RAIN-Global 2

Data Layers

Toggle on/off:

Opacity:

Soften edges (beta):

SciVisColor.org Blue/Ylw/Orange
ColorBrewer.org Spectral
ColorBrewer.org YellowGreen
ColorBrewer.org Blues+BlGrnYlw
ColorBrewer.org Red/Purple
ColorBrewer.org Greens+Purples
ColorBrewer.org Purple/Orange
ColorBrewer.org Grays

Clouds/rates transition blending (%): 30

Min. rate (mm/hr):

Accumulation Range (mm):

Phase Range (probability of Liquid Phase, %):

Night level (%): 70

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Time seek (hours; paused only):

Quality:

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Welcome to RAIN-Global 2!

RAIN-Global 2 is a high-performance web interface that displays animations of precipitation rates and accumulations from NASA's GPM IMERG data on an interactive virtual globe. Press "Play" to see the animation, and use your mouse/trackpad to navigate. Click "Data Layers" to see advanced controls.
Now viewing: Global IMERG-Late estimates for the yyyy-mm-dd , 2359 UTC

New features in RAIN-Global 2:

This tool encourages a deeper level of data exploration with these enhanced features:

View liquid and frozen precipitation rates side-by-side.
Select 3-day, 7-day, 10-day, or 14-day animations.
View the diurnal cycle with an animated day/night basemap.
Toggle layers on/off (liquid/frozen rates, accumulations, clouds, phase).
Change the color map for each data layer.
Adjust accumulation min./max. values from 25--800 mm.
Adjust animation speed from 0.50--1.25x.
Time seek from daily to half-hourly intervals.

Technical details:

RAIN-Global 2 is the next generation upgrade to RAIN-Global (version 1) and RAIN (2D), web interfaces that serve 7-day animations of precipitation rates and accumulations from GPM IMERG data, as well as cloudiness from geosynchronously observed IR data. Animations are updated daily for the week ending on the prior day. Use your mouse or trackpad to navigate around the globe or use the controls on the left to "fly to" a region, country/area, or city of interest. Select from a list of recent dates to view precipitation estimates for the week ending on that date.

RAIN-Global loads high-resolution animations of IMERG data that are pre-rendered with a combination of Python and Linux command-line tools on PPS's servers. The animations are then loaded into the three.js framework on the front-end to render them onto an interactive sphere and annotate them. In RAIN-Global2, a higher level of customization is offered via the control of each data layer. Layers can now be toggled on/off and color-adjusted on-the-fly. This is accomplished through the use of "shaders", which are small programs written in GLSL (OpenGL Shading Language) and executed by the graphics processing unit (GPU) on your computer. Shaders are optimized to be run on GPUs, so they free up resources on your CPU to run other tasks. Each data layer in RAIN-Global 2 now contains its own high-resolution video, which is "shaded" in realtime and synchronized with the other videos. These operations are very resource-intensive, so each user's experience will be different based on their hardware, OS, and browser. Modern hardware tends to improve performance. Browser performance tends to be best in Chrome, followed by Safari and Edge, while performance in Firefox may not be optimal. Click on the "?" near the Quality options to learn more about graphics quality in RAIN-Global 2.

FAQs:

Q: How do I save a video of RAIN-Global 2?
A: On Mac, press Command-Shift-5 to record a video of what's on the screen. On Windows, press Windows-Shift-R to record a video. In a future release of RAIN-Global, we will include a built-in video recorder.

Q: What is the "Phase" data layer?
A: Under "Data layers", you can show liquid rates, frozen rates, and accumulations, as well as a fourth data layer which can be toggled between two datasets:

Clouds (cloudiness from geosynchronous infrared satellite data):

Select clouds if you'd like to see how IMERG precip. estimates are influenced by infrared cloud-top brightness temperature measurements. Brightness temperatures range from approximately 6°C to -50°C.

Phase (based on the IMERG probabilityLiquidPrecip (PLP) parameter):

Select Phase if you'd like to see how the probability of liquid precipitation field affects the liquid vs. frozen precipitation phase transition. The lower end of the color map corresponds to frozen precip. (0%≤PLP<50%); the higher end corresponds to liquid precip. (50%≤PLP<100%).

