Nomads .

1. NOMADS

2. NOMADS is an agreement between
agencies who participate to have
common …
 Data and observation distribution software, format
independent and description methodology,
 Documentation and organization framework,
 Forum to plan and organize
 Funding avenue to direct $.
… for university, federal agencies and organizations, a
mechanism to obtain support for the dissemination
of their data sets.

3. Participants
U.S.-
NOAA, DOE, NASA,
NCAR, Unidata, COLA,
OPeNDAP Project,
& Several Universities
International-
CEOS
NERC
ESG
UK BADC
BOM /
Dept. of State via CAP

4. NOMADS
and the NCEP Real Time Component
 Wider information dissemination through web pages and
other avenues.
 Framework to create specialized and value added products
needs access to weather data.
 Facilitate communication among commercial, public,
research community and federal agencies.
 NOMADS is a system for participants to interact with
others using common protocols and formats. Existing
differences in details are mollified by software.
A solution for Recommendation 5 of “Fair Weather:
Effective Partnership in Weather and Climate Services”

5. RT-NOMADS at NCEP
 Distributed Ocean Data Server - OPEN_DAP (DODS)
based on metadata file descriptors and XML.
 Web based ftp, the NCEP ftp2u client and “Great
Displays” (pdisp), a grid analysis and display client.
 Model initialization ingredients, “The minimum set”
for model rerun/retrospective analysis ready
observations & restart files.
 The Real Time NCEP Operational model run history.
Consists of

6. RT-NOMADS is a service for science,
development and public access.
To distribute NCEP’s Operational data set to
researchers and the public.
To provide server software to NOAA projects who
need to serve their data through web services.
 NCEP NOMADS servers are the intermediary
between NCEP operational computers and NCDC
NOMADS archive servers.

7. Tools for Users on the server
 Pare down large file sizes of high resolution
initialization and model results.
 (re-) Group different data sets to create
needed products – such as initialization files
for model development.
 Subset the data sets in parameter space
 Subset the data sets in physical space
(subset the grid in 4 dimensions)

8. NCEP Real-Time Server
 Real time.
 Operational Suite of Model products.
 Forecast information for model comparison.
 Operational initialization and observations.
 Maintenance of codes, utilities for data
manipulation and grid transformation, sub-setting
 Documentation.
 Serves as transfer point to NCDC for NOMADS
archive of reruns and retrospectives.

9. The Server – Client distributed relationship:
A Common Sense Approach to Data Distribution
 ftp2u, Great Displays, and GDS allow sub-setting
of data by parameter, by 3D region, and by time.
 Allows for results with low band width! Eg.,
NASA/GSFC takes 1 hour to ftp entire GFS
(AVN) forecasts or 13 seconds to download their
desired fields (ftp2u).
 GDS: NOMADS participants serve up their data
sets through a client-server relationship, that is,
the data sets are internet ready and the display is
done by the client.
Examples of Clients :

10. Extending NOMADS to
Real Time
 The A in NOMADS is for Archive.
 NCEP historical cases for rerun/retrospective
ocean, atmosphere and climate.
 NCEP Real Time model output in the NOMADS
framework … so there is a seamless access to
these important data sets at NCEP and at NCDC!
RT-NOMADS provides the framework for long term
support to be available to keep up with modeling
advances.

11. RT-NOMADS is a prototype
 Provide proof of the concept that distributed systems
can serve data sets across agencies.
 Specify an Operational system for NOAA/TOC,
 Provide current state of the art capability and move
more complete data sets,
 Use benchmarks to characterize system loads in order
to determine costs and give NOAA administration the
information it needs to triage data resources.
Goals:

12. Data Application Protocol (DAP) using…

13. … GrADS client …. commands
Sdfopen http://nomad2:9090/dods/reanalysis-2/pgb/hgt
t = 1
'set gxout shaded'
while (t <= 1068)
'set t 't
'q time'
date=subwrd(result,3)
'draw title hgtprs 'date' 't
'd hgtprs'
'/home/wd23ja/grads/lib/cbarn.gs'
'swap'
t = t + 1
endwhile

14. Getting data without GrADS or a commercial
client:
http://140.90.198.156:9090/dods/eta/eta20030527/eta_00z.ascii?tmpprs[0:
0][0:0][30:130] [290:290]
#the order of the square bracked values is:
# [time][level][lat][lon]
# where lat is measured from the south pole (0)
# to equator (90) to NP (180)
(Use a “wget” and the URL with the ascii response in cron or a cgi-bin
script provides the needed number(s) when and where needed.)

