NSA Science
Scientific objectives for the NSA/AAO site are provided below:
- Provide the comprehensive data sets necessary to develop and test continually improved algorithms for GCMs to describe radiative transfer and cloud processes at high latitudes;
- Specifically focus on development of algorithms to describe:
- radiative transfer within both the clear and cloudy atmosphere, especially at low temperatures;
- physical and optical behavior of water (ice) and land surfaces, both bare and snow-covered, especially during transitions from winter to summer and back;
- physical and optical behavior of ice and mixed phase clouds.
- Temporal Priorities (issues to be pursued first, second, etc.):
- Infrared radiative transfer under cloudless skies for very cold, dry conditions. This issue pertains to both high latitudes and high altitudes (Instantaneous Radiative Flux (IRF) experiment).
- Influence of stratus clouds on solar radiative transfer near the surface. Start with liquid water clouds; next go to ice clouds; attack mixed phase clouds last (in order of increasing measurement challenges). This issue pertains to the influence of stratus clouds, and to high altitude ice (cirrus) clouds worldwide (IRF experiment).
- Influence of stratus clouds on infrared radiative transfer near the surface. Start with liquid water clouds; next go to ice clouds; address mixed phase clouds last. This issue has the same broad applicability as number 2 above.
- Solar radiative transfer to the surface under cloudless skies (IRF experiment).
- Interactions of surface albedo and related optical and physical factors with surface heating (SOM: Surface Optical Model experiments).
- Local factors affecting the formation and properties of stratus clouds (Cloud Behavior (CB) experiments; horizontal measurement scale, few km; eg. coastal, open lead, snow cover edge, lake and other discontinuity effects).
- Stratus cloud formation and evolution processes on GCM grid cell scales (Cloud Behavior/Single Column Model (CB/SCM) experiments).
Note that the temporal priorities are based in part upon the breadth of the instrumentation resources required to address each issue. Issues with higher temporal priorities can be addressed earlier in the NSA/AAO site development. Lower temporal priorities cannot be addressed until much more of the site instrumentation suite is in place and operating. Nevertheless, progress on each one of these issues is critical to the achievement of the NSA/AAO scientific objectives, and to the achievement of the overall goal of more accurate global and regional future climate predictions.
