Web Site Description

The NOAA ESRL GMD Carbon Cycle Interactive Atmospheric Data Visualization (IADV) Web site provides graphs of Carbon Cycle data, including our most up-to-date measurements, to the scientific community, as well as the general public, educators, students, the press, business and government policymakers.

Measurements of atmospheric carbon dioxide (CO2, beginning ~1980), methane (CH4, beginning 1983), carbon monoxide and molecular hydrogen (CO and H2, 1988), the stable isotopes of carbon dioxide (δ13C and δ18O of CO2, 1990), nitrous oxide and sulfur hexafluoride (N2O and SF6, 1996), and the stable isotopes of methane (δ13C of CH4, 1998) from discrete samples collected at more than 100 fixed surface locations and on aircraft and ships of opportunity are the cornerstone of the available data. Continuous CO2 and CH4 measurements from 4 GMD baseline observatories and continuous CO2 measurements from multiple levels on tall towers will also be made readily available.

Visitors may (1) view all data including near real-time preliminary Carbon Cycle measurement results; (2) obtain details about each sampling location; (3) manipulate and compare Carbon Cycle data sets; (4) create custom graphs; and (5) view their plots on-line with an option to save graphs in PDF format.

This web site is work in progress. Not all features are currently operational. Thank you for your patience.

Carbon Cycle Data

Carbon Cycle data are freely available directly from GMD and from the CDIAC and WMO WDCGG data archive centers. Before Carbon Cycle actual data are made available, they must undergo critical evaluation. Evaluation procedures ensure that (1) the standard reference gases used in making the measurements in Boulder and in the field are well characterized (i.e., calibrated before and after their use); (2) samples compromised during collection or analysis are identified, and (3) valid samples not representative of typical background conditions are identified. Quality control of the data requires considerable time and effort and is an essential part of Carbon Cycle operations.

Warning: Preliminary data include the Carbon Cycle's most up-to-date data and have not yet been subjected to rigorous quality assurance procedures. Preliminary data viewed from this site are "pre-filtered" using tools designed to identify suspect values. Filtering is performed each time a data set containing preliminary data is requested. Filtering, however, cannot identify systematic experimental errors and will not be used in place of existing data assurance procedures. Thus, there exists the potential to make available preliminary data with systematic biases. In all graphs, preliminary data are clearly identified. Users are strongly encouraged to contact Carbon Cycle (Dr. Pieter Tans, Group Chief [pieter.tans@noaa.gov]) before attempting to interpret preliminary data.

Learn more about Carbon Cycle measurements from this Web site and from the literature.

Getting Started

The IADV home page displays an interactive map showing Carbon Cycle sampling locations. Position the mouse over a sampling location to view a summary of available Carbon Cycle measurements from the site. The Popup summary may be de- or re-activated by pressing the hypertext just below the map title. Change the map view by clicking on the thumbnail images below the displayed map. Only locations displayed in the loaded map view may be selected.

Select a sampling location in one of three ways:

• Position the mouse over a site on map and press left mouse button
• Select a location from the pulldown site list
• Enter the 3-letter site code (e.g., BRW, MLO, etc...) or enough letters to uniquely identify the site (e.g., Barrow, Mauna, etc...) in the text input field and press the "Search" button

The user's current selection is shown in the shaded area on the left side of the page. By default, the IADV home page sets the current selection to Mauna Loa, Hawaii. Please note: The pulldown list and text input field respond to the mouse's movement over the map. Click on a site to change the current selection.

The Web site provides two Display Modes: Basic and Advanced. The Basic Display Options allow users to learn more about the sampling location and view several graphs that highlight features in the observations. The Advanced Display Options allow users to create custom graphs. Toggle between the two display modes by pressing the hypertext just below the active display option title.

Basic Display Options

In Basic mode, users may view graphs that are prepared and updated automatically. The list of available products will continue to grow as the IADV Web site evolves. Once the sample location is selected select a product option (e.g., time series, seasonal patterns, vertical profiles, site description). Some options require specification of gas and data type. Data type includes the sampling strategy and sample collection height. The submit button processes the user's request.

Advanced Display Options

Use Advanced Display Options to create custom graphs including overlays and multi-panel graphs. Select up to 12 data sets from one or more sampling locations for the "data cart". Once the cart has the desired data sets, select a graphing option and press the submit button to continue with custom graphing.

Advanced Display Options - Time Series

Advanced display options are currently available only for time series data. This option allows the user to create graphs with a specified X-axis, Y-axis, and data sets in one to four frames. Click on a frame number to specify or modify the parameters for the specific frame. To specify a range for the X-axis, select "custom scale". Enter a minimum and maximum value, the number of major divisions between the minimum and maximum value, and the the number of minor divisions between each major division. All frames on the page will then display a consistent scale for the X-axis. The Y-axis can vary on each frame. Select a frame and specify the custom Y-axis scale. Select the data set(s) to be plotted in the frame. Selecting another frame will automatically save the settings for the current frame or press "Get Plot". If desired, click on the data set hypertext to change the appearance of data symbols, smooth curve and trend lines. Press "Set" to save changes. Repeat this process for each data set in the cart. The custom graph can be viewed on-line and may also be saved in PDF format.

Request for Feedback

We welcome your suggestions and comments regarding this site. Please e-mail your comments to Dan Chao (danlei.chao@noaa.gov). If the site does not appear to be operating correctly, include in your e-mail the name and version of the browser, operating system, and a complete description of problem.