Mars Struck By Powerful Solar Storm Earlier This Month

While millions of earthlings were understandably obsessed with the prospect of a nuclear war erupting between the U.S. and North Korea, an unexpectedly strong blast from the Sun hit Mars this month.  The effects were observed by NASA missions in orbit and on the surface, according to an American Astronomical Society News release.  MAVEN Program Scientist Elsa Talaat, program scientist at NASA Headquarters, Washington, stated:
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"NASA's distributed set of science missions is in the right place to detect activity on the Sun and examine the effects of such solar events at Mars as never possible before."

She was referencing  a major solar event on Sept. 11, 2017 which sparked a global aurora at Mars more than 25 times brighter than any previously seen by the MAVEN orbiter, which has been studying the Martian atmosphere's interaction with the solar wind since 2014. It produced radiation levels on the surface more than double any previously measured by the  Mars Curiosity Rover's Radiation Assessment Detector, or RAD, since that mission's landing in 2012. The high readings lasted more than two days.  Needless to say, any 'MARS One' explorers left on that world would likely have experienced the brunt of the radiation and perished on the Red Planet.

Oddly, the solar storm affecting Mars occurred in conjunction with a spate of solar activity during what is usually a quiet period in the Sun's 11-year sunspot activity cycle. This event was big enough to be detected at Earth too, even though Earth was on the opposite side of the Sun from Mars.  According to Sonal Jain of the University of Colorado -Boulder's Laboratory for Atmospheric and Space Physics, who is a member of MAVEN's Imaging Ultraviolet Spectrograph instrument team:

"The current solar cycle has been an odd one, with less activity than usual during the peak, and now we have this large event as we're approaching solar minimum,"

This is an anomaly I referenced some two years ago,  in conjunction with disruptions of the solar tachocline and possible resulting disruptions of the meriodonal flow - affecting the alpha-omega torsional oscillations that give rise to the cycles of the (Babcock model) solar dynamo..  RAD Principal Investigator Don Hassler of the Southwest Research Institute's Boulder, Colorado, office, noted:

"This is exactly the type of event both missions were designed to study, and it's the biggest we've seen on the surface so far.  It will improve our understanding of how such solar events affect the Martian environment, from the top of the atmosphere all the way down to the surface."

The critical aspect, of course, is to trace such events to the energetic phenomena on the Sun and particularly the phenomenon of the solar 11- and 22-year cycles. (Which we believe are tied to the behavior of the solar dynamo.)

RAD monitored radiation levels inside the encapsulated spacecraft that carried Curiosity from Earth to Mars in 2011 and 2012 and has been steadily monitoring the radiation environment at Mars' surface for more than five years.  These RAD findings strengthen understanding of radiation's impact on Mars habitability, a key objective of the Curiosity mission. NASA is also using RAD findings for planning the safety of human-crew missions to Mars. Highly energetic solar events can significantly increase the radiation that penetrates through the atmosphere to the Mars surface. The increased radiation also interacts with the atmosphere to produce additional, secondary particles, which need to be understood and shielded against to ensure the safety of future human explorers. According to the SRI's Hassle:

"If you were outdoors on a Mars walk and learned that an event like this was imminent, you would definitely want to take shelter, just as you would if you were on a space walk outside the International Space Station.  To protect our astronauts on Mars in the future, we need to continue to provide this type of space weather monitoring there."

This is an important point, and I hasten to note the Mars One project ballyhooed the past several years has not as yet incorporated any space weather forecasts into its mission priorities. Indeed, the word out is there aren't even enough redundant systems - including in situ for protection on the planet - to ensure the survival of any potential crew.  Given this it's still puzzling how so many thousands could have even signed up.


Let's be clear the Sun is always emitting a continuous stream of charged particles, mainly electrons and protons, which form the solar wind.  Occasionally, eruptions called coronal mass ejections occur, with higher density, energy and speed of the ejected particles. As I have written in multiple previous posts these events vary in strength. Strong CMEs cause dramatic aurora displays on Earth, and very strong ones can disrupt communications. Some coronal mass ejections, such as this month's event, are broad enough in extent to affect planets in quite different directions from the Sun.  Forecasting them has become a priority in space weather and space physics research.


