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Tim Hoar

Associate Scientist
Institute for Mathematics Applied to Geosciences
National Center for Atmospheric Research
Boulder, CO 80307
thoar .at.
303.497.1708 (voice)
303.497.1298 (fax)

Projects    Publications    MySCD    links

I have two main duties as an Associate Scientist in IMAGe at the National Center for Atmospheric Research. Essentially, my job is to ensure that anyone, anywhere, on any architecture -- can download, install, and run the Data Assimilation Research Testbed (DART) software developed by the Data Assimilation Research Section (DAReS) AND (and this is more of a hobby) that Geophysical Statistics Project (GSP) visitors, post-docs, and collaborators have everything they need -- be it data, code, hardware, methodologies, programming, programming advice, home repair ...

Data Assimilation Research Testbed

The Data Assimilation Research Testbed (DART) is an effort led by Jeff Anderson to develop a suite of software to explore data assimilation methodologies instead of data assimilation programming. Our intent is to develop a very modular suite of models and observations to facilitate research in data assimilation and forecasting.

Royal Arch Hike


I have some pictures of a hike from NCAR to 'the quarry' and then up a VERY STEEP (didn't know it was that steep) social trail to Royal Arch. We didn't lose anyone, which was good. [pic 1] [pic 2] [pic 3] [pic 4] [pic 5] [pic 6] [pic 7] [pic 8] [pic 9] I'm saving all the incriminating photos of people 'running out of puff' (I just learned that one from an Aussie friend) for my retirement fund. Because we're a bunch of statisticians, I thought it would be fun to collect some data on the hike. I had two GPS units - a Garmin Forerunner 305, and a Garmin 60CSX. The breadcrumbs (tracks) from the units are: [forerunner tracks], and [60CSX tracks]. They have different sample rates, and the last line of each file has a different number of items, so you may want to delete that one before trying to ingest it. The best graphics will get posted here, the winner receiving another invite to the next hike. The consolation prizes will also be invitations to the next hike, so get your entry in now!

Select Publications (reverse chronologically, for the most part)

A much more complete list of publications and presentations is available at the NCAR/UCAR Opensky portal

Rosolem, R., T.J. Hoar, A. Arellano, J.L. Anderson, W.J. Shuttleworth, W. Zeng, and T.E. Franz, 2014
Translating aboveground cosmic-ray neutron intensity to high-frequency soil moisture profiles at sub-kilometer scale. Hydrology and Earth System Sciences,18, 4363-4379, DOI: 10.5194/hess-18-4363-2014.

Zhang, Y.-F., T.J. Hoar, Z.-L. Yang, J.L. Anderson, A.M. Toure, and M. Rodell, 2014
Assimilation of MODIS snow cover through the Data Assimilation Research Testbed and the Community Land Model version 4. Journal of Geophysical Research-Atmospheres, 119, 7091-7103, DOI: 10.1002/2013JD021329

Morozov, A.V., A.J. Ridley, D.S. Bernstein, N.S. Collins, T.J. Hoar, and J.L. Anderson, 2013
Data assimilation and driver estimation for the Global Ionosphere-Thermosphere Model using the Ensemble Adjustment Kalman Filter. Journal of Atmospheric and Solar-Terrestrial Physics, 104, 126-136, DOI: 10.1016/j.jastp.2013.08.016

Karspeck, A., S. Yeager, G. Danabasoglu, T.J. Hoar, N.S. Collins, K.D. Raeder, J.L. Anderson, and J. Tribbia , 2013
An ensemble adjustment Kalman filter for the CCSM4 ocean component. Journal of Climate, 26, 7392-7413, DOI: 10.1175/JCLI-D-12-00402.1

Hoteit, I., T.J. Hoar, G. Gopalakrishnan, N.S. Collins, J.L. Anderson, B. Cornuelle, A. Köhl, and P. Heimbach, 2013
A MITgcm/DART ensemble analysis and prediction system with application to the Gulf of Mexico. Dynamics of Atmospheres and Oceans, 63, 1-23, DOI: 10.1016/j.dynatmoce.2013.03.002

