Search results for "Planetary Science"

Iron mineralogy and aqueous alteration from Husband Hill through Home Plate at Gusev Crater, Mars: Results from the Mössbauer instrument on the Spiri…

2008

[1] Spirit's Mossbauer (MB) instrument determined the Fe mineralogy and oxidation state of 71 rocks and 43 soils during its exploration of the Gusev plains and the Columbia Hills (West Spur, Husband Hill, Haskin Ridge, northern Inner Basin, and Home Plate) on Mars. The plains are predominantly float rocks and soil derived from olivine basalts. Outcrops at West Spur and on Husband Hill have experienced pervasive aqueous alteration as indicated by the presence of goethite. Olivine-rich outcrops in a possible mafic/ultramafic horizon are present on Haskin Ridge. Relatively unaltered basalt and olivine basalt float rocks occur at isolated locations throughout the Columbia Hills. Basalt and oliv…

Characterization and petrologic interpretation of olivine-rich basalts at Gusev Crater, Mars

2006

Rocks on the floor of Gusev crater are basalts of uniform composition and mineralogy. Olivine, the only mineral to have been identified or inferred from data by all instruments on the Spirit rover, is especially abundant in these rocks. These picritic basalts are similar in many respects to certain Martian meteorites (olivine-phyric shergottites). The olivine megacrysts in both have intermediate compositions, with modal abundances ranging up to 20-30%. Associated minerals in both include low-calcium and high-calcium pyroxenes, plagioclase of intermediate composition, iron-titanium-chromium oxides, and phosphate. These rocks also share minor element trends, reflected in their nickel-magnesiu…

Transmediterranean flights, in the edge of two centuries

2004

Abstract Transmediterranean flights take place at 40 km altitude and approximately 38°N latitude. Sixty six successful trans-mediterranean crossings have been performed in the period 1977–2002. A summary of system requirements, that would assure state-of-the-art stratospheric balloon flights is presented. Details of the 2002 campaign, along with a historical review of the flights corresponding to the Nineties, 2000 and 2001, are presented.

Search for Microphysical Signatures of Stochastic Condensation in Marine Boundary Layer Clouds Using Airborne Digital Holography

2019

Thermal inertia mapping from NOAA-AVHRR data

1998

Abstract This paper presents a method to retrieve thermal inertia from NOAA-AVHRR data. The method, based on Xue and Cracknell's model (1992), involves using the phase angle information of the diurnal surface temperature change. The method needs three different NOAA overpasses of the same area throughout a single diurnal cycle. To apply this method we present a methodology that takes into account satellite calibrations, viewing geometry and correction of atmospheric effects. The advantage is that it does not need other data than the ones supplied by the satellite. Finally, we present the preliminary results obtained using the proposed method and the methodology for AVHRR data over the Iberi…

Effect of Unidirectional Vertical Wind Shear on Tropical Cyclone Intensity Change—Lower‐Layer Shear Versus Upper‐Layer Shear

2019

Crop type discrimination using Geo-Stat Endmember extraction and machine learning algorithms

2022

Observation of Terrestrial Gamma-Ray Flashes at Mid Latitude

2021

We present a sample of Terrestrial Gamma-ray Flashes (TGFs) observed at mid latitudes by the Atmosphere Space Interaction Monitor (ASIM). The events were detected between June 2018 and August 2020 in the latitude bands between 35° and 51° in both hemispheres, which we hereafter refer to as “mid latitudes.” The sample includes the first observations above urn:x-wiley:2169897X:media:jgrd57293:jgrd57293-math-0001 and consists of 14 events clustered in four geographical regions: north-west Atlantic and eastern USA; Mediterranean Sea; the ocean around South Africa; and north-eastern China and Siberia. We examine the characteristics of each event, both standalone and in the context of the global …

Mössbauer mineralogy of rock, soil, and dust at Gusev crater, Mars: Spirit's journey through weakly altered olivine basalt on the plains and pervasiv…

2006

The Moessbauer spectrometer on Spirit measured the oxidation state of Fe, identified Fe-bearing phases, and measured relative abundances of Fe among those phases for surface materials on the plains and in the Columbia Hills of Gusev crater. Eight Fe-bearing phases were identified: olivine, pyroxene, ilmenite, magnetite, nanophase ferric oxide (npOx), hematite, goethite, and a Fe(3+)-sulfate. Adirondack basaltic rocks on the plains are nearly unaltered (Fe(3+)/Fe(sub T) Px), and minor npOx and magnetite. Columbia Hills basaltic rocks are nearly unaltered (Peace and Backstay), moderately altered (WoolyPatch, Wishstone, and Keystone), and pervasively altered (e.g., Clovis, Uchben, Watchtower, …

Radio emissions from double RHESSI TGFs

2016

Abstract A detailed analysis of Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) terrestrial gamma ray flashes (TGFs) is performed in association with World Wide Lightning Location Network (WWLLN) sources and very low frequency (VLF) sferics recorded at Duke University. RHESSI clock offset is evaluated and found to experience changes on the 5 August 2005 and 21 October 2013, based on the analysis of TGF‐WWLLN matches. The clock offsets were found for all three periods of observations with standard deviations less than 100 μs. This result opens the possibility for the precise comparative analyses of RHESSI TGFs with the other types of data (WWLLN, radio measurements, etc.) In ca…