History and description
This data package contains monthly evaporation observations
collected at an evaporation pan instrument located at USDA Jornada
Experimental Range (JER) Headquarters. The evaporation pan was a
National Weather Service (NWS) instrument and is part of the NOAA
Global Historical Climate Network (GHCN). Monthly observations of
evaporation in inches of water were collected by USDA JER staff
and sent to the local National Weather Service office from around
1953 until the instrument was decommissioned in 1979. These
observations were made using standard U.S. climatological service
instrumentation and recording procedures. The data sent to the
local NWS office was subsequently quality controlled and assured
and made available on NOAA servers.
This dataset contains monthly evaporation data that are based on
observations stored in the JER database, which were ultimately
derived from floppy disks obtained from a NOAA office in Maryland.
Since this time, these JER data have undergone quality control and
assurance procedures different than those in place at NOAA (see
below), and the data therefore differ from what is available
currently from NOAA servers. There are far fewer missing
observations in this dataset than the NOAA dataset (see
"Additional documents" below).
All data from this evaporation pan that have undergone NOAA QA/QC
procedures are available by accessing the Jornada Experimental
Range, NM US GHCN station through the National Climatic Data
Center portal
(https://www.ncdc.noaa.gov/cdo-web/datasets/GSOM/stations/GHCND:USC00294426/detail).
Evaporation data going back to 1930 is retrievable from NOAA
servers, but there appear to be data issues prior to 1953.
Data evaluation by USDA and LTER staff
Discrepancies between this data set and data now available from
NOAA suggest that data entry errors or additional data filtering
has occurred at NOAA. This resulted in a higher frequency of
missing data in the data directly downloadable from NOAA servers.
This data package remains to document those discrepancies, but is
now considered complete and will not be updated in the future.
Additional documents
The attached history text file
"NOAA_JERHQ_ws_panevap_his.txt" describes the procedures
for identifying discrepancies between NOAA data and JER
headquarters data and the subsequent changes made in the included
data file.
The summary figures "local_vs_noaa_monthlyevap_diff.png"
and "local_vs_noaa_cumulative_monthlyevap.png" plot the
discrepancies between the local JER data and NOAA server data from
the most recent data request.
Related datasets
Daily temperature and precipitation observations from the JER
headquarters NOAA weather station (which the evaporation pan was
co-located with) are found in EDI package knb-lter-jrn.210379001.
Monthly temperature and precipitation summary data from this
weather station is found on EDI in package knb-lter-jrn.210379002.