Raeder, K and Anderson, Jeffrey L. and Collins, Nancy and Hoar, Timothy J. and Kay, Jennifer E. and Lauritzen, Peter H. and Pincus, Robert, 2012
DART/CAM: An Ensemble Data Assimilation for CESM Atmospheric Models Journal of Climate, 25, 6304-6317, DOI: 10.1175/JCLI-D-11-00395.1

Lee, C., W. G. Lawson, M. I. Richardson, J. L. Anderson, N. Collins, T. Hoar, and M. Mischna, 2011
Demonstration of ensemble data assimilation for Mars using DART, MarsWRF, and radiance observations from MGS TES Journal of Geophysical Research,116, E11011, doi:10.1029/2011JE003815

Anderson, J., T. Hoar, K. Raeder, H. Liu, N. Collins, R. Torn, and A. Arellano, 2009
The Data Assimilation Research Testbed: A Community Facility. Bulletin of the American Meteorological Society: 90 (9), 1283-1296

Khare, S.P., Anderson, J.L., Hoar, T.J., Nychka, D.W. 2008
An investigation into the application of an ensemble Kalman smoother to high-dimensional geophysical systems. Tellus Series A - Dynamic Meteorology and Oceanography: 60, 97-112, 10.1111/j.1600-0870.2007.00281.x.

Whitcher, B., T.C.M. Lee, J.B. Weiss, T.J. Hoar, and D.W. Nychka, 2008
A Multiresolution Census Algorithm for Calculating Vortex Statistics in Turbulent Flows. Journal of the Royal Statistical Society: Series C (Applied Statistics), 57 (3), 293-321

Anderson, J. L., B. Wyman, S. Zhang, and T. Hoar, 2005
Assimilation of surface pressure observations using an ensemble filter in an idealized global atmospheric prediction system. Journal of the Atmospheric Sciences, 62, 2952-2938

Hoar, T.J., R.F. Milliff, D. Nychka, C.K. Wikle, and L. Mark Berliner, 2003
Winds from a Bayesian Heirarchical Model: Computation for Atmosphere-Ocean Research. Journal of Computational and Graphical Statistics, Volume 4, Number 12, 781-807

Whitcher, B., J. Weiss, D. Nychka, and T.J. Hoar, 2003
Stochastic Multiresolution Models for Turbulence. Recent Advances and Trends in Nonparametric Statistics, M. Akritis and D. Politis (Eds.), pp. 497-509, Amsterdam: Elsevier.

Berliner, L.M, Nychka, D. and Hoar, T. (Eds.), 2000:
Studies in the Atmospheric Sciences, Springer-Verlag, New York.

Madden, R.A., Hoar, T.J., and Milliff, R.F., 1999:
Scatterometer winds composited according to the phase of the Tropical Interseasonal Oscillation. Tellus, 51A, 263-272

Hoar, T., 1999:
Bayes meets Big Iron. Proceedings of the 1999 Joint Statistical meetings, Journal of the American Statistical Association.

Milliff, R.F., Hoar, T.J., van Loon, H., and Raphael, M., 1999:
Quasi-stationary wave variability in NSCAT winds. J. Geophys. Res., 104, 11,425-11,436

Milliff, R.F., Hoar, T.J., and Madden, R.A., 1998:
Fast, eastward moving disturbances in the surface winds of the equatorial Pacific. Tellus, 50A, 26-41

Jones, R.H., Y. Zhang, and T.J.Hoar, 1997:
Constructing surface wind space-time maps from scatterometer data. manuscript

Trenberth, K.E., and Hoar, T.J., 1997:
El Niño and climate change. Geophys. Res. Lett., 24, No. 23, 3057-3060

Trenberth, K.E., and Hoar, T.J., 1996:
The 1990-1995 El Niño -Southern Oscillation Event: Longest on record. Geophysical Research Letters, 23, No. 1, 57-60

Shea, D.J., Worley, S.J. Stern, I.R. and Hoar, T.J., 1994:
An Introduction to Atmospheric and Oceanographic Data. NCAR/TN-404+IA, 132 pp.

Hoar, T.J., and Wilson, C.R., 1994:
Geosat Observations of Sea Level Response to Barometric Pressure Forcing. Geophysical Research Letters, 21, No. 23, 2515-2518

Various useful (to me) links.

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Last modified: Wednesday, 20-May-2015 08:43:58 MDT by
Tim Hoar -- thoar "at"