createHwDataframe: Characterize heat waves

In geanders/futureheatwaves: Find, Characterize, and Explore Extreme Events in Climate Projections

Description

This function takes a dataframe with identified heat waves and returns a dataframe that lists and characterizes all of the heat waves. If no heat waves were identified in a city, it returns a data frame with the same columns but no observations, to allow the empty dataframe to be joined without error to the dataframes for cities that do have heat waves under the definition.

Usage

createHwDataframe(city, threshold, heatwaves, ensembleSeries, i, global, custom)

Arguments

city	A character vector with the identification of the city being processed.
threshold	Numeric string with threshold temperature used in the heat wave definition, in degrees Fahrenheit.
heatwaves	A dataframe with the following columns: date: Date of each observation, in class "Date"; tmpd: Temperature in degrees Fahrenheit; hw: A binary variable designating whether a day is in a heat wave (0: not in a heat wave; 1: in a heat wave); and hw.number: A numeric value, 0 if the day was not part of a heat wave, otherwise the number of the heat wave to which the day belonged. This is the format of the output of IDheatwaves.
ensembleSeries	A list object giving the projection time series as well as a variety of other information for a single ensemble member. This is the output of processEnsemble.
i	An index specifying which city is being processed. This corresponds to the order of the cities in the citycsv file specified in gen_hw_set.
global	An list object created by gen_hw_set that includes user specifications (e.g., the path to the output directory, the path to the input climate projections, the dataframe with city locations).
custom	An list object created by gen_hw_set that includes user specifications (e.g., the name of the R function to use to identify heat waves, alternative upper and lower year boundaries for the data used to determine threshold temperatures for the heat wave definition, alternative upper and lower year boundaries for the projection period of the heat wave datasets being generated).

Value

A dataframe of identified and characterized heat waves for a single city and single ensemble member. Each row of this dataframe represents a heat wave, with the following columns:

• hw.number: A sequential number identifying each heat wave in a city;

• mean.temp: Average daily temperature across all days in the heat wave, in degrees Fahrenheit;

• max.temp: Highest daily temperature across days in the heat wave, in degrees Fahrenheit;

• min.temp: Lowest daily temperature across days in the heat wave, in degrees Fahrenheit

• length: Number of days in the heat wave;

• start.date: Date of the first day of the heat wave;

• end.date: Date of the last day of the heat wave;

• start.doy: Day of the year of the first day of the heat wave (1 = Jan. 1, etc.);

• start.month: Month in which the heat wave started (1 = January, etc.);

• days.above.80: Number of days in the heat wave above 80 degrees Fahrenheit;

• days.above.85: Number of days in the heat wave above 85 degrees Fahrenheit;

• days.above.90: Number of days in the heat wave above 90 degrees Fahrenheit;

• days.above.95: Number of days in the heat wave above 90 degrees Fahrenheit;

• days.above.99th: Number of days in the heat wave above the 99th percentile temperature for the city, using the period specified by the user with the referenceBoundaries argument in gen_hw_set as a reference for determining these percentiles;

• days.above.99.5th: Number of days in the heat wave above the 99.5th percentile temperature for the city, using the period specified by the user with the referenceBoundaries argument in gen_hw_set as a reference for determining these percentiles;

• first.in.season: Whether the heat wave was the first to occur in its calendar year (Note: this characteristic is likely not useful in southern hemisphere studies.);

• threshold.temp: The temperature used as the threshold for the heat wave definition in the city;

• mean.temp.quantile: The percentile of the average daily mean temperature during the heat wave compared to the city's year-round temperature distribution, based on the temperatures for the city during the period specified by the referenceBoundaries argument in gen_hw_set;

• max.temp.quantile: The percentile of the highest daily mean temperature during the heat wave compared to the city's year-round temperature distribution;

• min.temp.quantile: The percentile of the lowest daily mean temperature during the heat wave compared to the city's year-round temperature distribution;

• mean.temp.1: The city's average year-round temperature, based on the temperatures for the city during the period specified by the referenceBoundaries argument in gen_hw_set;

• mean.summer.temp: The city's average May–September temperature, based on the temperatures for the city during the period specified by the referenceBoundaries argument in gen_hw_set; and

• city: The identifier for the city, as given in the file specified in the citycsv argument of gen_hw_set.

Note

When calculating relative characteristics of heat waves, like the relative value of the heat wave's mean temperature, this function uses a time series from the date ranges specified by the user using the referenceBoundaries option in gen_hw_set. By default, these references are based on projection data from 2070 to 2079.

geanders/futureheatwaves documentation built on May 17, 2019, 12:14 a.m.