Background information about the characteristics of this data may be
found in An Introduction to Atmospheric and Oceanographic Datasets.
There is general basic information in its Introduction .
More specific information may be found in these chapter(s) or section(s):
Analyzed and Model Data .
You may wish to refer to Other Sources of Data .
Note that NCEP also made the Aviation (AVN) Analyses using the same model, but DSS
did not collect them.
TYPES:
Operational
Gridded analyses
Synoptic
Surface analyses
Upper air analyses
Sea analyses
Oceanographic
COVERAGE:
Global coverage
Latitude / longitude grid
Northern hemisphere and Southern hemisphere are in separate grids.
Information about the grid orientation is here.
NCEP Global Analyses on 1.0 degree grids are available, in DS083.2.
UPDATES:
Monthly
Updated usually about 2-3 weeks after the end of a month, but this
lag time can be irregular. We use files that NCEP prepares specifically
for us.
TIMES:
daily 12-hourly
at 00Z and 12Z
VARIABLES:
Land skin temperature and sea surface temperature are in one field.
A memo about SST analysis is
here.
As in DS082.0, the temperature may still actually be a virtual temperature.
LEVELS:
1000mb 850mb 700mb 500mb 400mb 300mb 250mb 200mb 150mb 100mb 70mb 50mb 30mb 20mb 10mb
surface upper-air troposphere mandatory tropopause stratosphere sigma
A surface subset has been built by DSS in DS083.1.
For stratospheric levels (70 to 0.4mb) on polar grids, please see DS067.3.
VARIABLE / LEVEL TABLES:
(in 1997: 101 grids max per hemisphere per analysis time)
10 z t u v
20 z t u v
30 z t u v
50 z t u v
70 z t u v
100 z t u v
150 z t u v
200 z t u v
tpause p t
250 z t u v
300 z t u v rh w
400 z t u v rh
500 z t u v rh w vort
700 z t u v rh w
850 z t u v rh w
925 z t u v rh
1000 z t u v rh
bound t u v
10m u v
2m t tmax tmin q rh
col rh pwat
sfc sfcp z sfct
sfc weasd landsea iceconc
soil-010 tsoil waterc
soil-200 tsoil waterc
msl slp
FORMAT:
Be aware of these processing issues.
MM5, WRF and RAMS users click here.
A little advice is available for: GRIB and GrADs (display) software
VOLUME:
Blocks are variable in size, typically about 7000 bytes, due to the dynamic packing of GRIB.
About 3MB/day and about 93MB/file.
COST:
You will find the latest available year's data, free, by clicking the 
tab in the navigation bar. All the data are available on the NCAR MSS.
Users with NCAR computing accounts have free access from the NCAR MSS through clicking the tab in the navigation bar.
For all others, costs depend on the amount requested, and the DSS standard charging rate applies unless their order qualifies for a substantially reduced charging rate, aka "direct copy rate" as shown on the service charges page.
We can extract a limited variety of subsets from the NCAR MSS files, such as whole grids or whole observations. This may greatly reduce our output charges, but not our input charges. Please inquire, but note that internal logical record reformatting or subsetting is usually not supported.
To send a data request to a staff member, please use this form.
