Hello all! Today we are going to be discussing hurricanes that were in the Pacific and Arctic Oceans–in this part of the world, hurricanes are called cyclones (other regions refer to these storms as typhoons). Mostly we will be focusing on an Arctic Cyclone (AC) that formed in August 2016, which will be referred to as AC16. There will also be references to a similar storm four years prior, called AC12. AC12 and other ACs can effect the Arctic area’s climate through seawater temperature or extent of sea ice, and have even been noted to affect living things in the Arctic Ocean.
In the middle of a rather active cyclone season, AC16 was a very strong storm, that at one point in its long lifespan of over a month took up the entire Pacific section of the Arctic Ocean. The article that discusses it further is our featured article for today, Extreme Arctic Cyclone in August 2016, written by , and
These authors used data on variables such as temperature, horizontal winds, and sea level pressure to investigate the storm. A simple algorithm of comparing sea level pressure to the same in nearby areas gave the center of the storm, though for storms that merged or split, this was done manually (instead of the computer algorithm).
AC16 first formed after the merge of two cyclones on the 4th of August, 2016. It wandered about, the way cyclones do, until the 13th, where it merged with another cyclone. On the 15th of August, it merged with yet another cyclone that had rapidly developed. At this point it was strikingly similar to AC12. AC12 had atmospheric pressure at its centers of 964.1 hectoPascals, a radius of 1035 kilometers (643 miles), while AC16 had 967.2 hectoPascals and a radius of 1028 kilometers (639 miles). Standard sea-level pressure is about 1013.25 hectoPascals, for comparison. At this point, AC12 and AC16 had also been at nearly the same spot on the globe, their centers off by only a few degrees in both longitude and latitude.
From the 19th to the 22nd of August, AC16 experienced even more mergings with other storms. On the 28th, it and two other cyclones formed a sort of three-centered cyclone that covered all of the Arctic Ocean. It merged with one of these the next day. There was another merging on the first of September. AC16 wandered about again, then fell apart on the 16th of September over the Canadian Arctic Archipelago, over a full month from when it first formed.
After each merging, the structure of each merging cyclone changed, often affecting the warm core at the upper levels of the storm (they have a colder core in the lower levels). The authors noted that the development of these storms had to do not only with the merging of warm cores (which accelerated the process), but also baroclinicity, which is a measurement of how lines of constant pressure intersect with the same for density.
Regardless of the name being used for such storms, cyclones have an obvious impact to our lives–even if they do not make landfall, they can still impact weather while offshore or farther out to sea. The more we study them, the more we learn of how they work, the more accurate our predictions of these impacts.
Schmaltz, Jeff. 2012 Arctic Cyclone. NASA Earth Observatory. 7 August 2012. Web.
The source of the image used in this post. Also shortly discusses the effect of such cyclones on sea ice.
National Oceanic and Atmospheric Administration. Glossary, Letter B. NOAA/National Ocean Service, n.d. Web.
Part of NOAA’s online glossary, for letter B. Used for an explanation of baroclinicity.
National Oceanic and Atmospheric Administration. What is the difference between a hurricane, a cyclone, and a typhoon? NOAA/National Ocean Service, 10 Oct. 2014. Web.
A short page on terminology.
Yamagami, A., Matsueda, M. and Tanaka, H. L. (2017), Extreme Arctic cyclone in August 2016. Atmos. Sci. Lett., 18: 307–314. doi:10.1002/asl.757
Today’s featured article.