Saturday, December 16, 2017

New version of monthly webGL surface temperature map page.

Moyhu has a maintained page here showing monthly surface temperature anomalies in an interactive webGL spherical shaded plot. The anomalies are based on the TempLS analysis, using unadjusted GHCN V3 and ERSST V5. TempLS provides the triangular mesh and normals (base 1961-90), and the anomalies are just the station monthly averages with these subtracted. The shading is set to give correct color at the nodes (stations). It is updated daily, so also provides a detailed picture from early in the month (which means the first few days are sparse).

The page had used its own webGL program, with a month selection mechanism (using XMLHTTPrequest to dowload data). I have been developing a general webGL facility (described here), and I wanted to make a nw page that conforms with that. This makes extra facilities available and is easier for me to maintain.

To do this I had to extend the WebGL facility, to a version I am currently calling V2.2. It is a considerable restructure, which will probably become V3. It enables me to replace the constructors of various parts of the page within the user files that go with each application, rather than writing it into the core facility. There were issues with making variables (and functions) visible to functions defines in separate files. I'm also now rather extensively using the MoyJS library.

The functionality of older MoyGL versions is preserved, and so, I hope, is the functionality of the page. One novelty of the version is a reintroduction of the flat globe pointing mechanism, which I used before WebGL. In the top right corner is a world map; you can click on any place to make the globe turn to show this point in he centre, with the longitude vertical (oriented). Otherwise, it's pretty much as in V2.1 as used previously.

The month selector is different. It is the box in the top right corner:


The three colored bars let you select decade (1900-2010), year (0-9) and month(1-12). The black squares show the current selection. As you click on the bars, these move, and the date in the red box below changes accordingly. When you have the date you want, click "Fetch and Show" and the data will be retrieved and a new plot will appear.

Since I am using unadjusted anomalies (1961-90), some exceptions will show out. I discussed here a method for remedying this, and of course adjusted data would also help. I am not currently using that method, which makes extrapolated current expected value the anomaly base. It is good for recent years, but gets troublesome in earlier years. I may offer it as an alternative some time.

Friday, December 8, 2017

November global surface temperature down 0.04°C

TempLS mesh anomaly (1961-90 base) was down from 0.724°C in October to 0.683°C in November. This compares with the larger reduction of 0.12°C in the NCEP/NCAR index, and a much greater fall (0.27) in the UAH LT satellite index. The TEmpLS average for 2017 so far is 0.720°C, which would put it behind 2016, and just behind 2015 (0.729°C). It's unlikely that December will be warm enough to change that order, or cool enough to lose third place (0.594°C in 2014).

Update 10 Dec: As Olof noted in comments, although I had tested and enabled use of ERSST 5 (instead of 4) earlier this year, it wasn't actually implemented (failure to correctly set a switch). It doesn't make much difference on a month to month basis. The fall in November was 0.064°C instead of 0.04°C, and the spatial pattern is very similar. But as he astutely noted, it does make a difference to 2017 versus 2015. The means for the last three years are 0.729, 0.835, and 0.758. That puts 2017 0.029°C clear of 2015, which means 2017 will be in second place if December exceeds 0.41°C, which seems likely.

The anomaly pattern showed two marked warm spots in W Siberia and N of Bering Strait, and less pronounced in SW US. Cool in Canada and E Siberia, fairly warm near the poles. Theer was a weak La Nina pattern; much less than with the NCEP/NCAR index.

Here is the temperature map:

Monday, December 4, 2017

November NCEP/NCAR global anomaly down 0.12°C from October

In the Moyhu NCEP/NCAR index, the monthly reanalysis anomaly average fell from 0.372°C in October to 0.253°C in November, 2017, making it the coolest month since June. The month started warm, with a cold period mid-month, and ended warm.

The main cold spots were China and E Siberia, and Canada. Arctic was warm, as were SW USA and European Russia. The Pacific showed a rather La Nina like pattern; cold in the SE and a band at the Equator. Warm around New Zealand/Tasmania.

Sunday, November 19, 2017

Pat Frank and Error Propagation in GCMs

This post reviews recent controversy over some strange theories of Pat Frank. It reviews his WUWT posts, blog discussion, some obvious errors, and more substantively, how error propagation really works in solution of numerical partial differential equations (pde, as GCM climate models are), why it is important, and why it is well understood. It's a bit long so I'll start with a TOC.


Friday, November 17, 2017

GISS October global up 0.1°C from September, now 0.9°C.

GISS warmed, going from 0.80°C in September to 0.90°C in October (GISS report here). That is very similar to the increase (now 0.105°C) in TempLS mesh. It was the second warmest October on record, after 2015. It is interesting to reflect on that month two years ago, which at 1.04°C was at the time by some margin the warmest month ever.

The overall pattern was similar to that in TempLS. Even warmer in Antarctica, cool in W US, and E Mediterranean, but the band of cool through to China is less continuous.

As usual here, I will compare the GISS and previous TempLS plots below the jump.

Wednesday, November 8, 2017

October TempLS global surface temperature up 0.11°C

TempLS mesh anomaly (1961-90 base) was up from 0.618°C in September to 0.73°C in October. This compares with the smaller rise of 0.055°C in the NCEP/NCAR index, and a similar rise (0.09) in the UAH LT satellite index.

The anomaly pattern was similar to the NCEP/NCAR picture. No great heat, except in Antarctica, but warm almost everywhere. A band of cool between the Sahara and Far East Russia, cool in the SE Pacific, and some cool in the western US. The change toward warmth at the poles will again lead to varying results in the major indices, with GISS likely to rise strongly compared with NOAA and HADCRUT. In fact, TempLS grid, which also has less coverage at the poles, fell slightly to October. Overall, sea temperatures rose a little, after dropping last month.

Roy Spencer noted the recent marked rise in the satellite records, which are now relatively a lot higher than the surface. I'll show (from here) the graph of the last four years on a common 1981-2010 base. Even UAH, which had been a low outlier for most of the time, is now well above the surface measures, and is not far below the 1998 peak.

Here is the temperature map: :

Friday, November 3, 2017

October NCEP/NCAR global anomaly up 0.055°C from September

In the Moyhu NCEP/NCAR index, the monthly reanalysis average rose from 0.317°C in September to 0.372°C in October, 2017, making it the warmest month since May It was again a very varied month; starting cool, them a warm spike, and cool again at the end.

The main feature was a big cool band from the Sahara through Siberia to China. Also cold in the SE Pacific, with some La Nina like pattern. Mixed at the poles, but more warm than cold. Since Antarctica was cold last month, this suggests the warming will be reflected more strongly in GISS/TempLS rather than NOAA/HADCRUT.