The retreat of the Arctic sea ice is reducing the albedo - the light reflectance of the Earth, at a greater rate than previously thought. This is according to a study that used data from instruments on NASA satellites.
The retreat of the Arctic sea ice is reducing the albedo - the light reflectance of the Earth, at a greater rate than previously thought. This is according to a study that used data from instruments on NASA satellites.
The study, carried out by researchers at the Script Institution of Oceanography at the University of California, San Diego, involved the use of data from the Clouds and Earth's Radiant Energy System instrument, CERES. Instruments of this type are found on the TRMM (Tropical Rainfall Measurement Mission), Terra, Aqua and Suomi NPP satellites shared by NASA and NOAA. The first CERES instrument was launched in December 1997 aboard TRMM.
As the sea ice melts, the Earth's surface becomes darker, and less light is returned to space. Because sunlight is prevented from returning to space, the Earth absorbs an increasing amount of the sun's energy.
The Arctic region has warmed by 2 degrees since the 40s. The minimum area of Arctic summer ice has shrunk by XNUMX% over the same period. This factor reduced the albedo of this area - the part of the light that reaches the Earth and is returned to space, and this is a change that the CERES instruments are able to measure.
More on the subject on the science website
- The jet stream that changed as a result of the warming of the North Pole caused the current winter mirages
- Another proof of warming: the ice season in the Arctic region was shortened by 24 days compared to 1950
- The lesson we need to learn from the destruction of ancient civilizations as a result of climate change
Christina Pistone, a doctoral student at Scripps and climate scientists in Eisenman and colleague Veerabhadaran Ramanathan, used satellite measurements to calculate albedo changes associated with changes in ice cover. The albedo is measured in percentages. Black surfaces have an albedo of zero percent and glacial surfaces indicate 100%. The albedo of fresh snow ranges from 80 to 90 percent, while the albedo of the ocean surface is less than 20 percent. The clouds and other factors such as aerosols and carbon also affect the albedo of the earth.
The researchers calculated that the total albedo of the Arctic fell from 52% to 48% between 1979 and 2011. The area of the Earth's surface that has turned dark is double that found in previous studies. They also compared their proposals to model simulations that assessed the ability of computer models to predict changes in albedo.
Previous studies have used a combination of computer models and observations to estimate how much extra energy has already been absorbed by the oceans. In contrast, the Scripps team preferred to directly examine the coordination between the albedo measurements made by NASA's CERES instrument data with observations of ice using radiometers for measurement by a microwave sensor (Imager SSM / I) on board meteorological satellites. This method avoids the inaccuracy inherent in the use of computer models.
"It is quite intuitive to expect that replacing white sea ice with a dark ocean will increase the heating." Pistone said.
"We used satellite measurements of albedo and sea ice to verify this and to measure the amount of heat added to the area due to ice loss. It was quite encouraging to see how two sets of data coming from two independent satellite instruments - agreed with each other."
"Scientists have been talking about the melting of the Arctic ice and the decrease in albedo for almost 50 years," said Ramanathan, a professor of climate and atmospheric sciences at Scripps who has conducted similar research into the global dimming effects of aerosols in the past. "This is the first time that this darkening effect has been recorded on the scale of the entire North Pole."
Whereas Eisenman, professor of climate dynamics, said that the warming of the Arctic region as a result of the albedo change reaches a quarter of the rate of warming of the entire earth.
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Is there hope? Right now we seem to be going to a very bad place and nothing is changing, do you see any positive direction in the air? What? spark? It seems that the only solution right now is to keep Shabbat all week...
As Captain Janeway used to say... "You have to hope for the best but be prepared for the worst"
You must not play with fire and take bets on all life on earth just because it is "uncertain" that the worst will happen.
ארי
I totally agree with that
I agree that the change that is happening right now is causing a catastrophe in the ecological structure.
I also agree with you that many species are going extinct in a mass extinction process.
But in general I maintain that those rapid changes can have a quick fix - if, for example, the albedo of the earth actually increases due to that global warming, it is possible that the temperatures have stabilized and will not rise any more.
By the way, note that in my assumption I said nothing and a half about what exactly it means to live on a planet that is more humid, hotter and covered by 70% clouds. It may be that the warming will stop thanks to the increase in albedo, but the environmental impact of such excess cloudiness could certainly be catastrophic.
