The Talk on “The Hiatus, Polar Vortex and the Blob”

本文主要讲诉了作者在2014年10月10号参加了一个大气科学讨论会，讨论会分成3个注意部分，关于“中断”,“极地漩涡”和“斑点”。然后了解到人类已经迫使气候变得越来越糟糕了，应该采取相应的补救措施，具体的讨论内容我们一起来看看吧

  On Friday October 10, 2014 I attended an atmospheric science colloquium, which is held nearly every Friday in Johnson Hall 075, UW. The speaker was Professor Dennis L.Hartmann with the Department of Atmospheric Sciences. The title of the talk was “The Hiatus, the Polar Vortex and the Blob”, which was concerned with the phenomenon of recent global warming pause as well as the Polar Vortex in 2014. Explanations were also proposed by using simulation and observation models. I felt really fortunate for having the chance to attend this talk which satisfied my curiosity for the current global climate change.
  The talk was divided into three main parts concerning “the Hiatus”, “the Polar Vortex” and “the Blob” respectively. The first and part was reviewing the recent global warming pause phenomenon called “the Hiatus” and several possible explanations were proposed. Firstly, the professor introduced that the global warming had been reducing since 1998. Secondly, there were four conspicuous aspects accounting for the warming pause, including reduced solar output, increased volcanic activity, less water vapor in stratosphere and natural variations in the rate at which the ocean took up heat. The professor showed us several valid data to help explain the reasons. Then, inspired by “the Hiatus” phenomenon, two main measures were proposed for human to stop the current warming. Since the net imbalance at the top of the atmosphere that was causing the warming was estimated to be about 0.6 Wm2 averaged over the surface of earth, we need to reduce the imbalance by about that much. One measure was to reduce the top of atmosphere energy imbalance, the other was to increase the rate of heat storage in the ocean. Finally, the professor provided a paper titled “Natural Variability, radiative forcing and climate response in the recent hiatus reconciled” from Nature Geography 2014. Besides researches on the forcing part including solar and volcanic activities, the author Markus Huber and Reto Knutti also did researches on the ENSO (EI NINO Southern Oscillation)’s impact on warming. To sum up this part, I learned about the Hiatus phenomenon and radiative forcing as well as natural variability (ENSO) could account for the cause to some extent.
  Apart from the part I’ve mentioned above, another two parts respectively were the Polar Vortex phenomenon in 2014 and “the Blob” in 2013. These two were closely related to the 2013-14 extreme cold winter in North America. The professor provided several professional plots including PDO (Pacific Decade Oscillation) and NPO (North Pacific Oscillation) curves to explain their impact on the surface temperature. He also pointed out that the second mode of monthly SST (Sea Surface Temperature) variability correlated with the cold weather in North America. In these two parts, the professor delivered the contents quite professionally and logically. Though I was unfamiliar with some indexes, the professor illustrated the phenomenon, the impact and cause by presenting clear graphics with easy understanding words. 
  Through the whole talk, not only do I learn about the presence and the possible causes for two conspicuous phenomena, but somewhat more importantly, I feel we human are in desperate need for drastic measures to prevent things going from bad to worse. I remember in one slide, it says “we are sure that human climate forcing is increasing”, restricting human activities needs to be guided by scientific instructions. This is where the meaning of study for atmospheric science lies, isn’t it?