Q: What is GPM?
A: The NASA Global Precipitation Measurement (GPM) mission is an international network of satellites that provide next-generation global observations of rain and snow. Building upon the success of the Tropical Rainfall Measuring Mission (TRMM), the GPM concept centers on the deployment of a "Core Observatory" satellite carrying an advanced radar / radiometer system to measure precipitation from space and serve as a reference standard to unify precipitation measurements from a constellation of research and operational satellites.

Q: What is IMERG?
A: NASA's Integrated Multi-satellitE Retrievals for GPM (IMERG) product combines information from the GPM satellite constellation to estimate precipitation over the majority of the Earth's surface. IMERG is particularly valuable over areas of Earth's surface that lack ground-based precipitation-measuring instruments, including oceans and remote areas.

Q: Why do the clouds abruptly cut off at high latitudes?
A: This tool uses the NOAA CPC IR 4km half-hourly dataset, which is also used as an input to IMERG, to estimate cloudiness. The CPC IR dataset covers between 60°S and 60°N latitude.

Acknowledgements:

- Daytime basemap: NASA Blue Marble
- Nighttime basemap: NASA Black Marble
- 3D sphere rendering: Three.js
- Color maps: Color Brewer and SciVisColor.
The developer acknowledges helpful contributions in 3D rendering from the threejs community (e.g., the panoglobe project), and in UI/UX design from others in the Earth data visualization community (e.g., earth.nullschool.net), which allowed this tool to be built in a modern, interactive format.
Owen Kelley (PPS/GMU; Research Scientist) and George Huffman (GSFC; GPM Project Scientist) provided helpful feedback on earlier versions of the animations. Erich Stocker (PPS Manager) suggested the idea of an interactive sphere with animated IMERG data and provided helpful UI/UX feedback. The IMERG algorithm development team (George J. Huffman, David T. Bolvin, Robert Joyce, Owen A. Kelley, Eric J. Nelkin, Jackson Tan, Daniel C. Watters, B. Jason West) and partners (Sarah Ringerud, David Wolff, and Yalei You), as well as Alex Gurvich (SSAI and NASA Scientific Visualization Studio), provided additional helpful feedback.

Curator/developer: B. Jason West (KBR, Inc. and NASA PPS/GPM)
NASA Official: Erich Stocker
Last Updated: 2026-03-09
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Graphics quality

RAIN-Global 2's performance is dependent on each individual user's hardware and software setup. If performance consistently hangs on your machine, try switching to Basic quality. If performance is smooth but you'd like higher quality graphics, try switching to Medium or High quality. If none of the settings work on your machine, try RAIN-Global (version 1) or RAIN (2D).
For reference, the specifications in RAIN-Global 2 for each quality setting are as follows:

Basic:

Source video resolution: 2k (2160x1080 pixels)
Blue/Black Marble basemap resolution: 6k (6480x3240 pixels)
threejs frame rate: 30 frames/second

Medium:

Source video resolution: 4k (4320x2160 pixels)
Blue/Black Marble basemap resolution: 8k (8192x4096 pixels)
threejs frame rate: 45 frames/second

High:

Source video resolution: 6k (6480x3240 pixels)
Blue/Black Marble basemap resolution: 10k (10240x5120 pixels)
threejs frame rate: 60 frames/second

Clouds and Phase

The fourth data layer can be toggled between two datasets:

Clouds (cloudiness from geosynchronous infrared satellite data):

Phase (based on the IMERG probabilityLiquidPrecip (PLP) parameter):

...syncing animation layers...
Playback will resume shortly. This may occur several times before syncing is complete, depending on your system hardware.

yyyy-mm-dd, hhmm UTC
NASA GPM IMERG-Late V07 Precipitation
period ending on , 2359 UTC

Liquid rate (mm/hr)

0.25

Frozen rate (mm/hr)

0.25

Accumulation (mm)

500

Cloudiness from GEO-IR