Specifying distance unit for multiple plots in single figure

I want to plot cone for cyclone tracking in 2-D. I shape file of India, I have columnar latitude,longitude,

lon=[91.5;91.2;91;90.8;90.6;90.1;89.3;88.6;88.1;87.7];

lat=[13.1;13.2;13.5;13.6;14.3;15.4;16.1;16.8;17.4;18.1];

Cone_radius=[19;37;56;74;83;102;130;157;176;213] %% radius is in km.

1 degree change in latutude/longitude = 111km

Firstly I m plotting shape file of India, over that track of cyclone is plotted with respect to lat, lon given above with refernce to lat, lon of shape file.

For plottong 2-D cone, I am using scatter plot with marker 'o'. which gives figure 1.

Problem with figure 1 is : circles are of fixed size. If I zoom into this figure, shape file will give a zoomed view but size of circles in scatter plot will be same.

Is there any way to link size of circles (in km) with grids of latitude/longitude(in km) so that these circles cover exact area (in km sqaure) in the map(shape file) whenever zoomed in ore zoomed out?

And how can I make a smoother plot like figure 2?

THANK YOU