THE PMIRR INSTRUMENT: SCIENTIFIC OBJECTIVES (Pressure Modulator Infrared Radiometer) General Examine general atmospheric circulation patterns and the thermal structure of the atmosphere. Circulation Understand how circulation causes atmospheric transport and climate change. Wind Derive information about atmospheric winds, especially wind shear, from global temperature observations. Dust Observe atmospheric dust to obtain a better understanding of the seasonal dust cycle, including initiation, spreading and dissipation fo planetary dust storms. Water Cycle Examine the Martian water cycle by understanding how the amount of water in the atmosphere changes with distance from the surface. Carbon Dioxide Cycle Understand the seasonal Carbon Dioxide (CO2) cycle, and how is interacts with the water and dust cycles. Polar Caps Determine how the heat balance at the polar caps changes over the course of a year, to understand the annual growth and recession of the caps. Temperature Record surface temperature, atmospheric temperature, and dust to understand how certain materials are distributed on the surface of Mars.