Sounding of the Atmosphere using Broadband Emission Radiometry (SABER)

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Instrument Web Site

SABER is an instrument, known as a multichannel infrared radiometer, designed to measure heat emitted by the atmosphere over a broad altitude and spectral range.

SABER's primary science objectives are to explore the MLTI region to determine its energy balance; atmospheric structure (how temperature, density, and pressure vary with altitude); chemistry (variations of key gases in the oxygen and hydrogen families); and the movement of air, or dynamics, between atmospheric regions (lower to higher altitudes, pole to equator, and east-west direction). It is also measuring sources of atmospheric cooling, such as the "air glow," which occurs when energy is radiated back into space.

The technique that SABER is using on TIMED to sound, or make measurements in, the atmosphere has never before been used to study the MLTI region in such detail. Once every 58 seconds, SABER scans up and down the Earth's horizon collecting data over an altitude range from approximately 180 kilometers (about 112 miles) down to the Earth's surface. It is measuring the vertical distributions of elemental constituents, such as ozone, water vapor, carbon dioxide, and nitrogen and hydrogen gases, as well as temperature.

Over the course of one orbit, SABER observes polar regions in one hemisphere to high latitudes in the opposite hemisphere. Over the course of a day, SABER makes measurements covering 15 longitude bands. During the course of the mission, the instrument will assemble a global picture of how the MLTI region is changing with latitude, longitude, altitude, and time.

SABER's observations are opening up a new area in the field of radiation balance. It is acquiring measurements in a range of the atmosphere where the radiation and chemistry are much different than in the lower atmospheric regions due to molecules being more sparse and less active.

SABER is the first instrument to measure the global-scale distribution of carbon dioxide concentrations within the MLTI region. Carbon dioxide, a greenhouse gas that's transported to Earth's upper atmosphere from the ground level where it's produced, results from natural emissions, fossil-fuel burning needed for heating, electric power generation, and a host of other industrial processes. SABER is measuring nitric oxide emissions, which scientists now believe is one of the primary gases responsible for the cooling of the upper atmospheric regions that TIMED will be studying.