GoMSS Nowcast System

The GoMSS Nowcast system is a software automation system that run the GoMSS (Gulf of Maine and Scotian Shelf) NEMO ocean model in a daily nowcast mode. The runs use as-recent-as-available forcing data or model products for open boundary conditions, river run-off flows, and atmospheric forcing. The atmospheric forcing comes from an Environment Canada high-resolution GEM 2.5km resolution model.

The runs are automated using an asynchronous, message-based architecture provided by the NEMO_Nowcast framework package. GoMSS_Nowcast is the Python package that uses the NEMO_Nowcast framework to implement the GoMSS Nowcast system.

Please see NEMO Nowcast Framework Architecture for a description of the system architecture.

The system runs on nemo2 host in the cluster.mathstat.dal.ca HPC cluster at Dalhousie University where it:

  • obtains the forcing datasets from web services

  • pre-processes the forcing datasets into the formats expected by NEMO

  • executes the run

to produce a daily nowcast of the state of the Gulf of Maine and Scotian Shelf region on the east coast of Nova Scotia.

Results of the automated daily model runs can be found in /data1/dlatornell/nowcast-sys/results/.

The system is patterned after, and uses some of the same software as, the Salish Sea NEMO Nowcast system.

Process Flow

The system workflow looks like:


Work flow of preparation for and execution of the daily runs.

The green, pink, and blue boxes in the figure above are GoMSS Nowcast System Workers/ They are Python processes that are launched by the system to do a particular job and terminate when that job is finished. The workers are defined in Python modules in the nowcast.workers and nemo_nowcast.workers namespaces.

The Scheduler is a long-running process that periodically checks the system clock and launches workers when their scheduled time to run is reached.


Licensed under the Apache License, Version 2.0

The GoMSS_Nowcast system code and documentation are copyright 2016-2019 by Doug Latornell, 43ravens.

They are licensed under the Apache License, Version 2.0. http://www.apache.org/licenses/LICENSE-2.0 Please see the LICENSE file for details of the license.