Hurricane Data Analysis Tool FAQ

• What is this tool for?
  
  To facilitate scientific users in accessing NASA satellite remote sensing data and increase interoperability among NASA data centers, the NASA Goddard Earth Sciences (GES) Data and Information Services Center (DISC), home of the GES Distributed Active Archive Center (DAAC), has recently developed a simple tool that allows users to visualize and analyze NASA's daily Quick Scatterometer (QuikSCAT) ocean surface wind, Tropical Rainfall Measuring Mission (TRMM) precipitation and TRMM Microwave Imager (TMI) sea surface temperature (SST). QuikSCAT, TRMM precipitation and TMI SST data are archived and distributed by the Physical Oceanography Distributed Active Archive Center (PO.DAAC) of the Jet Propulsion Laboratory (JPL), the DISC and the Remote Sensing Systems, respectively. Recently, we have added NCEP Reanalysis data products in order to provide users a better integrated tool. As a part of the DISC's Hurricane Portal, this tool is intended to facilitate researchers to investigate tropical cyclones, hurricanes and typhoons around the world without downloading data. It also helps them to investigate other oceanic and atmospheric events, such as, precipitation, monsoon events, island blocking effects, etc. Current functions include area (latitude-longitude) and time series (area averaging) plots and their overlays. More data and capabilities are coming.


• How to use this tool?
  
  a) Select a data group from Select Map Feature
  b) Select a base dataset and an overlay dataset
  c) Select a plot type (lat-lon map or time series) and a plot type for wind (vector or streamline)
  d) Select a rainfall product
  e) Select an area of interest using a computer mouse or type in latitudes and longitudes
  f) Select a time period
  g) Select or provide information for the color bar (for lat-lon map only)


• Can I get the data of a plot?
  
  No, currently this capability is not available but we have plans to add the capability in the future. Please go to data providers to obtain original data products. For TRMM, visit http://disc.sci.gsfc.nasa.gov/data/datapool/TRMM/index.html; for QuikSCAT, visit http://podaac.jpl.nasa.gov/; for TMI SST, visit http://www.ssmi.com/.


• How to plot a single dataset?
  
  Select the same dataset in both base dataset and overlay dataset.


• How can I create a customized color bar?
  Go to the color bar section, and select “custom” and type in min and max of the values for the color bar.


• What are the data resolutions?
  For TRMM and TMI SST, both are 0.25 degree. For QuikSCAT, the original L-3 product resolution is 0.25, however, for better visualization, we use the software provided by PODAAC to reduce the resolution to 1 degree. The NCEP products are all 1 degree.


• How frequently the datasets are updated?
  
  Typically 1-2 months because TRMM rainfall products are always delayed in that time frame.


• What NCEP data is used?
  
  The sea level pressure, zonal and meridional wind at 1000, 850, and 200 hPa level data available on the hurricane portal are obtained from NCEP's Global Forecast System analysis. The GFS analysis can be obtained from http://nomads.ncdc.noaa.gov. The GFS data archived on the hurricane portal are global (GFS product 003), have 1ºx1º spatial resolution and 4-times/day (6 hourly) temporal resolution. These data are available from NCEP beginning in February, 2004. A detailed description of the GFS model can be found on http://wwwt.emc.ncep.noaa.gov/gmb/moorthi/gam.html. A number of additional parameters from GFS will be available soon on the hurricane portal, including mass divergence profiles, potential temperature profiles, and vertical wind shear derived from the GFS products.


• When I select Area Plot and a time period, what will happen?
  You will get a time-averaged map for the region of interest. For wind, it is vector averaging.


• Which TMI SST product is used?
  The 3-day SST product. The daily will be added in near future.


• Any plan to add near-real-time products?
  Yes, if resources allowed.


• Any plan to add monthly products and anomaly analysis?
  Yes, if resources allowed.


• Any plan to overlay track data?
  Yes, it is under consideration.


• Any plan to plot a time series along the track?
  Yes, it is under consideration.