We present, to the best of our knowledge, a new method to retrieve tropospheric ozone (O3) profiles from ground-based ultraviolet spectroscopic measurements. This method utilizes radiance spectra in the Huggins bands (i.e., 300-340 nm) measured at three off-axis angles (e.g., 45 degrees, 75 degrees, and 85 degrees) normalized to direct-Sun irradiances or zenith-sky radiances with the total colu...

The Extreme-ultraviolet Imaging Spectrometer (EIS) on the Hinode spacecraft obtains high resolution spectra of the solar atmosphere in two wavelength ranges: 170 210 and 250 290 Å. These wavelength regions contain a wealth of emission lines covering temperature regions from the chromosphere/transition region (e.g., He II, Si VII) up to flare temperatures (Fe XXIII, Fe XXIV). Of particular inter...

The vertical distribution of ozone in the atmosphere of Mars is computed from ultraviolet spectra obtained by the Mariner 9 spacecraft. In the Northern Hemisphere the ozone scale height is much smaller than the atmospheric scale height in midlatitudes and increases rapidly to a maximum farther north. At high latitudes (above 60 °) there is no significant difference between the scale heights of ...

Mariner 6 and 7 ultraviolet spectrometers that flew by Mars in 1969 observed the Lyman-, dayglow of atomic hydrogen. Data in the altitude range 200 to 24,000 km are analyzed to determine the structure of the Martian exosphere. The classical evaporative theory is applied to calculate a hydrogen density distribution. A spherical model of the dayglow Lyman-a emission, using radiative transfer theo...

Four of the most active RS CVn stars (V711 Tau, II Peg, Gem, and UX Ari) have been observed for a total of 3Ms with the Extreme Ultraviolet Explorer satellite (EUVE) between 1992 and 2000 January. Flaring and quiescent states of extreme ultraviolet spectra ( 70–740) and light curves ( 75–175) have been analyzed to provide emission measure distributions (EMD) for these systems in the range logTe...

Terschlüsen, J. A. 2016. Constructing and Commissioning HELIOS – A High Harmonic Generation Source for Pump-Probe Measurements with sub 50 fs Temporal Resolution. The Development of Experimental Equipment for Extreme Ultraviolet Spectroscopy. Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 1360. 80 pp. Uppsala: Acta Universitatis Upsaliensis. ...

We report on the merging between southern polar coronal hole and an adjacent dimming induced by a mass ejection 2022 March 18, resulting in merged region persisting for at least 72 hrs. use remote sensing data from multiple co-observing spacecraft to understand physical processes during this event. The evolution of merger is examined using Extreme-UltraViolet (EUV) images obtained Atmospheric I...

The extreme ultraviolet quiet Sun spectrum, observed at normal incidence by the Coronal Diagnostic Spectrometer on the SOHO spacecraft, is presented. The spectrum covers the wavelength ranges 308–381 Å and 513–633 Å and is based on data recorded at various positions on the solar disk between October 1996 and February 1997. Datasets at twelve of these ‘positions’ were judged to be free from acti...

The miniature electron and ion spectrometer MEDUSA on Astrid-2 consists of two “top-hat”-type spherical electrostatic analyzers, sharing a common top-hat. Fast energy sweeps (16 electron sweeps and 8 ion sweeps per second) allow for very high temporal resolution measurements of a two-dimensional slice of the particle distribution function. The energy range covered, is in the case of electrons, ...

We present a Differential Emission Measure (DEM) analysis of the quiet solar corona on disk using data obtained by the Extreme-ultraviolet Imaging Spectrometer (EIS) on Hinode. We show that the expected quiet Sun DEM distribution can be recovered from judiciously selected lines, and that their average intensities can be reproduced to within 30%. We present a subset of these selected lines spann...