06-47.06 47.06s-47.06-21.16-47.06-47.06V315.1zm47.06-188.98c-25.9 0-47.06-21.16-47.06-47.06S139 32 164.9 32s47.06 21.16 47.06 47.06v47.06H164.9zm0 23.72c25.9 0 47.06 21.16 47.06 47.06s-21.16 47.06-47.06 47.06H47.06C21.16 243.96 0 222.8 0 196.9s21.16-47.06 47.06-47.06H164.9zm188.98 47.06c0-25.9 21.16-47.06 47.06-47.06 25.9 0 47.06 21.16 47.06 47.06s-21.16 47.06-47.06 47.06h-47.06V196.9zm-23.72 0c0 25.9-21.16 47.06-47.06 47.06-25.9 0-47.06-21.16-47.06-47.06V79.06c0-25.9 21.16-47.06 47.06-47.06 25.9 0 47.06 21.16 47.06 47.06V196.9zM283.1 385.88c25.9 0 47.06 21.16 47.06 47.06 0 25.9-21.16 47.06-47.06 47.06-25.9 0-47.06-21.16-47.06-47.06v-47.06h47.06zm0-23.72c-25.9 0-47.06-21.16-47.06-47.06 0-25.9 21.16-47.06 47.06-47.06h117.84c25.9 0 47.06 21.16 47.06 47.06 0 25.9-21.16 47.06-47.06 47.06H283.1z"/></svg>slack</a> </p> </li> </ul> </div> </div> </div>  </div> </footer> <script src="https://static.arxiv.org/static/base/1.0.0a5/js/member_acknowledgement.js"></script> </body> </html>

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