Abstract:  Remember the saying “All models are wrong, but some are useful”. Well, some of the useful models can be made realistic by ingesting experimental measurements through data assimilation. This presentation will show examples of how Global Scale Observations of the Limb and Disk (GOLD) mission observations played a crucial role in improving a whole atmospheric reanalysis. The NSF-NCAR Whole Atmosphere Community Climate Model with thermosphere-ionosphere eXtension (WACCMX) model is used as the forecasting model and Data Assimilation Research Testbed (DART) ensemble adjustment Kalman filter is used for the assimilation. In addition to assimilation of GOLD disk temperature and O/N2 observation, lower atmospheric meteorological observations and temperatures from NASA-SABER and Aura-MLS are also assimilated to improve the atmosphere of the Earth from surface to the thermosphere-ionosphere altitudes. The addition of the GOLD observations in the assimilation improved the thermosphere-ionosphere in the whole atmosphere reanalysis. This presentation will demonstrate the great potential of the GOLD data to improve satellite drag and forecasting, which is becoming very crucial for space traffic control.
 

Abstract: Spin glasses—large-scale networks of spins with deeply frustrated interactions—are canonical examples of complex matter. Although much about their structure remains uncertain, they inform the description of a wide array of complex phenomena, ranging from magnetic ordering in metals with impurities to aspects of evolution, protein folding, climate models, and combinatorial optimization. Indeed, spin glass theory forms a mathematical basis for neuromorphic computing and brain modeling. Advancing experimental insight into their structure requires repeatable control over microscopic degrees of freedom. Here, we achieve this at the atomic level using a quantum-optical system comprised of ultracold gases of Rb atoms coupled via photons resonating within a multimode optical cavity. The network of atomic ensembles scatter light from a transverse pump laser into the cavity modes to realize an unusual type of transverse-field spin glass with all-to-all connectivity. A superradiant phase transition occurs upon reaching a critical pump strength, concomitant with spin glass ordering. Spin configurations are observed in the superradiant cavity emission and reveal the emergence of replica symmetry breaking and nascent ultrametric structure as signatures of spin-glass order. The controllability provided by this new spin-glass system, potentially down to the quantum-spin-level, enables the study of spin-glass physics in novel regimes with application to quantum neural network computing.