Figure 10: Horizontal maps of linear trends of (a) the potential function ( ; contours + shadings) and (b) the stream function ( ; shadings) of the column-integrated water vapor flux , superimposed with the divergent and rotational components of the water vapor flux (vectors). Tropical cyclogeneses during the 1979–1995 and 1996–2010 periods are overlaid as blue dots and red dots, respectively.