Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2018 Aug 17;8:12375. doi: 10.1038/s41598-018-30812-z

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

© The Author(s) 2018

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

PMC Copyright notice

Application of the automated QRA-detection-scheme^20,21 for wave-4 at 300 hPa. Panels (a–d) correspond to March-April-May (MAM) 2016 and panels (e,f)–to MAM of years 1979–2016. (a) the detected waveguides (marked by black dots) for quasi-stationary, QRA wave-4. (b) the detected duration of the QRA periods for QRA wave-4 (marked in black). (c) the QRA wave 4 phase speed (in m/s) marked in colors, with corresponding color legend in the y-axis. (d) the amplitude of QRA wave-4 in units of standard deviation marked in colors, with respective color legend in the y-axis. (e) changes in the probability density function of amplitude vs. phase speed for different wave-4 components during QRA periods as compared to the non-resonance days (red and blue filled color contours designate, respectively, positive and negative changes in amplitude, with appropriate color legend shown in the y-axis). Solid black curves in panel (e) depict corresponding 1979–2016 MAM climatology. (f) the probability density function distribution for the wave-4 amplitudes during QRA periods (red curve) vs. non-resonance days (black curve), over 1979–2016 time span. When QRA conditions are granted the quasi-stationary component of wave-4 is significantly amplified. For more details, see^18,20,21.