Ninth International Conference on Permafrost ... - IARC Research

Soil Thermal and UV Radiation Monitoring on a Maritime Antarctic PermafrostArea by Means of REMS (Rover Environmental Monitoring Station-Mars ScienceLaboratory) SensorsIntroductionM. RamosDepartment of Physics, University of Alcalá, SpainJ. Gómez, E. Sebastian, J. Martín, C. ArmiensAstrobiological Center (INTA-CSIC), SpainJ.J. BlancoDepartment of Physics, University of Alcalá, SpainM.A. de PabloDepartment of Geology, University of Alcalá, SpainD. ToméDepartment of Physics, University of Alcalá, SpainThe present climatic characteristics of Mars induce theextensive presence of permafrost areas in this lonely planet(Carr 2006). Therefore, environmental parameters thatare included in Martian rover missions are the focus formonitoring thermal characteristics and soil surface evolutionin order to understand the active layer thickness and theenergy balance between the soil and the atmosphere.On the other hand, the intensity of the incoming UVradiation on the soil level is a key parameter of Marshabitability. Nevertheless, Mars conditions are quitedifferent to those observed on the Earth’s surface. On Earth,a deep ozone absorption band centered at 2550Ǻ preventsmost of the UV radiation from reaching the surface, whereason Mars, at least in low latitudes and in summer at highlatitudes, the full solar flux at wavelengths greater than1900Ǻ falls unattenuated onto the surface.The REMS (Rover Environmental Monitoring Station)is an environmental station designed by the Centro deAstrobiología (Spain) with the collaboration of nationaland international partners (CRISA/EADS, UPC and FMI),which is part of the payload of the MSL (Mars ScienceLaboratory) NASA mission to Mars (http://mars.jpl.nasa.gov/msl/overview/).This mission is expected to be launched in the final monthsof 2009, and mainly consists of a rover with a complete set ofscientific instruments; the rover will carry the biggest, mostadvanced suite of instruments for scientific studies ever sentto the Martian surface.Five sensors compose the REMS instrument: ground (GT-REMS) and air temperatures, wind speed and direction,pressure, humidity and ultraviolet radiation (UV-REMS).It also includes all the electronics and software required bysensor read out, signal conditioning and data transmissionto the rover. Wind vector, air temperature, and humidityand ground temperature sensors are located in small boomswhich are attached to the rover mast, while the ultravioletsensor is on the rover deck and pressure inside the rover bodyand connected with external ambient by a small opening (seeFig. 1).Figure 1. Mars Science Laboratory rover (MSL).MSL is the third rover generation sent to Mars and is thefirst time that a rover is equipped with an environmentalstation to characterize the local micrometeorology and itseffect on soil surface, as well the first time that ultravioletradiation at surface level will be recorded.Antarctic field testIn the 2007–08 Spanish Antarctic program, our scientificteam has included a field test related to the REMS sensor andits behavior on permafrost areas in the surroundings of theSpanish Antarctic Stations (SAS) that are built on Livingstonand Deception Islands (Maritime Antarctica).Livingston and Deception Islands are located in the sub-Antarctic South Shetland Archipelago at (62°39′S; 60°21′Wand 62°43′S, 60°57′W). The climate at sea level is coldoceanic, with frequent summer rainfall in low areas and amoderate annual temperature range. The climate reflectsthe strong influence of the circum-Antarctic low-pressuresystem (King et al. 2003).Data from different stations on King George Island (SouthShetland Archipelago) show the mean annual air temperature(MAAT) to be approximately -1.6°C near sea level and theannual precipitation to be about 500 mm.Permafrost in the South Shetland Islands is widespread251