USCRN HEAT EXPOSURE (HEAT01) FILES

                            UPDATED: 2021-08-13

README CONTENTS:
    1. GENERAL INFORMATION
    2. DATA VERSION / STATUS UPDATES
    3. FILE AND FILENAME FORMATS
    4. DATA FIELDS / FORMATS / IMPORTANT NOTES

********************************************************************************

1. GENERAL INFORMATION

This product is designed to provide heat index variables calculated hourly
for each USCRN station location. This product is fully documented by Rennie
et al. (2021). Beyond the hourly average air temperature, relative humidity,
and global solar radiation observed at the station, an hourly 10 meter wind
speed average is estimated from station observations 1.5 meters above ground,
and surface atmospheric pressure is extracted from either ERA5 reanalysis
historically, or NCEP RUC in near real time. The file contains three heat
exposure variables beyond air temperature: heat index (HI), apparent
temperature (AT) and wet bulb globe temperature (WBGT). Air temperature and
the three heat exposure indices have been provided in both metric (Degrees
Celsius) and standard customary units (Degrees Fahrenheit) for convenience of
the user.

Rennie, J.J., M.A. Palecki, S.P. Heuser, and H.J. Diamond, 2021. Developing
and validating heat exposure products using the U.S. Climate Reference
Network. J Applied. Meteor. Clim., 60, 543-558. https://doi.org/10.1175/JAMC-
D-20-0282.1

********************************************************************************

2. DATA VERSION / STATUS UPDATES

Status and Version Information for U.S. Climate Reference Network
Heat Exposure Dataset.

This is the initial Version 1.0.
********************************************************************************

3. FILE AND FILENAME FORMATS

The heat01 directory contains a single comma-separated-value (CSV) file for the
period-of-record time series of heat exposure values for each USCRN station.
Files are typically updated multiple times per day and are named according to
the following convention:

        CRNHE01TT-${name}.csv

        CRNHE01 = filename prefix to denote CRN HeatExposure01 data
             TT = 2-character file format number (currently 01)
        ${name} = station name (state location vector) (e.g. AZ_Tucson_11_W)

The 2-character sequence TT indicates the file format number and is updated
when the file format is changed.

********************************************************************************

4. DATA FIELDS / FORMATS

Each station file contains comma-separated fields with a single hour's
data per line. A summary table of the fields and a detailed listing of field
definitions/column formats are shown below.

Please be sure to refer to the "Important Notes" section below for essential
information.

All hourly data are calculated over the 60-minute period *ending* at the UTC
times shown.

Field#  Name                           Units
---------------------------------------------
   1    WBANNO                         XXXXX
   2    DATE_TIME                      YYYYMMDDHH
   3    LONGITUDE                      Decimal_degrees
   4    LATITUDE                       Decimal_degrees
   5    RELATIVE_HUMIDITY              %
   6    SURFACE_PRESSURE               hectoPascals or millibars
   7    SOLAR_RADIATION                Watts/square meter
   8    ESTIMATED_10_METER_WIND_SPEED  m/s
   9    DRY_BULB_TEMPERATURE_C         Celsius
   10   HEAT_INDEX_C                   Celsius
   11   APPARENT_TEMPERATURE_C         Celsius
   12   WET_BULB_GLOBE_TEMPERATURE_C   Celsius
   13   DRY_BULB_TEMPERATURE_F         Fahrenheit
   14   HEAT_INDEX_F                   Fahrenheit
   15   APPARENT_TEMPERATURE_F         Fahrenheit
   16   WET_BULB_GLOBE_TEMPERATURE_F   Fahrenheit

    1    WBANNO
              The station WBAN number.

    2    DATE_TIME
              The Universal Coordinated Time (UTC) date and hour of the observation.

    3    LONGITUDE
              Station longitude, using WGS-84.

    4    LATITUDE
              Station latitude, using WGS-84.

    5    RELATIVE_HUMIDITY
              RH average for hour, in percentage.

    6    SURFACE_PRESSURE
              --- SURFACE PRESSURE DESCRIPTION ---

    7    SOLAR_RADIATION
              --- SOLAR RADIATION DESCRIPTION ---

    8    ESTIMATED_10_METER_WIND_SPEED
              --- WIND SPEED DESCRIPTION ---

    9    DRY_BULB_TEMPERATURE_C
              Average air temperature, in degrees C, for the entire hour

    10   HEAT_INDEX_C
              --- HEAT INDEX DESCRIPTION ---

    11   APPARENT_TEMPERATURE_C
              --- APPARENT TEMPERATURE DESCRIPTION ---

    12   WET_BULB_GLOBE_TEMPERATURE_C
              --- WBGT DESCRIPTION ---

    13   DRY_BULB_TEMPERATURE_F
              Average air temperature, in degrees F, for the entire hour

    14   HEAT_INDEX_F
              --- HEAT INDEX DESCRIPTION ---

    15   APPARENT_TEMPERATURE_F
              --- APPARENT TEMPERATURE DESCRIPTION ---

    16   WET_BULB_GLOBE_TEMPERATURE_F
              --- WBGT DESCRIPTION ---