IEM Reanalysis (IEMRE)
IEM Reanalysis is an effort to provide a regular
dataset of Iowa Environmental Data without many of the problems associated
with single site observations. The IEM will continue to provide single
site observational data, but for some purposes, this dataset will be easier
to work with. No dataset is perfect and this dataset is provided
without warranty.
- Why do this?
Previously, the IEM has only provided raw observations with limited
quality control checks in place. Quality control is hard! Many times, users
are simply looking for something "close" and perhaps not as perfect as high
quality sensor observations can be. Producing a gridded analysis is one
way to produce a dataset from point observations which can be sampled as
a means of spatial interpolation.
- Isn't this a duplication of effort?
While there are other "reanalysis" type projects out there with
data freely available, many times their data does not update in near real-time
and does not include many of the datasets the IEM uniquely collects. We may
also produce an analysis on sub-hourly timescales.
Data Flow
1. Input Datasets
- NCEP Stage IV Precipitation
This is an hourly gridded product with precipitation estimates
derived by RADAR and then bias corrected by gauge data. The IEM
caches the grib data and makes hourly
plots available here.
- MRMS Precipitation
Currently, this is only used to populate a daily total in a
dedicated netcdf file.
- ASOS/AWOS Daily Summaries
- NWS Daily Climate Summaries
- HRRR/MERRA/NARR Daily Solar Radiation
- NWS COOPerative Observations
- Manually QC'd Iowa COOP data from Iowa's State Climatologist
- NCDC QC'd COOP Data
2. IEM ReAnalysis Gridded Datasets
3. Climodat Station Data
The location of the IEM Longterm tracked climate stations are used to
sample from the IEMRE grid to produce daily values of high / low
temperature, precipitation, snowfall, snow depth, and radiation. For
some stations, a direct copy of the corresponding ASOS station data
is used.
- Climodat Reports
These are pre-generated reports answering many of the commonly
asked climatology questions.
Data Availability
Hourly Interval | Daily Interval |
- 2 Meter Air Temperature
- 10 Meter Wind Speed and Direction
- Precipitation
|
- High and Low 2 Meter Air Temperature
- Precipitation
|
Data Access
Here are some JSON web services you may try.
MultiDay Request
================
Form: https://mesonet.agron.iastate.edu/iemre/multiday/{YYYY-MM-DD::date1}/{YYYY-MM-DD::date2}/{LAT}/{LON}/json
Example: https://mesonet.agron.iastate.edu/iemre/multiday/2010-05-01/2010-09-30/42.54/-96.40/json
IEMRE data is stored on the server as netCDF files. You can directly
download these files from here.