Modular Ocean Model
Encyclopedia
The modular ocean model is a three-dimensional ocean circulation model designed primarily for studying the ocean
climate
system. The model is developed and supported primarily by researchers at the National Oceanic and Atmospheric Administration
's Geophysical Fluid Dynamics Laboratory
(GFDL).
and Mike Cox. This code, along with a version generated at GFDL by Bert Semtner is the ancestor of many of the level-coordinate ocean model codes run around the world today. In the late 1980s, Ron Pacanowski, Keith Dixon, and Tony Rosati at GFDL rewrote the code in a modular form, enabling different options and configurations to be more easily generated and new physical parameterizations to be more easily included. This version became known as Modular Ocean Model v1.0 (MOM1). Subsequent development of the code by Pacanowski, Stephen Griffies and Matt Harrison at GFDL with considerable input from a scientific community of hundreds of users has resulted in significant evolution of the code up to the current version, designated MOM4. The development effort is currently headed by Stephen Griffies.
MOM has traditionally been a level-coordinate ocean model, in which the ocean is divided into boxes whose bottoms are located at fixed depths. Such a representation makes it easy to solve the momentum equations and the well-mixed, weakly stratified layer known as the ocean mixed layer
near the ocean surface. However, level coordinate models have problems when it comes to the representation of thin bottom boundary layers (Winton et al., 1998) and thick sea ice. Additionally, because mixing in the ocean interior is largely along lines of constant potential density rather than along lines of constant depth, mixing must be rotated relative to the coordinate grid- a process that can be computationally expensive. By contrast, in codes which represent the ocean in terms of constant-density layers (which represent the flow in the ocean interior much more faithfully)- representation of the ocean mixed layer becomes a challenge.
MOM4 is used as a code base for the ocean component of the GFDL coupled models used in the IPCC
assessment reports, including the GFDL CM2.X
model series. Earlier versions have been used in hundreds of scientific papers by authors around the world. MOM3 is used as the basis for the El Nino prediction system employed by the National Centers for Environmental Prediction
.
Ocean
An ocean is a major body of saline water, and a principal component of the hydrosphere. Approximately 71% of the Earth's surface is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas.More than half of this area is over 3,000...
climate
Climate
Climate encompasses the statistics of temperature, humidity, atmospheric pressure, wind, rainfall, atmospheric particle count and other meteorological elemental measurements in a given region over long periods...
system. The model is developed and supported primarily by researchers at the National Oceanic and Atmospheric Administration
National Oceanic and Atmospheric Administration
The National Oceanic and Atmospheric Administration , pronounced , like "noah", is a scientific agency within the United States Department of Commerce focused on the conditions of the oceans and the atmosphere...
's Geophysical Fluid Dynamics Laboratory
Geophysical Fluid Dynamics Laboratory
The Geophysical Fluid Dynamics Laboratory is a laboratory in the National Oceanic and Atmospheric Administration /Office of Oceanic and Atmospheric Research . The current director is Dr. V...
(GFDL).
Overview
The MOM model series owes its genesis to work at GFDL in the late 1960s by Kirk BryanKirk Bryan (oceanographer)
Kirk Bryan is an American oceanographer who is considered to be the founder of numerical ocean modeling. Starting in the 1960s at the Geophysical Fluid Dynamics Laboratory, then located in Washington, D.C., Bryan worked with a series of colleagues to develop numerical schemes for solving the...
and Mike Cox. This code, along with a version generated at GFDL by Bert Semtner is the ancestor of many of the level-coordinate ocean model codes run around the world today. In the late 1980s, Ron Pacanowski, Keith Dixon, and Tony Rosati at GFDL rewrote the code in a modular form, enabling different options and configurations to be more easily generated and new physical parameterizations to be more easily included. This version became known as Modular Ocean Model v1.0 (MOM1). Subsequent development of the code by Pacanowski, Stephen Griffies and Matt Harrison at GFDL with considerable input from a scientific community of hundreds of users has resulted in significant evolution of the code up to the current version, designated MOM4. The development effort is currently headed by Stephen Griffies.
MOM has traditionally been a level-coordinate ocean model, in which the ocean is divided into boxes whose bottoms are located at fixed depths. Such a representation makes it easy to solve the momentum equations and the well-mixed, weakly stratified layer known as the ocean mixed layer
Mixed layer
The oceanic or limnological mixed layer is a layer in which active turbulence has homogenized some range of depths. The surface mixed layer is a layer where this turbulence is generated by winds, cooling, or processes such as evaporation or sea ice formation which result in an increase in salinity...
near the ocean surface. However, level coordinate models have problems when it comes to the representation of thin bottom boundary layers (Winton et al., 1998) and thick sea ice. Additionally, because mixing in the ocean interior is largely along lines of constant potential density rather than along lines of constant depth, mixing must be rotated relative to the coordinate grid- a process that can be computationally expensive. By contrast, in codes which represent the ocean in terms of constant-density layers (which represent the flow in the ocean interior much more faithfully)- representation of the ocean mixed layer becomes a challenge.
MOM4 is used as a code base for the ocean component of the GFDL coupled models used in the IPCC
Intergovernmental Panel on Climate Change
The Intergovernmental Panel on Climate Change is a scientific intergovernmental body which provides comprehensive assessments of current scientific, technical and socio-economic information worldwide about the risk of climate change caused by human activity, its potential environmental and...
assessment reports, including the GFDL CM2.X
GFDL CM2.X
GFDL CM2.X is a coupled atmosphere-ocean general circulation model developed at the NOAA Geophysical Fluid Dynamics Laboratory in the United States...
model series. Earlier versions have been used in hundreds of scientific papers by authors around the world. MOM3 is used as the basis for the El Nino prediction system employed by the National Centers for Environmental Prediction
National Centers for Environmental Prediction
The United States National Centers for Environmental Prediction delivers national and global weather, water, climate and space weather guidance, forecasts, warnings and analyses to its Partners and External User Communities...
.
External links
- http://www.gfdl.noaa.gov/~lat/webpages/om/om_webpage.html
- http://www.gfdl.noaa.gov/~smg/pointers/geo_physics_abstracts/guide.pdf For a detailed guide to the codes and parameterizations of subgridscale processes.