Statistics

I had never heard what an Hovmöller diagram was until I watched the Deep Dive video produced by the Met OfficeUKMO The Meteorological Office is the United Kingdom's national weather service. It is an executive agency and trading fund of the Department for Business, Energy and Industrial Strategy and put out on their Youtube channel yesterday. The Hovmöller diagram was first introduced by Ernest Aabo Hovmöller (1912-2008), a Danish meteorologist, in a paper that he published in 1949. I had seen charts like it before used to display climate data, but hadn’t realised that they had a name. In reality they’re very similar to a heat map as far as I can see, but I decided to see if I could reproduce one in software that was as similar as possible to the one that Alex Deakin showed.
As you can see the X-axis displays values of longitude for a fixed line of latitude, in this case 55° north. The Y-axis displays dates over the last month. In the Hovmöller diagram above I’ve displaid MSLPMSLP Mean sea level pressure is the pressure at sea level, or, when measured at a given elevation on land, the station pressure reduced to sea level assuming an isothermal layer at the station temperature. values from six hourly reanalysis data. It clearly shows various anticyclonic spells in red and hot spots of cyclonicity in blue. I think it will come in very handy as another way of looking at global MSLP or temperature climate data over a longer period although I’ve still to write the code for that😉

17 consecutive months of above average mean temperatures in UK

The last 17 monthly mean temperature in the UKUK The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and Northern Ireland. have all been above the 1981-2010 LTALTA Long Term Average. This is usually defined as a 30 year period by the WMO. in the gridded climate data series from the UKMOUKMO The Meteorological Office is the United Kingdom's national weather service. It is an executive agency and trading fund of the Department for Business, Energy and Industrial Strategy. I’m sure we are going to hear a lot more about this particularly salient fact in the next few weeks, so I thought I would spend some time and write a viewer that displayed consecutive mean temperatures. I think I’ve come up with the best solution to visualise spells of above or below average climatic values, be they means of temperature, or totals of precipitation or sunshine.

It’s certainly true that there hasn’t been a longer, more incredible, spell of consecutive warm months in the gridded series since 1884, although there have been a couple of longer runs of consecutive cold months. The period between March 1885 and September 1886 saw 19 consecutive cold months for example. There are many ways of deriving statistics like this, using mean maximum or mean minimum, or perhaps changing the LTA.

November 14, 2022

Statistics, Temperature

17 consecutive months of above average mean temperatures in UK Read More »