Jim Steele: Why Antarctic Sea Ice Is the Better Global Climate Change Indicator

Posted: August 24, 2013 by tallbloke in Analysis, climate, general circulation, sea ice

This is a repost of an adaptation from Jim Steele’s book  Landscapes & Cycles: An Environmentalist’s Journey to Climate Skepticism. New talkshop contributor ‘docrichard’ should read it.


Guest essay by Jim Steele, Director emeritus Sierra Nevada Field Campus, San Francisco State University posted at WUWT on July 22nd 2013

Global warming theory predicts that rising levels of CO2 will gradually warm the air and cause an increasing loss of sea ice. As temperatures rise, ice nearer the equator was predicted to be the first to disappear and over the coming decades ice closer to the poles would be the last to melt. However that is not the reality we are now observing. Antarctic sea ice is mostly located outside the Antarctic Circle (Figure 1) and should be the first to melt due to global warming theory. Yet Antarctic sea ice has been increasing and expanding towards the equator contradicting all the models. As Dr. Laura Landrum from the National Center for Atmospheric Research wrote, “Antarctic sea ice area exhibits significant decreasing annual trends in all six [model] ensemble members from 1950 to 2005, in apparent contrast to observations that suggest a modest ice area increase since 1979.”10 (see Figure 2)



In contrast, most of the Arctic sea ice exists inside the Arctic Circle and should be last to melt. However during the Arctic’s coldest winters, Barents Sea ice still melts deep inside the Arctic circle. While cold March air temperatures maintained maximum ice further south in the Hudson Bay and Bering Sea, much of the Barents Sea has been ice-free. In 2012 the more southerly Bering Sea ice set records for maximum extent, similar to the maximum sea ice currently observed in the Antarctic. Clearly global greenhouse gases cannot be the cause of melting inside the Arctic, while simultaneously sea ice is expanding in the Bering Sea and the southern hemisphere. However ocean currents and natural ocean oscillations readily explain such behavior. Counter to the media hype, it is Antarctic sea ice that should be the most sensitive indicator of climate change caused by greenhouse gases because the Arctic sea ice is affected by too many other confounding factors.


Arctic vs Antarctic sea ice

1) Sea ice melts deep inside the Arctic Circle during the coldest of winters because warm water from the Atlantic and the Pacific intrude and melt the ice from below. During the past two decades scientists have observed an increase in the volume of warm water penetrating deep inside the Arctic Circle, which then preconditioned the polar ice cap for a greater loss of summer ice.3,8 Changes in the North Atlantic/Arctic Oscillation affect how much heated water is driven into the Arctic, which then causes the widespread melt seen in the Barents Sea and adjoining Kara Sea. Similarly the warm phase of the Pacific Decadal Oscillation drives more warm water through the Bering Strait into the Chukchi Sea.2,5,8


In contrast for millions of years the Antarctic Circumpolar Current (ACC) has created a formidable barrier that prevents any similar warm water intrusions. (The ACC is discussed further at the end of this essay). Therefore changes in Antarctic sea ice are not confounded by warm water intrusions, making Antarctic sea ice a better indicator of the effects of rising CO2 concentrations.

2) Any trend in the degree of summer melt in the Arctic is further confounded by the fluctuating concentrations of thin first year ice. Because continents surround the Arctic Ocean, Arctic Sea ice undergoes cycles of accumulating or reducing the amount of thick, multi-year sea ice that resists melting.2 When the winds pile sea ice against the Arctic shoreline, thicker multi-year ice accumulates. When the winds shift, that thicker ice is blown out past Svalbard into the north Atlantic, and is replaced by thinner, first-year ice that more readily melts each summer. The amount of multi-year ice in the Arctic is controlled by the direction of the winds and the Arctic oscillation.2 It was not warmer temperatures that removed the thickest Arctic Ice, but sub-freezing winds blowing from the coldest regions in the northern hemisphere.4,5

Due to the constraints of the continents, the maximum extent of Arctic sea ice in 1979 covered about 15 million square kilometers. In contrast, Antarctic sea ice is unconstrained by continental boundaries and each winter winds blowing from the cold Antarctic interior push the sea ice much further towards the equator. By September the sea ice covers 16 to 17 million square kilometers of the Antarctic Ocean, nearly 40% of the southern hemisphere’s ocean surface. Because sea ice is less likely to be piled against a shoreline to form thicker multi‑year ice, most of the Antarctic sea ice is relatively thin, first‑year ice.

