Surface Layer Stability Transition Research Minimum Neutral Event-to- Sunrise Time Interval: 2001 September Case Study

摘要

Near surface target acquisition and EO propagation significantly improve during the Surface Layer Stability Transition (SLST). Thus, this research expands Army Chief of Staff Shinseki's vision from 'to see first' to, 'to see better'. The SLST is also the starting and ending points for the atmospheric convection growth phase, an important factor in chemical warfare modeling. In 2001, the Meteorological-sensors Integration Team of the Army Research Laboratory conducted the last of three field experiments with the primary purpose of characterizing, modeling and exploiting repeatable patterns in the lower portion of the atmospheric boundary layer. The repeatable patterns investigated were the morning Stability Transitions (ST) or Neutral Events (NE). The 2001 September 19-21 test dates were selected based on a forecasted minimal time interval between the local Sunrise and an Ideal case NE Two previous field tests addressed the other minimum (March 2001) and a maximum (June 2001) Sunrise-to-NE time interval These Tests are documented separate. This Surface Layer Stability Transition research pursued two measurement and analysis methods: Eulerian (Tower Data) and quasi-Lagrangian (Rawinsonde data) The Experiment's results validated the Neutral Event Forecast Model, in that all three days showed a ST during the forecasted ST time period. Examples of extended and multiple STs were documented by the data, further enhancing the characterization of a desert stable-neutral-unstable morning transition over the Equinox time period. The information documented in this report serves a useful building block in support of the primary goal.