WORKSHOP DESCRIPTION

Background

Most of the attention to past climates on Mars has focused on conditions very early in the planet’s history where the valley networks, degraded terrains, and weathering products of late Noachian surfaces indicate at least episodically warm and wet environments. Much research has been carried out on this topic, and there have been numerous workshops and special conference sessions dedicated to understanding the climate of early Mars. Yet, no widely accepted solution has emerged. Whether the observed fluvial features were created by a thicker long-lived greenhouse atmosphere, an impact-generated transient climate, or a cooler environment in ways we haven’t yet discerned, are still being debated. This is partly the result of a poorly constrained observational database. The geological record is not well preserved, and climate models are not well constrained.

This is not the case for more recent climate change on Mars. There is mounting evidence that the climate system has changed considerably in the past 20 My. On this time-scale, the geological record is much better preserved. Polar layered terrains, remnant tropical mountain glaciers, and youthful ground ice all point to climate change associated with changes in the planet’s orbit parameters; changes that we can now accurately calculate. We also know the present mass and composition of the atmosphere and cap system, and we have a handle on how much CO2 might be stored in the subsurface in an exchangeable form, i.e., as buried ice or regolith adsorbate. Thus, for recent Mars we have much better constraints on the principle forcing functions: the mass and composition of the atmosphere and the latitudinal variation in solar insolation with time.

Purpose

The purpose of this workshop is to bring together the geological and climate communities to assess the evidence for and mechanisms behind recent climate change on Mars (roughly the past 20 My). The goal is to constrain the magnitude, timing, nature, and duration of these changes and relate those findings to possible forcing mechanisms. Thus, we seek observers to provide evidence for recent climate change and offer their interpretation on how it might have occurred. We also seek climate modelers to discuss how the climate system could change and what mechanisms were involved. The specific questions of interest are therefore:

  • What is the geological evidence for recent climate change on Mars?
  • What constraints does that evidence provide on the magnitude, timing, nature, and duration of climate change?
  • What is the nature and distribution of exchangeable surface and subsurface reservoirs of water and CO2 and how have they changed during the past 20My?
  • How does the climate system respond to changing orbit parameters? Specifically, what changes to the general circulation and dust, water, and CO2 cycles result and what are the implications for the mobilization and distribution of dust and volatiles around the planet?
Format

The workshop format will emphasize discussion. The plan is to develop a program that consists of 20 minute invited talks, 10 minute contributed talks, and about 30 minutes left for discussion at the end of each session. Depending on the level of interest, poster sessions may be necessary in order to preserve discussion time.

Workshop Sponsor

The NASA Ames Mars Climate Modeling Group is sponsoring the workshop.

Registration Fees

As this is a US government sponsored event, no registration fees will be charged.

Output

The final workshop abstracts will be published as a NASA Conference Proceedings.