(Measurements of sea ice extent differ depending on what concentration of ice cover is used as the threshold between ice and “no ice”. For example, by using a lower concentration, some authors report that Antarctica’s maximum coverage reaches 20 million km2. Here we use statistics supplied by the University of Illinois’ website The Cryosphere Today to allow an accessible comparison of the Arctic and Antarctic)

Despite more extensive winter ice, each summerAntarctic sea ice retreats much more rapidly than Arctic sea ice. Antarctica’s first-year ice can quickly shrink to a less than two million square kilometers. Even during the Arctic’s “historic” summer lows of 2007 and 2012, the Arctic still retained more sea ice than the Antarctic.

When the Arctic Oscillation shifts and blows thick multi-year ice out into the northern Atlantic, the Arctic is dominated by first year ice that behaves just like the rapidly melting Antarctic sea ice. A season of rapid summer melt is normal wherever first‑year ice predominates, whether it occurs in the Arctic or Antarctic, and is not an indicator of rising air temperatures. For example off the coast of Alaska, climate scientists reported a more rapid summer melt even though air temperatures were colder than average, simply because the winds had removed the thicker multi-year ice which was replaced with more rapidly melting first year ice.

Climate scientists acknowledge that due to Arctic Oscillation’s natural variability, “detection of possible long-term trends induced by greenhouse gas warming [is] most difficult.”3Therefore because the confounding percentages of trapped multi-year ice fluctuates greatly in the Arctic, trends in Antarctica’s sea ice are again a much cleaner indicator of global climate change.

3) There is so much warm, salty Atlantic and Pacific water lurking just 100 meters below Arctic Ocean’s surface, that it could melt the winter ice completely several times over. As climate scientists noted, ““There are arguments in support of an important role for oceanic heat in shaping the Arctic pack ice. They are often keyed to the presence of warm intermediate-depth (150–900 m) water of Atlantic origin” 3 Sea ice insulates the ocean surface from the stirring effects of the wind that will raise those warmer waters from intermediate depths. However once the insulating layer of ice is removed, the formation of thicker ice is delayed because the winds will now stir and raise warm subsurface waters. For example even when the Pacific Decadal Oscillation shifted to its cool phase and the volume of intruding Pacific water was reduced, the stirring effect of the winds still caused greater summer melt.6

4) When the effects of ventilating heat are removed, air temperatures show little warming. Most of the warming in the Arctic has not been caused by CO2‑warmed air from above, but from the ventilated warmth from Atlantic and Pacific waters. In addition to raising warmer water from below, thinner ice also allows more heat to ventilate than thicker ice. In fact before the insulating ice cover was blown out of the Arctic, climate scientists in the 1980s and 90s had measured a cooling trend writing, “In particular, we do not observe the large surface warming trends predicted by models; indeed, we detect significant surface cooling trends over the western Arctic Ocean during winter and autumn. This discrepancy suggests that present climate models do not adequately incorporate the physical processes that affect the polar regions.”1

Similarly if we examine winter air temperatures over the South Pole where heat from the ocean is not a factor, again there is no warming trend (Figure 4). In fact there is a slight cooling during the months of April May and June, which is consistent with the increasing Antarctic sea ice.


A Natural Experiment Has Begun

In 2010 Michael Mann and 8 other climate scientists wrote to Secretary Ken Salazar suggesting climate change had imperiled the polar bears stating, “Scientific studies and observations indicate that climate change is more rapid and pronounced in the Arctic than in other areas of the world. Data and modeling studies repeatedly document that the geography, ice albedo feedback and cloud feedbacks make this region extremely sensitive to climate forcings. The IPCC Fourth Assessment Report (AR4) found that the Arctic has warmed at twice the rate of the rest of the globe on average, and some areas have warmed even faster. Mean annual temperatures in Alaska have increased by 1.9 degrees Celsius in the past 50 years, almost three times the global average over the same time period, and by 3.5 degrees Celsius in winter, as reported by the U.S. Global Change Research Program.” They predicted, “Under current greenhouse gas emissions trends, Arctic summer sea ice has been projected to disappear in the 2030s or before, as reported by several recent studies.”

