Archives For ocean circulation

Changes in ocean circulation, especially perturbations and regular large scale changes like El Nino and La Nina, are significant in controlling climate and weather systems around the planet.  How El Nino Southern Oscillation (ENSO) events influence European weather is still not entirely clear.  Nevertheless it is known that Europe is not nearly as impacted by ENSO events as other large land masses.  In any case, the entire mid-latitude belt around the northern hemisphere has suffered a cold 2013 Spring so it seems unlikely that ENSO or other circulation perturbations in different oceans could alone be to blame for the cooling of the whole Northern Hemisphere.  In addition, the current ENSO status is in “neutral” which means we are between La Nina and El Nino events … blaming either would be churlish, so ocean circulation does not seem to be a prime suspect for killing Spring 2013… so we should set El Nino and La Nina free!
Nevertheless, it is interesting to note that, whilst Europe and North America have frozen, the North Atlantic has experienced higher than “normal” temperatures. So, whereas it could be partly to blame for the European Little Ice Age, this time the North Atlantic Drift warm ocean current also seems to be entirely innocent of killing off Spring 2013.

point to note: additional considerations regarding longer term thermal changes in oceans such as the Pacific Decadal Oscillation (PDO) and Atlantic Multidecadal Oscillation (AMO) are currently controversial, though widely used by global warming sceptics to indicate the relative importance of cycles in ocean circulation over CO2 contributions to climate change on a human time scale.  Sceptics consider Arctic ice loss and CO2 to be insignificant in comparison to orbital wobbles and ocean circulation cycles.  THIS is an excellent website which debunks many of the climate skeptic arguments.

Climate Cluedo!