This is a somewhat personal perspective of the changes in observing capabilities since the speaker's first flight on a DC-6 into Hurricane Donna (1960). Many of the advances during the early days of the National Hurricane Research Project, by pioneers such as Robert Simpson, Herbert Riehl, Joanne Malkus, Bill Gray, Noel LaSeur, Cecil Gentry, and Harry Hawkins, were in some ways fortuitous, because the mature hurricane proved to have a relatively simple structure. The primary and secondary circulation could be observed without inertial platforms or GPS technology. The thermal structure required nothing more sophisticated than the vortex or reverse flow thermometer. Vertical motions in the eyewall were determined by the effective technique of flying the aircraft at constant power setting and constant attitude and measuring the change in altitude. For these reasons, the hurricane was a perfect objective for imperfect technology; the tropical atmosphere outside of the mature hurricane proved to be far more challenging.

The “ordinary” tropical disturbance, unlike the mature hurricane, has weaker winds, weaker temperature gradients, complex but significant variations of humidity, and complex and rapidly-changing populations of shallow and deep convection. Most frustrating to the researcher, the synoptic scale, mesoscale, and convective scale events are all of importance, and unlike the hurricane, no simplifications are available such as assuming circular symmetry and compositing relative to a slowly-changing center. That is the principal reason that the GATE program (1974) assembled such a huge array of resources (40 ships, 13 airplanes) and even then was barely able to effect basic quantitative description of disturbances in the east Atlantic.

The realities of limited resources since GATE have placed a premium on developing remote sensing technologies that can be employed on satellites and a more limited number of aircraft, in order to attack the multi-scale scientific problems of tropical disturbances, hurricane genesis, and intensity change. In recent years, NASA has taken a leadership role in close collaboration with partners in NOAA and other agencies, with a series of programs that have the dual role of developing/testing new technologies while using existing as well as experimental observing tools. In 2010, NASA, NOAA, and the NSF were very effective in partnering to observe the genesis of Karl and Matthew; the talk ends with a few examples from 2010.