Introduction

September 29, 2025 · View on GitHub

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Visualization Environment for Rich Data Interpretation (VERDI): User’s Manual

U.S. EPA Contract No. EP-W-09-023, “Operation of the Center for Community Air Quality Modeling and Analysis (CMAS)”
Prepared for: Daiwen Kang
U.S. EPA, ORD/CEMM/AESMD/ADMB
E243-04 USEPA Mailroom
Research Triangle Park, NC 27711

Prepared by: Liz Adams (UNC-IE) and Yadong Xu (USEPA)
Date: Aug 13, 2025

Introduction

Background

This manual describes how to use the Visualization Environment for Rich Data Interpretation (VERDI). VERDI is a flexible and modular Java-based visualization software tool that allows users to visualize multivariate gridded environmental datasets created by environmental modeling systems such as the Community Multiscale Air Quality (CMAQ) modeling system, the Weather Research and Forecasting (WRF) modeling system, and Model for Prediction Across Scales (MPAS). These systems produce files of gridded concentration and deposition fields that users need to visualize and compare with observational data both spatially and temporally. VERDI can facilitate these types of analyses.

Initial development of VERDI was done by the Argonne National Laboratory for the U.S. Environmental Protection Agency (EPA) and its user community. Argonne National Laboratory work was supported by the EPA through U.S. Department of Energy contract DE-AC02-06CH11357.  Further development has been performed by the University of North Carolina Institute for the Environment under U.S. EPA Contract No. EP-W-05-045 and EP-W-09-023, by Lockheed Corporation under U.S. EPA contract No. 68-W-04-005, by General Dynamics Information Technology under U.S. EPA contract No. GS00Q09BGD0025 and Argonne National Laboratory.  VERDI is licensed under the GNU General Public License (GPL) version 3, and the source code is available through https://github.com/CEMPD/VERDI.  Instructions for developers within the community are included in the VERDI Developer Instructions (see Section 1.3). VERDI is supported by the Community Modeling and Analysis System (CMAS) Center under U.S. EPA Contract No. EP-W-09-023. The batch script and VERDI Script Editor were developed and documented under U.S. EPA Contract No. EP-D-07-102, through an Office of Air Quality Planning and Standards project managed by Kirk Baker. The CMAS Center is located within the Institute for the Environment at the University of North Carolina at Chapel Hill.

This manual describes VERDI version 2.2 released in September 2025.

The following are useful web links for obtaining VERDI downloads and support:

  1. VERDI Visualization Tool web site:

http://www.cmascenter.org/verdi

  1. CMAS download page for users of VERDI (requires a CMAS account):

https://www.cmascenter.org/download/forms/step_2.cfm?prod=11

  1. CMAS GitHub website for developers of VERDI:

https://github.com/CEMPD/VERDI

  1. VERDI Frequently Asked Questions (FAQs):

https://www.cmascenter.org/help/faq.cfm

Use pulldown menu to select VERDI product to view its FAQs.

  1. To query and ask questions use the new CMAS User Forum, by selecting the VERDI category: https://forum.cmascenter.org/c/verdi

  2. To query the older M3USER listserv for VERDI related technical support questions and answers: http://lists.unc.edu/read/?forum=m3user

  3. To query bugs and submit bug reports, questions, and/or requests:

https://github.com/CEMPD/VERDI/issues

Where to Obtain VERDI

You can download the latest version of VERDI from https://www.cmascenter.org/verdi/ (PDF see ([Fig-@fig:Figure1]) and ([Fig -@fig:Figure2])) (Github see: Figure1-1 and Figure 1-2). When you click on DOWNLOAD to download VERDI, you will be sent to the CMAS Model Download Center. To download and install VERDI, follow the instructions below, beginning at step 4. Alternatively, you may also begin at the CMAS web site https://www.cmascenter.org, and follow the instructions below:

  1. Log in using an existing CMAS account, or create a new CMAS account.

  2. Click the Download drop-down list and choose SOFTWARE.

  3. From the Software Download, Step 1 page go to the box Select Software to Download on the right side of the page. Use the drop-down list to select VERDI, and then click Submit.

  4. Select the product you wish to download, as shown in Figure 3 ([Fig1-@fig:Figure3])) . Also specify the type of computer on which you will run VERDI (i.e., Linux PC, Windows, or Other) from the items in the scroll list. Note that the compilers question is not relevant for VERDI so please select Not Applicable. Finally, click Submit.

  5. As shown in Figure 4 ([Fig1-@fig:Figure4])) follow the links to the appropriate version of the Linux, Mac, or Windows installation files. Links are also available for the current version of the documentation.

Figure 1. Top of VERDI Page; note DOWNLOAD and DOCUMENTATION links.

Top of VERDI Page{#fig:Figure1}

Figure 2. Bottom of VERDI Page

Bottom of VERDI Download Page{#fig:Figure2}

Figure 3. Downloading VERDI from the CMAS Web Site, Step 2.

Downloading VERDI from the CMAS Web Site, Step 2{#fig:Figure3}

Figure 4. Downloading VERDI from the CMAS Web Site, Step 3

Downloading VERDI from the CMAS Web Site, Step 3{#fig:Figure4}

Where to Obtain VERDI Documentation

Documentation is available in several locations, described below. Each location provides links to the available documentation for VERDI, which can be viewed in your web browser or downloaded and saved to your computer.

  • The main VERDI page has a link to Documentation.

  • The VERDI download page on the CMAS website contains links to all of the available documentation.

  • On the left-hand side of the www.cmascenter.org web site, open the drop-down menu for Help and choose Documentation. Select the documentation for VERDI from the drop-down list and click Search. Select the model release from the drop-down list and click Search. The resulting documentation pane shows that the available documentation for the chosen release of VERDI GitHub:Figure 5 or PDF:[Fig-@fig:Figure5].

Figure 5. VERDI Documentation on the CMAS Web Site

VERDI Documentation on the CMAS Web Site{#fig:Figure5}

  • To go directly to the most recent VERDI documentation click on DOCUMENTATION from the VERDI software: http://www.cmascenter.org/verdi. Figure 6 shows the list of documentation that is available for download for VERDI 2.2.

Figure 6. VERDI Documentation on the CMAS Web Site

VERDI Documentation on the CMAS Web Site{#fig:Figure6}

Help Desk Support for VERDI

You are encouraged to search the new CMAS User Forum, by selecting the VERDI category: https://forum.cmascenter.org/c/verdi or using the old M3USER listserv for VERDI-related technical support questions; report errors and/or requests for enhancement to the m3user forum. The m3user forum is supported by the community and also by CMAS to help users resolve issues and identify and fix bugs found in supported software products.

Future VERDI Development

As stated in Schwede et al. (2007),[1] “VERDI is intended to be a community-based visualization tool with strong user involvement.” The VERDI source code is available to the public under a GNU Public License (GPL) license at https://github.com/CEMPD/VERDI. This allows users who wish to make improvements to VERDI to download the software, and to develop enhancements and improvements that they believe may be useful to the modeling community. Examples could include user-developed readers for additional file formats and modules for additional plot types. Users may wish to contribute data analysis routines, such as adding the ability to do bilinear interpolation (smoothing), or to contribute other enhancements to the existing plot types. The direction of future development will depend on the resources and the needs of the modeling community. If you are interested in contributing code to VERDI, please review the information in Chapter 14, “Contributing to VERDI Development.”

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VERDI User Manual (c) 2025