noaa {VulnToolkit}

Downloads NOAA CO-OPS tide data

Description

Scrapes water level data (and other measurements) from NOAA CO-OPS website. NOAA's site limits the time period for data downloads, but these constraints are avoided by 'noaa()'. Requires internet connection and curl (check availablility using 'Sys.which("curl")').

Usage

noaa(begindate = "begindate", enddate = "enddate", station = "8467150",
met = FALSE, units = "meters", datum = "MHW", interval = "HL", time = "GMT", 
continuous = TRUE)

Arguments

begindate

first day of data to download. Format must be YYYYMMDD. If left unspecified, the first complete day of data will be used.

enddate

final day of data to download. Format must be YYYYMMDD. If left unspecified, the last complete day of data will be used.

station

station number, found on the NOAA Tides and Currents website (https://www.tidesandcurrents.noaa.gov/stations.html?type=Water+Levels). Station numbers can be numeric or a character string (necessary if first character is a zero). Default station is Bridgeport, CT.

met

whether meteorological data should be returned. This value can be 'TRUE' or 'FALSE'; if 'TRUE', all ancillary parameters are returned. At present, this only works with 6-minute and hourly data

units

can be 'feet' or 'meters'. Default is 'meters'

datum

vertical reference datum, set to 'MHW' by default. Can be 'station', 'NAVD', 'MLLW', 'MLW', 'MSL', 'MTL', 'MHW', 'MHHW', or 'IGLD' (some datums are not available at some sites)

interval

sets measurement interval; can be 'HL' (default), '6 minute', 'hourly', or 'monthly'.

time

can be 'LST', 'GMT', or 'LST/LDT'. Not all time zones are available for all data. GMT appears to have wider availability than LST, so it is the default.

continuous

determines whether a continuous time series is produced, with lengthy gaps in data filled in with NAs. By default, this is FALSE. This option only applies to data at evenly spaced intervals (i.e., 6 minute or hourly)

Details

Download water level and other data from NOAA CO-OPS website.

Value

dataset a dataframe with water levels, associated time stamps, a station ID column, and tide type (if interval is set to HL). The NOAA CO-OPS website has many odd data availabilty problems. Some data are not available in all time intervals or time zones.

Examples

## Not run: 
# Example requires an internet connection
bport2013 <- noaa(begindate = 20130101, enddate = 20131231, 
  station = "8467150", interval = "6 minute")

test2.1 <- noaa(begindate = "20100101", enddate = "20120101", interval = "hourly") 
test2.2 <- noaa(begindate = "20100101", enddate = "20120101", interval = "hourly", 
               continuous = TRUE) 
nrow(test2.1) # includes data on NOAA site (incomplete record)
nrow(test2.2) # fills gaps with NAs 
test2.3 <- noaa(begindate = "20100101", enddate = "20120101", interval = "hourly", 
               met = TRUE) 

## End(Not run)