Browsing by Author "Lumpe, J. D."
Now showing 1 - 3 of 3
Results Per Page
Sort Options
- The Global-Scale Observations of the Limb and Disk (GOLD) MissionEastes, R. W.; McClintock, William E.; Burns, A. G.; Anderson, D. N.; Andersson, L.; Codrescu, M.; Correira, J. T.; Daniell, R. E.; England, Scott L.; Evans, J. S.; Harvey, J.; Krywonos, A.; Lumpe, J. D.; Richmond, A. D.; Rusch, D. W.; Siegmund, O. H.; Solomon, S. C.; Strickland, D. J.; Woods, T. N.; Aksnes, A.; Budzien, S. A.; Dymond, K. F.; Eparvier, F. G.; Martinis, C. R.; Oberheide, J. (2017-10)The Earth's thermosphere and ionosphere constitute a dynamic system that varies daily in response to energy inputs from above and from below. This system can exhibit a significant response within an hour to changes in those inputs, as plasma and fluid processes compete to control its temperature, composition, and structure. Within this system, short wavelength solar radiation and charged particles from the magnetosphere deposit energy, and waves propagating from the lower atmosphere dissipate. Understanding the global-scale response of the thermosphere-ionosphere (T-I) system to these drivers is essential to advancing our physical understanding of coupling between the space environment and the Earth's atmosphere. Previous missions have successfully determined how the "climate" of the T-I system responds. The Global-scale Observations of the Limb and Disk (GOLD) mission will determine how the "weather" of the T-I responds, taking the next step in understanding the coupling between the space environment and the Earth's atmosphere. Operating in geostationary orbit, the GOLD imaging spectrograph will measure the Earth's emissions from 132 to 162 nm. These measurements will be used image two critical variables-thermospheric temperature and composition, near 160 km-on the dayside disk at half-hour time scales. At night they will be used to image the evolution of the low latitude ionosphere in the same regions that were observed earlier during the day. Due to the geostationary orbit being used the mission observes the same hemisphere repeatedly, allowing the unambiguous separation of spatial and temporal variability over the Americas.
- Initial Observations by the GOLD MissionEastes, R. W.; McClintock, William E.; Burns, A. G.; Anderson, D. N.; Andersson, L.; Aryal, S.; Budzien, S. A.; Cai, X.; Codrescu, M.; Correira, J. T.; Daniell, R. E.; Dymond, K. F.; England, Scott L.; Eparvier, F. G.; Evans, J. S.; Foroosh, H.; Gan, Q.; Greer, K. R.; Karan, D. K.; Krywonos, A.; Laskar, F., I; Lumpe, J. D.; Martinis, C. R.; McPhate, J. B.; Oberheide, J.; Siegmund, O. H.; Solomon, S. C.; Veibel, V.; Woods, T. N. (2020-07)The NASA Global-scale Observations of the Limb and Disk (GOLD) mission has flown an ultraviolet-imaging spectrograph on SES-14, a communications satellite in geostationary orbit at 47.5 degrees W longitude. That instrument observes the Earth's far ultraviolet (FUV) airglow at similar to 134-162 nm using two identical channels. The observations performed include limb scans, stellar occultations, and images of the sunlit and nightside disk from 6:10 to 00:40 universal time each day. Initial analyses reveal interesting and unexpected results as well as the potential for further studies of the Earth's thermosphere-ionosphere system and its responses to solar-geomagnetic forcing and atmospheric dynamics. Thermospheric composition ratios for major constituents, O and N-2, temperatures near 160 km, and exospheric temperatures are retrieved from the daytime observations. Molecular oxygen (O-2) densities are measured using stellar occultations. At night, emission from radiative recombination in the ionosphericFregion is used to quantify ionospheric density variations in the equatorial ionization anomaly (EIA). Regions of depletedFregion electron density are frequently evident, even during the current solar minimum. These depletions are caused by the "plasma fountain effect" and are associated with the instabilities, scintillations, or "spreadF" seen in other types of observations, and GOLD makes unique observations for their study. Plain Language Summary The NASA Global-scale Observations of the Limb and Disk (GOLD) mission has flown a dual-channel, ultraviolet-imaging spectrograph on SES-14, a communications satellite in geostationary orbit at 47.5 degrees W longitude. That instrument observes the Earth's far ultraviolet (FUV) airglow at similar to 134-162 nm. The observations performed include images of the Earth's sunlit and nightside disk, limb scans, and stellar occultations, from 6:10 to 00:40 universal time each day. Initial analyses reveal interesting and unexpected results as well as the potential for further studies of the Earth's thermosphere-ionosphere system and its responses to solar-geomagnetic forcing and atmospheric dynamics. Thermospheric temperatures and composition ratios for major constituents, O and N-2, near 160-km altitude and exospheric temperatures are retrieved from the daytime observations. Molecular oxygen (O-2) densities are measured using stellar occultations. At night, emission from radiative recombination in the ionospheric F region is used to quantify ionospheric density variations in the equatorial ionization anomaly (EIA). Regions of depleted F region electron density are frequently evident in the EIA, even during the current solar minimum.
- Large ice particles associated with small ice water content observed by AIM CIPS imagery of polar mesospheric clouds: Evidence for microphysical coupling with small-scale dynamicsRusch, D. W.; Thomas, G.; Merkel, A.; Olivero, J.; Chandran, A.; Lumpe, J. D.; Carstans, J.; Randall, C.; Bailey, S.; Russell, James M. III (2017-09)Observations by the Cloud Imaging and Particle Size (CIPS) instrument on the Aeronomy of Ice in the Mesosphere (AIM) satellite have demonstrated the existence of Polar Mesospheric Cloud (PMC) regions populated by particles whose mean sizes range between 60 and 100 nm (radii of equivalent volume spheres). It is known from numerous satellite experiments that typical mean PMC particle sizes are of the order of 40-50 nm. Determination of particle size by CIPS is accomplished by measuring the scattering of solar radiation at various scattering angles at a spatial resolution of 25 km(2). In this size range we find a robust anti-correlation between mean particle size and albedo. These very-large particle-low-ice (VLP-LI) clouds occur over spatially coherent areas. The surprising result is that VLP-LI are frequently present either in the troughs of gravity wave-like features or at the edges of PMC voids. We postulate that an association with gravity waves exists in the low-temperature summertime mesopause region, and illustrate the mechanism by a gravity wave simulation through use of the 2D Community Aerosol and Radiation Model for Atmospheres (CARMA). The model results are consistent with a VLP-LI population in the cold troughs of monochromatic gravity waves. In addition, we find such events in Whole Earth Community Climate Model/CARMA simulations, suggesting the possible importance of sporadic downward winds in heating the upper cloud regions. This newly-discovered association enhances our understanding of the interaction of ice microphysics with dynamical processes in the upper mesosphere. Published by Elsevier Ltd.