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Related papers: Background-subtracted Solar Activity Maps

200 papers

We present the initial results of an observational study into the variation of the dominant length-scale of quiet solar emission: supergranulation. This length-scale reflects the radiative energy in the plasma of the upper solar…

Solar and Stellar Astrophysics · Physics 2015-05-27 Scott W. McIntosh , Robert J. Leamon , Rachel A. Hock , Mark P. Rast , Roger K. Ulrich

Estimates of the photospheric magnetic, electric and plasma velocity fields are essential for studying the dynamics of the solar atmosphere, for example through the derivative quantities of Poynting and relative helicity flux and by using…

Solar and Stellar Astrophysics · Physics 2017-12-18 E. Lumme , J. Pomoell , E. K. J. Kilpua

Unsupervised multimodal change detection is pivotal for time-sensitive tasks and comprehensive multi-temporal Earth monitoring. In this study, we explore unsupervised multimodal change detection between two key remote sensing data sources:…

Image and Video Processing · Electrical Eng. & Systems 2024-01-18 Hongruixuan Chen , Jian Song , Naoto Yokoya

By using the unique database of SOHO/MDI full disk magnetograms from 1996 September to 2011 January, covering the entire solar cycle 23, we analyze the time-variability of the solar magnetic flux spectrum and study the properties of…

Solar and Stellar Astrophysics · Physics 2015-06-18 C. l. Jin , J. X. Wang

The emergence of a new discipline called space weather, which aims at understanding and predicting the impact of solar activity on the terrestrial environment and on technological systems, has led to a growing need for analysing solar…

Solar and Stellar Astrophysics · Physics 2010-05-31 T. Dudok de Wit

We summarize the fifty-year concerted effort to place the "activity" of the Sun in the context of the stars. As a working definition of solar activity in the context of stars, we adopt those globally-observable variations on time scales…

Solar and Stellar Astrophysics · Physics 2015-06-03 Philip G. Judge , Michael J. Thompson

Photometric variability of a directly imaged exo-Earth conveys spatial information on its surface and can be used to retrieve a two-dimensional geography and axial tilt of the planet (spin-orbit tomography). In this study, we relax the…

Earth and Planetary Astrophysics · Physics 2020-09-09 Hajime Kawahara , Kento Masuda

Solar activity can be witnessed in the form of sunspots and active regions, where the magnetic field is enhanced by up to a factor 1000 as compared to that of the quiet Sun. In addition, solar activity manifests itself in terms of flares,…

Solar and Stellar Astrophysics · Physics 2025-07-25 Gottfried Mann , Frédéric Schuller

In this work we introduce a new way of binning sunspot group data with the purpose of better understanding the impact of the solar cycle on sunspot properties and how this defined the characteristics of the extended minimum of cycle 23. Our…

The extreme ultraviolet portion of the solar spectrum contains a wealth of diagnostic tools for probing the lower solar atmosphere in response to an injection of energy, particularly during the impulsive phase of solar flares. These include…

Solar and Stellar Astrophysics · Physics 2015-09-16 Ryan O. Milligan

The vector magnetic field characteristics of superactive regions (SARs) hold the key for understanding why SARs are extremely active and provide the guidance in space weather prediction. We aim to quantify the characteristics of SARs using…

Solar and Stellar Astrophysics · Physics 2015-06-05 A. Q. Chen , J. X. Wang

For security, environmental, and regulatory purposes it is useful to continuously monitor wide areas for unexpected changes in radioactivity. We report on a temporal anomaly detection algorithm which uses mobile detectors to build a spatial…

Data Analysis, Statistics and Probability · Physics 2014-07-10 Alex Reinhart , Alex Athey , Steven Biegalski

Change detection (CD) is a fundamental task in Earth observation. While most change detection methods detect all changes, there is a growing need for specialized methods targeting specific changes relevant to particular applications while…

Image and Video Processing · Electrical Eng. & Systems 2024-08-14 Tahir Ahmad , Sudipan Saha

We present a dataset for investigating the impact of stellar activity on astrometric measurements using NASA's Solar Dynamics Observatory (SDO) images of the Sun. The sensitivity of astrometry for detecting exoplanets is limited by stellar…

Solar and Stellar Astrophysics · Physics 2023-10-20 Warit Wijitworasart , Zoe de Beurs , Andrew Vanderburg

Although there are now some tentative signs that the start of cycle 24 has begun there is still considerable interest in the somewhat unusual behaviour of the current solar minimum and the apparent delay in the true start of the next cycle.…

Solar and Stellar Astrophysics · Physics 2010-03-23 Stephen Fletcher , Roger New , Anne-Marie Broomhall , William Chaplin , Yvonne Elsworth

The solar magnetism is no more considered as a purely superficial phenomenon. The SoHO community has shown that the length of the solar cycle depends on the transition region between radiation and convection. Nevertheless, the internal…

Variations of the solar UV irradiance are an important driver of chemical and physical processes in the Earth's upper atmosphere and may also influence global climate. Here we reconstruct solar UV irradiance in the range 115-400 nm over the…

Solar and Stellar Astrophysics · Physics 2009-11-23 N. A. Krivova , S. K. Solanki , T. Wenzler , B. Podlipnik

Segment Anything Model (SAM) has demonstrated impressive zero-shot segmentation capabilities across natural image domains, but it struggles to generalize to the unique challenges of remote sensing data, such as complex terrain, multi-scale…

Computer Vision and Pattern Recognition · Computer Science 2025-09-22 Tianyang Wang , Xi Xiao , Gaofei Chen , Hanzhang Chi , Qi Zhang , Guo Cheng , Yingrui Ji

Soil assessment is important for mobile robot planning and navigation on natural and planetary environments. Terramechanic characteristics can be inferred from the thermal behaviour of soils under the influence of sunlight using remote…