Sonal Jain said,

"When a solar storm hits the Martian atmosphere, it can trigger auroras that light up the whole planet in ultraviolet light. The recent one lit up Mars like a light bulb. An aurora on Mars can envelope the entire planet because Mars has no strong magnetic field like Earth's to concentrate the aurora near polar regions. The energetic particles from the Sun also can be absorbed by the upper atmosphere, increasing its temperature and causing it to swell up."


The AAS report states that analysis of the Martian solar storm data is just beginning. According to MAVEN Principal Investigator Bruce Jakosky of the University of Colorado -Boulder:

 "We expect to get a better understanding of how the process operates in the upper atmosphere of Mars today, and a better understanding of how storms like this may have stripped away much of the Martian atmosphere in the past."

What  is even more critical for future Mars' exploration is predicting the occurrence of such storms to ensure any astronauts on the planet's surface have ample time to secure shelter - especially from the intense radiation of a major CME.

New Evidence The Sun Is Cooling: "Salvation" from Global Warming? No

Merely four years ago worries were afoot that the Sun had fallen 'asleep' and we might well be in store for another "Maunder Minimum" - a period of roughly 70 years beginning ca. 1645, which ushered in what's been called a  "little ice age ".  The sunspot counts reduced to zero and with them continental Europe experienced the lowest summer time temperatures in recorded history, and which adversely affected the crop growing season.

In 2009 such fears of a new little ice age were re-awakened, on account of 286 total spotless days accumulated in 2008, and 128 by the time of the 40th Meeting of the Solar Physics Division of the American Astronomical Society. This was held in Boulder, Colo. on June 12. However, as the meeting opened and specific papers were presented, some of the fears abated. For example, Frank Hill in his lecture 'A Helioseismic Comparison of the Solar Minima Preceding Cycles 23 and 24', noted the current cycle (24) was not yet exceptional - certainly in terms of spotless days aggregated. He pointed to 311 spotless days in 1913, and 287 spotless days for 1901. However, he also noted the lowest solar wind pressure since cycle 15, as well as the lowest irradiance in the modern (space observation) era.

But by early 2010, activity had begun to pick up and since then we beheld the Sun firing up not only large solar flares but coronal mass ejections - although the general trend of activity was still lower than for a typical cycle, see e.g.

Where the cycle in question is at the right side of the graph.  Note the total sunspot numbers generally lie below 100.

If something was disrupting the meriodonal flow and also the solar dynamo - then this pattern would be likely to recur for the next cycle, and hence we'd see the torsional oscillation flow initiated at much higher heliographic latitudes, maybe even 45 degrees or more. One explanation put forward is that the meriodonal flow just below the solar surface is slowing, or perhaps almost ceased. This would delay formation of sunspots at the proper solar latitudes even when high sunspot counts ought to be expected (from standard Babcock-Leighton solar dynamo theory.)

The graphic presented shows one modeling of the solar tachocline subjected to shear, which may account for the pushing up effect on the torsional oscillation flow and slowing of the meriodonal flow.

Now flash forward five years - to yesterday in fact- when it was reported in none other than the esteemed Financial Times, that scientists had found evidence for the Sun "cooling off" and have even forecast a "Grand Minimum" similar to the Maunder Minimum. In fact, the FT cites "1 in 5 solar physicists" as predicting cooler conditions over the next 50 years could rival those seen in Europe during the Maunder Minimum.

But climate change-global warming deniers would do best not to rush in and embrace these findings as a way to pooh-pooh global warming or its import. As I noted above, this behavior was effectively predicted 6 years ago at that SPD meeting when it was noted that changes in the meriodonal flow and also the solar dynamo - "would be likely to recur for the next cycle."  Which is precisely the cycle now being forecast as likely displaying this "grand" Maunder minimum.

For one thing, the total net change in global temperature is forecast to be on the order of  - 0.1C (or -0.1K). That computes to roughly -0.18F.   Six years ago, in his remarkable paper,  'Solar Irradiance: Recent Results and Future Research Plans',  Thomas N. Woods of the University of Colorado dealt with the solar irradiance aspect as it pertains to the Cycle 24, and in particular measurements made at the time.

Woods began by noting the assorted recent periods wherein irradiance measurably varied, including: the Medieval maximum, the Sporer minimum (1400s), the Maunder minimum (1600s), and the Dalton minimum (1800s). He noted with some emphasis that there is no single uniform value to characterize a time interval or period, since the irradiance itself can vary hugely on small or local scales. For example, solar flares can propel irradiance increases 50 times over normal and thereby briefly affect the radiance.

