Gregory Smith

Gregory Smith
Environment Canada | EC · Environmental Numerical Prediction Research

Ph.D, M.Sc., B.Sc.

About

79
Publications
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Publications

Publications (79)
Article
The Global Ensemble Prediction System (GEPS) of Environment and Climate Change Canada (ECCC) was recently upgraded to a coupled atmosphere, ocean and sea ice version from an uncoupled atmosphere only system. This has been operational since July 2019, with over a year of forecasts now available to evaluate the system throughout all seasons. Using me...
Article
Mesoscale eddy features are found ubiquitously throughout the world’s oceans. Many needs exist for numerical products from operational oceanographic systems to provide information on eddy properties. While numerous eddy identification and tracking methods have been developed for oceanic eddies, specific methods and metrics tailored to verify the sk...
Article
This is a review article invited by Atmosphere-Ocean to document the contributions of Recherche en Prévision Numérique (RPN) to Numerical Weather Prediction (NWP). It is structured as a historical review and documents RPN's contributions to numerical methods, numerical modelling, data assimilation, and ensemble systems, with a look ahead to potenti...
Article
Full-text available
Canada has the longest coastline in the world and includes diverse ocean environments, from the frozen waters of the Canadian Arctic Archipelago to the confluence region of Labrador and Gulf Stream waters on the east coast. There is a strong need for a pan-Canadian operational regional ocean prediction capacity covering all Canadian coastal areas i...
Article
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As resolutions of ocean circulation models increase, the advective Courant number – the ratio between the distance travelled by a fluid parcel in one time step and the grid size – becomes the most stringent factor limiting model time steps. Some atmospheric models have escaped this limit by using an implicit or semi-implicit semi-Lagrangian formula...
Article
The water following characteristics of six different drifter types are investigated using two different operational marine environmental prediction systems: one produced by Environment and Climate Change Canada (ECCC) and the other produced by the Norwegian Meteorological Institute (METNO). These marine prediction systems include ocean circulation...
Preprint
Full-text available
Canada has the longest coastline in the world and includes a diversity of ocean environments, from the frozen waters of the Canadian Arctic Archipelago to the confluence region of Labrador and Gulf Stream waters on the East Coast. There is a strong need for a pan-Canadian operational regional ocean prediction capacity covering all Canadian coastal...
Article
Full-text available
The oceanography sub-initiative of Canada’s Oceans Protection Plan was tasked to develop high-resolution nearshore ocean models for enhanced marine safety and emergency response, fitting into the multi-scale, multi-level nested operational ocean forecasting systems. For decision making on eventual 24/7 operational support, two ocean models (a struc...
Preprint
The water following characteristics of six different drifter types are investigated using two different operational marine environmental prediction systems: one produced by Environment and Climate Change Canada (ECCC) and the other produced by the Norwegian Meteorological Institute (METNO). These marine prediction systems include ocean circulation...
Article
The second version of the Canadian Seasonal to Interannual Prediction System (CanSIPSv2) was implemented operationally at Environment and Climate Change Canada (ECCC) in July 2019. Like its predecessors, CanSIPSv2 applies a multi-model ensemble approach with two coupled atmosphere-ocean models, CanCM4i and GEM-NEMO. While CanCM4i is a climate model...
Preprint
Full-text available
Abstract. As model resolutions increase, the Courant-Frederichs-Lewy (CFL) number based on advective motion becomes the limiting factor in setting the timestep of time-explicit circulation models. Some atmospheric models escape this limit by using an implicit or semi-implicit semi-Lagrangian formulation of advection. This formulation calculates flu...
Article
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A pan-Arctic sea-ice–ocean prediction system is assessed in terms of its ability to predict sea-ice velocity. This system is based on the Regional Ice Ocean Prediction System running operationally at the Canadian Centre for Meteorological and Environmental Prediction. A form drag parameterization is implemented in the system to allow spatially and...
