1 Accessing Global Precipitation Data Products via TRMM Online Visualization and Analysis System (TOVAS) Zhong Liu Center for Spatial Information Science and Systems (CSISS), George Mason University and NASA Goddard Earth Sciences Data and Information Services Center (GES DISC)

2 Outline Brief overview of TRMM Introduction of TOVASPrecipitation products in TOVAS TOVAS interface overview Functions and examples Other ancillary tools Future plans Other TRMM data and services at GES DISC Demos and hands-on exercises Questions

3 Brief Overview of TRMM Tropical Rainfall Measuring Mission (TRMM)Sampling footprint between 35°S and 35°N 4-D distribution of rainfall and latent heating over vastly under-sampled oceanic and tropical continental regimes

4 GES DISC is the TRMM data archive centerPR – 247Km (5km) TMI – 878km (5.1km, 85.5GHz) VIRS – 833 km (2.4km) GES DISC is the TRMM data archive center Courtesy of trmm.gsfc.nasa.gov

5 TOVAS Introduction Why TOVAS?

6 Traditional Way vs. TOVAS in Data Evaluation for a New UserBasic analysis and visualization (no software and data download needed) Traditional Way: Obtain data from a FTP site Read data manuals Learn software if available If not available, write your own software Write visualization software

7 TOVAS

8 Visualization and Analysis ServerReliable Flexible Low-cost System Description Visualization and Analysis Server Receive Parameters from Interface CGI Output to Web Browser GrADS Environment Compose GrADS Script Execute GrADS Script Generate Plot/ASCII Output Receive Parameters from Web Client Output to Web Client Data: Binary or GDS GrADS: The Grid Analysis and Display System (COLA)

9 Products in TOVAS Near-real-time Rainfall ArchivesGround Observation Archives Other Ancillary Products

10 Near-real-time 3-Hourly combined (3B42RT) 3-Hourly microwave (3B40RT) Hourly IR (3B41RT) Daily (derived from 3B42RT)

11 Rainfall Archives 3-Hourly (3B42) Daily (derived from 3B42) 10-day (derived from 3B42) Monthly (3B43, 3A12, 3A25, GPCP, etc.)

12 Ground Observation ArchivesWillmott ( , 0.5 deg) GPCC (1986 – present, 1 deg)

13 Others: •Monthly Global Precipitation (GPCP)• Prototype Interactive Inter-comparison of Rainfall Products • Monthly Rainfall (3B43 V6) Anomaly • Inter-Comparison of Rainfall Climatology

14 TRMM Web Interface Overview

15 TOVAS Landing Page: http://disc2.nascom.nasa.gov/Giovanni/tovas/New

16 Two types of GUIs

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20 Accessing new interfaces:

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26 TOVAS Functions and Examples

27 TOVAS Functions: Animation Lat-Lon Area Plot, Time-averaged Lat-Lon Plot, Difference Map Latitude-Time Hovmöller Plot Longitude-Time Hovmöller Plot Correlation Plot Comparison Plot Cross-Map Plot (Latitude-Height) Cross-Map Plot (Longitude-Height) Cross-Map Plot (Time-Height) Scatter Plot Scatter Plot, Time-averaged Time Series, Area-averaged Time Series Difference Time Series, Area Statistics

28 Other Features: Climatology Anomaly and normalized anomalyFine tune graphic output Output in other formats (e.g., NetCDF) Google Earth KMZ file output Application examples with real events FAQ and documentation Help desk

29 2D Lat-Lon Plots (Record breaking rainfall in the Mid-Atlantic Region in 2003)

30 2D Plots (The contribution of Isabel in 2003)

31 Time Series Plots Mid- Atlantic Region Alex, Charley, Gaston FloydIsabel Mid- Atlantic Region

32 Hovmoller Diagram (Mid-Atlantic Region)Multiple Tropical Storms Isabel Floyd

33 Anomaly (Positive anomaly due to Isabel in Sept., 2003)

34 Scatter Plot (Error vs Rain Rate, revealing biases)

35 ASCII data output for further analysis (e.g. MS. Excel)

36 Prototype Interactive Inter-comparison of Rainfall Products

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39 Other Ancillary Tools Hurricane Data Analysis Tool (HDAT)Other Giovanni Tools

40 Hurricane Data Analysis Tool: http://disc.gsfc.nasa.gov/HDATThe global merged IR product, also known as, the NCEP/CPC 4km Global (60ºN - 60ºS) IR Dataset, is one of TRMM ancillary datasets. 4 km IR Global (60ºN - 60ºS) 30 minutes Since Feb., 2000

41 Basic Functions and Features:Selection of area of interest Single image or multiple images (animation) Allow time skipping (1 hr., 2 hr., etc.) Allow different image sizes False color Fine tune graphic output

42 HDAT Landing Page

43 HDAT Landing Page (Cont.):

44 HDAT Landing Page (Cont.):

45 HDAT Landing Page (Cont.):

46 Examples: Category 2 cyclone Catarina – Landfall

47 AF Flight-447: Satellite Observation of Mesoscale Convective System Development on 1 June, 2009

48 Dust Strom (near Iraq and Saudi Arabia border)

49 Dust Storm (cont.)

50 TOVAS and HDAT 2009 2010 Flooding in Pakistan due to higher-than-normal monsoon rainfall between Jul – Aug. 2010

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53 Other Giovanni Tools: http://disc.sci.gsfc.nasa.gov/giovanniGiovanni: GES-DISC (Goddard Earth Sciences Data and Information Services Center) Interactive Online Visualization ANd aNalysis Infrastructure

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55 Cloud Water in g/m3 (scaled by 100)Cloud Ice in g/m3 (scaled by 100) Precipitation Ice in g/m3 (scaled by 100)

56 Future Plans for TOVAS:Add more functions IPWG: a proposal for adding IPWG validation algorithms is pending Add TRMM Level-2 orbital data (a prototype to extract 2A12 and 2A25 profiles is ready for YOTC) Add multi-sensor data (e.g., CloudSat)

57 Other TRMM data and services at GES DISCMirador Other data accessing methods

58 TRMM Data Archive at GES DISC

59 Data Volumes (as of Sept. 22, 2010)Standard products (L-1, L-2, L-3, orbital, gridded): ~20.3 TB (772,553 files) Ancillary data: ~1.9 TB (93,051 files) Ground based instruments: ~4.5 TB (1,853,484) Subsets: ~3.1 TB (2,995,019) File Total: 5,714,107 Total size: ~29.7 TB

60 Mirador Basic Features: http://mirador.gsfc.nasa.gov/Search features: Keyword/event search, projects, science focus areas Spatial subsetting (limited products) Format conversion (e.g., NetCDF)

61 Other Data Access Methods:Giovanni TOVAS (TRMM Online Visualization and Analysis System) GrADS Data Server (GDS) (subsetting and analysis services over the Internet) OPeNDAP (accessed by IDL, GrADS) The Open Geospatial Consortium (OGC) Web Map Server (WMS) Google Earth

62 Demos and Hands-on Exercises

63 Generate a lat-lon map Generate a time series and its ASCII data New interface and data download options

64 URLs: Contact: [email protected]TOVAS: HDAT: Mirador: Giovanni: GES DISC: Contact:

65 Thank You!