Oddly, Mann did not address the changes in intruding warm water or the Arctic Oscillation and Pacific Decadal Oscillation (PDO). It was the greater volume of warm water that had passed through the Bering Strait that had caused the extensive loss of sea ice in the Chukchi Sea in 2007 resulting in the historic summer low. But all that is now changing. Mann’ alarming trend of rising Alaskan temperatures has already reversed with the shifting to the PDO cool phase and Alaska is becoming the most rapidly cooling region on the globe, cooling by 1.3°C for just the recent decade.9 As the PDO trends to its cool phase and less Pacific water enters the Chukchi Sea, its sea ice is also recovering.


Likewise the Barents and neighboring Kara Sea are most affected by warm intruding Atlantic water, but as the Arctic Oscillation trends negative, less Atlantic water is pumped towards the poles. The 2013 increase of Kara Sea ice is likely a result. Unlike the Arctic, Antarctic waters are not so affected by cycles of intruding warm water, and its growing sea ice suggests that rising greenhouse gases exert a very trivial effect.

As the Pacific Decadal Oscillation and Arctic Oscillation shift to their cool phases and solar activity wanes, natural climate cycles predict that Arctic sea ice should recover within the next 5 to 15 years. Climate models have demonstrated that Arctic sea ice can recover in just a few years after the winds change.7 Allowing for a lag effect as subsurface heat ventilates and thicker multiyear ice begins to accumulate, recovery could be swift. If so, CO2 advocates like Mann and his allies who have based their political and scientific authority on predictions that Arctic Sea Ice will disappear by 2030 will likely suffer embarrassing unprecedented scientific and political repercussions.

Antarctic Circumpolar Current

Antarctic Circumpolar Current’s (ACC) oceanic barrier was first established when continental drift separated Antarctica from the other continents several million years ago. This allowed an unimpeded flow and the ACC became the world’s greatest and most powerful current, moving a hundred times more water than the all the earth’s rivers combined. As it strengthened and isolated the seas inside the ACC, Antarctic waters cooled dramatically. Inside the ACC species requiring warmer water soon became extinct, and the ACC still maintains a formidable thermal barrier that has thwarted invasions by cold-blooded marine species. Since its establishment, true sharks, true crabs, and some families of barnacles are uniquely absent inside the ACC, and many of Antarctica’s remaining cold-blooded species are found nowhere else. In contrast, the Arctic Ocean has been invaded by many North Atlantic and Pacific species that can persist at lower depths in warmer subsurface waters that circulate throughout the entire Arctic. The ACC’s thermal barrier is also why the Antarctic pack ice symmetrically extends far beyond the Antarctic Circle (Figure 1).

Literature Cited

  1. Kahl, J., et al., (1993) Absence of evidence for greenhouse warming over the Arctic Ocean in the past 40 years. Nature 361, 335 – 337.
  2. Venegas, S. A., and L. A. Mysak, 2000: Is there a dominant timescale of natural climate variability in the Arctic? J. Climate, 13, 3412–3434.
  3. Polyakov, I., et al., (2010) Arctic Ocean warming contributes to reduced polar ice cap. Journal of Physical. Oceanography, vol. 40, p. 2743–2756. doi: 10.1175/2010JPO4339.1.
  4. Rigor, I.G. and J.M. Wallace (2004), Variations in the Age of Sea Ice and Summer Sea Ice Extent, Geophys. Res. Lett., v. 31, doi:10.1029/2004GL019492.
  5. Rigor, I.G., J.M. Wallace, and R.L. Colony (2002), Response of Sea Ice to the Arctic Oscillation, J. Climate, v. 15, no. 18, pp. 2648 – 2668.
  6. Shimada, K. et al. , (2006) Pacific Ocean inflow: Influence on catastrophic reduction of sea ice cover in the Arctic Ocean. Geophysical Research Letters, vol. 33, L08605, doi:10.1029/2005GL025624.
  7. Tietsche, S.,et al. (2011) Recovery mechanisms of Arctic summer sea ice. Geophysical Research Letters, vol. 38, L02707, doi:10.1029/2010GL045698.
  8. Woodgate, R., et al. (2006) Interannual changes in the Bering Strait fluxes of volume, heat and freshwater between 1991 and 2004. Geophysical Research Letters, vol. 33, L15609, doi:10.1029/2006GL026931
  9. Wendler,G., et al. (2012) The First Decade of the New Century: A Cooling Trend for Most of Alaska. The Open Atmospheric Science Journal, 2012, 6, 111-116
  10. Landrum, L., et al. (2012) Antarctic Sea Ice Climatology, Variability, and Late Twentieth-Century Change in CCSM4. Journal of Climate, vol. 25, p. 4817‑4838.

