Variable Information Instructions

a.k.a., Instructions for providing information about current and historical data

We appreciate your help to provide information critical to interpreting your site’s data.

Important: Please review the site-specific instructions provided at the top of the Variable Information tool to help focus your effort.

The following sections provide instructions on how to use the Variable Information tool:

  • Section 1: Map standard AmeriFlux FP-In* formats to previously submitted data.
  • Section 2: Verify / Update height and instrument model information.
  • Section 3: Create a list of instrument models used to collect data.
  • Section 4: Tips for using the Variable Information tool.

* Note: FP-In is the current standardized format for uploading data to AmeriFlux. See Half-Hourly / Hourly Data Upload Format for details.

Special case are described in the FAQ. Contact with questions.

How long will this take?

We estimate 1-2 hours depending on the complexity of your data. We recommend providing as much information as you can now. More details can be added at a later time.

What will you need?

We recommend that you have an example of a submitted data file from your site available.
Instrument installation notes and documentation can also be helpful.


Section 1: Map FP-In Variables to historical data

Why is this information important? First, while we have attempted to map your older data to FP-In format, it is crucial that tower team personnel verify these mappings. Secondly, AmeriFlux users will be able to better understand and relate historical versions of your data to the newer FP-In format. Finally, traceability between iterations of data products is good data science.

If this is your first time verifying variable associations, values in the FP-In Variable column are our best guess at naming variables in the FP-In format.
We need you to confirm these FP-In Variables or correct them.
See site-specific instructions at the top of the Variable Information tool that explain how these mappings will be used for your site.

(1) Use the table on the Variable Information tab. Click the tab if not already selected.
Older (historical) data are listed in the gray columns and cannot be edited. If you detect errors, contact
Information about current data are listed in white columns and can be edited.
Hover over column names and grey cells for additional details.

(2) Compare previous data information (gray columns) with FP-In Variable column.
Use the tool tips in the column headers to learn more about the historical information.
The Customize Columns feature (located above the table on the right) can be used to see additional historical information.

(3) Update the FP-In Variable as follows:

  • If correct, leave the FP-In Variable as is. The information is already saved, but you may use the checkbox to indicate that the FP-In Variable name is correct (row becomes green).
  • If incorrect, modify the FP-In Variable (row becomes light green).
  • If the older variable is no longer included as part of your entire data record, delete the FP-In Variable (row becomes light green).
  • If you are unsure about a mapping, delete the FP-In variable (row becomes light green).
  • Variable mappings can be updated later.
  • Only variables provided using a valid FP-In format will be published in the AmeriFlux standard data product. The full list of FP-In Variables are listed in the dropdown menu by clicking on the right button of a FP-In Variable cell once you click on the cell. Qualifiers can be added as needed. Non-standard variables can be provided but will not be published. Contact to request support for additional variables.
  • If this is your first time inspecting the Variable Information tab, we have pre-filled the FP-In Variable column with our best guess of the corresponding FP-In Variable.
  • If we do not receive updates or edits of the prefilled FP-In Variables, we will consider them as an accurate mapping to older versions of submitted variables.


Section 2: Provide Height and Instrument Model Information

Height and instrument model information are two of the most requested types of supporting information that users request for AmeriFlux data.* Information supplied via the Variable Information tool will be made available to users of your site’s data.

* Collection of more detailed information, such as serial number, horizontal locations, and calibration information, will be supported in the future.

To provide height and instrument model information:

(1) Use the table on the Variable Information tab. Click the tab if not already selected.

(2) Add / Update Height and Instrument Model Information as needed.
Add / Update height information in meters. Use negative values for depths below the soil surface.
To update Instrument Model information, first complete the Instrument Model List tab (see Section 3). Select instrument models used at your site from the menu.
Select Show Historical Instruments to view previously provided information in the Instrument Model column.

(3) To add variables not previously submitted, click the New Variable button.
Enter the variable name in the FP-In Variable column.
You can enter multiple variables at a time (see instructions in Section 4).
Newly added rows will be highlighted in light green.

(4) Segment the data record to add changes in Height and/or Instrument Model that occur within the data record.
Click the Add button in the row of the variable whose information changed.
In the popup window, enter the changed height and / or instrument model information. Enter the Start Date when the change occured. See Section 4 for how to reuse information from the same instrument.
Select the Enter button, and a new row with the information will be inserted into the table. The segment will be marked with a before the FP-In Variable.