Article
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In the context of Canada’s Ocean Protection Plan (OPP), improved coastal and near-shore modelling is needed to enhance marine safety and emergency response capacity in the aquatic environment. In this study, the Nucleus for European Modelling of the Ocean (NEMO) is adopted to develop an ocean forecasting system for Saint John harbour in the Bay of...
Article
Full-text available
A fully coupled atmosphere–ocean–ice model has been used to produce global weather forecasts at Environment and Climate Change Canada (ECCC) since November 2017. Currently, the system relies on four uncoupled data assimilation (DA) components for initializing the fully coupled global atmosphere–ocean–ice forecast model: atmosphere, ocean, sea ice a...
Article
Full-text available
Operational oceanography can be described as the provision of routine oceanographic information needed for decision-making purposes. It is dependent upon sustained research and development through the end-to-end framework of an operational service, from observation collection to delivery mechanisms. The core components of operational oceanographic...
Article
Full-text available
A fully coupled atmosphere-ocean-ice model has been used to produce global weather forecasts at Environment and Climate Change Canada (ECCC) since November 2017. Currently, the system relies on four uncoupled data assimilation (DA) components for initializing the fully coupled global atmosphere-ocean-ice forecast model: atmosphere, ocean, sea ice a...
Article
Full-text available
There is a growing need for operational oceanographic predictions in both the Arctic and Antarctic polar regions. In the former, this is driven by a declining ice cover accompanied by an increase in maritime traffic and exploitation of marine resources. Oceanographic predictions in the Antarctic are also important, both to support Antarctic operati...
Article
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This paper summarizes recent efforts on Observing System Evaluation (OS-Eval) by the Ocean Data Assimilation and Prediction (ODAP) communities such as GODAE OceanView and CLIVAR-GSOP. It provides some examples of existing OS-Eval methodologies, and attempts to discuss the potential and limitation of the existing approaches. Observing System Experim...
Article
The importance of coupling between the atmosphere and the ocean for forecasting on time scales of hours to weeks has been demonstrated for a range of physical processes. Here, the authors evaluate the impact of an interactive air-sea coupling between an operational global deterministic medium-range weather forecasting system and an ice-ocean foreca...
Article
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In this time of a changing climate, it is important to know whether lake levels will rise, potentially causing flooding, or river flows will dry up during abnormally dry weather. The Great Lakes region is the largest freshwater lake system in the world. Moreover, agriculture, industry, commerce, and shipping are active in this densely populated reg...
Article
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Ocean–sea ice reanalyses are crucial for assessing the variability and recent trends in the Arctic sea ice cover. This is especially true for sea ice volume, as long-term and large scale sea ice thickness observations are inexistent. Results from the Ocean ReAnalyses Intercomparison Project (ORA-IP) are presented, with a focus on Arctic sea ice fie...
Article
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In the original publication of the article, Fig. 11 was published incorrectly. The correct version of Fig. 11 is provided here
Conference Paper
Ocean-Ice prediction systems maximize the information value of scarce in-situ ocean and ice observations. They provide assessed and forecast ocean and ice conditions that combine satellite observations and in-situ observations along with ocean and ice physics. Such information supports many applications and marine operations including navigation in...
Article
In some coastal regions of the Arctic Ocean, grounded ice ridges contribute to stabilizing and maintaining a landfast ice cover. Recently, a grounding scheme representing this effect on sea ice dynamics was introduced and tested in a viscous-plastic sea ice model. This grounding scheme, based on a basal stress parameterization, improves the simulat...
Article
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The polar regions have been attracting more and more attention in recent years, fuelled by the perceptible impacts of anthropogenic climate change. Polar climate change provides new opportunities, such as shorter shipping routes between Europe and East Asia, but also new risks such as the potential for industrial accidents or emergencies in ice-cov...
Article
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What: 120 scientists, stakeholders, and representatives from operational forecasting centers, international bodies, and funding agencies assembled to make significant advances in the planning of the Year of Polar Prediction; When: 13-15 July 2015; Where: WMO Headquarters, Geneva, Switzerland
Article
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A short-range high-resolution sea ice prediction system has been developed at Environment Canada. This study describes the first steps towards transitioning this system from a simple deterministic data assimilation system based on the three-dimensional variational (3D-Var) approach into a data assimilation system based on an ensemble of ensemble-va...
