by
Solflekkperiode 25 har startet
Klimanytt nr. 288. Redaktør: Ole Henrik Ellestad.
Forfattet av Jan-Erik Solheim.
Solforskere fra NASA kunngjorde på en pressekonferanse 15. september at solflekkperiode 25 har startet. Offisiell startmåned er desember 2019. Det betyr at solflekkperiode 24 ble nøyaktig 11 år. Den hadde middels lengde men ble den svakeste på 100 år (se også Klimanytt 57).
Flekker på solen er observert med teleskop fra 1610, men det var først etter daglige studier i nesten 40 år at en tysk apoteker ved navn Heinrich Schwabe i 1843 skrev at flekker på solen varier med en periode på omkring 10 år. Solflekkperioden har siden 1610 variert mellom 8 og 15 år, med en middelverdi på 11,06 år. Man regner med god oversikt over solflekkperiodene siden 1755. Perioden som startet da ble periode nr. 1.
Solflekkperiode 24 ble den svakeste på 100 år, og den 4. svakeste siden 1755. Den hadde maksimum i april 2014 med 114 solflekker, mens maksimum i gjennomsnitt er på 179 flekker. Bildet ovenfor viser solen ved maksimum i april 2014 sammenlignet med minimum i desember 2019. Det vi ser med vårt øye er mørke flekker fra områder med lavere temperatur. Men ser vi på sola med kamera som kan se ultrafiolett eller tar røntgenbilder, ser vi kraftige eksplosjoner på solskiven og ved randen kan vi se at materie blir kastet opp i magnetiske buer. Noen ganger så kraftig at bobler av ioniserte gasser blir kastet ut fra sola – og hvis retningen er riktig kan de treffe jorda. At en gass er ionisert betyr at den har elektriske ladninger. En vind fra sola med elektrisk ladete partikler passerer hele tiden jorda, men vinden blir sterkere og kan gi elektriske stormer når solaktiviteten stiger. Det gir oss kraftig nordlys, men kan også bety trøbbel for satellitter og elektriske ledningsnett på jorda.
NASA har varslet at solflekkperiode 25 vil bli omtrent som 24 i styrke, med et maksimum på 115 solflekker i 2025. Mest nordlys opptrer gjerne tre år etter maksimum.
Figuren her viser et gjennomsnitt av antall solflekker i 11-års perioder. Den heltrukne kurven er basert på tellinger av flekker og grupper av flekker. Den stiplete er basert kun på grupper av flekker. Det var det eneste en kunne se på 1600-tallet med små og dårlige teleskop. På kurven ser vi tre dype minima. Maunder minimum på 1600-tallet, Dalton minimum 1800-1820 og et ikke så dypt – men lengre minimum fra 1870 til 1930. Vi aner konturene av et nytt dypt minimum etter år 2000. Solflekkperiode 24 hadde i gjennomsnitt 50 solflekker, noe som svarer til antallet ved begynnelsen av Dalton minimum. NASA mener at vi vil ha noen svake solflekkperioder i tiden fremover, men ikke så svake som under Maunder minimum. Andre solforskere mener vi kan få et nytt Maunder minimum omkring 2040.
Klimamessig har de de dype og lange solflekkminima falt sammen med perioder med lavere temperatur. En serie med dype og lange minima startet på 1400-tallet og perioden fram til 1850-1900 kalles Den lille Istid (se Klimanytt 266). Vinterisen i Nord-Atlanteren strakte seg nesten ned til Skottland og elver i Tyskland og Themsen frøs om vinteren. Deretter har solaktiviteten og jordas temperatur steget og isen i Arktis har krympet.
Det blir spennende om vi får en overgang til et kaldere klima som følge av lav solaktivitet i dette århundre.
Mer om solas periodiske variasjoner og Den lille istid i Klimarealistenes hefte «Naturen styrer klima», artikkel 21, side 48-49.
These kind of posts are always inspiring and I prefer to read quality content so I happy to find many good point here in the post. writing is simply wonderful! thank you for the post
Generally I do not read post on blogs, but I would like to say that this write-up very forced me to take a look at and do it! Your writing style has been surprised me. Thank you, very great article.
Some tips i have usually told people today is that when searching for a good on-line electronics retail outlet, there are a few variables that you have to remember to consider. First and foremost, you want to make sure to choose a reputable as well as reliable store that has enjoyed great critiques and classification from other individuals and marketplace leaders. This will ensure you are handling a well-known store that provides good services and assistance to its patrons. Many thanks sharing your opinions on this blog.
