{"id":425,"date":"2025-11-17T19:59:30","date_gmt":"2025-11-17T19:59:30","guid":{"rendered":"https:\/\/atmos.ucla.edu\/roms\/?page_id=425"},"modified":"2025-11-20T15:43:36","modified_gmt":"2025-11-20T15:43:36","slug":"home","status":"publish","type":"page","link":"https:\/\/atmos.ucla.edu\/roms\/","title":{"rendered":"Home"},"content":{"rendered":"\n<p>The Regional Oceanic Modeling System (ROMS) is a circulation code<br>adaptable to different simulation domains ranging from basins to<br>estuaries. With suitable bathymetery, initialization, and forcing,<br>its goal is realism falsifiable by measurements. The ocean is highly<br>variable and heterogeneous, and the scope for novel modeling<br>applications is great.<\/p>\n\n\n\n<p>Its inception was an invitation by Scott Harper of the U.S. Office of<br>Naval Research to Dale Haidvogel and Jim McWilliams to create a new<br>simulation model. The primary focus was algorithmic. ROMS was<br>innovative with respect to its combination of an air-sea free surface,<br>a terrain-following vertical coordinate, higher-order diffusive<br>advection, pressure-gradient calculation, barotropic-baroclinic<br>mode splitting, higher-resolution nested subdomains, and time<br>stepping. These elements have endured with continuing model<br>evolution.<\/p>\n\n\n\n<p>ROMS is based on the incomressible, hydrostatic (Primitive) equations<br>that are appropriate to anisotropic currents with a horizontal scale<br>greater than, say, 1 km. Recent extensions are made to<br>non-hydrostatic dynamics for smaller-scale currents, even down to the<br>practices of Large-Eddy Simulations, at least in preliminary<br>simulations. Its subgrid-scale components are deliberately minimal,<br>with explicit vertical mixing schemes only in the surface and bottom<br>boundary layers and in interior regions with small Richardson number<br>(weak or negative stratification and strong vertical shear); these<br>parameterizations are likely to be adapted as model applications move<br>toward grids with a horizontal resolution dx less than 10 m.<\/p>\n\n\n\n<p>As a physical model it provides a foundation for various couplings<br>with other modeling systems: oceanic biogeochemistry, sediment<br>movement, surface gravity waves, data assimilation, and atmospheric<br>circulation and chemistry.<\/p>\n\n\n\n<p>ROMS is widely used by the sub-global, sub-climate oceanic modeling<br>community. It now has multiple distribution homes, and the UCLA group<br>continues to be a principal innovator and user.<\/p>\n\n\n\n<p>The UCLA ROMS code is open source, with a distribution at<br><a href=\"https:\/\/github.com\/CESR-lab\/ucla-roms\/\">https:\/\/github.com\/CESR-lab\/ucla-roms\/<\/a>. We are a small group of<br>scientists whose primary goal is scientific publications about<br>phenomenological discovery and dynamical interpretation. Hence, our<br>ability to provide training and trouble-shooting for a wider audience<br>is limited, although we aspire to be helpful. Reports of code errors<br>are welcome, of course.<\/p>\n\n\n\n<p>A list is appended of the actively collaborating group members at UCLA<br>and elsewhere.<\/p>\n\n\n\n<p>Also appended is an illustrative animation of the surface current<br>speed in a realistic Pacific Ocean simulation with dx = 6 km and<br>high-frequency surface and tidal forcing. The duration is half a<br>year.  Click to enlarge in a new window.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/atmos.ucla.edu\/roms\/wp-content\/uploads\/sites\/21\/2025\/11\/pachug_amp_an3.webp\" target=\"_blank\" rel=\" noreferrer noopener\"><img decoding=\"async\" src=\"https:\/\/atmos.ucla.edu\/roms\/wp-content\/uploads\/sites\/21\/2025\/11\/pachug_amp_an3.webp\" alt=\"\" \/><\/a><\/figure>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>The Regional Oceanic Modeling System (ROMS) is a circulation codeadaptable to different simulation domains ranging from basins toestuaries. With suitable bathymetery, initialization, and forcing,its goal is realism falsifiable by measurements. The ocean is highlyvariable and heterogeneous, and the scope for novel modelingapplications is great. Its inception was an invitation by Scott Harper of the U.S&#8230;.<\/p>\n","protected":false},"author":3,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-425","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/atmos.ucla.edu\/roms\/wp-json\/wp\/v2\/pages\/425","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/atmos.ucla.edu\/roms\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/atmos.ucla.edu\/roms\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/atmos.ucla.edu\/roms\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/atmos.ucla.edu\/roms\/wp-json\/wp\/v2\/comments?post=425"}],"version-history":[{"count":9,"href":"https:\/\/atmos.ucla.edu\/roms\/wp-json\/wp\/v2\/pages\/425\/revisions"}],"predecessor-version":[{"id":442,"href":"https:\/\/atmos.ucla.edu\/roms\/wp-json\/wp\/v2\/pages\/425\/revisions\/442"}],"wp:attachment":[{"href":"https:\/\/atmos.ucla.edu\/roms\/wp-json\/wp\/v2\/media?parent=425"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}