Long-term atmospheric pressure measurements across Central Europe reveal coherent oscillations at ultra-low frequencies (4 -- $7~mu$Hz), persisting over two decades. Using a demodulation technique adapted from signal processing, we identify reproducible spectral lines with complex phase modulation patterns. These signals are synchronized across geographically distant sensors and exhibit modulation periods ranging from months to decades. A prominent annual modulation suggests a correlation with Earth's orbital motion, implying a non-local origin. The inferred wave propagation speed ($sim 2.4times 10^6$ m/s) and wavelength ($sim 5times 10^{11}$ m) exceed known atmospheric dynamics, challenging current geophysical models. While the source remains unidentified, the findings suggest the presence of a previously unrecognized class of long-range atmospheric oscillations with potential astrophysical relevance.