15. NOMADS clients at NCEP
 Real Time Operational model data sets from GFS, and
ETA from present to one month ago.
 Attention to accumulation variable differences and high
and low resolution.
 Analysis pgb, restart files.
 Recent (“real time”) climate runs, ie., RSM.
 Observations (soon).
 Reanalysis-2 (and 1)
 AMIP type runs (Suru’s finest runs eg., 28 and 64 levels
1978-2002), sudden warming, ….
“Great Displays” (pdisp) and ftp2u
by Ebisuzaki and modified by Wang

16. MATLAB: A Commerical Client
server=‘nomad2:9090’;
directory=‘/dods/gdas/rotating/’; fext=‘ascii’;
model=‘gdas’; datestr=‘YYYYMMDDHH’; varname=‘hgt’;
varlevs=‘1’;
Arrc=[‘[‘,t1,’:’,t2,’][‘,nlev1,’:’,nlev2,’][‘,ilat1,’:’,ilat2,’][‘,ilon1,’:’,ilon2,’]’];
urlstring=[http://’,server,directory,model,datestr,’.’,fext,’?’,varname,arrc];
url = java.net.URL(urlstring); % connect to web page
Try
stream = openStream(url)
ireader = java.io.InputStreamReader(stream);
breader = java.io.BufferedReader(ireader);
Line = readLine(breader); disp(line);

17. Data Sets
 NOAAPORT Operations.
 Continuation of NCEP real time model
component.
 NCEP model initialization ingredients, “The
minimum set” for model rerun/retrospective
analysis ready observations & restart files.
Archives at NCDC

18. Model Data Requirements
from CLASS
Current Archive:
NOAAPort: 2TB/yr
GDAS/SSI: 400Gb/yr
NARR 10Tb
Total 12.5Tb
FY04
NCEP Hi-Res: +10TB/yr*
Total 22.5Tb
* 5 year retention only
North American
Regional Reanalysis
NCEP
Global Assimilation
Spectral Statistical
GDAS O/I
NCEP Hi-Res
Eta/Global
and NARR
NOAAPort
Gridded Output
HDSS
23TB/yr
Legend
Green- Existing Archive
Blue- Expected FY03/04
Rutledge and Alpert 6/03
FY03

19. Model Data Req’s - NWP and GCM’s
0
20
40
60
80
100
120
140
'04 '05 '06 '07
Volume Tb/Yr
GCM
Reanal
NWP*
Cumulative (Tb)
0
50
100
150
200
250
'04 '06 '08 '10
NWP*
Reanal
GCM
GCM- Global Climate Model
Reanal- N. Am. Regional Reanalysis
NWP- Numerical Weather Prediction
* 5-year rotating NWP archive

20. RT NOMADS Server at NCEP
 Two 1TB RAIDZONE servers
 http://nomad2.ncep.noaa.gov
 http://nomad1.ncep.noaa.gov (backup)
 Documentation web page under construction
 New disk space on order….

21. Non-Operational “Projects” can become NOMADS
participants to display their data sets:
 Install scripts for a GDS framework,
 Setup GDS XML file – see example on web
page, for example,…
 Including GDS administration updates new
additions transparently,
 “newxml” update script – to automatically
add new directories and files.
NOMADS gives guidance to:

22. (RT) NOAMDS data sets ….
 One data set (e.g, GRIB) provides the data
for all access applications.
 Control files (grib2ctl) and index files
(gribmap) create unique metadata
description.
 GDS can read HDF, NETCDF as well as
other formats.

23. NOMADS
and the NCEP Real Time Component
 NWS should make its data and products available in
Internet-accessible digital form.
 Information held in digital databases should be based on
widely recognized standards, formats, and metadata
descriptions to ensure that data from different observing
platforms, databases and models can be integrated and
used by all interested parties in the weather and climate
enterprise.
A solution for Recommendation 5 of “Fair Weather:
Effective Partnership in Weather and Climate Services”