The Future of Ultracool Dwarf Science with JWST
  Ultracool dwarfs exhibit a remarkably varied set of characteristics which hint at the complex physical processes acting in their atmospheres and interiors. Spectra of these objects not only depend upon their mass and effective temperature, but also their atmospheric chemistry, weather, and dynamics. As a consequence divining their mass, metallicity and age solely from their spectra has been a challenge. JWST, by illuminating spectral blind spots and observing objects with constrained masses and ages should finally unearth a sufficient number of ultracool dwarf Rosetta Stones to allow us to decipher the processes underlying the complex brown dwarf cooling sequence. In addition the spectra of objects invisible from the ground, including very low mass objects in clusters and nearby cold dwarfs from the disk population, will be seen for the first time. In combination with other ground- and space-based assets and programs, JWST will usher in a new golden era of brown dwarf science and discovery. 
Mark S. Marley (NASA ARC) and S.K. Leggett (Gemini Observatory)