c(person("Adam", "Sparks", role = c("aut", "cre"),
email = "adamhsparks@gmail.com",
comment = c(ORCID = "0000-0002-0061-8359")),
person("Tomislav", "Hengl", role = "aut",
email = "tom.hengl@isric.org",
comment = c(ORCID = "0000-0002-9921-5129")),
person("Andrew", "Nelson", role = "aut",
email = "dr.andy.nelson@gmail.com",
comment = c(ORCID = "0000-0002-7249-3778")),
person("Hugh", "Parsonage", role = c("cph", "ctb"),
email = "hugh.parsonage@gmail.com",
comment = c(ORCID = "0000-0003-4055-0835")),
person("Taras", "Kaduk", role = "ctb",
email = "taras.kaduk@gmail.com",
comment = "Suggestion for handling bulk station downloads more
efficiently"),
person("Gwenael", "Giboire", role = "ctb",
email = "gwenael.giboire@oda-groupe.com",
comment = "Several bug reports in early versions and testing feedback"),
person("Łukasz", "Pawlik", role = "ctb", email = "lukpawlik@gmail.com",
comment = "Reported bug in windspeed conversion calculation"),
person("Ross","Darnell", role = "ctb",
email = "Ross.Darnell@data61.csiro.au", comment = "Reported bug in 'Windows
OS' versions causing 'GSOD' data untarring to fail"))
Adam Sparks [aut, cre] (<https://orcid.org/0000-0002-0061-8359>),
Tomislav Hengl [aut] (<https://orcid.org/0000-0002-9921-5129>),
Andrew Nelson [aut] (<https://orcid.org/0000-0002-7249-3778>),
Hugh Parsonage [cph, ctb] (<https://orcid.org/0000-0003-4055-0835>),
Taras Kaduk [ctb] (Suggestion for handling bulk station downloads more
efficiently),
Gwenael Giboire [ctb] (Several bug reports in early versions and
testing feedback),
Łukasz Pawlik [ctb] (Reported bug in windspeed conversion calculation),
Ross Darnell [ctb] (Reported bug in 'Windows OS' versions causing
'GSOD' data untarring to fail)

Provides automated downloading, parsing, cleaning, unit conversion
and formatting of Global Surface Summary of the Day ('GSOD') weather data
from the from the USA National Centers for Environmental Information
('NCEI').  Units are converted from from United States Customary System
('USCS') units to International System of Units ('SI').  Stations may be
individually checked for number of missing days defined by the user, where
stations with too many missing observations are omitted.  Only stations with
valid reported latitude and longitude values are permitted in the final
data.  Additional useful elements, saturation vapour pressure ('es'), actual
vapour pressure ('ea') and relative humidity ('RH') are calculated from the
original data using the improved August-Roche-Magnus approximation (Alduchov
& Eskridge 1996) and included in the final data set.  The resulting metadata
include station identification information, country, state, latitude,
longitude, elevation, weather observations and associated flags.  For
information on the 'GSOD' data from 'NCEI', please see the 'GSOD'
'readme.txt' file available from,
<http://www1.ncdc.noaa.gov/pub/data/gsod/readme.txt>.