The Atmosphere Explorer mission

Dalgarno, A.; Hanson, W. B.; Spencer, N. W.; Schmerling, E. R.

doi:10.1029/rs008i004p00263

Cited by 75 publications

(26 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Photoelectrons have been used as a tool to determine the spectral and temporal variations of the solar irradiance driving the Earth's ionosphere [see, e.g., Dalgarno et al , 1973]. The early comparisons of observed photoelectron spectra with those calculated from models using observed EUV irradiance spectra and atmospheric composition [e.g., Nagy et al , 1977] showed general agreement at energies below about 50 eV (above ∼19 nm equivalent wavelength), but larger disagreements at higher energies (shorter wavelengths).…”

Section: Introductionmentioning

confidence: 99%

Photoelectrons as a tool to evaluate spectral variations in solar EUV irradiance over solar cycle timescales

et al. 2009

View full text Add to dashboard Cite

[1] There is limited information about the relative magnitude of the spectral variations in the ionizing component of solar irradiance on solar cycle timescales. We found that the Thermosphere, Ionosphere, Mesosphere, Energetics, and Dynamics (TIMED)/Solar Extreme Ultraviolet Experiment (SEE) Version 9 irradiance values predict relatively more ionospheric heating at solar minimum than those from Version 8. These changes have direct impacts on solar cycle timescale variations in ionospheric and thermospheric energy inputs derived from them. Photoelectron observations from the Fast Auroral Snapshot (FAST) satellite obtained from 2002 to 2008 are used with solar irradiance data, photoelectron flux models, and models of solar irradiance to examine the solar cycle variations of irradiance in the 4-27 nm range derived from the XPS sensor in the TIMED/SEE instrument suite. Good (±50%) agreement is found between daily photoelectron observations and model predictions. The largest differences between observed and modeled fluxes are in the 4-10 nm range, where the Fast Auroral Snapshot data show that the SEE Version 9 irradiances are systematically low. Our analysis suggests that variation on solar cycle timescales in the TIMED/SEE Version 9 and Flare Irradiance Spectral Model irradiance derived from them are systematically low in the 18-27 nm region. Because of uncertainties in the absolute value of the observed photoelectron fluxes and solar irradiances, differences between observed and modeled photoelectron fluxes are not sufficient to determine more exactly the magnitude of variation on solar cycle timescales of solar irradiance in the 4-27 nm region. These suggestions can be confirmed by higher spectral resolution observations that will be made on the Solar Dynamics Observatory mission.

show abstract

Section: Introductionmentioning

confidence: 99%

Photoelectrons as a tool to evaluate spectral variations in solar EUV irradiance over solar cycle timescales

et al. 2009

View full text Add to dashboard Cite

show abstract

“…The kind of instruments used on the Atmosphere Explorer 15 and Dynamics Explorer satellites can be adapted to tethered observations. Below 110 km, effects due to the motions of the payload through the ionosphere may make it impossible to infer A payload suitable for deployment should be capable of operation for at least 2 days near 110km.…”

Section: The Ionospherementioning

confidence: 99%

“…Heating of the tether will likely make operation at a lower altitude both difficult and expensive. A tether material for use at an altitude less than 100 km would have to retain mechanical strength at an operatReceived June 9, 1987; revision received Nov. 15,1987 ing temperature which quickly climbs beyond 800 deg as the altitude decreases. The operating lifetime of TSS is limited by two considerations.…”

Section: Introductionmentioning

confidence: 99%

Scientific missions for earth orbital tether systems

Webster

1988

Journal of Spacecraft and Rockets

View full text Add to dashboard Cite

The current available in situ data on the physical characteristics of the 90-130 km environment depends on sounding rocket and maneuverable satellite systems for its collection. Such data are, of necessity, sporadic in both time and space. The development of tethered systems in Earth orbit will allow global, long-term observations of this environment for the first time. In addition, tethered systems will allow spacial gradiometry at altitudes from 130-400 km without the extensive celestial mechanics required to coordinate multiple satellite observing programs. This paper reviews some of the outstanding science questions for the altitude regime from 90-400 km which require the use of tethered observing systems for study. These questions involve the structure, temporal evolution, and composition of the uppermost atmosphere/lowermost ionosphere, the distribution of the high spatial frequency components of the magnetic and gravity fields, and the spatial gradients of the properties of the lowermost magnetosphere/uppermost ionosphere.

show abstract

“…NASA's program for understanding the nearspace environment has involved three major thrusts: (1) to determine the interactions of the solar wind with the outer boundaries; (2) to determine the interactions of the solar photons with the atmosphere; and (3) to determine how the plasma streams produced by these interactions behave relative to one another. These endeavors include a first phase of exploration and discovery, followed by a systematic survey in which many measurements are taken to determine how all the quantities vary with time and space and with solar activity.…”

Section: Nasa's Upper Atyospmere Programmentioning

confidence: 99%

Into the thermosphere: the atmosphere explorers

Burgess¹,

Torr²

1989

Choice Reviews Online

View full text Add to dashboard Cite

AE lnves t i y a t ors0 FOREWORDToo frequently we look on a particular space mission as an event unto itself, one which should lead to great discoveries and revelations of understanding. Too frequently the actual results from a mission meld into the geographically distributed annals of esoteric scientific literature. Too frequently we do not tie off our missions with a summary of lessons learned or how they so tediously really came about, or of the human interactions.Into the Thermosphere goes far in rectifying those deficiencies. First, we are taken back over 300 years and thence trace the evolution of our discoveries and understanding of the atmosphere, marching along with the scientists and their technology of the day. Indeed, one feels the increased pace of discovery as the world of technology takes off in the early 20th century, pausing occasionally as in the early 1960's and then again expands rapidly with the advent of the satellite.Step-by-step we see the scientist's involvement go from that of an individual to that of a team participant, instruments evolve from simple to complex, data analysis grows from a reading of a strip chart to interaction with large computers. We see how the bits of data integrate over the years into a scientific comprehension. The Atmospheric Explorers are shown in their relationship to other contemporary missions, particularly Dynamics Explorer and the International Sun-Earth Explorers.The direct output of our spacecraft and instruments is data. Into the Thermosphere leads you through the essential, frequently tedious steps of the entire data acquisition and handling processnecessary but hardly sufficient. I believe the greatest contribution of Into the Thermosphere is its lucid explanation of the scientific results, always noting why a certain measurement was made and then tying the diverse experiments together into a coherent model of the thermosphere. One sees, feels, and almost hears the transformation of data into that ultimate product of space explorationknowledge.

show abstract

The Atmosphere Explorer mission

Abstract: A short description is presented of the general scientific objectives of the Atmosphere Explorer mission.

Cited by 75 publications

References 0 publications

Photoelectrons as a tool to evaluate spectral variations in solar EUV irradiance over solar cycle timescales

Photoelectrons as a tool to evaluate spectral variations in solar EUV irradiance over solar cycle timescales

Scientific missions for earth orbital tether systems

Into the thermosphere: the atmosphere explorers

Contact Info

Product

Resources

About