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20021107: Plan view of profiler data with snmap



Chris,

In order to see if the levels are variable,
are you looking at the profiler obs decoded from the
hourly BUFR, or 1hour/6minute NetCDF? 

I wrote the dcncprof and dcprof decoders to add the station
elevation to the observation height since that mkes it possible
to use with the guess fields of objective analysis with other
sources of data, but could be modified easily.

The data do have QC flags in the NetCDF files.

Steve Chiswell


>From: Chris Anderson <address@hidden>
>Organization: UCAR/Unidata
>Keywords: 200211080157.gA81vgX27249

>
>Hi,
>
>I have a few questions about generating plan views of FSL profiler data
>with snmap.  My goal is to view profiler in the height-above-ground-level
>(HAGL) coordinate rather than height coordinate of the data.  Is this possible
> ?
>
>I have tried a few things.  First, I have tried setting the levels
>parameter in snmap to the height that corresponds to the
>HAGL that I want to view.  For example, ground level for SLAI4 is 315 m.
>If I wanted to view data at 500 m HAGL, I would set LEVELS=815.
>
>The first problem I encountered was that data at other profiler stations
>was automatically interpolated to 815 m.  This produces a nice plot, but
>it isn't what I want, because 815 m is some HAGL other than 500 m HAGL at
>all other stations besides SLAI4.  I corrected this problem by setting
>LEVELS=815/MAN and CLEAR=Y and using a script to loop over all stations in
>which LEVELS was set to the height corresponding to 500m HAGL at all
>stations.  Is there a simpler way to do this?
>
>The next problem I have had is that on some days the height of profiler
>wind reports will differ from others.  This seems very odd, since the
>profiler data is set by the instrumentation to report at 250 m intervals.
>As an example I will use data from SLAI4.  The surface elevation at SLAI4
>is 315 m.  So, wind data should be reported at 815, 1065, 1315, 1565,
>1815, 2065, etc.
>
>On 20 Aug, 2002 the wind was reported at following heights:
>    815.00  7060.00
>    819.00  7060.00
>    933.00  6058.00
>   1024.00  5056.00
>   1226.00  6060.00
>   1300.00  6062.00
>   1491.00  6076.00
>   1655.00  4088.00
>   1741.00  4097.00
>   2402.00  7340.00
>   2497.00  9332.00
>
>But the next day, everything is fine:
>    815.00 38160.00
>   1065.00 28175.00
>   1315.00 25208.00
>   1565.00 24220.00
>   1815.00 22224.00
>   2065.00 21214.00
>   2315.00 23214.00
>   2565.00 24210.00
>   2815.00 24208.00
>   3065.00 21207.00
>   3315.00 21208.00
>   3565.00 21213.00
>
>Is this reporting problem an error in the data when it is recorded by the
>instrumentation, or is it a problem on our end, or is it arising as the
>data is being processed and transfered to us?
>
>This inconsistenty creates two problems for me.  First, I'm ucertain
>whether the data is trustworthy.  Second, the scripts I used to generate
>HAGL plots won't find the data, since it no longer is reported at the
>levels that are expected to contain data.
>
>Chris
>
>--------------
>Chris Anderson
>Graduate Research Assistant
>Iowa State University
>
>