(5) At any time during review, Save your work.
Rows that are saved will have their color changed from light green to green.
If errors are present, your work will not be saved. Click on each in the table for details about making corrections.
If an unusual value is detected, it will also be indicated with .
Remember to Save before leaving the page.


Section 3: Instrument Model List

To better associate instrument models with data variables, we need to know the instrument models used at your site in the past and presently.

Include all instrument models that have been used / are used to collect data submitted to AmeriFlux.
If many instruments of the same model type have been used, the instrument model only needs to be listed once.

To generate / update your site’s instrument model list:

  1. Select the Instrument Model List tab (click the tab) if it is not already selected.
  2. Use checkboxes to select the instrument models used at your site from the predefined list on the left. Selected models will be added to the Instrument Model List located on the right.
    • To remove an instrument model from the list, uncheck the checkbox.
    • If a model is not in the predefined list, select “Other” model type, enter details in the Comment field, and select the checkbox.
  3. Click the Save List button to save changes at any time. You can return to the list later to make further updates.

Tips for generating / updating your site’s instrument model list:

  • Hover over the model abbreviation for more details about the instrument model.
  • View historical information that your site has previously supplied as a reference (open list located on the lower left side of the tab).
  • Click the Import button to select a previously generated instrument model list. Use caution, importing a model list from another site will replace the current site’s list.


Section 4: Tips for using the Variable Information tool

General Tips

  • In the column Start Date for Height / Instrument Model, a cell filled with “start of data” indicates that the height and instrument model specified in that row was used from the starting timestamp of your half-hourly / hourly data. There is no need to fill in the start date for your data record.
  • For flux variables, you may provide two instrument models: a gas analyzer and sonic anemometer if appropriate.
  • Check the Show Historical Instruments checkbox to view historical instrument model information displayed in the Instrument Model column. If the instrument model is not updated using a standardized name included in the predefined list on the Instrument Model List tab, the instrument model will be published as “Other.”
  • Customize the table by selecting which columns are shown and by sorting the rows.
  • Hover over column names and gray cells for additional details.
  • Any rows left unchecked (white) will be assumed to have a correct mapping to older data (if applicable), FP-In Variable, and height / instrument model information.
  • All checkboxes and highlighting are applicable in the current session only. Marked rows will be unchecked (white) upon next visit to the website.

How to reuse height and instrument model information from the same instrument

The Variable Information tool supports a feature that allows reusing information from the same instrument for multiple variables collected by the instrument. To do so:

  1. Enter information for one of the variables collected by the instrument.
  2. For each additional variable that is collected by the instrument, select the in the Reuse values from… column in the additional variable’s row.
    • The table that pops up will show all unique combinations of height, instrument model, start date, and comment that currently exists in the table.
  3. Locate and select the combination that corresponds to the correct instrument.
    • The values will be inserted into the additional variable’s row.

How to enter multiple rows of data (i.e., using copy and paste)

The Variable Information tool supports a feature that allows entering multiple rows of data at once for columns FP-In Variable, Height, Start Date, and Comments.

Important: Proceed with caution. Column order must match or values will be entered incorrectly. Leave cells with no values empty.
Consider saving your work before entering multiple rows. If something goes amiss, reload the page to go back to the previously saved information (note: any row highlighting will be lost).

Note: Any combination of the FP-In Variable, Height, Start Date, and Comments columns may be copied/pasted. The entire row must be copy/pasted at the same time (i.e., you can not copy/paste individual columns).


  1. Arrange values to be copied in a spreadsheet (e.g., MS Excel or Google Spreadsheets) in the order that columns appear in the Variable Information table.
    • Do not worry about columns that may be intermixed in the table (e.g., Instrument Model). The tool will skip these columns when you paste the values.
    • Leave cells empty if there is no value to be copied/pasted.
  2. Copy the cells in spreadsheet. Do not copy the header row if you have one.
  3. On the Variable Information table, add a new variable (click the New Variable button).
    • A new row will be inserted into the table. The cursor will be located in the FP-In Variable column of this new row.
  4. With the cursor inside the FP-In Variable column of the new row, paste the cells from the spreadsheet.
    • Each row from the spreadsheet will be placed in the table in a new row below.
  5. For each of the new rows pasted into the table, select the Instrument Model from the row’s dropdown menu.