Information about the Atmospheric Variables Plotting Page
- Default date will be the last date available; usually yesterday
or today (if late in the day) for the NMC data. For the other
datasets it depends. The date represents the last day of the time
period for the specified number of days except for the Reynolds SST
data, where the date is the first day of the last week requested.
The NCEP daily analysis is generally available from 1980 onwards.
The OLR data are available from 1974-Nov 30 1998. The MSU
precipitation data are available from Jan 1979-Oct 1996. The
Reynolds SST is weekly and is available from Jan 1990-about 1 week
before the current date. Longterm means are based on 1985 to
- Number of days
- The number of days should be either the number of days that go
into an average for daily data or the number of weeks for weekly
data. The more days, the longer the plot will take. Reynolds SST
climo or anomaly plots will take even longer because the
climatology data is daily. The default number of days or weeks is
1. The maximum number of days allowed is 366.
- Most variables are from the NMC daily operational
analysis dataset. The exceptions are the OLR which is from the
interpolated OLR dataset, the SST which is from the Reynolds
weekly SST dataset, and the precipitation which is from the MSU precipitation
dataset. All data are daily except for the Reynolds SST which
is weekly. The Eddy geopotential heights are derived from the NMC
heights and are computed by removing the zonal mean at each
latitude for each day of the requested date range of the data. The
vector winds are computed by calculating the average u and v for
the time period and then plotting the magnitude and direction of
these wind components
- Plot type
- There are 3 plot types. The "Mean" plot represents the average
of the variable selected for the time period selected. The "Climo"
is the 5 day smoothed (2 days before to 2 days after) yearly long
term mean average for the data (except for Reynolds SST, which is a
simple 7 day average). "Anomaly" is the "Mean" value minus the
- There are 5 projections plus a custom projection. They are
defined as follows:
Northern Hemisphere: 0-90N, 0-360W in using a
polar stereographic projection
Globe: 90S-90N 0E-360W
United States: 20N-65N; 235-285 polar stereographic
Custom: Choose your own (specify lat/lon boundaries from S-N
and E to W)
- Specify latitude and longitude ranges. If you need a plot to
span the the dateline, you can specify the eastern boundary to be
greater than 360. For example, plot from 180W eastward to 180E, you
can specify 180,540 for the longitude ranges.
- Color scheme
- Information will go here when I figure it out.
- Contour labels will be drawn if yes is chosen. The
default is no.