ארי
I agree that life is an essential part of the chemical structure of the upper layers. James Lovelock wrote a book at the time in which he claimed that you don't need to go to Mars to see if there is life there, it's enough to look at the chemical composition.
But - pay attention to several points:
1) As long as the changes are slow enough, life will balance with the environment. I think that's what you mean.
2) Rapid change can destroy life. For example, human actions create a rate of extinction of species that is no different than the rate of extinction at the end of the age of the dinosaurs. Think about it - maybe half of the species that exist today, will not exist in 40 years.
3) In any case, even if there is a balance - the balance is of life as a whole, not of species. That is - life will probably survive almost any change, but the existing species, including humans, will not necessarily survive.
All this assuming there is no God of course…..
Eric, you are definitely more mature than me 🙂 I need to learn it from you (no sarcasm).
In any case, everything you stated does not contradict what Nissim and I said.
Read this article, I hope you find it at least interesting (even if it doesn't convince you)
http://www.calcalist.co.il/local/articles/0,7340,L-3596568,00.html
Friends, there is no debate here, but a discussion - and my discussion and Nissim's has somewhat deviated from the topic of the article here.
Miracles and MH - although there used to be much more oxygen, it was only created thanks to the animals - and not as a result of normal chemical processes. In other words - the animals changed the Earth's atmosphere.
The animals also regulate the salinity level in the oceans - because otherwise it would not be possible to solve the "salinity paradox" - even though all the streams flow to the sea and from there to the ocean, the salinity level remains stable. This is thanks to the animals living in the sea.
In addition, the chemical composition of the earth's lithosphere (and especially the continental crust) is different as a result of the existence of life on the earth's surface - when the animals die, they land on the oceanic crust, and the oceanic crust lands under another continental crust, at the tremendous temperatures and pressures in these processes, rocks and compounds are formed which then reach the tops of mountains - and these rocks would not exist without the animals.
Add to this the fact that the earliest evidence of animals is about 3.5 billion years ago - a little after the creation of the Earth and its cooling to a temperature that can support life - the ecological system can be seen as an integral part of the chemical processes that take place in the Earth's lithosphere and atmosphere.
Although Eric wrote more words and mathematical equations, he reasoned with miracles.
There used to be much more nitrogen, then much more oxygen and now we are in the situation we are now... the animals always go extinct/adapt themselves to the changes of nature. It is not true to say that nature will always be balanced (as long as man does not interfere, no), both factually it is not true and it does not make sense...
And in general, man is part of the animal...
So anyway, your intuition in choosing a side was wrong this time 🙂
(And hey, you two are so smart...)
Anyway - if I may say so, then Eric won. Not because he's right (I have no idea) but because he seems to have tried harder than miracles and that in itself puts me on his side.
Eric - well done!
In any case, it seems to me that there is an additional parameter to everything you said (and as I mentioned, I really don't understand it like you do) and that is the atmosphere itself... will it be able to contain all the liquids coming from below??
ארי
On the contrary... the forms of life today are adapted to the oxygen concentration that exists today. In the past there was a time with a higher concentration of oxygen and there were suitable life forms, such as giant insects.
Lowering the oxygen concentration will harm all forms of life, including plants and other oxygen producers.
It is true that the source of oxygen is living things, but it is not true to say that there is a balance. Definately not.
Miracles,
This is not accurate - the salinity level, the oxygen level, etc. - all are kept at their current level thanks to life cycles that "engineer" the chemistry of our planet.
ארי
The planet does not support life - life adapts itself to the planet. In particular, the species that are not adapted, or are able to adapt themselves, become extinct.
Miracles - obviously there is warming. It is clear that this changes the ecosystem around us, in a way that causes us and many other animals - damage.
But, it may very well be that our planet, which maintains being "alive" - that is, supporting life on it for billions of years - has mechanisms to correct this problem. And if there is - you need to know it and get to know them.
ארי
I agree with you that the cloud covers have an effect, it seems pretty clear to me. I do think it is necessary to shout, because most of the information I hear, which supports that there is no warming problem, is not reliable.
Miracles - obviously I arbitrarily chose an increase in cloudiness to 70%. My demonstration here shows that since clouds have a very large albedo coefficient (more than ice), their influence should be taken into account. By the way, it is clear that the albedo in the North Pole will show a very dramatic change - after all, there is an ocean under the ice, and the differences between the albedos in this area are very high. In addition, the area receives little radiation relative to the lower altitude lines, and therefore the formation of clouds there is smaller.
