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Integrated Multi-satellitE Retrievals for GPM (IMERG) data are now in Giovanni-4

Precipitation data from the Global Precipitation Measurement (GPM) mission

Integrated Multi-satellitE Retrievals for GPM (IMERG) data are now in Giovanni-4

Giovanni shapefile image analysis for Japan, showing heavy rainfall around Tokyo due to passage of Super Typhoons Phanfone and Vongfong in October 2014.

Integrated Multi-satellitE Retrievals for GPM (IMERG) data are now in Giovanni-4

 

The NASA Goddard Earth Sciences Data and Information Services Center (GES DISC) has recently added all of the half-hourly and monthly *Final* IMERG data variables to the next generation of Giovanni, Giovanni-4 (G4). Giovanni is a Web-based application developed by the GES DISC that provides a simple and intuitive way for users to visualize, analyze, and access vast amounts of Earth science remote sensing data, without having to download the data.

Tables 1 and 2 contain the data fields, variable names, and units of the variables in the half-hourly and monthly IMERG products. In Giovanni-4, they can be accessed by clicking this link.

 
 
Table 1. List of data fields, their variable names, and the variable units for half-hourly (3IMERGHH) data files (from http://pmm.nasa.gov/sites/default/files/document_files/IMERG_doc.pdf).
 
Data field
 
Variable name
Units
Snapshot precipitation – calibrated
precipitationCal
mm/hr
Snapshot precipitation – uncalibrated
precipitationUncal
mm/hr
Calibrated-precipitation random error
randomError
mm/hr
Merged PMW precipitation
HQprecipitation
mm/hr
PMW source sensor identifier
HQprecipSource
index values
PMW source time
HQobservationTime
min. into half hour
IR precipitation
IRprecipitation
mm/hr
Kalman filter weight for IR
IRkalmanFilterWeight
percent
Probability of liquid precipitation phase
probabilityLiquidPrecipitation
percent
 
 
Table 2. List of data fields, their variable names (in the data structure), and the variable units for monthly (3IMERGM) data files (from http://pmm.nasa.gov/sites/default/files/document_files/IMERG_doc.pdf).
 
Data field
 
Variable name
Units
Satellite-gauge precipitation
precipitation
mm/hr
Satellite-precipitation random error
randomError
mm/hr
Gauge relative weighting
gaugeRelativeWeight
percent
Accumulation-weighted probability of liquid precipitation phase
probabilityLiquidPrecipitation
percent
 
 
New analytical capabilities have recently been added to G4. Following are some examples:
 
  1. G4 now provides the ability to access, visualize, and analyze variables from additional NASA missions, such as TRMM, AIRS, MERRA, etc. These variables can be analyzed simultaneously with IMERG data variables.
  2. G4 users are now able to search variables from different disciplines, missions, and projects that have different spatial and temporal resolutions. For example, a search for “TOVAS” will list all the variables from TRMM and GPM (Fig. 1). The “data facet” display allows quick sorting of the results (Fig. 1). 
  3. Shapefiles are now available for states in the United States. Shapefiles are also available for countries (Fig. 1). The addition of watershed boundaries for major rivers is in progress. [BT: watershed shapefiles are in development; their addition is in progress]
  4. Global and customized animation files (animated GIFs) can be downloaded (Fig. 2).
  5. Other analysis options include interactive scatter plot, user-defined climatology, and seasonal time series, along with several standard options, such as data maps and time-series.
 
 
A screenshot of the new Giovanni-4 and Japan rainfall analysis
 
Figure 1. Top: A screenshot of the new Giovanni-4 showing new features such as search, faceting, shapefile, etc. Bottom: An example of a shapefile image analysis for the country of Japan, showing heavy rainfall in the capital region of Tokyo due to the passage of Super Typhoons Phanfone and Vongfong on October 2014.  (Click on the image to see a MUCH BIGGER version.)
 
Animation of global precipitation intensity from the half-hourly IMERG product on June 15, 2014,
 
Figure 2. Animation of global precipitation intensity from the half-hourly IMERG product on June 15, 2014, showing a flooding rain event in the Midwestern United States (see http://trmm.gsfc.nasa.gov/publications_dir/iowa_rain_2014.html for details). Regional animations can be obtained as well (not shown) by choosing an area of interest on the Giovanni-4 landing page.  [ Click to view the full-size version. ]   
 
 

Access Giovanni-4:

 
IMERG only:
 
 
 
TOVAS:
 
 
 
IMERG Data Product landing pages:
 
 
 
 

 


Questions or comments? Email the NASA GES DISC Help Desk: gsfc-help-disc@lists.nasa.gov

 

 

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Last updated: Mar 18, 2015 10:19 AM ET
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