A surface discharge plasma jet controlled by a dielectric barrier layer is developed to generate a uniform plasma plume in ambient air at atmospheric pressure through using argon as the working gas. The discharge characteristics of the plasma jet are investigated by electrical and optical methods. It is found that the discharge pulses only exist in the positive half cycle of the applied voltage and the pulse number increases with the increasing of the gas flow rate. Spatially resolved measurements are implemented on the plasma plume for the positive half cycle of the applied voltage. It has been found that the plasma plume behaves just like a plasma bullet under different experimental conditions. Each pulse corresponds to a bullet propagating process. The total light emission signal is compared with the discharge current signal, and it is found that the total light emission signal has a time lag with the discharge current signal. The delay time between them obeys the Normal distribution. It decreases with the increasing of the peak value of the applied voltage or the gas flow rate. The gas temperature of the discharge is investigated by using an optical fiber thermometer, and results show that the gas temperature increases with the increasing of the applied voltage or the decreasing of the gas flow rate. Through analyzing the gas discharge mechanism, these experimental phenomena are investigated qualitatively.