Turbulent helium gas cell as a new paradigm of daily meteorological fluctuations?

We compare the spectral properties of long meteorological temperature recor ds with laboratory measurements in small convection cells. Surprisingly, th e atmospheric boundary layer sampled on a daily scale shares the statistica l properties of temperature fluctuations in small-scale experiments. This f act can be explained by the hydrodynamical similarity between these seeming ly very different systems. The results suggest that the dynamics of daily t emperature fluctuations is determined by the soft turbulent state of the at mospheric boundary layer in the continental climate.