“Climate spiral” – Plotting GISS Surface Temperature

NASA has been collecting surface temperature for more than over 100 years, and the GISS Surface Temperature analysis from 1888 onward. It is an estimate of global surface temperature change.

The temperature analysis schema was defined in the late 1970s by James Hansen and the complete analysis and method are documented in Hansen and Lebedeff (1987). To put it simply is a method of global temperature change that is used for comparison with one-dimensional global climate models.

Data

The website (https://data.giss.nasa.gov/gistemp/ ) offers loads of data and I am using the Global-mean monthly, seasonal, and annual means, 1880-present, updated through most recent month: TXT, CSV

It need some prior data preparation, namely min and max values, as it is required by radarchart function.

library(ggradar)
library(fmsb)
library(scales)
library(RColorBrewer)

#data txt and preparation
df <-read.csv("Documents/GLB.Ts+dSST.csv",header = TRUE, sep = ",", skip = 1, dec="." )[1:13]
df <- as.data.frame(sapply(df[1:143,], as.numeric))
df_months <- names(df)[2:13]
df_years <- df$Year
rownames(df) <- df_years
df <- df[,2:13]

# adding max min
max_min <- data.frame(
  Jan = c(1.4, -0.85), Feb = c(1.4, -0.85), Mar = c(1.4, -0.85),
  Apr = c(1.4, -0.85), May = c(1.4, -0.85), Jun = c(1.4, -0.85),
  Jul = c(1.4, -0.85), Aug = c(1.4, -0.85), Sep = c(1.4, -0.85),
  Oct = c(1.4, -0.85), Nov = c(1.4, -0.85), Dec = c(1.4, -0.85)
)
rownames(max_min) <- c("Max", "Min")
#merging
df <- rbind(max_min, df)

# Set graphic colors
nb.cols <- length(df_years)
mycolors <- colorRampPalette(brewer.pal(8, "Set2"))(nb.cols)
colors_border <- mycolors  
colors_in <- alpha(mycolors, 0.3) 

Data visualisation

Adding the radarchart and looping through the years:

for (i in 1:length(df_years)){
  y <- df_years[1:i]
  df_tmp <- df[rownames(df)%in%y,1:12]
  df_tmp <- rbind(max_min, df_tmp)
  radarchart( df_tmp, maxmin=TRUE, axistype=1,seg=3,vlabels = df_months,
              plwd=0.5 , plty=1,centerzero=FALSE,caxislabels = c(-1, 0, 1, 1.4),
              cglcol="grey", cglty=2, axislabcol="black",  
              vlcex=1.2,
              title= paste0("GISS Surface temperature for years until ", tail(y,1)) )  
  legend(x=-0.35, y=0.15, legend = tail(y,1), bty = "n", pch=30 , col=colors_in , text.col ="black", cex=1.3, pt.cex=3)
}

Changes through time stretch from 1888 until 2023. The scale of this radar charts go from -1ºC to 1.4ºC (with 0 and 1 as reference lines).

Year 1900

Year 1950

Year 2000

Year 2022

The spikes and bursts in temperature over the past 30 years are mind-boggling

As always, code is available on Github in  Useless_R_function repository. The sample file in this repository is here (filename: Climate_spiral.R) Check the repository for future updates.

Happy R-coding and stay healthy!