A Next Generation Strategy for Weather Forecasting: Extending Observation Into the Upper Atmosphere

It is now well understood that tropospheric weather continuously imprints its signature on the upper atmosphere. These dynamic systems radiate their signature into the upper atmosphere with expanding scales, producing waves and winds that could be observed and used to infer the evolution of the underlying state. It has been shown by a variety of groups that the wave and wind fields in the upper atmosphere can act as powerful boundary conditions on the evolution of weather systems. Yet this signature goes relatively unobserved on a global scale. Obviously it would be best done from orbiting sensors, if possible.

Such observations are a challenge due to the nature of the small scale waves and their time evolution. Sensors that observe the atmosphere through occultation or thermal limb observations (ex: GPSRO and thermal imagers) are inherently limited to resolutions of 100 to 200 km in the horizontal, and adequate temporal coverage would require a large number of sensors, prohibitively expensive with current technology. Consequently, observations of temperature and moisture fields that drive dynamic weather conditions are often smoothed to the point of limited value for forecasting. However, satellite related sensor technology now makes it possible to observe these parameters in the upper atmosphere at resolutions required to fill the current deficiencies.

This talk describes a multi-sensor small satellite approach for monitoring atmospheric dynamics and moisture, from surface to 200 km on spatial and temporal scales required for advancing weather forecasting. Vicarious and synergistic calibration schemes, stellar occultation, modern focal plane arrays, unfolding antenna and solar panels, passive microwave and LWIR radiometry, gas filtered radiometry (both limb and nadir), arcsecond attitude control and knowledge, and soon-to-be terabyte-per-pass laser downlinks can be combined to enable the next big advance in observing global dynamics. We show how these space proven capabilities eliminate on-board calibration, enhance retrieval quality, and glean previously undetected dynamics required for advancing weather forecasting. Relative to past sensors, those in this proposed constellation are remarkably simple and low cost, while forging new capabilities in weather observation.