{"id":1547,"date":"2021-08-27T18:38:16","date_gmt":"2021-08-27T18:38:16","guid":{"rendered":"https:\/\/aurorasaurudev.wpengine.com\/?p=1547"},"modified":"2023-12-26T21:44:48","modified_gmt":"2023-12-26T21:44:48","slug":"laura-learns-aurora-ive-got-the-power","status":"publish","type":"post","link":"https:\/\/blog.aurorasaurus.org\/?p=1547","title":{"rendered":"Laura Learns Aurora: I\u2019ve Got the Power!"},"content":{"rendered":"

Laura here! I am an aurora enthusiast, but new to the science side. Fortunately, the Aurorasaurus blog and website are full of great resources that I\u2019ll be sharing out as I cultivate my knowledge.\u00a0<\/span><\/p>\n

One of these is the <\/span>Space Weather Data page<\/span><\/a>, a graph that shows the strength of solar wind power. In short, the higher the solar wind power, the better the chance of showy aurora in about an hour local time. The data comes from the DSCVR satellite, which is between the Earth and Sun and provides a one hour advance warning of incoming space weather. But what is solar wind power and how does it work? Check out this beginner-intermediate level post by former intern Sean McCloat!\u00a0<\/span><\/p>\n

(For a more advanced discussion, <\/span>click here<\/span><\/a> to explore a scientific paper by Dr. Syun-Ichi Akasofu, in which he talks about the parameters upon which Solar Wind Power is based.)<\/span><\/p>\n

Breaking news!<\/strong> Even as we were\u00a0posting\u00a0this blog, the Solar Wind Power jumped upward\u2014so eyes on the skies tonight!<\/p>\n

\"A<\/a>
Solar Wind Power showing the likely impact of a small CME which erupted from the Sun on 2021-08-23 or 24.<\/figcaption><\/figure>\n
\n

In our previous posts, we describe how the density, speed and magnetic field strength and direction of the\u00a0solar wind<\/a>\u00a0are measured,\u00a0what Bz is<\/a>,\u00a0and what those mean for the aurora. We also introduced a handy parameter called the solar wind power that combines all these measurements. \u00a0Here, we provide more detail about the solar wind power that we use at Aurorasaurus.<\/p>\n

Solar wind power is a value that is calculated based on measurements of physical properties of the solar wind (and CMEs when they occur). \u00a0The solar wind power increases in value as the speed of the solar wind and strength of its magnetic field increases. \u00a0The extent to which the magnetic field lines point in the Bz direction (see part 3) is also quantified in the calculations by describing the interplanetary magnetic field (IMF) clock angle. \u00a0The solar wind power increases as the IMF clock angle approaches the \u201c6 o\u2019clock position\u201d (that is, when Bz is approaching south).<\/p>\n

Solar wind power is measured in watts. \u00a0These watts are the same watts that are used to rate lightbulbs: the higher the wattage, the brighter the light bulb (when comparing two bulbs with the same efficiency). \u00a0Similarly for the aurora, the higher the wattage of the solar wind power, the brighter and larger the aurora will be. \u00a0However, the solar wind power is only proportional to aurora activity, not equivalent the way wattage is for light bulbs. \u00a0Aurorasaurus graphs the strength of the solar wind power\u00a0here<\/a>. \u00a0based off of real-time measurements taken by ACE. \u00a0Since ACE is located at L1, it takes about an hour for the solar wind it measures to actually impact Earth.<\/p>\n

\"solar-wind-blog-post\"<\/a><\/p>\n

In this way, solar wind power is useful for anticipating aurora activity by looking at the average value over the last hour. Fluctuations minute-to-minute or huge spikes in the power will not greatly affect what latitudes the aurora will be seen.<\/p>\n

Recall the windmill analogy from Part 2, where the aurora generated by the solar wind is like a windmill that is spun by regular wind. \u00a0A few strong gusts might get the blades to move a little bit, but if there is a strong sustained wind, then the blades can start and continue to spin. \u00a0Similarly, a few small spikes in the solar wind power may not be enough to stir up sustained aurora activity. \u00a0However, a sustained strong solar wind will be enough to stir up continuous aurora. \u00a0The solar wind power parameter was developed by eminent space physicist\u00a0Dr. Akasofu<\/a>\u00a0(who is also credited with coining the phrase \u201csub storm\u201d). \u00a0You can find more information about how solar wind power affects the aurora in\u00a0Dr. Akasofu\u2019s 1981 paper<\/a>. As indicated by the yellow, orange and red labels on the solar wind power plot, the stronger the wind, the further south the aurora will be visible. \u00a0Note that the the color coded indicators approximate the furthest extent and intensity of the aurora.<\/p>\n

To be concluded:\u00a0Part 4 will wrap up this series of blog posts by comparing the solar wind power to another common parameter for characterizing geomagnetic activity – the Kp index<\/a>.<\/p>\n

***<\/p>\n

Sean McCloat interned with Aurorasaurus in the summer of 2015 while\u00a0pursuing his masters degree in\u00a0Space Studies at the University of North Dakota with a\u00a0focus on the planetary sciences and astrobiology. He\u00a0helped analyze the project\u2019s data, contributed to scientific papers, presentations, and blog posts, and became good friends with Rory, the Aurorasaurus plush doll mascot.<\/p>\n

 <\/p>\n","protected":false},"excerpt":{"rendered":"

Laura here! I am an aurora enthusiast, but new to the science side. Fortunately, the Aurorasaurus blog and website are full of great resources that I\u2019ll be sharing out as I cultivate my knowledge.\u00a0 One of these is the Space Weather Data page, a graph that shows the strength of solar wind power. In short,… Read More »Laura Learns Aurora: I\u2019ve Got the Power!<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":1551,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"rop_custom_images_group":[],"rop_custom_messages_group":[],"rop_publish_now":"initial","rop_publish_now_accounts":[],"rop_publish_now_history":[],"rop_publish_now_status":"pending","neve_meta_sidebar":"","neve_meta_container":"","neve_meta_enable_content_width":"off","neve_meta_content_width":70,"neve_meta_title_alignment":"","neve_meta_author_avatar":"","neve_post_elements_order":"","neve_meta_disable_header":"","neve_meta_disable_footer":"","neve_meta_disable_title":"","footnotes":""},"categories":[18,24,7,2,17,4,12],"tags":[20,21,23],"class_list":["post-1547","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-analyzing-aurorasaurus-data","category-citizen-science","category-education","category-about-aurorasaurus","category-other-resources-for-aurora-hunters","category-solar-events","category-understanding-the-aurora","tag-auroras","tag-citizen-science","tag-northern-lights"],"_links":{"self":[{"href":"https:\/\/blog.aurorasaurus.org\/index.php?rest_route=\/wp\/v2\/posts\/1547","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.aurorasaurus.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.aurorasaurus.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.aurorasaurus.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.aurorasaurus.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1547"}],"version-history":[{"count":0,"href":"https:\/\/blog.aurorasaurus.org\/index.php?rest_route=\/wp\/v2\/posts\/1547\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blog.aurorasaurus.org\/index.php?rest_route=\/wp\/v2\/media\/1551"}],"wp:attachment":[{"href":"https:\/\/blog.aurorasaurus.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1547"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.aurorasaurus.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1547"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.aurorasaurus.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1547"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}