Daniel Holdaway, Research Scientist II

Daniel Holdaway


NASA Goddard
Bldg 33, Room C112
Greenbelt, MD 20771

Phone: 301-614-6158


Dr. Holdaway is a scientist working in NASA Goddard's Global Modeling and Assimilation Office (GMAO). He works within the data assimilation group and participates on the development of data assimilation techniques. His interests are in the development of the tangent linear and adjoint versions of the GEOS-5 model physics, particularly the moisture physics.


Dr. Holdaway graduated from the University of Exeter in 2005, with a degree in Mathematics. Having gained an interest in the mathematical models used in the prediction of the atmosphere he decided to continue at Exeter and undertook an MSc in Computation Science and Modelling, graduating in October 2006 with Distinction (First Class Honors). He then undertook a PhD in Mathematics at Exeter, under the supervision of Prof. John Thuburn and Dr. Nigel Wood, graduating in May 2010. The Met Office sponsored project compared the use of the Lorenz and Charney-Phillips vertical staggering for coupling of large scale dynamics to the planetary boundary layer. His focus was on the ability of the two types of grids to capture the Rossby, inertia-gravity, acoustic and physics normal modes of the atmosphere.

After graduating from Exeter, Dr. Holdaway briefly worked as a post-doc in the Engineering Department of Exeter University, working on computational fluid dynamics of local wind flow using OpenFOAM with a view to optimal wind turbine placement. The work involved working closely with a local company that was looking to build and sell a highly portable wind powered generator.

He moved to the USA in February 2011 to begin working for GESTAR. Under the supervision of Dr. Ron Errico and Dr. Ron Gelaro, he has made significant improvements to the tangent linear and adjoint models used for observation impacts and 4DVAR data assimilation. He has developed the convection, cloud model, radiation, boundary layer, chemistry and advection components of the linear model.

In addition, he is interested in using the adjoint for sensitivity studies, for example, using the adjoint to understand the sensitivity to dust in the formation of cyclones off the West Coast of Africa. He collaborates with the Navy Research Laboratory in Monterey, CA on adjoint techniques applied to tropical cyclones.