As it seems to me... It is difficult to make a short answer... It should be known what means "unusual solar activity" and what actualy means "atmospheric distubances". But generaly we could say that there is a tight relation between solar activity (space weather) and atmosphere (thermosphere, ionosphere), plasmasphere and magnetosphere. But it depends on the parameters of solar disturbances. This relation could apear on the diferent altitudes and latitudinal regions. 

I am extremely satisfied with that answer. As suggested there is a need of extensive study  of  solar activity (space weather) and atmosphere (thermosphere, ionosphere), plasmasphere and magnetosphere.

highly nonlinear relation solar activity with space weather and atmospheric disturbances

The interaction between the solar wind and the earth's magnetosphere has been extensively studies by the Cluster mission from ESA. Perhaps take a look at that on the ESA website. I helped to build the magnetometers fro that mission at Imperial College London. They have huge experience in solar (heliospheric) physics. Hope that helps!

There is an strong relationship between Solar activity (Space weather) and atmosphere mainly ionosphere, plasmasphere and magnetosphere. There are several papers published on this topic. You can read the review paper given below and the references there in:

The space weather of the earth is affected by the activity of the sun. Most of these effects like CME, Solar flares, X ray bursts affect the ionosphere and plasmasphere both positively and negatively i.e. increase or decrease in the plasma content. The effect of the eleven year solar cycle on the earth's ionosphere (F region) or total has been reported to be non linear at the peak and bottom of the solar cycle. One may like to read the attached paper published recently.

There is a strong relationship between  solar activity and atmospheric disturbance. The study of the interaction between solar wind-magnetospheric coupling and magnetosphere-ionosphere coupling still at an expository stage and has not been fully resolved. The reasons may be ascribed to the complexity of the solar activity-magnetosphere-ionosphere coupling. It depends on the solar activity parameters one is using. However, for better understanding of this relationship one need to study the latitudinal, longitudinal and hemispheric dependence.

So, I strongly agree and satisfy with the answer of Dr. Roman Yurik.

Yes,  there is a relation between solar activity and space weather

For example during the year 2003 an equatorial coronal hole was acting during the main part of the year, and this year was  the most geomagnetically disturbed  year since one century and a half. see the paper of Zerbo et al. 2012, on the solar cycle 23, see my bibliography.

From coronal hole high speed solar wind are flowing and they generate a lot of geomagnetic activity. They can produce Joule heating in the auroral zone which disturb thermospheric Wind circulation, electric current circulation and as a consequence create  geomagnetic disturbance

There is another kind of solar activity related  to change in  temperatue. During the Maunder minimum (40 years)  the sunspots disappear and this prroduce aa decrease in temperature in Europe see paper of Legrand et al., Annales Geophysicae 1990, see my bibliography

Unusual solar activity is space weather by definition and can lead to atmospheric expansion and ionisation, particle effects at spacecraft and aircraft, communications  and GPS disruption and grid blackouts. Suggest you look at the Royal Academy of Engineering Report  on Extreme Space Weather of  Feb13 and available from their website. The earth has just had a near miss from an event on the far side of the Sun as seen by Stereo-B. This region is now earth facing and giving further events but much less intense.

There are very large voolme of literature on the effect of Solar Wind parameters on the earth magnetospher-ionosphere andgeomagnetism. But solar weather affecting atmosphere at meteorological regionis very  uncertain and not much studied.

R>G>Rastogi

You are correct. There are well documented effects on technology but the influence on tropospheric weather is much more controversial. There was a "Little Ice Age" coincident with the Maunder Sun Spot Minimum in 1645-1710. Currently the CLOUDS experiment  at CERN is examining the influence of cosmic rays and aerosols on cloud formation.

I agree with the  statement above! The relationship is widely accepted yet the details of the coupling are an open research field.

Some of the Living Reviews Publications (http://solarphysics.livingreviews.org/Articles/subject.html) in the "Sun-Earth Connection" section might be of interest.

Best Regards

Alexander

• If space  weather is taken as changes in interplanetary space or the magnetosphere or the ionosphere then there is definite relationship with unusual solar activity. If space weather is taken as changes in atmospheric region below100 km then there is no definite answer. Some twenty years back this was a hot subject but I feel there is no  clear example of relationship.

" I feel there is no clear example of relationship".

Dear Dr Rastogi,

Could you please explain a little more what do you mean?

1. There are not published observations suggesting a correlation between extreme space weather events and extreme atmospheric weather variations.

2. Despite the existed observational correlations  you "feel there is no" well explained physical interpretations. Which ones?

1 or. 2?

It is not my main of interest, but as as space physist I have met a strong evidence supporting #1. I also believe that there are hopeful  attempts  to interpret the space-atmospheric correlated extreme events (i.e. Clilvert et al. 2014 and references therein)

I hope that my questions and comments may be useful in the discussion.

best regards

Fr Georgios Anagnostopoulos

Demokritos Univ. of Thrace, Greece

I have writen on that

https://www.researchgate.net/profile/Dimis_Poulos

Yes there tis relation of unusual solar activity with space weather and atmospheric disturbances

See the paper Zerbo et al.,  2012 : during solar cycle 23  there are equatorial coronal holes during many days and the influence on solar wind and geomagnetic activity is very strong

Zerbo, J-L., C. Amory-Mazaudier, F. Ouattara, Geomagnetism during solar cycle 23: Characteristics, 2012, J. Adv Res http://dx.doi.org/10.1016/j.jare.2012.08.010