CoastalWx Posted October 25, 2011 Share Posted October 25, 2011 Does anybody specifically know or can point me to some literature as to how a solar minimum is able to cause high latitude blocking? I've heard anything from lack of particles bombarding O3 molecules to a weakening Brewer Dobson circulation allowing the PV to be weakened and disturbed from tropospheric waves from below. Some of this went against what I thought so if anyone knows of anything good or has an explanation..let me know. TIA. Link to comment Share on other sites More sharing options...
Ginx snewx Posted October 25, 2011 Share Posted October 25, 2011 Does anybody specifically know or can point me to some literature as to how a solar minimum is able to cause high latitude blocking? I've heard anything from lack of particles bombarding O3 molecules to a weakening Brewer Dobson circulation allowing the PV to be weakened and disturbed from tropospheric waves from below. Some of this went against what I thought so if anyone knows of anything good or has an explanation..let me know. TIA. http://www.eiscat.rl.ac.uk/Members/mike/publications/pdfs/2010/267_Woollings_2010GL044601.pdf Link to comment Share on other sites More sharing options...
CoastalWx Posted October 25, 2011 Author Share Posted October 25, 2011 http://www.eiscat.rl...010GL044601.pdf I'll check the links. I just wanted to get a better understand of the physics behind it. What about a Solar Min causes the blocking? What is the physical mechanism(s) behind it? I have heard different ones. Truth is, I don't think we really fully know either. Link to comment Share on other sites More sharing options...
Ginx snewx Posted October 25, 2011 Share Posted October 25, 2011 I'll check the links. I just wanted to get a better understand of the physics behind it. What about a Solar Min causes the blocking? What is the physical mechanism(s) behind it? I have heard different ones. Truth is, I don't think we really fully know either. I believe this paper answers some of your questions, of course there is much supposition as there is in most Solar Science, the dat however is real, the cause?? Link to comment Share on other sites More sharing options...
Ginx snewx Posted October 25, 2011 Share Posted October 25, 2011 The leading theory is the effect on lower stratospheric temperature and that effect on Atlantic jet stream speed and resulting eddies. Link to comment Share on other sites More sharing options...
CoastalWx Posted October 25, 2011 Author Share Posted October 25, 2011 I believe this paper answers some of your questions, of course there is much supposition as there is in most Solar Science, the dat however is real, the cause?? Thanks for posting that btw. Link to comment Share on other sites More sharing options...
Ginx snewx Posted October 25, 2011 Share Posted October 25, 2011 Thanks for posting that btw. No prob, the whole solar influence on weather emerging science is very interesting to me. Link to comment Share on other sites More sharing options...
Typhoon Tip Posted October 26, 2011 Share Posted October 26, 2011 It's fascinating - perhaps related is the SSWE, which are a separate phenomenon with regard to all blocking forms. My own hypothesis is that these have an extraterrestrial connection. T is a variable in the electrical conductance of a fluid medium, and since magnetic field strength is inversely proportional to electrical field strength, perhaps the equations can be reworked around solar polarity, or even cosmic ray bombardment. By the way, thunderstorm electrical activity has recently been shown to be correlated to cosmic rays causing electrons in the top of the clouds to begin cascading; this was found because the electrical fields of a thundercloud are actually mathematically shown to not be quite strong enough to break down the ambient insilation of free air - where is the additional charge coming from? I have read papers about 03; as you intimated, low solar activity causes higher residence times for ozone, which is a very effective temperature absorber and can lead blocking as upper levels begin to warm from that influence. Link to comment Share on other sites More sharing options...
weatherwiz Posted October 27, 2011 Share Posted October 27, 2011 Speaking of solar... How do I use this website in order to find out whether or not solar activity is high and past data where I can see which years were in a solar minimum and solar maximum. http://spaceweather.com/ Link to comment Share on other sites More sharing options...
wxmanmitch Posted November 19, 2011 Share Posted November 19, 2011 I found an interesting article on this topic that found a strong positive correlation between the NAO and the geomagnetic aa index. Geomagnetic indices basically quantify the amount of horizontal disturbance in the earth's geomagnetic field from solar storms. It was also found that there is a strong negative correlation between the NAO and galactic cosmic rays (GCRs). The physical reasoning behind this article is that solar activity determines the quantity of GCRs that can reach and penetrate into the atmosphere. Strong solar winds tend to prevent GCRs from reaching the earth's atmosphere, while weaker solar winds allow more GCRs to reach us. As GCRs are an ionizing radiation, they will impact the number of ionized particles in the atmosphere. It is thought that these ionized particles can act as cloud seeders and affect the amount of stratus cloud cover over the oceans. In sum, less solar activity (lower geomag indices) means more GCRs, more ionization, and more oceanic stratus. As the mid-latitudes are normally the cloudiest, it will lead to an increase of cloud cover in these areas. Increased cloud cover will result in a general cooling and lower pressure/height anomalies over the mid-latitudes relative to the high latitudes. This may result in an increased likelihood of a negative NAO. Very interesting read. For the full article go here: http://www.john-daly.com/theodor/solarnao.htm Link to comment Share on other sites More sharing options...
