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We present a detailed analysis of oxygen ion velocity distributions in the extended solar corona, based on observations made with the Ultraviolet Coronagraph Spectrometer (UVCS) on the SOHO spacecraft. Polar coronal holes at solar minimum…

Astrophysics · Physics 2009-11-13 Steven R. Cranmer , Alexander V. Panasyuk , John L. Kohl

Solar oscillations frequencies show a distinct change with solar activity. The changes in frequencies can be used to study the time variation of solar structure. We discuss constraints on the changes in solar structure with time as obtained…

Astrophysics · Physics 2007-05-23 Sarbani Basu

Differences between observed and theoretical eigenfrequencies of the Sun have characteristics which identify them as arising predominantly from properties of the oscillations in the vicinity of the solar surface: in the super-adiabatic,…

We study the variability of major atmospheric absorption features in the disk-integrated spectra of the Earth with future application to Earth-analogs in mind, concentrating on the diurnal timescale. We first analyze observations of the…

Earth and Planetary Astrophysics · Physics 2015-06-12 Yuka Fujii , Edwin L. Turner , Yasushi Suto

A radiative-convective climate model is used to calculate stratospheric temperatures and water vapor concentrations for ozone-free atmospheres warmer than that of modern Earth. Cold, dry stratospheres are predicted at low surface…

Earth and Planetary Astrophysics · Physics 2015-10-28 James F. Kasting , Howard Chen , Ravi Kumar Kopparapu

Solar wind charge exchange (SWCX) is the primary contamination to soft X-ray emission lines from the Milky Way (MW) hot gas. We report a solar-cycle ($\approx 10$ yr) temporal variation of observed \ion{O}{7} and \ion{O}{8} emission line…

Solar and Stellar Astrophysics · Physics 2022-05-11 Zhijie Qu , Dimitra Koutroumpa , Joel N. Bregman , Kip D. Kuntz , Philip Kaaret

Luminosity, which is the total amount of radiant energy emitted by an object, is one of the most critical quantities in astrophysics for characterizing stars. Equally important is the temporal evolution of a star's luminosity because of its…

Solar and Stellar Astrophysics · Physics 2022-06-20 L. E. A. Vieira , G. Kopp , T. Dudok de Wit , L. A. da Silva , F. Carlesso , A. Barbosa , A. Muralikrishna , R. Santos

Extreme precision radial-velocity spectrometers enable extreme precision stellar spectroscopy. Searches for low-mass exoplanets around solar-type stars are limited by the physical variability in stellar spectra, such as the short-term…

Solar and Stellar Astrophysics · Physics 2023-11-01 Dainis Dravins , Hans-Günter Ludwig

A recent paper states that ultraviolet backradiation from the solar transition region and upper chromosphere strongly affects the degree of ionization of minority stages at the top of the photosphere, i.e., in the temperature minimum of the…

Solar and Stellar Astrophysics · Physics 2015-06-04 R. J. Rutten , H. Uitenbroek

The Solar and Heliospheric Observatory (SOHO) was launched in December 1995 with a suite of instruments designed to answer long-standing questions about the Sun's internal structure, its extensive outer atmosphere, and the solar wind. This…

Astrophysics · Physics 2007-05-23 Steven R. Cranmer

A planet's spectrum is dynamic and only represents a time-dependent snapshot of its properties. Changing atmospheric conditions due to climate and weather patterns, particularly variation in cloud cover, can significantly affect the…

Earth and Planetary Astrophysics · Physics 2025-03-13 Soumil Kelkar , Prabal Saxena , Ravi Kopparapu , Joy Monteiro

Tropospheric ozone (O3) is a greenhouse gas which can absorb heat and make the weather even hotter during extreme heatwaves. Besides, it is an influential ground-level air pollutant which can severely damage the environment. Thus evaluating…

Atmospheric and Oceanic Physics · Physics 2021-05-06 Yu-Wen Chen , Sourav Medya , Yi-Chun Chen

Measurements of oscillation frequencies of the Sun and stars can provide important independent constraints on their internal structure and dynamics. Seismic models of these oscillations are used to connect structure and rotation of the star…

Solar and Stellar Astrophysics · Physics 2015-05-18 Jishnu Bhattacharya , Shravan. M. Hanasoge , H. M. Antia

Evidence is emerging for physical links among clouds, global temperatures, the global atmospheric electrical circuit and cosmic ray ionisation. The global circuit extends throughout the atmosphere from the planetary surface to the lower…

Atmospheric and Oceanic Physics · Physics 2007-05-23 R. G. Harrison

Synchronously orbiting, tidally-locked exoplanets with a dayside facing their star and a permanently dark nightside orbiting dim stars are prime candidates for habitability. Simulations of these planets often show the potential to maintain…

Earth and Planetary Astrophysics · Physics 2020-07-15 Marie-Pier Labonté , Timothy M. Merlis

Since the 1920s, when the three oscillations ENSO, NAO and NPO were found and defined, the theory of ocean-atmosphere coupling is particularly important in explaining the phenomena of atmospheric physics, then defined more than ten climate…

General Physics · Physics 2017-09-25 Jishi Zhang , Jingrong Lu , Haidong Huang , Xiaoning Liu , Yafeng Zhao , Zhiyang Wang , Jinlei Mo

Temperature and ozone volume mixing ratio profiles obtained from the Halogen Occultation Experiment (HALOE) aboard the Upper Atmospheric Research Satellite (UARS) over India and over the open ocean to the south during the period 1991-2001…

Atmospheric and Oceanic Physics · Physics 2009-05-29 S. Fadnavis , Devendraa Siingh , G. Beig , R. P. Singh

By reflecting solar radiation and reducing longwave emissions, clouds regulate the earth's radiation budget, impacting atmospheric circulation and cloud dynamics. Given the diurnal fluctuation of shortwave and longwave radiation, a shift in…

Atmospheric and Oceanic Physics · Physics 2017-03-28 Jun Yin , Amilcare Porporato

By comparing neutrino fluxes and central temperatures calculated from 1000 detailed numerical solar models, we derive improved scaling laws which show how each of the neutrino fluxes depends upon the central temperature (flux $\propto…

Astrophysics · Physics 2008-11-26 John N. Bahcall , Andrew Ulmer

This paper presents an overview of results obtained during the CAWSES II period on the short term variability of the Sun and how it affects the near Earth space environment. CAWSES II was planned to examine the behavior of the solar…

Solar and Stellar Astrophysics · Physics 2015-04-27 Nat Gopalswamy , Bruce Tsurutani , Yihua Yan