Adapted from Landscapes & Cycles: An Environmentalist’s Journey to Climate Skepticism

  1. ren says:

    But the last block in the stratosphere caused a cooling of the ocean on the north and decrease in sea ice in the Antarctic.

  2. ren says:

    Current thickness of the ozone layer in the southern hemisphere.

  3. hunter says:

    I read a long time ago that the polar sea ice extent tends to oscillate in opposite directions. Antarctic growth while Arctic drops; Arctic growth while Antarctic drops. If we are finished with this phase of the Arctic sea ice shrinking, perhaps we will see the Antarctic stop its growth.
    It is notable both that world sea ice extent has remained flat and that the AGW hype industry has worked hard to ignore that fact.

  4. Stephen Wilde says:

    The Arctic sea ice lags about ten years behind any change in global temperature trend due to it taking that long for changes in trend in Pacific waters to circulate to the Arctic Ocean.

    If any trend lasts longer than ten years or so then both polar regions will start to come back into line.

    The less active sun has resulted in no significant El Nino events for nearly ten years. The last significant El Nino in the early 2000s culminated in the 2012 record ice melt. The 1997/8 El Nino gave the 2007 ice melt.

    With the warm water supply now cut ff for at least ten years we should see sea ice at both poles start to increase together but as regards the Antarctic note that the further north the sea ice spreads the harder it is to maintain it so we could see slowing Antarctic sea ice growth whilst the Arctic recovers quickly.

    The initial changes in trend are solar induced in my opinion.

  5. crikey says:

    Nice linky here

    This ~50-60r yr ?oscillation time series indicates the Arctic surface temp’ is due for a phase change
    see link here

    From this graph.
    Upward in temp’ phase……. 1915 – 1935 = 20 yr
    Downward in temp’ phase … 1935 -1965 = 30 yr
    upward phase in arctic temp . 1965- ? 1995??? = 30 yrs

    Generally ..According to the Arctic air temp’ oscillation the Artic temperature should be on a cooling trend currently?

  6. ren says:

    Crikey the latter temperature anomalies graph shows that the last two phases lasting about 35 years. Thus, the positive phase should be completed around 2020.

  7. ren says:

    I’ll give you links so you can see for themselves. http://www.cpc.ncep.noaa.gov/products/stratosphere/
    Lock vortex south between 5 and 10 hPa.

  8. Jim Steele says:

    @crikey upward phase in arctic temp . 1965- ? 1995??? = 30 yrs

    From what latitudes and locations are those temperatures based. Kahl’s 1993 paper found cooling from 1950 to 1990 over the Arctic Ocean

  9. Paul Vaughan says:

    It’s very refreshing seeing common sense about the role of equator-pole-temperature-gradient-driven-wind in terrestrial climate.

    Solid work Jim.

    – –

    Something worthy of retooling & adaptation to more broadly acknowledge sun climate attractors:

    Soon, W.; & Legates, D.R. (2013). Solar irradiance modulation of equator-to-pole (Arctic) temperature gradients: empirical evidence for climate variation on multi-decadal timescales. Journal of Atmospheric and Solar-Terrestrial Physics 93, 45-56.

    Click to access soon_legate.pdf

    Recently I received a question about TSI reconstructions that led to some new insights that could be injected as a game-changer at any time…
    (I’m not suggesting I’m feeling trigger-happy, but I’ve identified a TSI-controversy-trigger. Restraint is the most crucial human capacity…)

    – –


  10. Brian H says:

    And just why is lotsa sea ice a good thing, again?

  11. crikey says:

    Hi JIM.. I have used that Arctic surface temp cycle graph for my research on cycles so l hoped it was ok? Are you concerned about its accuracy?
    I have tracked down some information regarding that Arctic surface temp graph you inquired about.
    The graph you inquire about JIM ( ARCTIC surface temps’) was linked to what looks like a Polyakov’s .web site.
    who ‘s research paper was writen in 2003
    polyakov et al. [2003a]).
    THE WEB SITE ..where l linked the graph
    Content preparation by I.Polyakov and U.Bhatt.
    IPCC report..mention POLYAKOV 2003
    Substantial low-frequency variability is evident in various atmosphere and ice parameters (Polyakov et al., 2003a,b), complicating the detection and attribution of arctic changes. Natural multi-decadal variability has been suggested as partly responsible for the large warming in the 1920s to 1940s (Bengtsson et al., 2004; Johannessen et al., 2004) followed by cooling until the 1960s. In both models and observations, the interannual variability of monthly temperatures is at a maximum at high latitudes (Räisänen, 2002).
    This link has an incerable compendium of infornmation on ARCTIC research papers and includes discussion on POLYALOV 2003
    THe name of the paper l believe is at the bottom of this post. I haven’t read it .But l am sure will explain the dat collection method cheers
    In the same year, Polyakov et al. (2003) derived a surface air temperature history that stretched from 1875 to 2000, based on measurements carried out at 75 land stations and a number of drifting buoys located poleward of 62°N latitude. From 1875 to about 1917, the team of eight U.S. and Russian scientists found the surface air temperature of the huge northern region rose hardly at all; but then it climbed 1.7°C in just 20 years to reach a peak in 1937 that was not eclipsed over the remainder of the record….
    ….they compared the results of this exercise with the long-term history of Arctic Surface Air Temperature (SAT) developed by Polyakov et al. (2003). Their ACWT record, to quote them, revealed the existence of “two distinct warm periods from the late 1920s to 1950s and in the late 1980s-90s and two cold periods, one at the beginning of the record (until the 1920s) and another in the 1960s-70s.” The SAT record depicted essentially the same thing, ….
    In discussing their findings, Polyakov et al. say that, like Arctic SATs, Arctic ACWTs are dominated, in their words, “by multidecadal fluctuations with a time scale of 50-80 years.” In addition, both records indicate that late twentieth century warmth was basically no different from that experienced in the late 1930s and early 1940s, a time when the air’s CO2 concentration was fully 65 ppm less than it is today
    …..SOON … performed a number of statistical analyses on (1) a composite Arctic-wide SAT record constructed by Polyakov et al. (2003),

    Polyakov, I.V., Bekryaev, R.V., Alekseev, G.V., Bhatt, U.S., Colony, R.L., Johnson, M.A., Maskshtas, A.P. and Walsh, D. 2003. Variability and trends of air temperature and pressure in the maritime Arctic, 1875-2000. Journal of Climate 16: 2067-2077.


  12. crikey says:

    Hey.. REN.. Yes thanks for the updates on the SH Stratospheric warming
    With your help and another l have been compiling a case study on my personal research blog
    and have been updating with maps everyday
    I have been adding the updates to the comments section. The first comment is the newest information
    Go to comments for the latest snaps

    A summary
    The Stratosphere over the Antarctic has collapsed. Looks like a sink hole
    The result is a decline in height of atmosphere over the pole and a cooling anomaly and High pressure at the surface layer and a significant decline in ozone concentration

    The downward ‘force?’ has created a raised atmospheric anomaly around the periphery of the south pole . Looks like a donut. The air is rising around the westerly belt with warm stratospheric anomalies above the westerly belt. The Jetstream is also raised in places
    .Near the African coast a particularly strong uplift has caused a deeper penetration into the stratosphere with a significant warm temperature anomaly occurring.
    The rising air is consistent with a broad band of westerly belt low pressure across the southern ocean
    The Ozone level has increased substantially with the rising air over the westerly belt. Particularly high at the SWW ‘hot spot’

    THe MET office global; sat pic’ is indicating an intense low circulation in the area of the SWWnear sth Africa
    Thanks REN.. Keep us informed..

    Temperatures at MAWSON on the Antarctic looked quite ‘normal’ no strong anomalies as yet?

  13. J Martin says:

    Paul Vaughan said ” Restraint is the most crucial human capacity…”

    It is ?

  14. ren says:

    Crikey let me tell you what I think. First, it seems to me that the effects of such anomalies last longer than the lock, which could be seen in winter in the northern hemisphere.
    Second, look at what I said above in the article about C14 on cosmic rays. It seems to me that the spikes of radiation have an impact on ozone near the poles.

  15. crikey says:

    REN.. What is a ‘lock’ ..Could you explain a little..

    It would be interesting to do a study on that hypothesis REN.. Some research may have already been done on that..

    I had a quick look at what l could find related to current solar and cosmic ray activity that could have triggered the collapse of polar stratospheric air

    Firstly .. A post by Leif Svalgard suggests that what we see now in the neutron count is the result of an event some 6-12 months before?
    quote from comments ..


    Leif Svalgaard says:
    March 15, 2009 at 8:57 am
    The cosmic modulation has a time shift of 6-12 months

    with respect to solar activity.

