  Cloud computing has recently evolved as a popular computing infrastructure
for many applications. Scientific computing, which was mainly hosted in private
clusters and grids, has started to migrate development and deployment to the
public cloud environment. eScience as a service becomes an emerging and
promising direction for science computing. We review recent efforts in
developing and deploying scientific computing applications in the cloud. In
particular, we introduce a taxonomy specifically designed for scientific
computing in the cloud, and further review the taxonomy with four major kinds
of science applications, including life sciences, physics sciences, social and
humanities sciences, and climate and earth sciences. Our major finding is that,
despite existing efforts in developing cloud-based eScience, eScience still has
a long way to go to fully unlock the power of cloud computing paradigm.
Therefore, we present the challenges and opportunities in the future
development of cloud-based eScience services, and call for collaborations and
innovations from both the scientific and computer system communities to address
those challenges.
