Harold Ritchie

Department of Oceanography
Dalhousie University
Halifax, NS
B3H 4J1

e-mail: Harold.Ritchie@Dal.Ca
or Harold.Ritchie@ec.gc.ca
Phone: (902) 494-5192
FAX: (902) 494-2885

Harold Ritchie, an adjunct professor in the Department of Oceanography at Dalhousie University, specializes in numerical weather prediction and is also the lead Meteorological Service of Canada (MSC) research scientist for the Atlantic Environmental Prediction Research Initiative (AEPRI) which has been established in Halifax to join with other partners in conducting research and development for an environmental prediction capability in the Atlantic region. This is considered to be now feasible for two main reasons. Firstly, in recent years major advances have been made in a variety of numerical modelling activities covering a wide range of space and time scales, and extending to new applications. Secondly, in parallel with these advances in our scientific knowledge and modelling capabilities, there has also been a rapid evolution in computer technology leading to the availability of ever increasing supercomputer power. As a result we now have the scientific and technical capabilities to build comprehensive environmental prediction systems integrating expertise from a wide range of disciplines and addressing important issues in both research and operational prediction modes. The Atlantic Region of Canada is considered to be an ideal location for such an initiative. In addition to being a hyperactive environmental area, there is already a solid base of government, university, and private industry expertise specializing in atmospheric and oceanic sciences, and operational meteorology.

Although it is intended to develop as comprehensive an environmental prediction system as possible, the research focus is maritime environmental aspects such as regional atmosphere / ocean / ice / wave model coupling and the parameterization of related physical processes. The construction and testing of such an integrated regional prediction system is a major first step, requiring a close and productive collaboration of many key players. This is being accomplished in a phased manner, starting with the construction of a baseline system by combining prototype components that already exist for the synoptic (several days) time scale and the Atlantic Region space scale. The atmospheric component is being supplied by the Canadian operational regional forecast model, which is being coupled with an ocean wave forecast model and the ocean data assimilation and prediction system that Keith Thompson and his group have developed in the Oceanography Department at Dalhousie University (Dal). Coastal atmospheric and oceanic prediction and processes will be a major emphasis, particularly in the early phases of the initiative, with many potential applications for offshore activities. Related to AEPRI, the NSERC / MARTEC / MSC Industrial Research Chair in Regional Ocean Modelling and Prediction has also been established in the Oceanography Department with chair holders Richard Greatbatch and Jinyu Sheng. In the past two years significant progress has been made in AEPRI projects particularly in collaboration with Dal. The first project that has been brought to fruition through the AEPRI collaborations is the transfer of the storm surge model from Dal to the Maritimes Weather Centre where it has been implemented as Canada's first operational storm surge prediction system.

The main ongoing AEPRI sub-projects are: coupled atmosphere-wave models, coupled atmosphere-hydrology models, atmosphere-ocean coupling, coupling data assimilation and prediction systems for coastal applications, atmosphere / land-surface coupling, atmosphere / chemical transport model coupling, coupling with estuary models, and developing expert systems for marine applications. The Department of Oceanograhpy at Dalhousie University and the MSC are key partners in AEPRI which is providing graduate student research opportunities. Recent Publications

Recent Publications

1994 H. Ritchie and A.M. Leduc: "Analysis and Experiments with a Slow Start Procedure", Mon. Wea. Rev., 122, 729-744.

1994 H. Ritchie and C. Beaudoin: "Approximations and Sensitivity Experiments with a Baroclinic semi-Lagrangian Spectral Model", Mon. Wea. Rev., 122, 2391-2399.

1995 S. Peng, L.A. Mysak, H. Ritchie, J. Derome and B. Dugas: On the Differences Between Early and Middle Winter Atmospheric Responses to Sea Surface Temperature Anomalies in the Northwest Atlantic. J. Climate, 8, 137-157.

1995 H. Ritchie, C. Temperton, A. Simmons, M. Hortal, T. Davies, D. Dent and M. Hamrud: "Implementation of the Semi-Lagrangian Method in a High Resolution Version of the ECMWF Forecast Model", Mon. Wea. Rev., 123, 489-514.

1995 L. Fillion, H. Mitchell, H. Ritchie and A. Staniforth: "The Impact of a Digital Filter Finalization Technique in a Global Data Assimilation System", Tellus, 47, 304-323.

1996 H. Ritchie and M. Tanguay: "A Comparison of Spatially Averaged Eulerian and Semi-Lagrangian Treatments of Mountains", Mon. Wea. Rev., 124, 167-181.

1996 Houtekamer, P.L., L. Lefaivre, J. Derome, H. Ritchie, and H.L. Mitchell: "A system simulation approach to ensemble prediction", Mon. Wea. Rev., 124, 1225-1242.

1996 Ek, N., and H. Ritchie: "Forecasts of hydrological parameters over the Mackenzie River Basin: sensitivity to initial conditions, horizontal resolution and forecast range", Atmos.-Ocean, 34, 675-710.

1997 H. Ritchie: "Application of the Semi-Lagrangian Method to Global Spectral Forecast Models", Numerical Methods in Atmospheric and Oceanic Modelling, NRC Research Press, 445-467 .

1997 H.Ritchie and A. Robert: "A Historical Perspective on Numerical Weather Prediction: a 1987 Interview with Andre Robert", Numerical Methods in Atmospheric and Oceanic Modelling, NRC Research Press,1-24.

1998 R.E. Stewart, H.. G. Leighton, P. Marsh, G.W.K. Moore, H. Ritchie, W.R. Rouse, E.D. Soulis, G.S. Strong, R.W. Crawford, and B. Kochtubajda: " The Mackenzie GEWEX Study: The water and energy cycles of a major north-flowing North American river", Bull. Of the Amer. Met. Soc.,79, 2665-2683.

1999 E.H. Berbery, K. Mitchell, S. Benjamin, T. Smirnova, H. Ritchie, R. Hogue and E. Radeva: "Assessment of Land Surface Energy Budgets from Regional and Global Models", Journal of Geophysical Research, 104, D15, 19329-19348.

2000 Benoit, R., P. Pellerin, N. Kouwen, H. Ritchie, N. Donaldson, P. Joe and R. Soulis, "On the Use of Coupled Atmospheric and Hydrologic Models at Regional Scale", Mon. Wea. Rev., 128, 1681-1706.

2001 E. Radeva and H. Ritchie: "Impact of the Canadian Land Surface Scheme on Monthly Ensemble Predictions of Water and Energy Budgets over the Mackenzie River Basin", Atmos.-Ocean, in press.

2001 J. Derome, G. Brunet, A. Plante, N. Gagnon, G.J. Boer, F.W. Zwiers, S.J. Lambert, J. Sheng and H. Ritchie: "Seasonal Predictions Based on Two Dynamical Models", Atmos.-Ocean, conditionally accepted.

2001 Z. Cao, M. Wang, B.A. Proctor, G.S. Strong, R.E. Stewart, H. Ritchie and J. E. Burford: "On the Processes Associated with the Water Budget and Discharge of the Mackenzie Basin during the 1994/1995 Water Year", Atmos.-Ocean, accepted.

2001 S.J. Saucier, F. Roy, D. Gilbert, P. Pellerin and H. Ritchie: "The Formation and Circulation Processes of Water Masses and Sea Ice in the Gulf of St. Lawrence", J Geophys Res., conditionally accepted.

This page last updated April 5, 2001.
Physical Oceanography
Atmospheric Science