Subsetting of the regions is made possible through SHBAAM (Satellite Hydrology Bits Analysis And Mapping)

The following steps highlight the several functions of the GRACE web app

1. Select a Region

   Click the "Select a Region" dropdown and select an option

   Or simply select the Global Map tab from the navigation pane

2. View different storage types

   You have four options to choose from:

   • Total Water Storage Anomaly(GRACE Data), Surface Water Storage Anomaly(derived from GLDAS Model), Soil Moisture Storage Anomaly(derived from GLDAS Model), Groundwater Storage Anomaly(Calculated/inferred using previously mentioned storage types).
3. View different signal solutions

   You have four options to choose from:

   • JPL, CSR, GFZ, or an ensemble average of the three previously mentioned solutions.
   • Studies have shown that each of these solutions may prove to be more accurate in different locations in the world. A citation of articles may be provided in the future for reference.
4. View different timesteps

   You have two options to choose from:

   • Move the slider in the lower left-hand corner of the map
   • Select a date from the dropdown on the left
5. View Animation
   • Use the animation controls in the lower left-hand corner of the map to start or stop animation
   • Use the fps slider on the right side of the control bar to increase and decrease animation speed
6. Contour/Map Settings
   • Use the Select symbology dropdown to view different color schemes for the map contours.
   • Use the Max and Min toggles in the top left corner of the page to adjust the contour values. The opacity toggle allows you to adjust the transparency of the map data layer
7. View Time Series

   The Grace application allows the user to generate a time series plot for a specific location. To generate a time series:

   • Click on the Marker Icon on the left side of the map, then place the marker within the data region.
   • The Time Series for that point will be generated below the map.

   Note: You can also click anywhere on the time series graph to change the layer shown on the map to a specific time. The time series can be exported in a number of formats by clicking the menu button on the chart(top-right).

8. Click 'Exit' in the top-right of the app to return to the Main Apps Library

External Resources and Links:

View Code

About SERVIR

Privacy and Terms of Conditions

A Developers API is provided for those who wish to incorporate the GRACE Tethys APP data into their own separate application or script.

API Methods

All API methods must be called using the following pattern:

/apps/[parent-app]/api/[MethodName]/?param1=value1&param2=value2&...paramN=valueN

See documentation and specific examples for all available methods below.

GetPointValues

Example:

Since the satellite mission began, the JPL, CSR, and GFZ solutions have been provided by the official GRACE Science Data System. The differences between these solutions are often small and fall within the error bounds of the raw GRACE data. Several papers have been written regarding the benefits of using different solutions in different parts of the world. For your reference, these papers are cited below:

One paper in particular suggested that the ensemble average of the three signal solutions proved to be most acurate. This solution is the reccomendation given to users on the grace.jpl.nasa.gov website where the grace data is distributed.

See below:

Explain Grid Resolution and Total Water Storage

Explain Leakage Errors, Measurement Errors, and Scale Factors Layers

Explain GLDAS data and calculating proper mean

Explain how Groundwater was derived

Link to shell script for reference