Archive for the ‘Surfacestation’ Category

Australians cool Melbourne

Posted: January 23, 2015 by tchannon in Surfacestation, UHI, weather


Mr Trewin also noted that the Bureau had recently changed its Melbourne monitoring site from the Royal Society of Victoria on La Trobe Street in the city to Olympic Park, near Rod Laver Arena. Maximum temperatures recorded at the new site were on average 1.2 degrees cooler, particularly on cool days, because air coming from the south and west was travelling over parklands rather than the through the city.

h/t to handjive at notricks

Head image from an article by Anthony Watts at Steve McIntyre’s ClimateAudit 2007 article 6 years ago. (I’ve add the red circles)


BOM report it here, no mention of why

. Above is how BOM show the station.

Even rainfall data will be wrong with those tall nearby structures and fences.

The Age reported the closure here. No mention of why.


Maybe not an expected article from me right now but as things turn up…


During a recent cold snap there were at times clear skies and a calm. Here is evidence of a profound difference between Met Office sites when site exposure and UHI thermal mass can upset natural radiative cooling.

The Farnborough site is in my estimation WMO Class 1 whereas RHS Wisley is poor, in an orchard designed to make a microclimate. Wisley however has been cited in literature and government chambers (and by Phil Jones) in relation to UHI in comparison with a record setting London site, specifically a site I have omitted from the surfacestation work. Overloaded with too much information.


Cool weather

Posted: December 29, 2014 by tchannon in Analysis, Surfacestation, weather

Been away for a variety of reasons, has been a horrible few weeks including frenetic work on software workarounds. Several personal matters were far worse. Lets hope that is the end of it, more stuff keeps on dumping on me.

The weather is a tad chilly in England, went down to -6.8C at Katesbridge Northern Ireland last night (27th into 28th) [UPDATE] and what happened next? See comments and link to another blog article with data, went off the bottom of plot shown here –Tim][UPDATE 2, -8.8C ]


It might drop further tonight, flat anti-cyclone calm over the UK, unusually clear skies but there is still humidity to freeze out.

We had a remarkable day today in southern England, clear sunny all day with flat calm, just right to look at insolation and radiation balance.


I may be boring folks yet detail is what breaks to understanding. This is rather fun, things fit. 


UK extremes


Parameter Location Value
Highest maximum temperature Gravesend 14.1 °C
Lowest maximum temperature Pennerley 5.7 °C
Lowest minimum temperature South Newington -2.0 °C
Highest rainfall Redesdale Camp 19.8 mm
Sunniest Leconfield 6.0 hours

Issued at: 2303 on Tue 04 Nov 2014


Hourly data, a peak temperature which elsewhere seems to coincide with a short period of high visibility, probably sunshine. But look at the green wind data trace, falling west wind, calm, east wind then resume west. Humidity drops low.  The station is on a tidal estuary.

The estimate tide from various web sites at Gravesend-Broadness was low tide at 16 hours but the PLA chart for Tilbury which is 2km downstream is  0.76 m @  17:10 hrs


History of Met Office Gravesend-Broadness site

Posted: November 4, 2014 by tchannon in History, Surfacestation


Image OpenStreetMap / Author

New information has appeared so this is based on photographic evidence. The drawings are approximate and simple.

Those who want to look and with access to Google Earth here is a ZIP of Google KMZ files (4kB). Invoke and will go to the image for the date given.
51.464261° 0.310574°

The Met Office station commenced operation during 1996. It is not a full station. I assume it is treated as a minor synoptic station.


Last day of October 2014 (31/10/2014) was lovely and warm over much of eastern England, particularly the south east. Mostly weak sunshine and a slight southerly wind. The Gravesend site has in the past been the subject of questioning why it is so warm, estuary, not in town.

There was a south wind too in the Cairngorms where the temperature gradually rose all day, with a twist, the wind was rising from 48 mph to 60+ mph, gusted to 84 before last thing the wind shifted and fell. This suggests a general flow.


This confusing plot shows an unusual situation. The highest temperature was recorded at Gravesend, logged by the Met Office as 23.6C, 0.3C above the hour mean. The oddity is this occurred an hour earlier than the other group of stations, or perhaps is an effect of quantisation.


This article is cross posted from Tim’s blog as of interest to some Talkshop readers with a few extra sentences likely to raise discussion. 

