get_met_data {stationaRy}

Get data from a meteorological station

Description

Obtain one or more years of meteorological data for a particular station.

Usage

get_met_data(
  station_id,
  years = NULL,
  full_data = FALSE,
  add_fields = NULL,
  make_hourly = TRUE,
  local_file_dir = NULL
)

Arguments

station_id

A station identifier composed of the station's USAF and WBAN numbers, separated by a hyphen.

years

The years for which station met data will be collected. If not specified then all records for all available years will be obtained for the station.

full_data

Include all additional meteorological data found in the dataset's additional data section?

add_fields

A vector of categories for additional meteorological data to include (instead of all available categories).

make_hourly

Transforms data to force values to the start of each hour. All data is bucketed by hour and all missing hours are filled with NAs. This regularizes each year of data, where the number of records per year of data will be either 8760 or 8784 (depending on whether a year is a leap year). By default to this is TRUE.

local_file_dir

Path to local meteorological data files. If specified, then data files will be downloaded to and retrieved from this location and not from the remote data store.

Value

Returns a tibble with at least 10 variables. While times are recorded using the Universal Time Code (UTC) in the source data, they are adjusted here to local standard time for the station's locale.

id

A character string identifying the fixed weather station from the USAF Master Station Catalog identifier and the WBAN identifier.

time

A datetime value representing the observation time.

temp

Air temperature measured in degrees Celsius. Conversions to degrees Fahrenheit may be calculated with (temp * 9) / 5 + 32.

wd

The angle of wind direction, measured in a clockwise direction, between true north and the direction from which the wind is blowing. For example, wd = 90 indicates the wind is blowing from due east. wd = 225 indicates the wind is blowing from the south west. The minimum value is 1, and the maximum value is 360.

ws

Wind speed in meters per second. Wind speed in feet per second can be estimated by ws * 3.28084.

atmos_pres

The air pressure in hectopascals relative to Mean Sea Level (MSL).

dew_point

The temperature in degrees Celsius to which a given parcel of air must be cooled at constant pressure and water vapor content in order for saturation to occur.

rh

Relative humidity, measured as a percentage, as calculated using the August-Roche-Magnus approximation.

ceil_hgt

The height above ground level of the lowest cloud cover or other obscuring phenomena amounting to at least 5/8 sky coverage. Measured in meters. Unlimited height (no obstruction) is denoted by the value 22000.

visibility

The horizontal distance at which an object can be seen and identified. Measured in meters. Values greater than 16000 are entered as 16000 (which constitutes 10 mile visibility).

Examples

## Not run: 
# Obtain two years of data from the
# met station with the ID value of
# "999999-63897" 
met_data <- 
  get_met_data(
    station_id = "999999-63897",
    years = 2013:2014
  )

## End(Not run)