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After opening the data selection window,
user must select the dataset(s) first. If you are using
a browser that supports the Java Applet and JavaScripts
features used in EPIC Web Browser, the location range
will be drawn on the world map for the dataset you selected
and the text fields (above the map) will be updated to
show the time range and total number of data files avalible
from the dataset(s) you selected.
- Click on the next button on the dataset selection window
go to the refine data selection window.
Step 2. Refine Data Selection
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On refine data selection window, user
can specify the location range by Mouse-Drag on map or
enter values to text fields. User can also specify other
desired selection criteria.
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All the selection criteria are optional.
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If you do not specify any selection criteria,
then all data will be selected (potentially tens of thousands
of data sets).
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Click on the [Search] button or "next"
button to start the searching process.
Step 3. Data Plotting, Listing and Downloading
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The results of the search will be a scrolling
list of data sets which met the selection criteria. From
this scrolling list, you can select a data set for plotting,
listing or downloading.
EPIC
data selection terminology
Datasets - referrs to a collection
of data, generally from a region. Generally, all data has been
collected by PMEL scientists, unless otherwise noted. Data origin
information is always included in the data file as metadata.
- Pacific - data from the Pacific Ocean
- non-PMEL - data obtained or collected by scientists
at institutions outside PMEL
- NODC - from
the NODC
World Ocean Atlas CD-ROM 1994 of bottle data.
- S.Indian - South Indian Ocean
- S.Pacific - South Pacific Ocean
- S.Atlantic - South Atlantic Ocean
- Reid - Reid and Mantyla bottle
data for the whole globe is available - Courtesy of
Dr. Alex Orsi, who formatted this data set for use in EPIC
- FOCI - CARD FOCI data
- WCOAST - Data from the West coast of the US
- PUGET - Puget Sound data
- ASIA - Data from Asia (China Sea, Sulu Sea)
- Arctic - Data from the West Arctic
- Vents - Data from the hydrothermal venting area in
the mid-latitudes of the North Pacific Ocean
- Alaska - data from the Gulf of Alaska and Bering
Sea
EPIC data types fall into
three categories:
- Profile Data Types - One-dimensional data sets indexed
by pressure or depth, specifically, data collected by
CTD, XBT or from Bottles. We Profile data into these groups:
- Time Series Data Types - One dimensional data set
indexed by time, such as that collected by instruments such
as an anemometor, a current meter or a thermistor on a moored
buoy. We devided time series data into these groups:
- "Met" --
for Surface Meteorology data including
Wind, Air Temperature, Relative
Humidity, Shortwave Rediation, Barometric Pressure,
etc.;
- "Ocean"
-- Ocean data including Ocean
Temperature, Pressure, Salinity, Conductivity,
etc.
- "Drf" -- Drifter buoy
data.
- Track Data Types - Data collected along the track
of a moving platform such as a ship or a drifting buoy. Examples
are shipboard Acoustic Doppler Current Profiler (ADCP) data
and drifting buoy data. Track data is one- or two-dimensional
data, indexed by time and sometimes by pressure. For each
time point, variables include latitude, longitude and any
measurements made by instruments on the moving platform.
Select
or locate data by specifying one or more of the following
selection criteria. Any of the criteria can be ignored.
If no criteria are specified, then all data in the database
will be selected, potentially tens of thousands of data sets
(not recommended).
- Longitude range - to
specify a range of of longitudes, enter the Westernmost
and Easternmost longitudes as numbers between -180 and
+ 180. West is negative and East is positive.
- e.g., -110.5 is 110.5 degress West longitude,
near the West coast of South America, 137 is 137 degrees
East longitude, near the East coast of Indonesia,
both in the Pacific Ocean.
Longitudes can also be entered with E or W to indicate
the hemisphere.
- e.g., 110W, 110w, 110 W, 110 w and -110 are
equivalent ways of specifying 110W, and 137E, 137e,
137 E, 137 e, and 137 are equivalent ways of specifying
137 degrees East longitude.
- Latitude range - to
specify a range of latitudes, enter two latitudes as numbers
between -90 and 90. South is negative and North is positive.
- e.g., -10.5 is 10.5 degrees South latitude,
and 10 is 10 degrees North latitude.
Latitudes can also be entered with N or S to indicate
hemisphere.
- e.g., 10.5S, 10.5s, 10.5 S, 10.5 s, and -10.5
are equivalent ways of entering 10.5 degrees South
latitude.
- Date range - All data
sets which contain some data inside the specified time
range will be selected.
- Depth range - Depths
in the ocean are entered as positive numbers, increasing
downwards towards the bottom of the ocean. The surface
of the ocean is 0, and 6000 meters deep in the ocean is
6000.
- For profile data (CTD, XBT, or Bottle data), this
is the depth or pressure range which you REQUIRE
the data to cover. For example, if you enter 0,1000,
that means you will reject a CTD data file which only
includes data from the surface to 500 meters depth,
but will accept a CTD data file which includes data
from the surface to 5000 meters depth.
- For time series data, any time series from an instrument
inside the specified depth range will be selected.
- Month sub-range - If
you have selected a multi-year date range, and you only
want to choose data within certain months, i.e.,
the Northern hemisphere summer (Jun-Aug), then enter the
subset of months to be searched.
- Delta-t is the time interval
between data points in Time-Series files. You can select
min and max Delta-t, or leave it blank and all delta-t
values will be considered in the search.
- String(s) to locate in Filename
- This search criteria is included for the convenience
of scientists familiar with the EPIC data sets. File names
often contain identifying information, such as Cruise
identification for CTD data. This search criteria allows
selection of data based on this identifying informaton.
Enter one or more character strings, separated by spaces.
Data with file names containing all the specified character
strings will be selected.
Once data is selected, there are options for the individual
casts or stations for profile data selection or for the individual
time series, and other options for the entire set of selected
data sets.
- Cast options (profile
data selection) - A cast referrs to profile data
collected at a single location. A cast is sometimes called
a station, and this data is stored in a single EPIC data
file. Cast options are operations on an individual
cast, such as making a property versus property plot or
listing the data from a single profile.
- Time-Series Options
(time series data selection) - are operations on an individual
time-series, such as making a plot or listing the data
from a single time-series.
- Variables (time series
data selection ) - Most Time-Series Data Sub-Types have
only a single variable, like Barometric Pressure, but
some, like Wind include Zonal and Meridional wind.
-
Pointer
file options - An EPIC pointer file is a list
of data file names. Pointer file options are choices
for different operations on a whole collection or list
of data files, such as making a location plot, editing
the pointer file, or downloading the pointer file to your
local disk.
Criteria for a test of
demonstration
For a test or demonstration
of profile data selection, try the following selection
criteria (Pacific CTD data in longitude range 96W to
94W and latitude range 3N to 5N):
- Dataset: Pacific (CTD)
- Longitude range: Westernmost = 96w and Easternmost =
94w
- Latitude range: Northmost = 5N and Southmost = 5S
- Time range: 1-30 April 1982
- --> Try a MERIDIONAL Section Plot of temperature
from 0-300 m
For a test or demonstration
of time series data selection, try the following selection
criteria (Alaska Current data in longitude range 120E to
120W and latitude range 45N to 80N):
- Dataset: Alaska (Ocean)
- Longitude range: Westernmost = 120E and Easternmost
= 120W
- Latitude range: Northmost = 80N and Southmost = 45N
- Time range: Jan 1 1990 - Dec 31 1995
- Click "Search" at the bottom of the page
- Click "Go" at the bottom of the page
- --> Select up to 6 variables and click "Go" to make
a time series plot
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