WONDERFUL Post.thanks for share..extra wait .. ?
Unquestionably consider that that you said. Your favorite reason appeared to be on the net the easiest thing to understand of. I say to you, I definitely get annoyed while other people consider issues that they just don’t understand about. You managed to hit the nail upon the highest and also defined out the whole thing with no need side-effects , other folks could take a signal. Will likely be again to get more. Thanks
Thanks a bunch for sharing this with all people you really recognize what you are talking about! Bookmarked. Kindly also seek advice from my web site =). We can have a link alternate contract between us!
Aw, this was a very nice post. In idea I wish to put in writing like this moreover taking time and precise effort to make an excellent article! I procrastinate alot and by no means seem to get something done.
Thanks for your posting on this blog. From my personal experience, there are times when softening upward a photograph could possibly provide the professional photographer with a little an imaginative flare. Sometimes however, this soft blur isn’t precisely what you had in your mind and can often times spoil a normally good image, especially if you consider enlarging this.
Nice blog. Could someone with little experience do it, and add updates without messing it up? Good information on here, very informative.
Howdy just wanted to give you a quick heads up. The text in your content seem to be running off the screen in Internet explorer. I’m not sure if this is a formatting issue or something to do with internet browser compatibility but I thought I’d post to let you know. The style and design look great though! Hope you get the problem resolved soon. Thanks
With havin so much content do you ever run into any issues of plagorism or copyright infringement? My site has a lot of unique content I’ve either created myself or outsourced but it looks like a lot of it is popping it up all over the web without my permission. Do you know any methods to help stop content from being ripped off? I’d genuinely appreciate it.
Hiya, I am really glad I’ve found this information. Nowadays bloggers publish just about gossips and net and this is actually irritating. A good blog with interesting content, that’s what I need. Thank you for keeping this web-site, I will be visiting it. Do you do newsletters? Can’t find it.
Exactly what I was looking for!
My brother recommended I might like this blog. He used to be entirely right. This put up actually made my day. You cann’t imagine just how so much time I had spent for this information! Thanks!
It is really a nice and useful piece of info. I?m glad that you shared this useful information with us. Please keep us informed like this. Thank you for sharing.
Of course, what a great site and informative posts, I will add backlink – bookmark this site? Regards, Reader
Of course, what a great site and informative posts, I will add backlink – bookmark this site? Regards, Reader
I have observed that car insurance providers know the cars and trucks which are at risk from accidents along with other risks. In addition they know what sort of cars are prone to higher risk and also the higher risk they’ve already the higher a premium amount. Understanding the simple basics of car insurance will assist you to choose the right type of insurance policy that can take care of your requirements in case you happen to be involved in an accident. Many thanks for sharing the particular ideas for your blog.
Hey there! I’m at work browsing your blog from my new iphone 4! Just wanted to say I love reading your blog and look forward to all your posts! Carry on the fantastic work!
I think this is among the most vital information for me. And i am glad reading your article. However should statement on few basic issues, The website style is perfect, the articles is actually great : D. Excellent task, cheers
You are a very smart person! 🙂
Another issue is that video games are usually serious anyway with the principal focus on understanding rather than enjoyment. Although, we have an entertainment element to keep your kids engaged, each one game is generally designed to develop a specific set of skills or program, such as mathmatical or scientific discipline. Thanks for your article.
I would share your post with my sis.
I appreciate your work, thanks for all the great blog posts.
That is really fascinating, You’re an excessively skilled blogger. I’ve joined your rss feed and look forward to in the hunt for extra of your magnificent post. Additionally, I’ve shared your website in my social networks!
Nice Post. It’s really a very good article. I noticed all your important points. Thanks.
hey thanks for the info. appreciate the good work
You are not right. I am assured. I can prove it. Write to me in PM, we will talk.
I do agree with all the ideas you’ve presented in your post. They’re really convincing and will definitely work. Still, the posts are very short for beginners. Could you please extend them a little from next time? Thanks for the post.
I’m in awe of the author’s talent to make complex concepts approachable to readers of all backgrounds. This article is a testament to her expertise and passion to providing valuable insights. Thank you, author, for creating such an captivating and insightful piece. It has been an unforgettable experience to read!
I believe this web site has some really wonderful info for everyone : D.