  Aim. We construct a new arc model to represent the global perturbation
induced by the Jupiter Trojans for the development of the modern planetary
ephemerides.
  Methods. The Jupiter Trojans are divided into two groups: (1) the 226 biggest
ones with absolute magnitudes $H<11$, have well determined masses and are
treated as individual bodies; (2) the remaining small ones with $H\geqslant11$,
are modeled by two discrete arcs centered at Jupiter's L4 and L5 points,
respectively. Then we derived the parameters characterizing the arcs, such as
the total mass, the mass ratio, and the spatial distributions. Uncertainties on
the fitted parameters have also been taken into account.
  Results. We find that the total mass of all the Jupiter Trojans, including
the undiscovered ones, is most likely about $1.861\times 10^{-5}$ Earth mass.
Then the global perturbation of the trojan population induced on the Earth-Mars
distance is numerically estimated to be about 70 m during the 2014-2114 time
interval. We also give a simple analytic expression. For the satellites of Mars
and Jupiter, however, the change of the distance between the Earth and a
satellite can be much more significant, reaching on tens of thousands of meters
over one century, due to perturbations of the Jupiter Trojans.