    This is because it takes the solar wind that long to fill the heliosphere [ 100 AU * 4 days per AU ], so if solar ‘minimum’ were 6 months ago, we should only begin to see a decrease in CRs about now or in the next few months
    and some other events this month

    REN had suggested that solar and changes to cosmic ray flux may be responsible for the anomaly in the upper air over the south pole
    I have tried to find any suspect solar activity that may have caused the stratospheric air over the south pole to collapse

    REN… I couldn’t find anything solar around or on on the 24 th Aug 2013 ? What could have caused the cosmic rays to suddenly drop?

    Here is what l found leading up to the 24 th August 2013

    1st August 2013
    found this you tube ……Massive black hole on sun

    3rdAugust 2013
    First Forbush decrease of the 24th Solar Activity Cycle registered by Aragats Neutron Monitors
    After long absolutely calm period, Sun started to presentfirst signs of activity. A shock detected by the Ace Spacecraft at 3August indicated the arrival of at least one CME (Coronal Mass Ejection) causedby the long duration C3 flare on August 1.
    CME hit Earth’s magnetic field on August 3rd at 17:40 UT. TheKp-index reached 6 (DST index -70nT) and this indicates a G2 Level GeomagneticStorm, lasted nearly 12 hours. Correspondingly Neutron monitors demonstratecoherent changes of the hourly count rates as seen in the Figure 2. Thestrength of the geomagnetic storm was not very large and cosmic ray intensity depletion (so calledForbush decrease) do not enhance 2.5%; however very similar pattern of theintensity changes demonstrate by remote monitors do not leave any doubts thatthey are caused by the disturbances of the geomagnetic field due to arrivedhuge clouds of magnetized solar plasma. Other ASEC monitors as well as worldwidenetwork of SEVAN monitors did not register event due to higher cutoff rigidity.

    Sunny Day does a daily commentary on the suns activity so l went to see what went on close to the 24 th august 2013
    Commentary by ‘Sunny Day’

    19th August 2013
    “A Sun Diving Comet has been spotted and observed approaching the Sun earlier today on the SOHO satellite imagery ”

    20th Aug 2013
    “I actually noted the Sun is very lively with 10 active regions – over 161 Sunspots ”

    “This is what I am looking at – if she goes the eruption and possible CME will be squarely Earth facing. Will be interesting but nothing to be worried about of course…. just some spectacular footage to observe”

    Kevin from Solarham.com has posted the below images showing the CME released by the filament lifting off from the Sun’s surface. Most likely to have some Earthbound components but how much we will learn shortly – gee looks rather strong if you ask me.

    I have asked ‘sunnyday’ for some help.

    I am not disagreeing with your hypothesis
    Some substantial evidence required

  16. ren says:

    Crikey contrary to appearances, cosmic rays interact strongly with the atmosphere, especially during low solar activity, and so we are now compared to previous cycles.
    Particle may collide with a nucleus in the atmosphere, producing a number of secondaries. These
    secondaries have their own fate in the atmosphere, in particular they may suffer further collisions
    and interactions forming an atmospheric cascade (e.g., Dorman, 2004). Because of the thickness
    of the Earth’s atmosphere (1033 g/cm2 at sea level) the number of subsequent interactions can
    be large, leading to a fully-developed cascade (also called an air shower) consisting of secondary
    rather than primary particles. A schematic view of the atmospheric cascade is shown in Figure 5.
    Three main components can be separated in the cascade:
    • The “hadronic” nucleonic component is formed by the products of nuclear collisions of primary cosmic rays and their secondaries with the atmospheric nuclei, and consists mostly of
    superthermal protons and neutrons.
    • The “soft” or electromagnetic component consists of electrons, positrons and photons.
    • The “hard” or muon component consists mostly of muons; pions are short lived and decay
    almost immediately upon production, feeding muons and the “soft” component.
    The development of the cascade depends mostly on the amount of matter traversed and is
    usually linked to residual atmospheric depth, which is very close to the static barometric pressure,
    rather than to the actual altitude, that may vary depending on the exact atmospheric density

    Click to access lrsp-2013-1Color.pdf

  17. ren says:

    In the south blockade continues. Therefore, the Atacama Desert is snowing.

  18. […] osservazione da questo punto di vista. Questi meccanismi, sono molto efficacemente chiariti in questo post pubblicato su Tallbloke, un lavoro che vi invito a leggere. A cui però devo sollevare una critica, e cioè quella di non […]