Index of /pub/data/uscrn/products/daily01
USCRN/USRCRN DAILY FILES
UPDATED: 2017-07-06
README CONTENTS:
1. GENERAL INFORMATION
2. DATA VERSION / STATUS UPDATES
3. DIRECTORY / FILE ORGANIZATION
4. FILE AND FILENAME FORMATS
A. YEARLY
B. SNAPSHOTS
C. UPDATES
5. DATA FIELDS / FORMATS / IMPORTANT NOTES
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1. GENERAL INFORMATION
NCDC provides access to daily data from the U.S. Climate Reference Network /
U.S. Regional Climate Reference Network (USCRN/USRCRN) via anonymous ftp at:
ftp://ftp.ncdc.noaa.gov/pub/data/uscrn/products/daily01
and an identical web interface at:
http://www1.ncdc.noaa.gov/pub/data/uscrn/products/daily01
Before using these data, be sure to review this document carefully, as well
as any announcements within the main (daily01) directory.
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2. DATA VERSION / STATUS UPDATES
Status and Version Information for U.S. Climate Reference Network Data
##########################
Version change: 2.1 to 2.1.1
Commencement Date: 2017-06-20
Completion Date: 2017-06-30
Variables impacted: Precipitation
Effective June 30, 2017, recalculation using the Official Algorithm
for Precipitation (OAP) 2.1.1 has been completed. The purpose of this
recalculation is described in Appendix A of the OAP 2.1 documentation:
https://www1.ncdc.noaa.gov/pub/data/uscrn/documentation/maintenance/2016-05/USCRN_OAP2.1.Description_PrecipChanges.pdf
##########################
Status change: Correction
Correction Applied: 2017-05-01
Variables impacted: Precipitation for 3 stations
From July 2016 until May 1, 2017, the precipitation values for
the following stations and time periods were mistakenly missing on
the website and in the FTP product files:
NC Asheville 8 SSW 2004-05-01 to 2004-11-01
SC McClellanville 7 NE 2005-05-01 to 2005-11-01
CA Stovepipe Wells 1 SW 2004-05-01 to 2005-06-01
Precipitation data for these stations/time periods that were downloaded
during the affected time period should be re-acquired.
##########################
Version change: 2.0 to 2.1
Commencement Date: 2016-05-12
Completion Date: 2016-06-13
Variables impacted: Precipitation
Relative Humidity (RH)
Temperatures from RH Sensor
Thermometer Shield Aspiration Fan Speeds
Air Temperature (when fan speeds are low)
Beginning May 12, 2016, USCRN changed the current data set to
version 2.1 from v2.0. This version change was retroactively applied to
all USCRN/USRCRN stations for their period-of-record 5-minute measurements
from 2016-05-12 until 2016-06-13. [Note that during this period of
reprocessing, data on the website and in these FTP products contained
a mixture of v2.0 and v2.1 values.]
Version 2.1 includes minor precipitation algorithm changes and
changes/additions to the quality control ranges for acceptable
relative humidity (RH) values, temperatures measured with the
RH sensors, and for the speed of the fans which are used to
aspirate the air temperature sensors. For precipitation, the Official
Algorithm for Precipitation (OAP) v2.1 was implemented which
addresses a minor correction to v2.0 that guards against
overally large (> 0.3 mm) precipitation residuals from one hour
being transferred to the next hour. Further information can be found at
http://www.ncdc.noaa.gov/crn/documentation.html.
##########################
Version change: 1.0 to 2.0
Commencement Date: 2015-08-17
Completion Date: 2015-09-15
Variables impacted: Precipitation
The original Official Algorithm for Precipitation
(OAP) version 1.0 was operational until August 17, 2015 and used a
pairwise comparison and moving reference depth to calculate
precipitation. Precipitation data accessed and/or downloaded
prior to this date were calculated using OAP v1.0.
Beginning August 17, 2015, all precipitation data were
calculated using a new processing algorithm, OAP v2.0. In addition,
the v2.0 algorithm was retroactively applied to all USCRN/USRCRN
stations for their periods of record (PORs) starting when 5-minute
data began being collected. The reprocessing took approximately four
weeks to recalculate all station's existing values from v1.0 to v2.0
for their PORs and was completed on September 15, 2015.
