For GPU based simulations (e.g. solving equations with partial derivatives on GPU) one could store (and render) floating point data in textures. In core OpenGL ES 2.0, there are ratified extensions GL_OES_texture_half_float and GL_OES_texture_float.
In FireFox I can use gl.FLOAT data in gl.texImage2D()
gl.texImage2D(gl.TEXTURE_2D, 0, gl.ALPHA, tSize, tSize, 0, gl.ALPHA, gl.FLOAT, new WebGLFloatArray(pixels));
http://www.ibiblio.org/e-notes/webgl/tex_float.html
but with 8-bit limited precision (i.e. 1/512 is passed as 0)
http://www.ibiblio.org/e-notes/webgl/tex_float0.html
How can I use 32 bit floating point textures in WebGL?