Archives par mot-clé : Solar Cycles

Current Solar Cycle The Third Quietest In More Than 250 Years Of Observation

by F. Bosse & Prof. F. Vahrenholt, December 27, 2018 in ClimateChangeDispatch


The sun was much less active in November than normal, comparing all solar cycles 1-23 up to month no. 120 since the beginning of the systematic survey in 1755, the first year of solar cycle 1.

The latest observed SSN (sunspot number) was a meager 5.9 for the monthly average.

On 16 days the sun was completely “spotless.” The maximum number over the days of November was 15, which does not mean that there were 15 spots – no, the number indicates that 5 spots were observed in a maximum of 1 spot group.

So there was very low spot activity, only 20% of the average value.

92 New Papers (2018) Link Solar Forcing To Climate . . . Some Predict Solar-Induced Global Cooling By 2030!

by K. Richard, December 27, 2018 in NoTricksZone


When it comes to the Sun’s influence on climate, one conclusion is certain: there is no widespread scientific agreement as to how and to what extent solar activity and its related parameters (i.e., galactic cosmic rays, geomagnetic activity, solar wind flux) impact changes in the Earth’s temperature and precipitation.

The disagreement is so chasmic and the mechanisms are so poorly understood that scientists’ estimates of the influence of direct solar irradiance forcing between the 17th century and today can range between a negligible +0.1 W m-2 to a very robust +6 W m-2 (Egorova et al., 2018Mazzarella and Scafetta, 2018).

There is no consensus on the amplitude of the historical solar forcing. The estimated magnitude of the total solar irradiance difference between Maunder minimum and present time ranges from 0.1 to 6 W/m2 making uncertain the simulation of the past and future climate.”  (Egorova et al., 2018)

 

Earth’s upper atmosphere cooling off dramatically and cosmic rays continue to increase as deep solar minimum approaches

by Paul Dorian, November 5, 2018 in PerspectaWeather


Overview

The sun is blank again today and has been without sunspots about 60% of the time this year as the current historically weak solar cycle heads towards the next solar minimum. Solar cycle 24 is currently on pace to be the weakest sunspot cycle with the fewest sunspots since cycle 14 peaked in February 1906. Solar cycle 24 continues a recent trend of weakening solar cycles which began with solar cycle 21 that peaked around 1980. The last time the sun was this blank in a given year on a percentage basis was 2009 during the last solar minimum when 71% of the time was spotless. That last solar minimum actually reached a nadir in 2008 when an astounding 73% of the year featured a spotless sun – the most spotless days in a given year since 1913. All indications are that the fast-approaching next solar minimum may be even quieter than the last one which was the deepest in nearly a century.

One of the natural consequences of a solar minimum is for the upper part of the Earth’s atmosphere to cool down. Another natural impact of decreasing solar activity is the weakening of the ambient solar wind and its magnetic field which, in turn, allows more cosmic rays to penetrate the solar system. The intensification of cosmic rays can have important consequences on such things as the safety of airline passengers and astronauts in space, Earth’s cloud cover and climate, and possibly even on lightning.

Daily observations of the number of sunspots since 1 January 1977 according to Solar Influences Data Analysis Center (SIDC). The thin blue line indicates the daily sunspot number, while the dark blue line indicates the running annual average. The recent low sunspot activity is clearly reflected in the recent low values for the total solar irradiance. Compare also with the geomagnetic Ap-index. Data source: WDC-SILSO, Royal Observatory of Belgium, Brussels. Last day shown: 31 October 2018. Last diagram update: 1 November 2018.