  This paper reports on the measurement of the large-scale anisotropy in the
distribution of cosmic-ray arrival directions using the data collected by the
air shower detector ARGO-YBJ from 2008 January to 2009 December,during the
minimum of solar activity between cycles 23 and 24. In this period, more than
200 billion showers were recorded with energies between 1 and 30 TeV. The
observed two-dimensional distribution of cosmic rays is characterized by two
wide regions of excess and deficit, respectively, both of relative intensity
0.001 with respect to a uniform flux, superimposed on smaller size structures.
The harmonic analysis shows that the large-scale cosmic-ray relative intensity
as a function of R.A. can be described by the first and second terms of a
Fouries series. The high event statistics allow the study of the energy
dependence of the anistropy, showing that the amplitude increases with energy,
with a maximum intensity at 10 TeV, and then decreases while the phase slowly
shifts toward lower values of R.A. with increasing energy. The ARGO-YBJ data
provide accurate observations over more than a decade of energy around this
feature of the anisotropy spectrum.
