Simulating a Liquid Water Cycle in Early Mars Climate Scenarios

Develop and incorporate a liquid water cycle into the NASA Ames Research Center (ARC) Mars Global Climate Model (GCM)

Camilla: A Centaur reconnaissance and impact mission concept

Centaurs, minor planets with a semi-major axis between the orbits of Jupiter and Neptune (5–30 AU), are thought to be among the most diverse small bodies in the solar system. These important targets for future missions may have recently been Kuiper Belt Objects (KBOs), which are thought to be chemically and physically primitive remnants of the early solar system. While the Kuiper Belt spans distances of 30–50 AU, making direct observations difficult, Centaurs' proximity to the Earth and Sun make them more accessible targets for robotic missions. Thus, we outline a mission concept designed to reconnoiter 10199 Chariklo, the largest Centaur and smallest ringed body yet discovered. Named for a legendary Centaur tamer, the conceptual Camilla mission is designed to fit under the cost cap of the National Aeronautics and Space Administration (NASA) New Frontiers program, leveraging a conservative payload to support a foundational scientific investigation to these primitive bodies. Specifically, the single flyby encounter utilizes a combined high-resolution camera/VIS-IR mapping spectrometer, a sub-mm point spectrometer, and a UV mapping spectrometer. In addition, the mission concept utilizes a kinetic impactor, which would provide the first opportunity to sample the composition of potentially primitive subsurface material beyond Saturn, thus providing key insights into solar system origins. Such a flyby of the Chariklo system would provide a linchpin in the understanding of small body composition, evolution, and transport of materials in the solar system

High-Resolution Modeling of the Dust and Water Cycles with the NASA Ames Mars Global Climate Model

NASAs Mars Climate Modeling Center at Ames Research Center is currently undergoing an exciting period of growth in personnel, modeling capabilities, and science productivity. We are transitioning from our legacy Arakawa C-grid finite-difference dynamical core to the NOAA/GFDL cubed-sphere finite-volume dynamical core for simulating the climate of Mars in a global framework. This highly parallelized core is scalable and flexible, which allows for significant improvements in the horizontal and vertical resolutions of our simulations. We have implemented the Ames water ice cloud microphysics package described in Haberle et al. (2018) into this new dynamical core. We will present high-resolution simulations of the dust and water cycles that show that sub-degree horizontal resolution improves the agreement between the vertical distribution of dust and water ice and observations. In particular, both water ice clouds and dust are transported to higher altitudes due to stronger topographic circulations at high resolution. Preliminary results suggest that high-resolution global modeling is needed to properly capture critical features of the dust and water cycles, and thus the current Mars climate

Field Measurements of Terrestrial and Martian Dust Devils

Surface-based measurements of terrestrial and martian dust devils/convective vortices provided from mobile and stationary platforms are discussed. Imaging of terrestrial dust devils has quantified their rotational and vertical wind speeds, translation speeds, dimensions, dust load, and frequency of occurrence. Imaging of martian dust devils has provided translation speeds and constraints on dimensions, but only limited constraints on vertical motion within a vortex. The longer mission durations on Mars afforded by long operating robotic landers and rovers have provided statistical quantification of vortex occurrence (time-of-sol, and recently seasonal) that has until recently not been a primary outcome of more temporally limited terrestrial dust devil measurement campaigns. Terrestrial measurement campaigns have included a more extensive range of measured vortex parameters (pressure, wind, morphology, etc.) than have martian opportunities, with electric field and direct measure of dust abundance not yet obtained on Mars. No martian robotic mission has yet provided contemporaneous high frequency wind and pressure measurements. Comparison of measured terrestrial and martian dust devil characteristics suggests that martian dust devils are larger and possess faster maximum rotational wind speeds, that the absolute magnitude of the pressure deficit within a terrestrial dust devil is an order of magnitude greater than a martian dust devil, and that the time-of-day variation in vortex frequency is similar. Recent terrestrial investigations have demonstrated the presence of diagnostic dust devil signals within seismic and infrasound measurements; an upcoming Mars robotic mission will obtain similar measurement types

Exploring changes in dust particles size distribution on Mars during 2018 Global Dust Storm with a 3D Global Climate Model

International audienc

Resistência depois da morte: restituindo humanidade ao Homo Sacer Resistance after death: restoring humanity to Homo Sacer

Este artigo examina práticas de testemunhar e testemunho que surgiram como resposta às contínuas mortes de migrantes nos desertos do sudoeste dos Estados Unidos. Eu sugiro que estas práticas podem ser consideradas uma forma de resistência, na medida em que restituem a humanidade àqueles que morreram e, ao fazê-lo, reconhecem que nosso mundo de fronteiras contemporâneo abriga os espíritos daqueles que viajaram pelas perigosas trilhas criadas por fronteiras visíveis e invisíveis. A esperança por políticas mais humanas depende de tal tipo de reconhecimento; e mantê-los vivos na memória pública é fundamental para promover mudança. Este artigo também argumenta por uma ampla conceituação do que significa testemunhar e dar testemunho. As práticas examinadas variam desde contar estórias de migrantes, a prestar ajuda humanitária, e práticas para identificar os restos de migrantes que morreram e, assim, restituir suas identidades.<br>This paper examines practices of bearing witness and testimony that have arisen in response to the continuing migrant deaths in the southwestern deserts of the United States. I suggest that these practices can be considered a kind of resistance in that they restore the humanity to those who have perished and in doing so acknowledge that our contemporary bordered world harbors the spirits of those of have travelled he dangerous paths created by visible and invisible boundaries. The hope for more humane policies depends upon such an acknowledgement and keeping them alive in the public memory is key to promoting change. This paper also argues for a broad conceptualization of what it means to witness and provide testimony. The practices examined range from telling migrants' stories, to providing humanitarian aid, to practices of identifying the remains of migrants who have died and thus restoring their identity