Abstract: The present disclosure discloses a method for automatically identifying south troughs by improved Laplace and relates to the technical field of meteorology. The method includes the following steps: acquiring grid data of a geopotential height field; calculating a gradient field of the geopotential height field in an x direction; searching for a turning point where a gradient value turned from being negative to being positive, and cleaning the gradient field; calculating a divergence of the x direction to obtain an improved Laplacian numerical value L?; performing 0,1 binarization processing on the L? to obtain a black-and-white image and a plurality of targets of potential troughs, merging the black-and-white image and the plurality of targets of the potential troughs by expansion, recovering original scale through erosion, and selecting an effective target through an angle of direction of a contour and an axial ratio.

Abstract: A session management network element discovery method includes that a network repository function network element receives a first identifier from a mobility management network element, where the first identifier is for identifying a home location of a terminal device. The network repository function network element determines a first session management network element based on the first identifier, where a home location identifier of the first session management network element is the same as the first identifier. The network repository function network element sends an identifier of the first session management network element to the mobility management network element.