OAP v2.0 marked a fundamental shift in the procedures used to calculate
precipitation. The new algorithm uses a weighted average approach
based on each sensor's noise level. It has greatly improved the
network's capacity to detect lighter precipitation with greater
confidence. For details, see Leeper et. al., 2015,
(http://journals.ametsoc.org/doi/abs/10.1175/JTECH-D-14-00185.1) and
http://www.ncdc.noaa.gov/crn/documentation.html.
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3. DIRECTORY / FILE ORGANIZATION
The daily01 directory contains the following subdirectories:
- /2000 through the present year
-- useful for obtaining the most up-to-date data from one or more
stations for a particular year or years (typically updated on a daily
basis).
- /snapshots
-- useful for obtaining data from all stations for all years.
The entire dataset (as of the date/time of the filename) can be
downloaded in a single compressed file. New snapshot files are created
on a regular basis; the most recent file contains the most recent set
of data.
- /updates
-- real-time files broadcast over NOAAPort; stored in yearly
subdirectories. These files have the daily values for all stations
processed that day.
- /obsolete
-- files which are now considered to be obsolete and unsuitable for
scientific uses but are available as a historical record of work.
********************************************************************************
4. FILE AND FILENAME FORMATS
A. YEARLY
Each yearly subdirectory in daily01 contains one file for each USCRN/USRCRN
station listing its daily data in ASCII text format. The files are named
according to the following convention:
CRND01TT-YYYY-${name}.txt
CRND01 = filename prefix to denote CRN Daily01 data ** See note below.
TT = 2-character file format number (currently 03)
YYYY = 4-digit year
${name} = station name (state location vector) (e.g. AZ_Tucson_11_W)
** Filename prefix revision:
On April 11, 2011 15:00 UTC, the prefix 'CRNDAILY' was replaced with
'CRND01' and changed retroactively for all years.
The 2-character sequence TT indicates the file format number and is updated
when the file format is changed. Previous changes were applied retroactively
for all years and are outlined below:
1. [Transition from format '01' to '02']
On March 22, 2011 15:00 UTC the format of the Daily product was
changed by removing the COOPNO (Cooperative Observer Program Number)
column. This had been the second column in the format, starting at
character 7 and ending at character 12. With the removal of
this column, all following columns were shifted to the left by
7 characters. The contents of the shifted columns remained the same.
2. [Transition from format '02' to '03']
On January 7, 2013 15:00 UTC the format of the Daily product was
changed by adding the SUR_TEMP_DAILY_TYPE column. This became the
12th column in the format, starting and ending at character 88.
With the addition of this column, all the following columns were
shifted to the right by 2 characters. The contents of the shifted
columns remained the same.
B. SNAPSHOTS
The 'snapshots' directory contains a series of compressed (.zip) files.
Each file contains the entire data archive of USCRN/USRCRN daily01 data as
of the date/time shown on its filename. Once uncompressed, the directory and
file structure are identical to the yearly subdirectories (as explained
above). Snapshots are created and uploaded at regular intervals, and are
named according to the following convention:
CRND01TT-YYYYMMDDHHmm.zip
CRND01 = filename prefix to denote CRN Daily01 data ** See note below.
TT = 2-character file format number (see above)
YYYY = 4-digit year files generated
MM = 2-digit month files generated (01=Jan, ..., 12=Dec)
DD = 2-digit day of month files generated
HH = 2-digit hour of day files generated
mm = 2-digit minute files generated
** Filename prefix revision:
Snapshot files created prior to April 11, 2011 15:00 UTC, use the
'CRNDAILY' prefix.
Users may obtain the most recent archive of data for all stations and all
years by downloading the most recent file in this directory. As improvements
to the dataset are made, the snapshot files serve as a historical record of
the archive through time.
C. UPDATES
The 'updates' directory contains a record of the real-time files which are
produced daily and broadcast over NOAAPort (SXXX91 CRND01). Each
file contains all the USCRN/USRCRN daily data from every station loaded into
the database since the last transmission. The yearly subdirectories contain
a collection of ASCII files named according to the following convention:
CRND01TT-YYYYMMDDHHmm.txt
CRND01 = filename prefix to denote CRN Daily01 data ** See note above.
TT = 2-character file format number (see above)
YYYY = 4-digit local year
MM = 2-digit local month (01=Jan, ..., 12=Dec)
DD = 2-digit local day of month
HH = 2-digit local standard time hour of day (always 23)
mm = 2-digit minute (always 59)
The 'updates' files are named according to the calendar date of the
observations. The daily records for the previous calendar day are generated
several times each day to ensure that late arriving data are included.
