A current hypothesis for the early climate of mars postulates that the southern highlands were covered by a cold-locked ICE sheet (e.g., recent works by head, fastook, wadsworth and others). This is…

This federal grant award to the University of Colorado, Boulder, aims to help assess the climate conditions on Mars during the late Noachian period by comparing the geomorphic properties of valley networks to those produced from landscape evolution models. The $500,667.69 award will fund research to characterize Martian valley networks, run numerical models for both warm-wet and cold-icy climate hypotheses, and compare the observed and modeled valley network morphologies. This effort directly contributes to NASA's goals of understanding Mars' ancient climate and geologic evolution. The University of Colorado will leverage its expertise in planetary science and landscape modeling to deliver this research, which has implications for assessing Mars' astrobiological potential. No set-aside designation was used for this grant award.

A current hypothesis for the early climate of mars postulates that the southern highlands were covered by a cold-locked ICE sheet (e.g., recent works by head, fastook, wadsworth and others). This is in contrast to the hypothesis that early mars was warm and wet and maintained favorable climatic conditions for an active hydrological cycle and even a vast northern ocean. Contradicting results from climate modeling and observations of the geologic record on mars must be reconciled in order to gain a more complete understanding of the processes that governed the evolution of the surface of mars and its astrobiological potential. The overarching goal of this proposed research is to help assess the climatic conditions on mars during the late noachian by comparing the geomorphic properties of valley networks to those produced from landscape evolution models. Our primary objectives for this effort are to: (1) characterize extensive valley networks on mars using several indices common in the terrestrial geomorphology community, (2) run numerical landscape evolution models forced by boundary conditions representing both the warm-wet and cold-ICY hypotheses (plus intermediate models to these end-members) to generate the same geomorphic indices, and (3) test the cold-ICY and warm-wet hypotheses by comparing observed valley network morphology with modeled results using developed metrics for comparison. To accomplish these objectives, we plan to: (1) mosaic high-resolution digital elevation models (dems) for areally extensive martian valley networks, (2) analyze dems with the topotoolbox plug in for matlab using channel-long profiles, slope-area plots, and river cross profiles, (3) model end-member and intermediate scenarios for an ICY-cold and warm-wet environment in vetted landscape evolution models (i.e., landlab and marsim) with existing and also modified components for channel incision, disturbancedriven diffusion, precipitation, and ICE sheet melting, and (4) compare the empirical results from the martian surface with predicted morphologies produced from the modeling scenarios. We anticipate that the results of this research will provide new insights into the conditions of the martian climate during the late noachian. Specifically, this research will add novel (for mars) quantitative geomorphic tests to assess whether the ancient climate was warm and wet, cold and ICY, or somewhere in between. If cold-ICY highlands climate modeling predictions are correct, the observed morphological characteristics of valley networks should be validated by modeling efforts in those landscape evolution modeling scenarios. If the geomorphic features and indices are only consistent with warm-wet landscape modeling, then new constraints must be adapted for future climate models. This proposed research directly contributes to NASA's mepag's goal II, objective c, "understand the processes and history of climate on mars' by "characterizing mars' ancient climate and underlying processes" and also goal III, objective a, "understand the origin and evolution of mars as a geological system" by "documenting the geologic record preserved in the crust and interpreting the processes that have created that record." this effort will also address mdap's top level goal by enhancing the scientific return from mission data and we expect to incorporate multiple datasets from mars express, mars global surveyor, and mars reconnaissance orbiter. We will complete data analysis, theoretical work, and modeling based on the existing datasets. The valley networks are paramount to understanding of the history of water on mars and its past climate, which is essential in assessing mars' astrobiological potential.