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)

Outline Brief overview of TRMM Introduction of TOVAS Precipitation 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

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

GES DISC is the TRMM data archive center PR – 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

TOVAS Introduction Why TOVAS?

Traditional Way vs. TOVAS in Data Evaluation for a New User Basic 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

TOVAS

Visualization and Analysis Server Reliable 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)

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

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

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

Ground Observation Archives Willmott (1950-1999, 0.5 deg) GPCC (1986 – present, 1 deg)

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

TRMM Web Interface Overview

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

Two types of GUIs

Accessing new interfaces:

TOVAS Functions and Examples

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

Other Features: Climatology Anomaly and normalized anomaly Fine 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

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

2D Plots (The contribution of Isabel in 2003)

Time Series Plots Mid- Atlantic Region Alex, Charley, Gaston Floyd Isabel Mid- Atlantic Region

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

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

Scatter Plot (Error vs Rain Rate, revealing biases)

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

Prototype Interactive Inter-comparison of Rainfall Products

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

Hurricane Data Analysis Tool: http://disc.gsfc.nasa.gov/HDAT The 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

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

HDAT Landing Page

HDAT Landing Page (Cont.):

HDAT Landing Page (Cont.):

HDAT Landing Page (Cont.):

Examples: Category 2 cyclone Catarina – Landfall

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

Dust Strom (near Iraq and Saudi Arabia border)

Dust Storm (cont.)

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

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

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

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)

Other TRMM data and services at GES DISC Mirador Other data accessing methods

TRMM Data Archive at GES DISC

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

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)

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

Demos and Hands-on Exercises

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

URLs: Contact: Zhong.Liu@nasa.gov TOVAS: http://disc2.nascom.nasa.gov/Giovanni/tovas/ HDAT: http://disc.sci.gsfc.nasa.gov/HDAT Mirador: http://mirador.gsfc.nasa.gov/ Giovanni: http://disc.sci.gsfc.nasa.gov/giovanni GES DISC: http://disc.sci.gsfc.nasa.gov/ Contact: Zhong.Liu@nasa.gov

Thank You!