********************************************************************************
5. DATA FIELDS / FORMATS
Each station file contains fixed-width formatted fields with a single day's
data per line. A summary table of the fields and a detailed listing of field
definitions/column formats are shown below.
Fortran users will find the column widths and counts useful.
The file "HEADERS.txt", found in the daily01 directory, is designed to be
prepended to the data for use with spreadsheet programs, data extraction tools
(e.g. awk) or any other programming language. This file contains the following
three lines:
1. Field Number
2. Field Name
3. Unit of Measure
Please be sure to refer to the "Important Notes" section below for essential
information.
All daily data are calculated over the station's 24-hour LST day.
Field# Name Units
---------------------------------------------
1 WBANNO XXXXX
2 LST_DATE YYYYMMDD
3 CRX_VN XXXXXX
4 LONGITUDE Decimal_degrees
5 LATITUDE Decimal_degrees
6 T_DAILY_MAX Celsius
7 T_DAILY_MIN Celsius
8 T_DAILY_MEAN Celsius
9 T_DAILY_AVG Celsius
10 P_DAILY_CALC mm
11 SOLARAD_DAILY MJ/m^2
12 SUR_TEMP_DAILY_TYPE X
13 SUR_TEMP_DAILY_MAX Celsius
14 SUR_TEMP_DAILY_MIN Celsius
15 SUR_TEMP_DAILY_AVG Celsius
16 RH_DAILY_MAX %
17 RH_DAILY_MIN %
18 RH_DAILY_AVG %
19 SOIL_MOISTURE_5_DAILY m^3/m^3
20 SOIL_MOISTURE_10_DAILY m^3/m^3
21 SOIL_MOISTURE_20_DAILY m^3/m^3
22 SOIL_MOISTURE_50_DAILY m^3/m^3
23 SOIL_MOISTURE_100_DAILY m^3/m^3
24 SOIL_TEMP_5_DAILY Celsius
25 SOIL_TEMP_10_DAILY Celsius
26 SOIL_TEMP_20_DAILY Celsius
27 SOIL_TEMP_50_DAILY Celsius
28 SOIL_TEMP_100_DAILY Celsius
1 WBANNO [5 chars] cols 1 -- 5
The station WBAN number.
2 LST_DATE [8 chars] cols 7 -- 14
The Local Standard Time (LST) date of the observation.
3 CRX_VN [6 chars] cols 16 -- 21
The version number of the station datalogger program that was in
effect at the time of the observation. Note: This field should be
treated as text (i.e. string).
4 LONGITUDE [7 chars] cols 23 -- 29
Station longitude, using WGS-84.
5 LATITUDE [7 chars] cols 31 -- 37
Station latitude, using WGS-84.
6 T_DAILY_MAX [7 chars] cols 39 -- 45
Maximum air temperature, in degrees C. See Note F.
7 T_DAILY_MIN [7 chars] cols 47 -- 53
Minimum air temperature, in degrees C. See Note F.
8 T_DAILY_MEAN [7 chars] cols 55 -- 61
Mean air temperature, in degrees C, calculated using the typical
historical approach: (T_DAILY_MAX + T_DAILY_MIN) / 2. See Note F.
9 T_DAILY_AVG [7 chars] cols 63 -- 69
Average air temperature, in degrees C. See Note F.
10 P_DAILY_CALC [7 chars] cols 71 -- 77
Total amount of precipitation, in mm. See Note F.
11 SOLARAD_DAILY [8 chars] cols 79 -- 86
Total solar energy, in MJ/meter^2, calculated from the hourly average
global solar radiation rates and converted to energy by integrating
over time.
12 SUR_TEMP_DAILY_TYPE [1 chars] cols 88 -- 88
Type of infrared surface temperature measurement. 'R' denotes raw
measurements, 'C' denotes corrected measurements, and 'U' indicates
unknown/missing. See Note G.
13 SUR_TEMP_DAILY_MAX [7 chars] cols 90 -- 96
Maximum infrared surface temperature, in degrees C.
14 SUR_TEMP_DAILY_MIN [7 chars] cols 98 -- 104
Minimum infrared surface temperature, in degrees C.
15 SUR_TEMP_DAILY_AVG [7 chars] cols 106 -- 112
Average infrared surface temperature, in degrees C.
16 RH_DAILY_MAX [7 chars] cols 114 -- 120
Maximum relative humidity, in %. See Notes H and I.
