Thank you for finally addressing this issue that was reported several
weeks ago. I wish there could have been more notification than on the
day of the server switch so I could have time to fix things.
One point of clarification. Loading a bundle in IDV 5.1u2 will not
prompt you for a new variable name. It just gives an error that the
variable can't be found and hence no display is created. This means
that anyone using bundles that have variables with new names will have
to remake their bundles.
Sigh.....
Don
On 5/18/15 12:25 PM, Unidata THREDDS Support wrote:
Greetings IDV users,
As thredds.ucar.edu is switched to the 4.6 version of the THREDDS Data Server
(TDS),
you may notice the same names of variables have changed. Specifically, you will
likely
encounter the case where Mixed Interval variable have been renamed to indicate
that
they are no longer mixed, but rather fixed interval variables. As an example,
if we consider
the Rapid Refresh Model, the following old variable name:
Convective_precipitation_surface_Mixed_intervals_Accumulation
has been changed to:
Convective_precipitation_surface_1_Hour_Accumulation
Why did this happen? The THREDDS group has looked over all cases of Mixed
Interval
Variables in the data we serve out and we noticed that, in some cases, mixed
intervals were
not needed, and we we able to reduce these to single interval variables.
Again, considering the Convective Precip variable from the Rapid Refresh, the
old variable:
Convective_precipitation_surface_Mixed_intervals_Accumulation
actually contained two types of intervals over which the accumulation occurred
(thus
the "mixed interval" in the name). One interval was the 1 hour interval:
accumulation over forecast hours 0-1, 1-2, 2-3, 3-4., etc.
The second interval contained a total run accumulation:
accumulation over forecast hours 0-1, 0-2, 0-3, 0-4, etc.
When served as a mixed interval, the data would look something like:
accumulation over forecast hours 0-1, 0-1, 1-2, 0-2, 2-3, 0-3...
The end result is that, when displayed in the IDV, the precip field would
appear to
"jump" around in magnitude when animated. However, given the simplicity of how
these intervals were actually "mixed", we were able to, on the server side,
remove
the total accumulation over the run portion of the grids while only serving the
1 hour
accumulation grids. Since the total run accumulation can be computed from the
1 hour interval accumulations, this seems like the reasonable thing to do.
Depending on the model, the mixed interval grid may be rename as a
1_hour_Accumulation, or a 3_hour_Accumulation (other interval lengths
will be possible in the future, I'm sure). That means replacing all of the Mixed
Interval Variable names with a 1 hour Accumulation variable name is not a
safe option.
After much discussion with the IDV group over the past year+, we've agreed that
in these cases (where data fundamentally change meaning), it's best to allow
users of the IDV to see that these changes have occurred. We are not big fans of
silently changing the meaning of the variables. Further, we aren't sure how
aware
users are of the complexity of these mixed interval data, so this will bring
these issues
to the forefront. For users of IDV bundles, this means you will need to
re-save your
bundle after being prompted to select a new variable.
We hope you find these reduced mixed interval variables are more useful, and
please know that we are working on a solution for the more complex types of
mixed intervals (for example, every mixed interval in the GFS output). Because
these more complex mixed interval variables still show up as Mixed Interval
variables (and are very nuanced), be very cautious when using them as they are
likely NOT what you think or hope they might be.
In the coming weeks we will be doing a series of blog posts explaining in detail
how these mixed interval grids come about, and why there are cases where
the reduction of a mixed interval variable is not as simple as the case above.
Here is a list of the datasets, and associated variables, where these changes
occur:
Rapid Refresh collections (for old name, replace 1_Hour with Mixed_intervals):
Convective_precipitation_surface_1_Hour_Accumulation
Large-scale_precipitation_non-convective_surface_1_Hour_Accumulation
NAM 12km NOAAPORT (for old name, replace 3_Hour with Mixed_intervals):
Convective_precipitation_surface_3_Hour_Accumulation
Percent_of_Frozen_Precipitation_surface_3_Hour_Accumulation
Probability_of_0p01_inch_of_precipitation_POP_surface_3_Hour_Accumulation
Probability_of_Freezing_Precipitation_surface_3_Hour_Accumulation
Thunderstorm_probability_surface_3_Hour_Accumulation
Total_precipitation_surface_3_Hour_Accumulation
NAM 12km CONDUIT (for old name, replace 3_Hour with Mixed_intervals):
Baseflow-Groundwater_Runoff_surface_3_Hour_Accumulation
Convective_precipitation_surface_3_Hour_Accumulation
Deep_Convective_Heating_Rate_entire_atmosphere_single_layer_3_Hour_Average
Downward_Short-Wave_Radiation_Flux_surface_3_Hour_Average
Large_Scale_Condensate_Heating_Rate_entire_atmosphere_single_layer_3_Hour_Average
Snow_melt_surface_3_Hour_Accumulation
Storm_Surface_Runoff_surface_3_Hour_Accumulation
Total_precipitation_surface_3_Hour_Accumulation
Water_equivalent_of_accumulated_snow_depth_surface_3_Hour_Accumulation
NAM 20km NOAAPORT (for old name, replace 3_Hour with Mixed_intervals):
Convective_precipitation_surface_3_Hour_Accumulation
Percent_of_frozen_precipitation_surface_3_Hour_Accumulation
Probability_of_freezing_precipitation_surface_3_Hour_Accumulation
Probability_of_precipitation_surface_3_Hour_Accumulation
Snow_depth_surface_3_Hour_Accumulation
Thunderstorm_probability_surface_3_Hour_Accumulation
Total_precipitation_surface_3_Hour_Accumulation
NAM 40km CONDUIT (for old name, replace 3_Hour with Mixed_intervals):
Baseflow-Groundwater_Runoff_surface_3_Hour_Accumulation
Convective_precipitation_surface_3_Hour_Accumulation
Downward_Long-Wave_Radp_Flux_surface_3_Hour_Average
Downward_Short-Wave_Radiation_Flux_surface_3_Hour_Average
Evaporation_surface_3_Hour_Accumulation
Ground_Heat_Flux_surface_3_Hour_Average
Large-scale_precipitation_non-convective_surface_3_Hour_Accumulation
Latent_heat_net_flux_surface_3_Hour_Average
Potential_Evaporation_surface_3_Hour_Accumulation
Sensible_heat_net_flux_surface_3_Hour_Average
Snow_Phase_Change_Heat_Flux_surface_3_Hour_Average
Snow_melt_surface_3_Hour_Accumulation
Storm_Surface_Runoff_surface_3_Hour_Accumulation
Total_cloud_cover_entire_atmosphere_single_layer_3_Hour_Average
Total_precipitation_surface_3_Hour_Accumulation
Upward_Long-Wave_Radp_Flux_atmosphere_top_3_Hour_Average
Upward_Long-Wave_Radp_Flux_surface_3_Hour_Average
Upward_Short-Wave_Radiation_Flux_atmosphere_top_3_Hour_Average
Upward_Short-Wave_Radiation_Flux_surface_3_Hour_Average
Water_equivalent_of_accumulated_snow_depth_surface_3_Hour_Accumulation
Thank you,
The THREDDS Development Team
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--
Don Murray
NOAA/ESRL/PSD and CU-CIRES
303-497-3596
http://www.esrl.noaa.gov/psd/people/don.murray/
