  We explore the weak lensing E- and B-mode shear signals of a field of galaxy
clusters using both large scale structure N-body simulations and multi-color
Suprime-cam & Hubble Space Telescope observations. Using the ray-traced and
observed shears along with photometric redshift catalogs, we generate mass maps
of the foreground overdensities by optimally filtering the tangential shear
that they induce on background galaxies. We then develop and test a method to
approximate the foreground structure as a superposition of NFW-like halos by
locating these overdensities and determining their mass and redshift, thereby
modeling the background correlated shear field as a sum of lensings induced by
the foreground clusters. We demonstrate that the B-mode maps and shear
correlation functions, which are generated by similarly filtering the cross
shear in this method, are in agreement with observations and are related to the
estimated cluster masses and locations as well as the distribution of
background sources. Using the foreground mass model, we identify several
sources of weak lensing B-modes including leakage and edge effects, source
clustering, and multiple lensing which can be observed in deep cosmic shear
surveys.
