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| 2. |
- Daniau, A. -L, et al.
(författare)
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predictability of biomass burning in response to climate changes
- 2012
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Ingår i: Global Biogeochemical Cycles. - 0886-6236 .- 1944-9224. ; 26, s. GB4007-
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Tidskriftsartikel (refereegranskat)abstract
- Climate is an important control on biomass burning, but the sensitivity of fire to changes in temperature and moisture balance has not been quantified. We analyze sedimentary charcoal records to show that the changes in fire regime over the past 21,000 yrs are predictable from changes in regional climates. Analyses of paleo-fire data show that fire increases monotonically with changes in temperature and peaks at intermediate moisture levels, and that temperature is quantitatively the most important driver of changes in biomass burning over the past 21,000 yrs. Given that a similar relationship between climate drivers and fire emerges from analyses of the interannual variability in biomass burning shown by remote-sensing observations of month-by-month burnt area between 1996 and 2008, our results signal a serious cause for concern in the face of continuing global warming.
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| 3. |
- Forrest, ARR, et al.
(författare)
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A promoter-level mammalian expression atlas
- 2014
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 507:7493, s. 462-
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Tidskriftsartikel (refereegranskat)
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| 4. |
- Gómez-Elvira, J., et al.
(författare)
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REMS : The environmental sensor suite for the Mars Science Laboratory rover
- 2012
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Ingår i: Space Science Reviews. - : Springer Science and Business Media LLC. - 0038-6308 .- 1572-9672. ; 170:1-4, s. 583-640
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Tidskriftsartikel (refereegranskat)abstract
- The Rover Environmental Monitoring Station (REMS) will investigate environmental factors directly tied to current habitability at the Martian surface during the Mars Science Laboratory (MSL) mission. Three major habitability factors are addressed by REMS: the thermal environment, ultraviolet irradiation, and water cycling. The thermal environment is determined by a mixture of processes, chief amongst these being the meteorological. Accordingly, the REMS sensors have been designed to record air and ground temperatures, pressure, relative humidity, wind speed in the horizontal and vertical directions, as well as ultraviolet radiation in different bands. These sensors are distributed over the rover in four places: two booms located on the MSL Remote Sensing Mast, the ultraviolet sensor on the rover deck, and the pressure sensor inside the rover body. Typical daily REMS observations will collect 180 minutes of data from all sensors simultaneously (arranged in 5 minute hourly samples plus 60 additional minutes taken at times to be decided during the course of the mission). REMS will add significantly to the environmental record collected by prior missions through the range of simultaneous observations including water vapor; the ability to take measurements routinely through the night; the intended minimum of one Martian year of observations; and the first measurement of surface UV irradiation. In this paper, we describe the scientific potential of REMS measurements and describe in detail the sensors that constitute REMS and the calibration procedures. © 2012 Springer Science+Business Media B.V.
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| 10. |
- Arvidson, R. E., et al.
(författare)
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Opportunity Mars Rover mission : Overview and selected results from Purgatory ripple to traverses to Endeavour crater
- 2011
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Ingår i: Journal of Geophysical Research. - Hoboken : Wiley-Blackwell. - 0148-0227 .- 2156-2202. ; 116, s. E00F15-
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Tidskriftsartikel (refereegranskat)abstract
- Opportunity has been traversing the Meridiani plains since 25 January 2004 (sol 1), acquiring numerous observations of the atmosphere, soils, and rocks. This paper provides an overview of key discoveries between sols 511 and 2300, complementing earlier papers covering results from the initial phases of the mission. Key new results include (1) atmospheric argon measurements that demonstrate the importance of atmospheric transport to and from the winter carbon dioxide polar ice caps; (2) observations showing that aeolian ripples covering the plains were generated by easterly winds during an epoch with enhanced Hadley cell circulation; (3) the discovery and characterization of cobbles and boulders that include iron and stony-iron meteorites and Martian impact ejecta; (4) measurements of wall rock strata within Erebus and Victoria craters that provide compelling evidence of formation by aeolian sand deposition, with local reworking within ephemeral lakes; (5) determination that the stratigraphy exposed in the walls of Victoria and Endurance craters show an enrichment of chlorine and depletion of magnesium and sulfur with increasing depth. This result implies that regional-scale aqueous alteration took place before formation of these craters. Most recently, Opportunity has been traversing toward the ancient Endeavour crater. Orbital data show that clay minerals are exposed on its rim. Hydrated sulfate minerals are exposed in plains rocks adjacent to the rim, unlike the surfaces of plains outcrops observed thus far by Opportunity. With continued mechanical health, Opportunity will reach terrains on and around Endeavour's rim that will be markedly different from anything examined to date. Copyright 2011 by the American Geophysical Union.
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| 11. |
- Conrad, P.G., et al.
(författare)
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Environmental Dynamics and the Habitability Potential at Gale Crater, Mars
- 2013
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Konferensbidrag (refereegranskat)abstract
- The assessment of environmental habitability potential involves measurement of the chemical and physical attributes of the system as well as their dynamic interplay. The environmental dynamics describe the availability of both energy sources and raw materials for meeting the requirements of organisms and for altering the environment. Energetic exchange can also determine the preservation potential for organic materials in the rock record. During its first year at Gale Crater, the Mars Science Laboratory payload has directly measured the chemistry and physical attributes, e.g., temperature, humidity, radiation, pressure, etc. of the martian atmosphere. Curiosity has also acquired chemical and mineralogical data, both from a wind drift deposit of fines and from two examples of a sedimentary rock formation in a region of Gale Crater called Yellowknife Bay, some 445 meters to the east of Bradbury Landing, where Curiosity initially touched down. These data enabled inferences to be made regarding depositional environment and past habitability potential at Gale Crater. The rock chemistry data reveal signs of aqueous interaction i.e., H2O, OH and H2 and sufficient elemental basis (C, H, O, S and possibly N) for plausible nutrient supply, should Mars have ever had autotrophic prokaryotes to exploit it, and a range of redox conditions tolerable to Earth microbes is indicated by the presence of clay minerals. Curiosity’s observations of the chemical, physical and geologic features of Yellowknife Bay point to a formerly habitable environment.
