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We present the results of our study of cross-correlations between long-termmulti-band observations of the radio variability of the blazar 3C 279. Morethan a decade (2008-2022) of radio data were collected at seven differentfrequencies ranging from 2 GHz to 230 GHz. The multi-band radio light curvesshow variations in flux, with the prominent flare features appearing first athigher-frequency and later in lower-frequency bands. This behavior isquantified by cross-correlation analysis, which finds that the emission atlower-frequency bands lags that at higher-frequency bands. Lag versus frequencyplots are well fit by straight lines with negative slope, typically ~-30day/GHz. We discuss these flux variations in conjunction with the evolution ofbright moving knots seen in multi-epoch VLBA maps to suggest possible physicalchanges in the jet that can explain the observational results. Some of thevariations are consistent with the predictions of shock models, while othersare better explained by a changing Doppler beaming factor as the knottrajectory bends slightly, given a small viewing angle to the jet.

Multi-band Cross-correlated Radio Variability of the Blazar 3C 279