August 2014 there was a meteorological gift of both exceptional conditions and good data. What can be learnt?

Three Met Office sites showed a signature of exponential cooling. This requires clear sky and a calm. Given somewhat limited parameter hourly data the following shows the commonality. The computed terminal conditions are shown later in this article.


Benson and Santon Downham data has been normalised to Katesbridge[3], which has the least noisy data or the three.

Achieving a close overlay requires taking earth rotation into account, dusk and dawn move relatively both by geographic location and the peculiar movement throughout the year as night length changes, these do not move together [1]. Fractional delay (less that the sample period) was used to equalize diurnal time. (see the two blog articles here)

Dusk appears to be the important factor, a surprising finding, I assume cooling is time from dusk, dawn terminates cooling.

General information, under essentially calm conditions wind drops for a period during the night then reappears just after dawn. (not shown here)

Temperature normalisation defined is for the cold period, not as accurate for Benson where the better site exposure (more open) led to more wind at times.


Surfacestations news

Posted: July 29, 2014 by tchannon in Surfacestation

This is a brief post pointing at my own low traffic blog where I am asking for assistance with finding a few Met Office sites. Not a pretty post, will bore ordinary readers but if you are tech, maybe.

On the other hand there is a huge list of Bing and Google links to aerial images. (150+)
Example, where is Sheffield CDL not a full site, temperature and humidity, that is the location given. :-)
[update]  shep has found it, see comments ]


Guest post from Roger Andrews, who says: ” This is a review that extends Euan Mearns’ article on sunshine hours, cloud cover and SAT in the UK over mainland Europe and the North Atlantic. It reveals some interesting features that I make no attempt to explain – basically because I can’t – but someone else may have some ideas.” Apologies to Roger A for the delay in getting this article posted.

by Roger Andrews

The recent “UK temperatures since 1933” post discussed the relationships between sunshine hours, which were assumed to be an inverse cloud cover proxy, on surface air temperatures (hereafter SAT) at 23 UK stations. Here I summarize the relationships between sunshine hours, cloud cover and SAT over  Europe using observations from ~30 stations selected from the European Climate Assessment (ECA) data set (acknowledgement as requested to Klein Tank, A.M.G. and Coauthors, 2002. Daily dataset of 20th-century surface air temperature and precipitation series for the European Climate Assessment. Int. J. of Climatol., 22, 1441-1453.) Station locations are shown in Figure 1:



This is a guest post by Jerry Lundry

Two plots are presented for annual average temperature in the United States Historical Climate Network (USHCN). This data set is highly regarded by some in climate science and is sometimes used as a surrogate for world-wide temperatures. Among its attributes are its coverage of a large land mass (the forty-eight contiguous United States), dense coverage of that land mass (1218 stations), and records that are complete to 1912 and missing only about eighty stations back to 1895. Temperatures for all stations are also provided for 1908.

In 2012, the author downloaded and produced annual average temperatures for this data set. The first figure below provides average annual temperatures for 1908 and 1912-2011. The curve faired through the data is a standard Excel sixth-order polynomial. This curve shows minima in years 1914 and 1970, and maxima in years 1940 and 2004, give or take a year or two.


Figure 1



I haven’t time to edit this properly, so I hope Roger Andrews will forgive me for just pasting his email into this guest post and lobbing in the images. Somewhere in the archives there’s a post From RA in which he used my cumulative solar technique to get some good fits too. I’ll link it  if anyone finds it. You’ve all seen data before, and know what to do…

Here are the results of the empirical models I ran five or so year ago, plotted on the three sets of figures linked to below and accompanied by a writeup, sort of.  The first set of figures allows for both anthropogenic and natural forcings. Results are presented for the 60-90N, 30-60N, 0-30N, 0-30S and 30-60S latitude bands and for the area-weighted global average of these bands. (There weren’t enough data to put together a comparison for 60-90S.)



Image courtesy Microsoft and providers, please strictly non-commercial.

Bing image location 50.7795 -1.83622

Highest reported temperature was at Hurn (Bournemouth Airport) a known poor synoptic Met Office site, although it could be worse. There is a bit of a mystery.

