Annual Temperature Plots

Annual Temperature Plots
Ships

The GHCN land data provided with the GHCN Temperature Plotter contains data for 7 "ships" in the adjusted data - 9 in the raw (unadjusted) data.

I consider these to be of little value and filter them out by default. Filter and selection controls are located on the Filters tab.

Details

These images show the ship data and where the ships are located. My biggest problem with these is that there is no data after about 1990. Two of these, the ones with the largest negative trends, are omitted from the adjusted data. Another three don't have enough data to pass the basic baseline filter (15 years of data between 1960 and 1991). As a result, of the nine, only four would be used in most averages.

In addition, ship data is spotty and unreliable and should never be combined with high quality fixed station data.

For these reasons, I omit all the provided ship data from the normal station selection process.

That said, options on the Filters tab allow you to include it if you want.

Ship data	Ship locations

Actual temperatures from the ships	The green dots are the ships -- 7 adjusted - 9 raw
Both images initially display adjusted data - Move the mouse over either image to see the raw (unadjusted) data

Image creation details

The temperature graphs and map images were created using the following procedure

On the Filters tab - uncheck Always exclude "ship" data
On the Basic Filters tab
- Change the required number of baseline samples to 2
- Click Compute New Baseline
On the Filters tab - in the Ships section, click Add
On the Plot Controls tab
- Set these values - ymin=0 ymax=17 xmin=1900 xmax=2015
- Click the Stations checkbox to apply the values
- Click Add up to 20 Selected Stations
In the Stations plot - set the series colors as desired
The graph and map images were captured by right clicking the mouse and selecting the appropriate (browser dependent) menu option

That procedure needs to be followed for both the adjusted and unadjusted (raw) data.

For the raw data, after following the procedure, I had to manually select ships K & D in order to display them in the order shown in the plots.

Ship J

Of the group, Ship J probably has the most adjustment - from a cooling of 1.23°C/century to a warming of 1.14°C/century. This, along with the shortness of the record length, is why I consider this ship's data to be of little value.

Ship J data	Ship J location

Actual temperatures from Ship J - Raw-blue Adjusted-red	The green dot in the North Atlantic is Ship J

The Berkeley Earth analysis is quite humorous - they report "a station move"! Really, a ship at sea moved to another location? How is that possible?

At any rate, after they "fixed" the data the new cooling rate was larger than before - -0.94°C/century was change to -2.67°C/century.

On the other hand, GHCN changed the slope from a cooling to a warming.

Note: All the images on this page can be zoomed by simply using the mouse wheel.
Double click to toggle full size to default size

Author: Robert Clemenzi