Archives For sunspot cycles

Spring 2013 across much of the northern hemisphere mid-latitude landmasses has been notable for extreme cold, record breaking snow falls and severe winter storms.  Northern Europe, Scandinavia, Russia, Western and North Canada, North and Eastern USA and NE China and Northern Japan have all been exposed to many more prolonged incursions of cold air from the Arctic than in “normal” years.  The blue and green colours on the temperature anomaly map above show areas experiencing a record breaking March of well below average temperatures (“anomalies”), some exceeding an average of 10°C below the temperature expected.  The map for 2013 year-to-date looks very similar, so the whole of late winter has been colder.  The satellite photo shows widespread snow across the whole northern hemisphere mid-latitudes: a good indication of how extra-ordinary this late winter has been.

So, what is responsible for this extreme late winter weather?   Here is a fun round-up of some of the main “suspects” on the Climate Cluedo board: which of them killed Spring 2013?  Click on each (as posted!) and find a quick judgement on their culpability in the death of Spring 2013! 

  1. Blocking high pressure / weaker jet stream
  2. Loss of Arctic sea ice
  3. Solar activity: sunspot cycles
  4. Volcanic eruptions
  5. El Nino / La Nina / ocean currents
  6. Long term climate change and orbital cycles
  7. Sudden Stratospheric Warming (started January)
  8. Human activity (to be dealt with later!)

Thought of some more suspects? Please leave a comment to add them!

Whilst the output of the sun varies very little (it is called “solar constant” for good reason), various other measurable factors such as solar magnetic activity, sunspot cycles and irradiance have all been raised as possible suspects for the crime of killing Spring 2013 across the northern hemisphere. Low solar energy receipt has been correlated with a colder northern hemisphere by influencing northern blocking.  A low point in sunspot activity called the “Maunder Minimum” has been closely associated with the onset of the Little Ice Age when the Thames regularly froze over every winter. Solar flares have been associated with warming of the upper atmosphere which has, in turn, been linked to higher pressure in the polar regions.
Links (correlations) have also been found between sunspot cycles and the extent of sea ice in the North Atlantic. Nevertheless, correlating solar activity and the climate on Earth has been surprisingly difficult to pin down.  Importantly, correlating sunspot activity with any climatic variable does not indicate a causal link. Wiggly lines on graphs may coincide but does one cause the other?  It is all still full of controversy. Even the IPCC recognise that, whilst there is some evidence to suggest a link between warming and increases in solar activity between 1750 and 1950, the measurable increase in global warming far exceeds any change in solar output. Since 1979, when measurements of sun output started in space, there has been no long-term significant increase in solar energy.  Sunspots are frequently hauled in to account for weather and climate changes but the evidence is hard to pin on them and almost entirely circumstantial!  Sunspots are intertwined with the greatest driver of our weather, the Sun, however, with such flimsy evidence the jury is still out on this suspect. With other major suspects under questioning it seems reasonable to let solar energy go free.

Climate Cluedo!