SwePub
Tyck till om SwePub Sök här!
Sök i SwePub databas

  Extended search

Träfflista för sökning "WFRF:(Martin Javier) ;lar1:(ltu);pers:(Gõmez Elvira Javier)"

Search: WFRF:(Martin Javier) > Luleå University of Technology > Gõmez Elvira Javier

  • Result 1-10 of 19
Sort/group result
   
EnumerationReferenceCoverFind
1.
  • Gõmez-Elvira, Javier, et al. (author)
  • Curiosity's rover environmental monitoring station : Overview of the first 100 sols
  • 2014
  • In: Journal of Geophysical Research - Planets. - 2169-9097 .- 2169-9100. ; 119:7, s. 1680-1688
  • Journal article (peer-reviewed)abstract
    • In the first 100 Martian solar days (sols) of the Mars Science Laboratory mission, the Rover Environmental Monitoring Station (REMS) measured the seasonally evolving diurnal cycles of ultraviolet radiation, atmospheric pressure, air temperature, ground temperature, relative humidity, and wind within Gale Crater on Mars. As an introduction to several REMS-based articles in this issue, we provide an overview of the design and performance of the REMS sensors and discuss our approach to mitigating some of the difficulties we encountered following landing, including the loss of one of the two wind sensors. We discuss the REMS data set in the context of other Mars Science Laboratory instruments and observations and describe how an enhanced observing strategy greatly increased the amount of REMS data returned in the first 100 sols, providing complete coverage of the diurnal cycle every 4 to 6 sols. Finally, we provide a brief overview of key science results from the first 100 sols. We found Gale to be very dry, never reaching saturation relative humidities, subject to larger diurnal surface pressure variations than seen by any previous lander on Mars, air temperatures consistent with model predictions and abundant short timescale variability, and surface temperatures responsive to changes in surface properties and suggestive of subsurface layering. Key Points Introduction to the REMS results on MSL mission Overiview of the sensor information Overview of operational constraints
  •  
2.
  •  
3.
  • Hassler, Donald M., et al. (author)
  • Mars’ surface radiation environment measured with the Mars Science Laboratory’s Curiosity Rover
  • 2014
  • In: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 343:6169
  • Journal article (peer-reviewed)abstract
    • The Radiation Assessment Detector (RAD) on the Mars Science Laboratory’s Curiosity rover began making detailed measurements of the cosmic ray and energetic particle radiation environment on the surface of Mars on 7 August 2012. We report and discuss measurements of the absorbed dose and dose equivalent from galactic cosmic rays and solar energetic particles on the martian surface for ~300 days of observations during the current solar maximum. These measurements provide insight into the radiation hazards associated with a human mission to the surface of Mars and provide an anchor point with which to model the subsurface radiation environment, with implications for microbial survival times of any possible extant or past life, as well as for the preservation of potential organic biosignatures of the ancient martian environment.
  •  
4.
  • Kim, Myung-Hee Y., et al. (author)
  • Comparison of Martian surface ionizing radiation measurements from MSL-RAD with Badhwar-O'Neill 2011/HZETRN model calculations
  • 2014
  • In: Journal of Geophysical Research - Planets. - 2169-9097 .- 2169-9100. ; 119:6, s. 1311-1321
  • Journal article (peer-reviewed)abstract
    • Dose rate measurements from Mars Science Laboratory-radiation assessment detector (MSL-RAD) for 300 sols on Mars are compared to simulation results using the Badhwar-O'Neill 2011 galactic cosmic ray (GCR) environment model and the high-charge and energy transport (HZETRN) code. For the nuclear interactions of primary GCR through Mars atmosphere and Curiosity rover, the quantum multiple scattering theory of nuclear fragmentation is used. Daily atmospheric pressure is measured at Gale Crater by the MSL Rover Environmental Monitoring Station. Particles impinging on top of the Martian atmosphere reach RAD after traversing varying depths of atmosphere that depend on the slant angles, and the model accounts for shielding of the RAD “E” detector (used for dosimetry) by the rest of the instrument. Simulation of average dose rate is in good agreement with RAD