On average though, with such violent inputs smoothed out, the Earth's temperature changes by about +0.07 K (kelvin) over a solar cycle. Compare this to the 1.6 K change (current est. increase) arising from global warming over the past 100 years mostly traced to human use of fossil fuels. Thus, the greenhouse component is nearly 23 times greater.

Even if the solar forcing on climate is enhanced by positive feedbacks the amplification is usually no more than a factor 2. So that 0.07 K increases become  0.14 K increases. The human component is still more important by a factor 11.4, a point made by Woods when he emphasized that the recent results support the hypothesis that anthropogenic greenhouse gases are the primary contributor. This despite all the politicos, think tanks and yahoos who keep blabbering that climate change arises from "natural cycles" - meaning the Sun is responsible.

Now, let's consider this projected -0.1K cooling in context. What does it really mean given the preceding? It means at most 0.1K lower temperatures relative to the AGW (anthropocentric greenhouse warming) -forecast increments. In other words, if AGW now forecasts a 2.6K - 3.5 K increase by 2100 that now becomes 2.5K - 3.4K. If humans somehow get their acts together and get serious about controlling carbon inputs maybe we can still hold the line at a 2.0K increase by 2011 - which would then be adjusted to a 1.9K increase. But let's face it, this isn't too likely given humans haven't shown much pluck even with the climate "hangman's noose" staring them in the bloody face.

Of course, regional differences owing to a number of other factors could render the cooling changes greater. For example, some climatologists are forecasting northern Europe could experience cooling from -0.4C to -0.8 C.  To put this in context again, if a 2.6C increase is projected by 2050 that means for northern Europe the net warming increment could be tamped down to 2.6C - 0.8C =  1.8C which might make the climate barely more tolerable - say without the specter of the 11,000 heat deaths reported in 2003.

But more sober solar scientists aren't prepared to offer much solace, such as Sarah Ineson of the UK Met Office. She's quoted in the FT as saying:

"What the study shows is the Sun isn't going to save us from global warming".

Indeed. Since most solar physicists concur that the solar meriodonal flow - for which a slowing incepts cooling - isn't likely to remain constant over multiple cycles. Thus, for the next 22-year (polarity) cycle, the flow could speed up, with the result that we'd observe many more sunspots emerging at lower (typical) heliographic latitudes with much higher irradiance. Then you'd have the worst possible combination of high solar irradiance and much higher CO2 concentration- which in 35 years, at the rate of 2 ppm/yr would be nearly 400 ppm + 70 ppm = 470 ppm or within the threshold for  the runaway greenhouse effect.

To offer another perspective, during solar cycle 20 – over which I also conducted investigations on solar flares and their effects- the then Solar Max satellite used an active cavity radiometer (ACRIM) to measure temperature increases arising from higher activity – especially as generated by more convection at the periphery of large spots. The differential measured was something on the order of +0.1C at the Sun! Since the radiant energy must now transit 150 million kilometers, and its intensity falls off as the inverse square, one can see this would translate into negligible increases at Earth. In a similar vein, a  -0.1C cooling would translate into negligible reductions for the global mean.

What about longer period increases (or decreases) in solar luminosity associated with its possibly being a variable star – as opposed to sporadic sunspot outbursts?

The maximal magnitude of inherent solar -induced climate variability was probably first highlighted by Sabatino Sofia et al in their paper Solar Constant: Constraints on Possible Variations Derived from Solar Diameter Measurements, in Science, Vol. 204, 1306, 1979. Their estimate was a solar change in irradiance of roughly 0.1 % averaged over each solar cycle. (Irradiance is a measure of the energy per square meter received from the Sun).

Thus – if the solar irradiance effect at Earth (solar constant) is normally about 1360 watts/m^2, this would imply an increase (or decrease) of roughly  +1.36 W/m^2.. The problem is that there is not enough hard observational evidence to support this for any time in the past century – when global warming spiked to serious levels. Some like Sofia have argued that even if it had occurred, it would only engender a temperature change of perhaps plus or minus one-fourth of one degree, or significantly less than what has been documented.

The bottom line, as Dr. Ineson put it, is we should not look to the cooling Sun for our salvation.

I could not agree more!