Article
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The availability of GODAE Oceanview-type ocean forecast systems provides the opportunity to develop high-resolution, short- to medium-range coupled prediction systems. Several groups have undertaken the first experiments based on relatively unsophisticated approaches. Progress is being driven at the institutional level targeting a range of applicat...
Article
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Operational ocean forecast systems provide routine marine products to an ever-widening community of users and stakeholders. The majority of users need information about the quality and reliability of the products to exploit them fully. Hence, forecast centres have been developing improved methods for evaluating and communicating the quality of thei...
Article
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The marine environment plays an increasingly important role in shaping economies and infrastructures, and touches upon many aspects of our lives, including food supplies, energy resources, national security and recreational activities. Global Ocean Data Assimilation Experiment (GODAE) and GODAE OceanView have provided platforms for international co...
Article
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The interannual-decadal variability of the wintertime mixed layer depths (MLDs) over the North Pacific is investigated from an empirical orthogonal function (EOF) analysis of an ensemble of global ocean reanalyses. The first leading EOF mode represents the interannual MLD anomalies centered in the eastern part of the central mode water formation re...
Article
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The dramatic reduction in the number of observation data from the Tropical Atmospheric Ocean (TAO)/ Triangle Trans-Ocean Buoy Network (TRITON) array since 2012 has given rise to a need to assess the impact of those data in ocean Data Assimilation (DA) systems. This paper provides a review of existing studies evaluating the impacts of data from the...
Article
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The GODAE OceanView systems use various data assimilation algorithms, including 3DVar, EnOI, EnKF and the SEEK filter with a fixed basis, using different time windows. The main outputs of the operational data assimilation systems, the increments, have been compared for February 2014 in various regions. The eddy-permitting systems’ increments are si...
Article
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As part of the work of the GODAE OceanView Inter-comparison and Validation Task Team (IV-TT), 6 global ocean forecasting systems spread across 5 operational oceanography forecast centres were inter-compared using a common set of observations as a proxy for the truth. The ‘Class 4’ in the title refers to a set of forecast verification metrics define...
Article
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This paper compares the performance of short-range operational ocean forecasts, using ‘observational space’ metrics developed under GODAE OceanView (GOV). Best estimates (behind the real-time analysis) and forecasts are inter-compared for the Australian region (0-50S, 90-180E) for 2013. Systems considered include those developed in Australia, Franc...
Article
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Under GODAE OceanView the operational ocean modelling community has developed a suite of global ocean forecast, reanalysis and analysis systems. Each system has a critical dependence on ocean observations - routinely assimilating observations of in-situ temperature and salinity, and satellite sea-level anomaly and sea surface temperature. This pape...
Article
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The mean flow and meso-scale eddy variability in the region around the Grand Banks of Newfoundland (GBN) are quantified by analyzing surface drifter observations, mean dynamic topography (MDT), along-track satellite altimeter observations, and the solutions of two high-resolution ocean models. By increasing the horizontal resolution from 6.5 km (CR...
Chapter
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In order to advance polar prediction capabilities, the WWRP Polar Prediction Project (PPP) has been established as one of three THORPEX (THe Observing System Research and Predictability EXperiment) legacy activities. The aim of PPP, a ten year endeavour (2013-2022), is to promote cooperative international research enabling development of improved w...
Article
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Intercomparison and evaluation of the global ocean surface mixed layer depth (MLD) fields estimated from a suite of major ocean syntheses are conducted. Compared with the reference MLDs calculated from individual profiles, MLDs calculated from monthly mean and gridded profiles show negative biases of 10–20 m in early spring related to the re-strati...
Article
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Global simulations are presented focusing on the atmosphere-ice-ocean (AIO) surface layer (SL) in the Arctic. Results are produced using an ocean model (NEMO) coupled to two different sea ice models: the Louvain-La-Neuve single-category model (LIM2) and the Los Alamos multicategory model (CICE4). A more objective way to adjust the sea ice-ocean dra...
