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Related papers: A homogeneous aa index: 1. Secular variation

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Accurate measurement of the local component of geodetic motion at GPS stations presents a challenge due to the need to separate this signal from the tectonic plate rotation. A pressing example is the observation of glacial isostatic…

Geophysics · Physics 2021-08-20 Ross J. Turner , Anya M. Reading , Matt A. King

Classical secular theory can be a powerful tool to describe the qualitative character of multi-planet systems and offer insight into their histories. The eigenmodes of the secular behavior, rather than current orbital elements, can help…

Earth and Planetary Astrophysics · Physics 2014-01-29 Christa Van Laerhoven , Richard Greenberg

This paper explores a possible linkage between solar motion about the solar system center of mass and the quasi-periodicity evident in the pressure and temperature of planet atmospheres. We establish that dominant mid frequency range…

Earth and Planetary Astrophysics · Physics 2023-08-25 Ian R. Edmonds

Global and regional annual mean temperature data have been analysed by many groups to determine the linear trends of temperature over climatological time scales. The near consistent results generally show an increase of about 0.07 {\deg}C…

Atmospheric and Oceanic Physics · Physics 2019-08-23 Kamsali Nagaraja , S. C. Chakravarty

Gaia mission will offer an exceptional opportunity to perform variability studies. The data homogeneity, its optimised photometric systems, composed of 11 medium and 4-5 broad bands, the high photometric precision in G band of one milli-mag…

Astrophysics · Physics 2007-05-23 Laurent Eyer

Using data from orbits one to eleven of the Parker Solar Probe (PSP) mission, the magnetic field spectral index was measured across a range of heliocentric distances. The previously observed transition between a value of $-5/3$ far from the…

Solar and Stellar Astrophysics · Physics 2023-07-11 J. R. McIntyre , C. H. K. Chen , A. Larosa

Solar wind-magnetosphere coupling, its causes and consequences have been studied for the last several decades. However, the assessment of continuously changing behaviour of the sun, plasma and field flows in the interplanetary space and…

Solar and Stellar Astrophysics · Physics 2013-12-09 Badruddin , O. P. M. Aslam

Krasinsky and Brumberg (2004 Celest. Mech. Dyn. Astron., 90, 267) reported a secular increase of the astronomical unit (AU) of 15 meters per century. Recently, Miura et al. (2009, PASJ, 61) proposed that a possible angular momentum transfer…

Earth and Planetary Astrophysics · Physics 2015-05-14 Yousuke Itoh

We present a first systematic study on the cross-sectional temperature structure of coronal loops using the six coronal temperature filters of the Atmospheric Imaging Assembly (AIA) instrument on the Solar Dynamics Observatory (SDO). We…

Solar and Stellar Astrophysics · Physics 2015-05-27 Markus J. Aschwanden , Paul Boerner

At high frequencies beyond the acoustic cut-off, a peak-like structure is visible in the solar power spectrum. Known as the pseudo-modes, their frequencies have been shown to vary in anti-phase with solar magnetic activity. In this work, we…

Solar and Stellar Astrophysics · Physics 2024-09-06 Laura Jade Millson , Anne-Marie Broomhall , Tishtrya Mehta

DEM analysis is a major diagnostic tool for stellar atmospheres. But both its derivation and its interpretation are notably difficult because of random and systematic errors, and the inverse nature of the problem. We use simulations with…

Solar and Stellar Astrophysics · Physics 2013-06-17 Chloé Guennou , Frédéric Auchère , Elie Soubrié , Karine Bocchialini , Susanna Parenti

During the last years, much attention has been paid to the astrometric implications of the galactic aberration in proper motions (GA). This effect causes systematic errors in astrometric measurements at a microarcsecond level. Some authors…

Instrumentation and Methods for Astrophysics · Physics 2015-02-03 Zinovy Malkin

The Kepler mission has been fantastic for asteroseismology of solar-type stars, but the targets are typically quite distant. As a consequence, the reliability of asteroseismic modeling has been limited by the precision of additional…

Solar and Stellar Astrophysics · Physics 2017-09-13 Travis Metcalfe , Orlagh Creevey , Jennifer van Saders

Radio interferometer arrays with non-homogeneous element patterns are more difficult to calibrate compared to the more common homogeneous array. In particular, the non-homogeneity of the patterns has significant implications on the…

Instrumentation and Methods for Astrophysics · Physics 2021-05-26 Jake L. Jones , Randall B. Wayth

It is shown that the periodic alteration of night and day provides a chaotic dissipation mechanism for the North Atlantic (NAO) and Southern (SOI) climate oscillations. The wavelet regression detrended daily NAO index for last 60 years and…

Atmospheric and Oceanic Physics · Physics 2010-07-20 A. Bershadskii

Climate change is commonly associated with an overall increase in mean temperature in a defined past time period. Many studies consider temperature trends at the global scale, but the literature is lacking in in-depth analysis of the…

Applications · Statistics 2022-10-12 Qibin Duan , Clare A. McGrory , Glenn Brown , Kerrie Mengersen , You-Gan Wang

The existing set of type Ia supernovae (SNe Ia) is now sufficient to detect oscillatory deviations from the canonical $\Lambda$CDM cosmology. We determine that the Fourier spectrum of the Pantheon data set of spectroscopically well-observed…

Astrophysics of Galaxies · Physics 2019-04-22 Sasha R. Brownsberger , Christopher W. Stubbs , Daniel M. Scolnic

We report on an ongoing investigation into a seismic calibration of solar models designed for estimating the main-sequence age and a measure of the chemical abundances of the Sun. Only modes of low degree are employed, so that with…

Astrophysics · Physics 2009-11-13 G. Houdek , D. O. Gough

The solar activity, which is driven by a variable magnetic field, exhibits changes along several time scales, the 11-year being the most known. In addition to the SunSpot Number, the Ca II K index and the Mg II index are indices widely…

Solar and Stellar Astrophysics · Physics 2024-05-28 Raffaele Reda , Valentina Penza

Leaf Area index is widely used metric for the assessment of vegetation dynamics and can be used to assess the impact of regional/local climate conditions. The underlying continuity of high resolution spatio-temporal phenological processes…

Quantitative Methods · Quantitative Biology 2021-05-20 Andrew B Whetten , Hannah Demler
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