February 2016 brought record-warm anomalies on earth
UBIMET: Global temperatures 1,21 degrees above the 20th century mean, last below-average month 30 years ago
Vienna, 03/19/2016 – With a temperature anomaly of 1,21 degrees above the global long-term mean, the month of February set a new temperature record in the 137-year period of measurements. According to the Austrian weather service UBIMET, the second month of 2016 continues an impressive series of above average months in the past few decades: Since December 1984, every single month has been warmer than average, while the anomalies have become increasingly strong as well in the last couple of years. The main driving forces behind the most recent record are the ongoing strong El Niño and the exceptional low arctic sea ice extent.
Global temperatures continue to head for new records. Austria observed its second warmest February in history after 1966 while globally, the highest monthly mean temperature on record was measured. „Compared with the 20th century mean the second month of the year was 1,21 degrees too warm“, says UBIMET meteorologist Josef Lukas. According to the US National Oceanic and Atmospheric Administration (NOAA), February 2016 surpassed the previous record set in 2015 by 0,33 degrees. A very remarkable feature is the regularity of temperature records that are tied or even surpassed on a global scale. This past February was the most recent example in a series of ten consecutive months that broke a global temperature record.
In recent years, warmer than average months seem to have become the norm. The last below-average month on earth was December 1984. Since then, all following 374 months have been too warm.
The largest anomalies were measured on the northern hemisphere. „This year's February was an astonishing 1,55 degrees too warm“, explains Lukas. „The observed February temperatures in the Arctic were more than 5 degrees above the average, anomalies that have never been observed before in that area. There are just few regions on earth that experienced cooler than normal conditions. Over the Northern Atlantic, in Antarctica and in the upper Kamchatka Peninsula, February was cooler than average. Considering the vast area where February was too warm, these anomalies are negligible.
Arctic sea ice still on record low
In high latitudes of the northern hemisphere, temperature anomalies were particularly large. In these regions, sea ice extent usually reaches its seasonal maximum in mid to late March. „Arctic sea ice extent for February was around one million square kilometers below the 1981 to 2010 mean“, explains Lukas. „The more ice is covering the ocean, the more of the incoming solar radiation is reflected by the white surface.“ If the sea ice extent decreases like this year, more radiation is being absorbed by the dark ocean surface. This leads to a much stronger warming which in turn leads to more melting ice and so on.
Strong El Niño warming the world
Another quite significant reason for the recent series of temperature records is El Niño. It is accompanied by high sea surface temperatures (SST) in the tropical central and eastern Pacific Ocean. „These SST anomalies influence not only the local but also the atmospheric circulation in other parts of the world“, says Lukas. „The current El Niño is nearly as strong as the previous record event in 1998 when the third warmest February on earth was registered.“
The current El Niño is slowly weakening, however the atmosphere will only slowly react to this. For this reason, the coming months will likely also be too warm. According to British studies, 2016 is on track to become the hottest year ever.