24 hours ending 2200 on 14 Jul 2013:
UK Highest max 0900-2100 31.0 °C Hurn
Lowest max 0900-2100 12.9 °C Lerwick
Lowest min 2100-0900 3.6 °C Katesbridge
Highest rainfall 2100-2100 4.8 mm Cassley
Sunniest 2100-2100 14.3 hours Morecambe
Last updated: 0001 on Mon 15 Jul 2013

The Met Office hourly data for Hurn peaks at 29.0C, so there is a brief peak for some reason. Looking at other data 29 or so would be fair enough. How did 2C materialise?



The dear Met Office have been pushing over the past few days about HOTTEST EVER THIS YEAR. Face it Met Office, enjoying life does not involve screaming or fear unless you are a kid.

Current 2013 UK maximum temperature confirmed

The current 2013 UK maximum temperature was recorded on Saturday 13 July, with 31.4 C at Heathrow. Wales also saw its highest 2013 temperature with 30.2 C at Llysdinam. The previous maximum of 29.9 C from Monday 8 July, at Edenfel, remains the current highest for Northern Ireland. Scotland saw its highest 2013 temperature on Tuesday 9 July, with 28.7 C at Strathallen Airfield. Issued at 2319 on Sat 13 Jul 2013.

Heathrow like most temperature breakers is a defective site. How about fixing it?


Chilbolton: data update, 107 days

Posted: June 1, 2013 by tchannon in Dataset, Surfacestation


This post is is primarily for a data release, 107 days, 16th Feb 2013 through 31st May 2012 less one day. (I was indisposed)



Figure 1

Since mid February 2013 I have been capturing high time resolution data from the Chilbolton Observatory web site, done for the previous day. This is processed from .PNG files into numeric data here. [1]

Data exists for about 23 hours a day at a few minutes between samples, data currently amounts to about 56,000 readings.



Sometimes the sun shines through, reflects off and other optical effects of cloud. This does lead to insolation well in excess of the maximum for the time of year. An instance is shown above complete with an hourly sky thumbnail which almost caught one at the time, the effect comes and goes very quickly.


Surfacestation Fyvie Castle

Posted: May 6, 2013 by tchannon in Analysis, Surfacestation


Fyvie Castle, Aberdeenshire, Scotland. A National Trust property, web site entry

57.442805° -2.389692° Google browser map
Altitude 55 metres

AWS since 1994, manual data record from 1959

Estimated Class 4, fails Class 3 on ground cover within 10 metres. (to WMO 1046, 2010)

UHI, microclimate, in a garden. Distance, none.

I need to add I have a close lat/long but no cross reference images or other information so I might have incorrectly located the Stevenson screen.


What follows shows nothing new but is food for thought given the matter of pyrgeometers on the Talkshop.


Figure 1

1st May was a particularly sunny day in southern England but cool, with a continuing wind from Norway via the North Sea.


Surfacestation Killowen

Posted: April 28, 2013 by tchannon in Analysis, Surfacestation


Red line and arrow, line of sight for Google Streetview, see below.

Killowen, County Down, Northern Ireland, Killowen Outdoor Centre, Carlingford Lough.

Data from 1997, as AWS from about 2000, older data somewhere near from 1961
24 hours ending 2200 on 27 Apr 2013:
UK Highest max 0900-2100 12.9 °C Killowen

54.076877° -6.184006° Bing maps, Google maps

Altitude 4 metres

Estimated Class 4, fails Class 3 on > 10% “Ground covered with natural and low vegetation (<25 cm) representative of the region;” and “at more than 10 m from artificial heat sources and reflective surfaces (buildings, concrete surfaces, car parks, etc.)” with 10 metres. (hedge / wall)

UHI, local, isolated marina, heated public centre, vehicle parking, signs of outfall close to lough edge. Distance, none.


Surfacestation Writtle

Posted: April 27, 2013 by tchannon in Analysis, Surfacestation


Writtle, Essex. (at Writtle college, just west of Chelmsford)
Records marked from 1940 but the location then not known.
Recent conversion to full AWS 2009.

51.733441° 0.429085°

Altitude 32 metres

Estimated Class 4, fails Class 3 on “Ground covered with natural and low vegetation (<25 cm) representative of the region;” within 10 metres. As a secondary station this seems hard but a ploughed field some of the year is inconsistent.

UHI moderate, housing to south and south west, agricultural college with glasshouses to north, edge of large town of Chelmsford 1.2km, centre 2.7km to the east.