17 RH_DAILY_MIN [7 chars] cols 122 -- 128
Minimum relative humidity, in %. See Notes H and I.
18 RH_DAILY_AVG [7 chars] cols 130 -- 136
Average relative humidity, in %. See Notes H and I.
19 SOIL_MOISTURE_5_DAILY [7 chars] cols 138 -- 144
Average soil moisture, in fractional volumetric water content (m^3/m^3),
at 5 cm below the surface. See Notes I and J.
20 SOIL_MOISTURE_10_DAILY [7 chars] cols 146 -- 152
Average soil moisture, in fractional volumetric water content (m^3/m^3),
at 10 cm below the surface. See Notes I and J.
21 SOIL_MOISTURE_20_DAILY [7 chars] cols 154 -- 160
Average soil moisture, in fractional volumetric water content (m^3/m^3),
at 20 cm below the surface. See Notes I and J.
22 SOIL_MOISTURE_50_DAILY [7 chars] cols 162 -- 168
Average soil moisture, in fractional volumetric water content (m^3/m^3),
at 50 cm below the surface. See Notes I and J.
23 SOIL_MOISTURE_100_DAILY [7 chars] cols 170 -- 176
Average soil moisture, in fractional volumetric water content (m^3/m^3),
at 100 cm below the surface. See Notes I and J.
24 SOIL_TEMP_5_DAILY [7 chars] cols 178 -- 184
Average soil temperature, in degrees C, at 5 cm below the surface.
See Notes I and J.
25 SOIL_TEMP_10_DAILY [7 chars] cols 186 -- 192
Average soil temperature, in degrees C, at 10 cm below the surface.
See Notes I and J.
26 SOIL_TEMP_20_DAILY [7 chars] cols 194 -- 200
Average soil temperature, in degrees C, at 20 cm below the surface.
See Notes I and J.
27 SOIL_TEMP_50_DAILY [7 chars] cols 202 -- 208
Average soil temperature, in degrees C, at 50 cm below the surface.
See Notes I and J.
28 SOIL_TEMP_100_DAILY [7 chars] cols 210 -- 216
Average soil temperature, in degrees C, at 100 cm below the surface.
See Notes I and J.
IMPORTANT NOTES:
A. All fields are separated from adjacent fields by at least one space.
B. Leading zeros are omitted.
C. Missing data are indicated by the lowest possible integer for a
given column format, such as -9999.0 for 7-character fields with
one decimal place or -99.000 for 7-character fields with three
decimal places.
D. Daily data are calculated using the station's local day.
E. There are no quality flags for these derived quantities. When the
raw data are flagged as erroneous, these derived values are not
calculated, and are instead reported as missing. Therefore, these
fields may be assumed to always be good (unflagged) data, except
when they are reported as missing.
F. The daily values reported in this dataset are calculated using
multiple independent measurements for temperature and precipitation.
USCRN/USRCRN stations have multiple co-located temperature sensors
that make 10-second independent measurements which are used to
produce max/min/avg temperature values at 5-minute intervals. The
precipitation gauge is equipped with multiple load cell sensors to
provide independent measurements of depth change at 5-minute
intervals.
G. On 2013-01-07 at 1500 UTC, USCRN began reporting corrected surface
temperature measurements for some stations. These changes
impact previous users of the data because the corrected values
differ from uncorrected values. To distinguish between uncorrected
(raw) and corrected surface temperature measurements, a surface
temperature type field was added to the daily01 product. The
possible values of the this field are "R" to denote raw surface
temperature measurements, "C" to denote corrected surface
temperature measurements, and "U" for unknown/missing.
H. Relative humidity is computed from 5-minute values in almost all
cases. All USCRN stations now report 5-minute averages, however the
two Asheville, NC stations reported only hourly RH values until
2007-02-22.
I. USRCRN stations do not measure solar radiation, surface temperature,
relative humidity or soil variables, so those fields are shown as
missing data.
J. USCRN stations have multiple co-located soil sensors that record
independent measurements. The soil values reported in this dataset
are an average of the day's hourly soil measurements which are
calculated from the multiple independent measurements. Soil
moisture is the ratio of water volume over sample volume
(m^3 water/m^3 soil).
K. In accordance with Service Change Notice 14-25 from the National
Weather Service, NCDC stopped providing data from the 72
Southwest Regional Climate Reference Network (USRCRN) stations on
June 1, 2014. The historical data for these stations remain
available.