{"id":7312,"date":"2019-02-02T14:18:00","date_gmt":"2019-02-02T12:18:00","guid":{"rendered":"http:\/\/www.randform.org\/blog\/?p=7312"},"modified":"2019-02-05T16:30:53","modified_gmt":"2019-02-05T14:30:53","slug":"what-is-going-on-at-the-sun","status":"publish","type":"post","link":"https:\/\/www.randform.org\/blog\/?p=7312","title":{"rendered":"What is going on at the Sun?"},"content":{"rendered":"

In the randform blog post Information about solar irradiance measurements sought,<\/a> I had posted a visualisation of irradiance data from the Laboratory for Atmospheric and Space Physics (LASP).<\/a> In the post it was discussed that there could be a rise in irradiance based on the data from their SORCE mission<\/a>. I think the rise is also somewhat visible in this interactive plot at the Interactive Solar Irradiance Data Center (LISIRD)<\/a>…that is it is visible until about July 2015. In this post I also posted a picture of the line 774nm, i.e. “red light” which is slightly out of the visible spectrum.<\/a> The reason was that it seemed that specific line ranges displayed a stronger rise than others (see circles in the other image in this post). Back then I even made some screenshots from the LISIRD visualization, here you can see the close-by line 798.83nm:<\/p>\n

\"\"<\/a><\/p>\n

Here it is again in my visualization:
\n\"\"<\/a><\/p>\n

Both visualizations look pretty much the same apart from some visualization effects. But this is how the line in the above time range (here until Dec 18 in 2016) looks as of today in the new LISIRD app:<\/p>\n

\"\"<\/a><\/p>\n

So things look very differently since about early summer 2015. Is this a correction?
\n
\n<\/br>
\nWhy might this be interesting ?
\nIt is certainly important to understand whether the irradiance of the sun is getting stronger or not, decide yourself whether this makes the discussion of those issues interesting.
\nThe historical total irradiance is usually reconstructed via sun spot activity and measurements are sought to be brought into accordance<\/a> with those reconstructions. This should work fairly well if there are no major changes in how the sun is operating. It may though be less suitable if major changes would take place. The sunspot activity is currently actually rather in decline, have a look at the American Relative Sunspot Number – Daily, Time Series <\/a>. So accordingly a reconstructed time series like from Empire<\/a> (please type in 797nm, I found no direct linking possibility) displays a reconstructed irradiance which is currently also rather in decline. You can obseverve this for example by noting that the total irradiance in Feb. 2003 (i.e. a little after the last peak) is in the Empire series about the same as for the following peak in July 2014.
\nThis isn’t though in the SORCE measurement. There the peak in July 2014 seems on average higher than at the beginning of the measurement in Feb 2014 (as of today).<\/p>\n

What about that 798.83nm line?
\nSpecific line ranges might eventually be linked to certain nuclear processes in the sun. A discussion about this at Azimuth Forum.<\/a><\/p>\n

So here now again a screenshot of the 798.83nm line as it has been continuing in the correction through 2017 and 2018:
\n\"\"<\/a><\/p>\n

….no further comment necessary, I think.
\nSo again my question to the randform audience: Do you know of any other direct irradiance measurements?<\/p>\n

addition 05022019:
\nDue to requests from commenters, here some additional info.
\nAs far as I know the SORCE data is currently the only openly available off-earth spectral irradiance data, which covers the spectral ranges and time ranges (covering at least some years ) in question. I had written an email to the head of the world radiation center in Dec 2016 where I asked whether there are other data sets but got no answer.
\nBy the way on their web page the world radiation center states<\/a>:<\/p>\n

Swiss researchers are hoping for a mitigation of climate change: Sounds crazy, but solar radiation could mitigate global warming by up to 0.5\u00b0C. Researchers are now checking whether this is justified.<\/p><\/blockquote>\n

There is one mission (also mentioned on the main LISIRD page<\/a>) which provides spectral data from 265-500nm, the dutch<\/a> OMI Spectral Irradiance.<\/a> <\/p>\n

But first the SORCE lines:
\nThe line 500.8nm from end 2016:
\n\"\"<\/a><\/p>\n

Here the “corrected” 500.8nm line from SORCE<\/a>:<\/p>\n

\"\"<\/a><\/p>\n

And here the 500nm line from OMI:<\/a><\/p>\n

\"\"<\/a><\/p>\n

It looks more like the above mentioned uncorrected versions.<\/p>\n","protected":false},"excerpt":{"rendered":"

In the randform blog post Information about solar irradiance measurements sought, I had posted a visualisation of irradiance data from the Laboratory for Atmospheric and Space Physics (LASP). In the post it was discussed that there could be a rise in irradiance based on the data from their SORCE mission. I think the rise is […]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[25,15,26,2,34,7,6,1,14],"tags":[],"_links":{"self":[{"href":"https:\/\/www.randform.org\/blog\/index.php?rest_route=\/wp\/v2\/posts\/7312"}],"collection":[{"href":"https:\/\/www.randform.org\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.randform.org\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.randform.org\/blog\/index.php?rest_route=\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.randform.org\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=7312"}],"version-history":[{"count":31,"href":"https:\/\/www.randform.org\/blog\/index.php?rest_route=\/wp\/v2\/posts\/7312\/revisions"}],"predecessor-version":[{"id":7352,"href":"https:\/\/www.randform.org\/blog\/index.php?rest_route=\/wp\/v2\/posts\/7312\/revisions\/7352"}],"wp:attachment":[{"href":"https:\/\/www.randform.org\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=7312"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.randform.org\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=7312"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.randform.org\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=7312"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}