CoastalWx Posted November 19, 2011 Author Share Posted November 19, 2011 I found an interesting article on this topic that found a strong positive correlation between the NAO and the geomagnetic aa index. Geomagnetic indices basically quantify the amount of horizontal disturbance in the earth's geomagnetic field from solar storms. It was also found that there is a strong negative correlation between the NAO and galactic cosmic rays (GCRs). The physical reasoning behind this article is that solar activity determines the quantity of GCRs that can reach and penetrate into the atmosphere. Strong solar winds tend to prevent GCRs from reaching the earth's atmosphere, while weaker solar winds allow more GCRs to reach us. As GCRs are an ionizing radiation, they will impact the number of ionized particles in the atmosphere. It is thought that these ionized particles can act as cloud seeders and affect the amount of stratus cloud cover over the oceans. In sum, less solar activity (lower geomag indices) means more GCRs, more ionization, and more oceanic stratus. As the mid-latitudes are normally the cloudiest, it will lead to an increase of cloud cover in these areas. Increased cloud cover will result in a general cooling and lower pressure/height anomalies over the mid-latitudes relative to the high latitudes. This may result in an increased likelihood of a negative NAO. Very interesting read. For the full article go here: http://www.john-daly...or/solarnao.htm Thanks Mitch. I'll check it out. A few months ago, I mentioned that I was unsure of how strong the NAO would be since we were having an uptick in solar activity. I thought maybe the NAO would average out negative, but perhaps weakly so with periods of sustained negative values much more transient. Now I fully admit to not knowing much in this part of meteorology, but I wonder if some of this stratospheric behavior currently, is part of the solar uptick. Some would argue that we still have low Ap values, but even if you go back in time..there is defintely a correlation to the NAO. Link to comment Share on other sites More sharing options...
CoastalWx Posted November 19, 2011 Author Share Posted November 19, 2011 Thanks Mitch. I'll check it out. A few months ago, I mentioned that I was unsure of how strong the NAO would be since we were having an uptick in solar activity. I thought maybe the NAO would average out negative, but perhaps weakly so with periods of sustained negative values much more transient. Now I fully admit to not knowing much in this part of meteorology, but I wonder if some of this stratospheric behavior currently, is part of the solar uptick. Some would argue that we still have low Ap values, but even if you go back in time..there is defintely a correlation to the NAO. Either way, I still think we have a good chance of seeing some blocking...either up by AK or in the Davis Straits in the form of a -NAO come January. Link to comment Share on other sites More sharing options...
weatherwiz Posted November 19, 2011 Share Posted November 19, 2011 Either way, I still think we have a good chance of seeing some blocking...either up by AK or in the Davis Straits in the form of a -NAO come January. The SST configuration around Greenland would argue for this as well as the QBO. Link to comment Share on other sites More sharing options...
wxmanmitch Posted November 20, 2011 Share Posted November 20, 2011 Despite the recent uptick in sunspot activity, it's still below where it would normally be at this point in the sunspot cycle. It is now expected that sunspot cycle 24 will be considerably weaker than 23 was. In fact, some are speculating that we may be entering a second Maunder minimum. Although the ap index is off it's lows from late 2009, it's still very low. There is typically about a 1.5 to 2.5 year lag between the peak in sunspot activity and the peak in geomagnetic activity. I'm not sure why this is, as this is not an area I'm too familiar with. We did have a few recent flares and auroral storms, but it has still been pretty quiet, by and large. If one goes by the ap index and the research in the article I posted, a negative NAO and general blockiness would be favored this winter. It may take a while to get there though, but I think it will happen as we head deeper into Dec. and especially Jan. SSTAs in the N. Atlantic are conducive for a negative NAO as well. For the latest solar cycle charts you can go here: http://www.swpc.noaa.gov/SolarCycle/ Link to comment Share on other sites More sharing options...
ski MRG Posted November 20, 2011 Share Posted November 20, 2011 Despite the recent uptick in sunspot activity, it's still below where it would normally be at this point in the sunspot cycle. It is now expected that sunspot cycle 24 will be considerably weaker than 23 was. In fact, some are speculating that we may be entering a second Maunder minimum. Although the ap index is off it's lows from late 2009, it's still very low. There is typically about a 1.5 to 2.5 year lag between the peak in sunspot activity and the peak in geomagnetic activity. I'm not sure why this is, as this is not an area I'm too familiar with. We did have a few recent flares and auroral storms, but it has still been pretty quiet, by and large. If one goes by the ap index and the research in the article I posted, a negative NAO and general blockiness would be favored this winter. It may take a while to get there though, but I think it will happen as we head deeper into Dec. and especially Jan. SSTAs in the N. Atlantic are conducive for a negative NAO as well. For the latest solar cycle charts you can go here: http://www.swpc.noaa.gov/SolarCycle/ Nice posts by all. Very interesting stuff. It'll will be fun to follow going forward. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.