The seasonal polar caps of Mars consist of CO2 that condenses from the atmosphere to form surface ice at high latitudes following the autumnal equinox in both hemispheres. The seasonal caps are prominent features of Mars, first viewed by Herschel in 1784. They extend as far as 40ºS in the southern hemisphere and 55ºN in the northern hemisphere. Approximately 25% of the martian atmosphere is cycled annually into and out of the seasonal caps. Consequently, the seasonal CO2 cycle plays a primary role in general circulation. Questions about the seasonal caps that remain unresolved concern local cap properties (column abundance, volumetric density, geometric thickness, albedo, and emissivity), energy balance terms, and CO2 condensation mechanisms. The rate of seasonal deposition and sublimation of CO2 ice is determined by the local energy balance, which depends on insolation, atmospheric properties (for example, dust optical depth), emissivity and albedo of the surface, advection of energy by the atmosphere, and energy storage within the regolith.
Since 1997, five spacecraft have observed Mars polar processes, resulting in an unprecedented amount of data at spatial and spectral resolutions and ranges not available from prior missions in the 1960s and 1970s. These datasets provide a view of the seasonal caps in five dimensions: three spatial, one temporal, and one spectral (compositional). The vast amount of new data and the complex nature of the Mars polar processes necessitate the bringing together of Mars polar scientists from around the world into a small group environment where the data, models, and emerging theories and understandings can be discussed.
The Third International Workshop on Mars Polar Energy Balance and the CO2 Cycle will consist of 30-minute invited keynote presentations, 15-minute contributed oral presentations, time for extended discussion, and a dedicated poster session. Each oral presentation will be followed by a 15-minute discussion period, to encourage interaction among attendees by providing a generous amount of time for questions, clarification, and suggestions. On Wednesday, July 22, there will be a one-day field trip to glaciers at Mount Rainier National Park. The field trip will be led by researchers active in the area and will be an integral part of the workshop.
This workshop will bring together approximately 35–50 scientists from the international community to discuss all aspects of the polar energy balance and how this affects the CO2 cycle. A small group setting will facilitate intensive discussion of problems and issues in an attempt to identify the most promising approaches to understanding these polar systems and to develop a collaborative interdisciplinary research agenda.