I would like to see studies that measure the level of albedo in cloudier areas, relative to their decreasing albedo in the North Pole.
As I showed in my calculations, even very inaccurate calculations - the point is the principle - any change in the clouds will affect the albedo and the temperature of the earth.
The rejection of my calculations as if they are imprecise and reminiscent of erroneous assumptions in the past is not serious - after all, I did not pretend to write a doctorate on the subject, but this is a response on the Internet. The calculations may not be exact, but they point to a subject that is not sufficiently studied in my opinion in the context of global warming.
It is easy to be a prophet of wrath and shout "Our Father in heaven, how we have sinned!" In the context of the warming, but it might be worth checking whether our planet has self-repair mechanisms. One of them is the increased albedo of cloudiness.
ארי
Your approximations do not seem reasonable to me. The problem with warming is a matter of a few degrees, and I think the errors in your relatives are much more than a few degrees. The precision, so to speak, in your calculations remind me of the calculation of Calvin for the age of the world.
It's really not accurate.
The albedo of clouds is higher than the albedo of ice, what's more, in the South Pole most of the ice sits on land and the albedo difference (the radiation reflection coefficient of a certain surface) is much smaller than between ice and the ocean.
In fact, I think that there are not enough studies that refine the increase in the amount of clouds following global warming as a balancing effect - in fact, clouds have an albedo of 0.5-0.8 (compared to an ocean of 0.5-0.7).
Let's assume that due to the warming of the earth, the cloud cover on the earth will increase to 70%.
An increase in cloud cover to 70% would increase the Earth's planetary albedo, which would increase the amount of solar radiation reflected from the Earth's surface. As of today, the albedo of Kadhwa is 30%, i.e. 0.3. The albedo of clouds ranges from 0.5-0.8, which means that an average value of 0.65 can be assumed. If we divide equally the remaining 30% of the earth's surface between the albedo of the oceans and the land, in the average values as shown in the same table, we will get 0.035 and 0.225 respectively. Now calculate the general albedo of the earth in the following way:
70% * 0.65 + 15% * 0.225 + 15% * 0.035 = 0.494
That means the Earth's albedo will now be 0.494, a value approximately 40% higher than the Earth's current albedo. This means about 40% more than the sun's radiation would have been reflected directly from the earth into space.
Now we consider E as the radiation power emitted into space from one unit of the Earth's area, by placing the updated albedo in the radiative equilibrium formula:
E = (1-A)*S / 4
We will get that:
E = 174.57 W/m2
Now put in the Stefan-Boltzmann equation:
174.57 = σT4
And it seems that the following effective temperature is obtained:
T = 235.55K
That is, a black body emitting a radiation power of 174.57 watts/m2 will have a temperature of 235.55 Kelvin. That is, the Earth can be considered a black body with a temperature of -37.59 degrees Celsius.
For comparison, as of today, at Earth's current albedo, that temperature is about -18 degrees Celsius (255 Kelvin). If we take into account the greenhouse effect in its current intensity, which as of today raises the earth by another 35 degrees Kelvin, we will arrive at the fact that the surface of the earth will cool down to an average temperature of -2.59 Celsius.
I searched and didn't find enough studies on the subject, so I think that until they investigate the effect of the increased cloudiness that will certainly be created by warming, I don't think it will be possible to determine unequivocally where we are going, or whether the planet is not able to repair itself (in fact, increased cloudiness will certainly affect the weather in the form of such and such superstorms).
In short, we went...
Fan
More evaporation means more moisture in the air, and water vapor itself is a greenhouse gas. I don't think it's exactly a balance.
In addition, I read that there is a lot of frozen methane in the depths of the sea, and the warming of the water may cause the emission of this gas, and here you have another greenhouse gas....
Indeed, the warming is very problematic, but there is a balancing factor (it is not clear how much damage will happen until it takes effect)
As the earth warms (up to a certain degree the sky starts to disappear but this is not the case) there is more rain (and also more flowing water) so the absorption rate of CO2 increases so that it should moderate the warming.
Fan
For the "deniers":
Measurements in the last 13 years have shown that:
The warming over the Indian Ocean (and the Pacific) is not increasing as expected,
Now there is an explanation for the phenomenon:
It turns out that because of the warming, trade winds are increasing,
The winds stir the water, a stir that brings up cold water from the depths,
The cold water moderates the warming,
But when the process stops, the ocean will emit the accumulated heat
And the warming process will increase...