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| 12. |
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| 13. |
- Harri, A.-M., et al.
(författare)
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Mars Science Laboratory relative humidity observations : Initial results
- 2014
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Ingår i: Journal of Geophysical Research - Planets. - 2169-9097 .- 2169-9100. ; 119:9, s. 2132-2147
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Tidskriftsartikel (refereegranskat)abstract
- The Mars Science Laboratory (MSL) made a successful landing at Gale crater early August 2012. MSL has an environmental instrument package called the Rover Environmental Monitoring Station (REMS) as a part of its scientific payload. REMS comprises instrumentation for the observation of atmospheric pressure, temperature of the air, ground temperature, wind speed and direction, relative humidity (REMS-H), and UV measurements. We concentrate on describing the REMS-H measurement performance and initial observations during the first 100 MSL sols as well as constraining the REMS-H results by comparing them with earlier observations and modeling results. The REMS-H device is based on polymeric capacitive humidity sensors developed by Vaisala Inc., and it makes use of transducer electronics section placed in the vicinity of the three humidity sensor heads. The humidity device is mounted on the REMS boom providing ventilation with the ambient atmosphere through a filter protecting the device from airborne dust. The final relative humidity results appear to be convincing and are aligned with earlier indirect observations of the total atmospheric precipitable water content. The water mixing ratio in the atmospheric surface layer appears to vary between 30 and 75 ppm. When assuming uniform mixing, the precipitable water content of the atmosphere is ranging from a few to six precipitable micrometers.
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| 14. |
- Harri, A.-M., et al.
(författare)
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Pressure observations by the Curiosity rover : Initial results
- 2014
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Ingår i: Journal of Geophysical Research - Planets. - : John Wiley & Sons. - 2169-9097 .- 2169-9100. ; 119:1, s. 82-92
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Tidskriftsartikel (refereegranskat)abstract
- REMS-P, the pressure measurement subsystem of the Mars Science Laboratory (MSL) Rover Environmental Measurement Station (REMS), is performing accurate observations of the Martian atmospheric surface pressure. It has demonstrated high data quality and good temporal coverage, carrying out the first in situ pressure observations in the Martian equatorial regions. We describe the REMS-P initial results by MSL mission sol 100 including the instrument performance and data quality and illustrate some initial interpretations of the observed features. The observations show both expected and new phenomena at various spatial and temporal scales, e.g., the gradually increasing pressure due to the advancing Martian season signals from the diurnal tides as well as various local atmospheric phenomena and thermal vortices. Among the unexpected new phenomena discovered in the pressure data are a small regular pressure drop at every sol and pressure oscillations occurring in the early evening. We look forward to continued high-quality observations by REMS-P, extending the data set to reveal characteristics of seasonal variations and improved insights into regional and local phenomena. Key Points The performance and data quality of the REMS / MSL pressure observations. MSL pressure observations exhibit local phenomena of the Gale crater area. Small pressure oscillations possibly linked to gravity waves. ©2013. American Geophysical Union. All Rights Reserved.
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| 16. |
- Reeves, Jessica M., et al.
(författare)
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Palaeoenvironmental change in tropical Australasia over the last 30,000 years - a synthesis by the OZ-INTIMATE group
- 2013
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Ingår i: Quaternary Science Reviews. - : Elsevier BV. - 0277-3791 .- 1873-457X. ; 74, s. 97-114
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Tidskriftsartikel (refereegranskat)abstract
- The tropics are the major source of heat and moisture for the Australasian region. Determining the tropics' response over time to changes in climate forcing mechanisms, such as summer insolation, and the effects of relative sea level on exposed continental shelves during the Last Glacial period, is an ongoing process of re-evaluation. We present a synthesis of climate proxy data from tropical Australasia spanning the last 30,000 years that incorporates deep sea core, coral, speleothem, pollen, charcoal and terrestrial sedimentary records. Today, seasonal variability is governed largely by the annual migration of the inter-tropical convergence zone (ITCZ), influencing this region most strongly during the austral summer. However, the position of the ITCZ has varied through time. Towards the end of Marine Isotope Stage (MIS) 3, conditions were far wetter throughout the region, becoming drier first in the south. Universally cooler land and sea-surface temperature (SST) were characteristic of the Last Glacial Maximum, with drier conditions than previously, although episodic wet periods are noted in the fluvial records of northern Australia. The deglacial period saw warming first in the Coral Sea and then the Indonesian seas, with a pause in this trend around the time of the Antarctic Cold Reversal (c. 14.5 ka), coincident with the flooding of the Sunda Shelf. Wetter conditions occurred first in Indonesia around 17 ka and northern Australia after 14 ka. The early Holocene saw a peak in marine SST to the northwest and northeast of Australia. Modern vegetation was first established on Indonesia, then progressively south and eastward to NE Australia. Flores and the Atherton Tablelands show a dry period around 11.6 ka, steadily becoming wetter through the early Holocene. The mid-late Holocene was punctuated by millennial-scale variability, associated with the El Nino-Southern Oscillation; this is evident in the marine, coral, speleothem and pollen records of the region.
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