PhD from The University of Arizona
Applied Math (Planetary Science)
firstname . lastname @jpl.nasa.gov
My doctoral advisors were Dr. Karl Glasner (Applied Math) and Dr. Shane Byrne (Planetary Science). I graduated from UA in 2010 (Dissertation: Modeling Aeolian Dune and Dune Field Evolution - .pdf) and was a NASA Postdoc (NPP) modeling inflationary flows under the advise of Sue Smrekar at the Jet Propulsion Laboratory. In 2013, I was hired on as a Systems Engineer at JPL, supporting the Mars Reconnaissance Orbiter (MRO) and the NASA Mars Program Office, who manage the logistics of the Mars Exploration Program Analysis Group (MEPAG).
For my full CV (.pdf), click here.
My JPL profile can be found here.
PhD, Applied Mathematics, Summer 2010, University of Arizona
MS, Applied Mathematics, December 2005, University of Arizona
MS, Space Studies, July 2004, International Space University (Strasbourg, France)
BS (with honors), Mathematics, June 2003, California Institute of Technology
Diniega, S., C.J. Hansen, C.H. Hugenholtz, C.M. Dundas (submitted). A new dry hypothesis for the formation of Martian linear gullies. Icarus.
Diniega, S., S.E. Smrekar, S. Anderson, E. Stofan (in revision). The influence of temperature-dependent viscosity on lava flow dynamics. JGR.
Diniega, S. and 17 co-authors (2013). Mission to the Trojan Asteroids: lessons learned during a JPL Planetary Science Summer School mission design exercise. Planet. Space Sci. 76, 68-82. doi:10.1016/j.pss.2012.11.011i ArXiv copy
Dundas C.M., S. Diniega, C.J. Hansen, S. Byrne, A.S. McEwen (2012), HiRISE observations of seasonal activity and morphological changes in Martian gullies. Icarus 220, 124-143. doi:10.1016/j.icarus.2012.04.005
Bridges, N.T., M.C. Bourke, P.E. Geissler, M.E. Banks, C. Colon, S. Diniega, M.P. Golombek, C.J. Hansen, S. Mattson, A.S. McEwen, M.T. Mellon, N. Stantzos, B.J. Thomson (2012), Planet-wide sand motion on Mars. Geology 40, no. 1: 31-34. doi:10.1130/G32373.1.
Hansen, C. J., M. Bourke, N.T. Bridges, S. Byrne, C. Colon, S. Diniega, C. Dundas, K. Herkenhoff, A. McEwen, M. Mellon, G. Portyankina, N. Thomas (2011), Seasonal erosion and restoration of Mars northern polar dunes. Science 331, no. 6017: 575-578. doi: 10.1126/science.1197636 SOM
Diniega, S., S. Byrne, N.T. Bridges, C.M. Dundas, A.S. McEwen (2010) "Seasonality of present-day Martian dune-gully activity." Geology 38, no. 11, 1047-1050. doi:10.1130/G31287.1
This study was featured in a Science Meeting Brief for the 2009 AGU Fall meeting. It also is the focus of a JPL and UA press releases and has been added to NASA's photo journal.
Dundas, C.M., A.S. McEwen, S. Diniega, S. Byrne, S. Martinez-Alonso (2010), "New and recent gully activity on Mars as seen by HiRISE." Geophysical Research Letters 37, L07202. doi:10.1029/2009GL041351
Diniega, S., K. Glasner, S. Byrne. (2010) "Long scale evolution of aeolian sand dune fields: influences of initial conditions and dune collisions." Geomorphology (special edition: Planetary Dunes) 121, 55-68. doi:10.1016/j.geomorph.2009.02.010
Pelletier, J.D., T. Engelder, D. Comeau, A. Hudson, M. Leclerc, A. Youberg, S. Diniega. (2009) "Tectonic and structural control of fluvial channel morphology in metamorphic core complexes: The example of the Catalina-Rincon core complex, Arizona" Geosphere 5: 385-407. doi:10.1130/GES00221.1
Hey, R.N., F. Martinez, S. Diniega, D.F. Naar, J. Francheteau, Pito93 Scientific Team. (2002) "Preliminary attempt to characterize the rotation of seafloor in the Pito Deep area of the Easter Microplate using a submersible magnetometer." Marine Geophysical Research 23: 1-12. doi:10.1023/A:1021257915420
American Geophysical Union
Society for Industrial and Applied Mathematics
My research interests lie in the development and application of models of landform evolution. The goal of this research is to determine qualitative and quantitative connections between environmental conditions and landform morphology, which is needed to make predictions about future landform evolution (using current or extrapolated environmental conditions) or the derivation of past environmental conditions (based on current morphology). The latter point is my primary focus, as I am especially interested in interpreting surface and environment history from landforms seen in remotely sensed images of planetary surfaces.
As a mathematician working on geomorphological questions, I have found that an interdisciplinary approach provides me with a unique and useful perspective in identification of key environmental parameters and geological processes. The use of simple mathematical models aids in decoupling complex geologic behavior. Additionally, simulation and/or analysis of model equations helps in the identification and quantification of subtle relationships between processes and/or environmental parameters. However, these models require validation and calibration, which can only be done through observations and geological studies. Such studies are vitally important in qualitative identification of possible relationships, which can validate and guide modeling efforts.
My dissertation research was on aeolian sand dune evolution. In particular, I attempted to isolate and quantify influencing or limiting environmental factors that create apparent characteristic dune sizes and spatial distributions, as observed in dune fields on the Earth and Mars. To evaluate dune evolution, I used a continuum two-layer model which (1) estimates the sand flux amount based on the wind shear stress over the topography, and (2) relates this to changes in dune topography via mass conservation. To study dune field evolution, I used the dune evolution model to define simple dune migration and interaction rules. These rules were used to dictate the behavior of dunes within a field, which were approximated as discrete particles. Although very simplistic, this model yields a preliminary, but detailed, ability to predict the formation of a patterned dune field through dune collisions (Diniega et al. 2009).
At JPL, I also study lava flow dynamics. As lava viscosity can increase 1-2 orders of magnitude due to small decreases in temperature, an initially uniform-velocity flow can spontaneously focus into low-viscosity/high-temperature "fingers" due to small temperature variations. I am quantitatively investigating the onset and evolution of such fingers within a uniform lava sheet flow due to an influx of lava with slightly-variable temperature. Through the use of numerical simulation and steady-state analysis of model equations, I look for solutions that would provide pahoehoe and other lava flows with a natural mechanism for the formation of lava channels/tubes within a sheet lava flow. This work has application to both Earth and planetary volcanology studies as pahoehoe lava flows dominate terrestrial basaltic lavas and the eruption/emplacement mechanics that yield long lava flows on the Earth and other planetary bodies (e.g., Mars) are not yet well understood.
Finally, I am part of a group that is monitoring gully activity on Mars and trying to understand the present-day formation and evolution mechanisms of these features. Our work strongly suggests a seasonal (winter/early spring), dry process, most likely related to CO2 frost sublimation. An interesting video (which I narrated) explaining some of the changes seen on the northern dunes can be found here.
I was supported through the latter half of my PhD program by the NASA Jenkins Pre-doctoral Fellowship Program.