Abstract:Based on the lightning location data of ADTD in Zhejiang Province from 2007 to 2018, the distribution and related parameters of multiple return strokes of cloudtoground (CG) lightning are analyzed. The results show that the number of multiple return stroke flashes accounts for 26.79% of the total CG number. The positive flashes are dominated by singlereturn stroke CG lightning flashes. The mean stroke number of positive CG and negative CG is 1.04 and 1.65, and the maximum stroke number is 5 and 21, respectively. The interannul variation features of multiple stroke CG lightning flashes and total CG lightning flashes are consistent. The daily changes of positive CG and negative CG show multimodal and unimodal distributions, respectively. The arithmetic mean current intensity of the positive multiple stroke lightning is 72.06 kA, and that of the negative is -36.89 kA. The average current for CG flashes of particular multiplicity has a tendency of decreasing with the stroke order. Furthermore, about 40% of multiple stroke CG flashes have at least one subsequent stroke, with the initial peak electric field stronger than that of the first return stroke. The current intensities of the first return stroke and flowing stroke of CG show a lognormal distribution, in which the stroke frequency is the highest when the current intensity is from 15 kA to 45 kA. The arithmetic mean interval stroke of positive CG lightning is 125.47 ms, and the negative is 138.14 ms. The geometric mean interval stroke of positive CG lightning is 56.73 ms, and the negative is 98.95 ms. The interval of stroke lightning also shows a lognormal distribution. The mean interval has a tendency of decreasing with the stroke order. The distribution of interval distance between first return stroke and flowing stroke shows a quasinormal distribution, and the strokes mostly occur within the range of 1 km.