measurements for the first 200 sols and reproduces the observed variation of surface dose rate with changing heliospheric conditions and atmospheric pressure. Model results agree less well between sols 200 and 300 due to subtleties in the changing heliospheric conditions. It also suggests that the average contributions of albedo particles (charge number Z < 3) from Martian regolith comprise about 10% and 42% of the average daily point dose and dose equivalent, respectively. Neutron contributions to tissue-averaged effective doses will be reduced compared to point dose equivalent estimates because a large portion of the neutron point dose is due to low-energy neutrons with energies.
  •  
5.
  • Rafkin, Scot C.R., et al. (author)
  • Diurnal variations of energetic particle radiation at the surface of Mars as observed by the Mars Science Laboratory Radiation Assessment Detector
  • 2014
  • In: Journal of Geophysical Research - Planets. - 2169-9097 .- 2169-9100. ; 119:6, s. 1345-1358
  • Journal article (peer-reviewed)abstract
    • The Radiation Assessment Detector onboard the Mars Science Laboratory rover Curiosity is detecting the energetic particle radiation at the surface of Mars. Data collected over the first 350 Martian days of the nominal surface mission show a pronounced diurnal cycle in both the total dose rate and the neutral particle count rate. The diurnal variations detected by the Radiation Assessment Detector were neither anticipated nor previously considered in the literature. These cyclic variations in dose rate and count rate are shown to be the result of changes in atmospheric column mass driven by the atmospheric thermal tide that is characterized through pressure measurements obtained by the Rover Environmental Monitoring Station, also onboard the rover. In addition to bulk changes in the radiation environment, changes in atmospheric shielding forced by the thermal tide are shown to disproportionately affect heavy ions compared to H and He nuclei.
  •  
6.
  • Hamilton, Victoria E., et al. (author)
  • Observations and preliminary science results from the first 100 sols of MSL Rover Environmental Monitoring Station ground temperature sensor measurements at Gale Crater
  • 2014
  • In: Journal of Geophysical Research - Planets. - : John Wiley & Sons. - 2169-9097 .- 2169-9100. ; 119:4, s. 745-770
  • Journal article (peer-reviewed)abstract
    • We describe preliminary results from the first 100 sols of ground temperature measurements along the Mars Science Laboratory's traverse from Bradbury Landing to Rocknest in Gale. The ground temperature data show long-term increases in mean temperature that are consistent with seasonal evolution. Deviations from expected temperature trends within the diurnal cycle are observed and may be attributed to rover and environmental effects. Fits to measured diurnal temperature amplitudes using a thermal model suggest that the observed surfaces have thermal inertias in the range of 265-375?J m-2 K-1 s-1/2, which are within the range of values determined from orbital measurements and are consistent with the inertias predicted from the observed particle sizes on the uppermost surface near the rover. Ground temperatures at Gale Crater appear to warm earlier and cool later than predicted by the model, suggesting that there are multiple unaccounted for physical conditions or processes in our models. Where the Mars Science Laboratory (MSL) descent engines removed a mobile layer of dust and fine sediments from over rockier material, the diurnal temperature profile is closer to that expected for a homogeneous surface, suggesting that the mobile materials on the uppermost surface may be partially responsible for the mismatch between observed temperatures and those predicted for materials having a single thermal inertia. Models of local stratigraphy also implicate thermophysical heterogeneity at the uppermost surface as a potential contributor to the observed diurnal temperature cycle. Key Points Diurnal ground temperatures vary with location Diurnal temperature curves are not well matched by a homogeneous thermal model GTS data are consistent with a varied stratigraphy and thermophysical properties.
  •  
7.
  •  
8.
  •  
9.
  •  
10.
  •  
Skapa referenser, mejla, bekava och länka
  • Result 1-10 of 19

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Close

Copy and save the link in order to return to this view