Orbital Obliquity and Solar Insolation Linked to Mars Polar Layersby Tommy on 6/09/2012
Reading the climate record of the Martian polar layered deposits, C.S. Hvidberg, K.E. Fishbaugh, M. Winstrup, A. Svensson, S. Byrne, K. Herkenhof, Icarus, In Press.
The Martian polar regions have layered deposits of ice and dust. The stratigraphy of these deposits is exposed within scarps and trough walls and is thought to have formed due to climate variations in the past. Insolation has varied significantly over time and caused dramatic changes in climate, but it has remained unclear whether insolation variations could be linked to the stratigraphic record. We present a model of layer formation based on physical processes that expresses polar deposition rates of ice and dust in terms of insolation. In this model, layer formation is controlled by the insolation record, and dust-rich layers form by two mechanisms: 1) increased summer sublimation during high obliquity, and 2) variations in the polar deposition of dust modulated by obliquity variations. The model is simple, yet physically plausible, and allows for investigations of the climate control of the polar layered deposits (PLD). We compare the model to a stratigraphic column obtained from the north polar layered deposits (NPLD) and show that the model can be tuned to reproduce complex layer sequences.