Annual Temperature Plots

Annual Temperature Plots - Overview

I have developed a tool to plot annual GHCN temperature data from over 5,000 global sites.

Available Datasets
Dataset	GHCN adjusted	GHCN unadjusted	GHCN adjusted+ocean	GHCN unadjusted+ocean
# of Stations	5255	5551	6139	6435

The quality of the data, and of any analysis performed with that data, is of interest to everyone. However, the number of years of data from each station is also important. For instance, there are 5255 GHCN adjusted sites.

Of those, only 4567 have 15 years of data between 1961 and 1990 - the default baseline
Of those, only 1000 have 8 years of data between 1900 and 1910 - selected by user defined filter
Of those, only 520 have 8 years of data between 2000 and 2010 - via another filter

So an argument can be made that only 520 sites have a sufficient amount of valid information to try and determine if Global Warming is occurring or not. (Based on those stations - the Earth is warming, but there is no correlation with CO2.)

Plots | Excluded stations | Oceans | Features | Acknowledgment

Plots

Plots with trend lines
A normal plot	A High/Low Volume (station count) plot

This is what you normally see. The trend line can be turned off.	As you can see, the Volume (number of stations) shows how the number of stations varies with time.

Excluded stations

One of the advantages of the tool is that you can see which stations are being used and which ones are excluded as you apply various filters.

All 5255 GHCN adjusted land stations
The 4567 green stations have 15 years of data between 1961 and 1990	Only 520 green stations are left after applying the 3 filters listed above

Oceans

The ocean data is a bit weird, and I am sure it is based on the best science available. But I don't trust it!

Each "station" represents a huge amount of ocean
The sampling methods are highly varied
The sampling locations are very spotty
Ocean currents wonder all over the place
Some of the data pretends to go back to 1900 - that has to be pretty lame !

At any rate, using the tool, it is pretty obvious that the sampling patterns changed during the 2 world wars.

All 884 ocean stations (from GHCN adjusted+ocean) - green have data, purple do not, red are land/not selected
Ocean stations with at least 15 years of data between 1900 and 1920	Ocean data showing less data (low volume) during war


Ocean stations with less than 4 years data between 1918 and 1923	Ocean stations with less than 4 years data between 1940 and 1945

Features

The map can be zoomed
You can select and see which sites to average with either a mouse or a data range filter
You can change the baseline start and end dates and specify how many samples a valid site must have in that period
You can select either temperatures or anomalies
Selected data can be downloaded in a tab delimited csv (spreadsheet) file
Each plot can have several data series at the same time
Each series can have a different color
You can change the series name that is displayed
The plot axes can be dynamic or fixed
You can turn trend lines off and on - the slopes (°Celsius/Decade) appear in the legend
The High/Low plot provides trend lines on all 3 series - Average, High, Low
You can see how the number of available stations varies with time

Acknowledgment

This plot routine is based on the 08 May 2015, version of the Temperature Tool used in Week 2 - Temperature of UQx: Denial101x Making Sense of Climate Science Denial.

Their help video (by Kevin Cowtan) is pretty good and mostly still applies to the new program.

My tool (with a change log) is expanded and enhanced, but uses the same data.

Author: Robert Clemenzi