BROWN DWARFS ARE SUBSTELLAR OBJECTS WHOSE PHYSICAL AND ATMOSPHERIC PROPERTIES BRIDGE GIANT PLANETS TO STARS. LIKE JUPITER BROWN DWARFS EXPERIENCE WEATHER PATTERNS DETECTED AS PHOTOMETRIC OR TIME-RESOLVED SPECTROSCOPIC VARIABILITY DUE TO PHOTOSPHERIC INHOMOGENEITIES AND THEIR RAPID ROTATION. IN BROWN DWARFS COLDER THAN 1900K VARIABILITY IS CAUSED BY HETEROGENEOUS CLOUD COVERAGE IN THEIR ATMOSPHERES. PATCHINESS IN CLOUDS AND VARYING OPACITIES ALLOW LIGHT FROM DEEPER LAYERS OF THE ATMOSPHERE TO REACH THE SURFACE OF THE PHOTOSPHERE. UNDERSTANDING VARIABILITY AND THE VERTICAL STRUCTURE OF BROWN DWARF ATMOSPHERES IS A CRUCIAL STEP TOWARDS DETAILED CHARACTERIZATION OF EXOPLANET ATMOSPHERES AND THEIR WEATHER SYSTEMS AS YOUNG BROWN DWARFS OVERLAP IN TEMPERATURES AND SURFACE GRAVITIES WITH GIANT EXOPLANETS. IN THE NEXT FEW YEARS JWST AND GROUND-BASED 30M TELESCOPES WILL ACHIEVE EXQUISITE DETAIL IN BROWN DWARF AND EXOPLANET OBSERVATIONS POSSIBLY EVEN TO BEGIN THE SEARCH FOR BIOSIGNATURES IN EXOPLANET SPECTRA. THEREFORE IT IS CRUCIAL AND TIMELY TO PURSUE DETAILED SPECTROSCOPIC STUDIES TO CHARACTERIZE LOW TEMPERATURE ATMOSPHERES. VARIABILITY SURVEYS UNTIL NOW HAVE BEEN UNINFORMED AS THERE IS NO METHOD TO IDENTIFY VARIABLE BROWN DWARF CANDIDATES A PRIORI AND BOTH LIGHT CURVES AND TIME-RESOLVED SPECTROSCOPY ARE RESOURCE-INTENSIVE OBSERVATIONAL TECHNIQUES. WE PROPOSE A TECHNIQUE TO IDENTIFY CANDIDATE VARIABLE BROWN DWARFS FROM A SINGLE LOW-RESOLUTION NEAR-INFRARED SPECTRUM TO INFORM THESE SEARCHES. THE SPECTRAL SIGNATURES RESULTING FROM INHOMOGENEOUS CLOUD COVERAGE AND LEADING TO PHOTOMETRIC VARIABILITY ARE SIMILAR TO THOSE FROM BLENDEDLIGHT SPECTRAL BINARIES. ESSENTIALLY BOTH SPECTRA LOOK LIKE A BLEND OF TWO DIFFERENT TEMPERATURE ATMOSPHERES. SPECTRAL BINARIES ARE SYSTEMS OF ULTRACOOL DWARFS OF DIFFERENT SUBTYPES WHOSE PROXIMITY IN ANGULAR SPACE YIELDS A SINGLE UNRESOLVED PECULIAR SPECTRUM. THE PATCHINESS IN CLOUD COVERAGE AND VARYING CLOUD OPACITIES ALLOW THE OBSERVER TO PEER DEEPER INTO HOTTER LAYERS OF THE ATMOSPHERE LEADING TO A SIMILAR BLENDED-LIGHT EFFECT ON THE SPECTRUM OF A SINGLE VARIABLE OBJECT. THE SPECTRAL BINARY TECHNIQUE IS ABLE TO IDENTIFY BLENDED ATMOSPHERES WHETHER THEY ORIGINATE FROM TWO BINARY COMPONENTS OR TWO CLOUD DECKS IN A SINGLE OBJECT. THEREFORE WE CAN OPTIMIZE THE TECHNIQUE TO IDENTIFY VARIABLE BROWN DWARFS ON THEIR OWN. WE PROPOSE A PILOT PROGRAM TO OPTIMIZE THE SPECTRAL BINARY TECHNIQUE TO IDENTIFY HIGH-PROBABILITY CANDIDATE PHOTOMETRICALLY VARIABLE BROWN DWARFS WITH A SINGLE LOW-RESOLUTION NEAR-INFRARED SPECTRUM FOLLOWING THESE STEPS: - GATHER ALL PUBLICLY AVAILABLE NEAR INFRARED SPECTRA OF ULTRACOOL DWARFS LATER THAN L3 INCLUDING YOUNG AND FIELD BROWN DWARFS - ANALYZE AND REFINE EXISTING SPECTRAL INDICES FOR REDUNDANCY WITH PRINCIPAL COMPONENT ANALYSIS - DESIGN NEW SPECTRAL INDICES FOR VARIABILITY BY IDENTIFYING THE STATIC SIGNATURES OF VARIABILITY AND/OR CLOUDS FROM SPECTRA OF KNOWN VARIABLE BROWN DWARFS - VALIDATE TECHNIQUE AND DELIVER NEW HIGH-PROBABILITY CANDIDATES FROM ARCHIVAL NEAR-INFRARED SPECTRA OF FIELD AND YOUNG L- AND T-TYPE BROWN DWARFS - FUTURE FOLLOW-UP AFTER THIS PILOT PROGRAM WILL INCLUDE ADAPTIVE OPTICS IMAGING TO CONFIRM BINARY SYSTEMS AND TESS LIGHT CURVES TO MEASURE VARIABILITY ON CANDIDATES THUS ENABLING FUTURE EXOPLANET ATMOSPHERE STUDIES. THIS PROPOSAL ALIGNS WITH TWO OF NASA'S STRATEGIC GOALS BOTH PHYSICS OF THE COSMOS AND EXOPLANET EXPLORATION. AS AN IMMEDIATE GOAL THE DESIGN OF THE TECHNIQUE WILL PROVIDE CANDIDATES FOR VARIABILITY SEARCHES PERMITTING A DEEPER UNDERSTANDING OF ULTRACOOL ATMOSPHERES. WE WILL STUDY VARIABILITY SIGNATURES IN PARALLEL BETWEEN YOUNG AND FIELD BROWN DWARFS TO UNDERSTAND THE ROLE OF SURFACE GRAVITY IN SHAPING THE VERTICAL STRUCTURE OF ULTRACOOL ATMOSPHERES. SINCE YOUNG BROWN DWARFS ARE PROXIES TO DIRECTLY-IMAGED EXOPLANETS OUR ATMOSPHERIC STUDIES CAN BE DIRECTLY MAPPED TO EXOPLANET ATMOSPHERES.