Article
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As part of the CONCEPTS (Canadian Operational Network of Coupled Environmental PredicTion Systems) initiative, a high-resolution (1/12°) ice–ocean regional model is developed covering the North Atlantic and the Arctic oceans. The long-term objective is to provide Canada with short-term ice–ocean predictions and hazard warnings in ice-infested regio...
Article
Current large-scale sea ice models represent very crudely or are unable to simulate the formation, maintenance and decay of coastal landfast ice. We present a simple landfast ice parameterization representing the effect of grounded ice keels. This parameterization is based on bathymetry data and the mean ice thickness in a grid cell. It is easy to...
Article
In recent years, the demand for improved environmental forecasts in the North has intensified as maritime transport and offshore exploration increase. As a result, Canada has accepted responsibility for the preparation and issuing services for the new Arctic MET/NAV Areas XVII and XVIII. Environmental forecasts are being developed based on a new in...
Article
Recent increases in marine traffic in the Arctic have amplified the demand for reliable ice and marine environmental predictions. This paper presents the verification of ice forecast skill from a new system implemented recently at the Canadian Meteorological Centre called the Global Ice Ocean Prediction System (GIOPS). GIOPS provides daily global i...
Article
Full-text available
As part of the CONCEPTS (Canadian Operational Network of Coupled Environmental PredicTion Systems) initiative, The Government of Canada is developing a high resolution (1/12°) ice–ocean regional model covering the North Atlantic and the Arctic oceans. The objective is to provide Canada with short-term ice–ocean predictions and hazard warnings in ic...
Data
Ocean and sea ice conditions are simulated for the period 2003-2009 using the model configuration described in Dupont et al. (2015). The model includes the Arctic and the North Atlantic oceans, and has a horizontal resolution of 1/12 degree, equivalent to an average of approximately 5km in the Arctic. There are 50 vertical levels in the model. The...
Article
Uncertainty in ocean analysis methods and deficiencies in the observing system are major obstacles for the reliable reconstruction of the past ocean climate. The variety of existing ocean reanalyses is exploited in a multi-reanalysis ensemble to improve the ocean state estimation and to gauge uncertainty levels. The ensemble-based analysis of signa...
Article
Full-text available
Uncertainty in ocean analysis methods and deficiencies in the observing system are major obstacles for the reliable reconstruction of the past ocean climate. The variety of existing ocean reanalyses is exploited in a multi-reanalysis ensemble to improve the ocean state estimation and to gauge uncertainty levels. The ensemble-based analysis of signa...
Article
Full-text available
Deep convection in the Labrador Sea is an important component of the global ocean ventilation. The as-sociated loss of heat to the atmosphere from the interior of the sea is thought to be mostly supplied by me-soscale eddies, generated either remotely or as a result of convection itself—processes that are not resolved by low-resolution ocean climat...
Article
Despite the availability of several atmospheric reanalyses (e.g. ERA-Interim) there exists both considerable uncertainty in surface forcing fields for ice/ocean modelling and sensitivity to the choice of product used. Here we introduce a relatively high-resolution alternative forcing dataset for ice–ocean models derived from the Canadian Meteorolog...
Article
Our ability to simulate and understand oceanic conditions of the Gulf of St Lawrence (GSL) has significantly increased in the last decade with the development of regional ocean models combining scientific knowledge, oceanographic data, and comput-ing techniques. This has created opportunities for their integration with meteoro-logical forecast mode...
Article
Full-text available
Experiments assimilating the RAPID dataset of deep temperature and salinity profiles at 26.5◦N on the western and easternAtlantic boundaries into a 1◦ global NEMO ocean model have been performed. The meridional overturning circulation (MOC) is then assessed against the transports calculated directly from observations. The best initialization found...
Article
With the ever-increasing interest in resource exploitation and marine transport in the Arctic there is a mounting need for improved knowledge about the current and future environmental conditions in the Arctic. This need is being addressed in Canada by a tri-ministerial initiative called the Canadian Operational Network of Coupled Environmental Pre...