For Department
of Oceanography Biennial Report 1999-2000 and web page
Harold Ritchie
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
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 André
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.