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 Subiectul mesajului: Vaporii de apa si norii versus clima
MesajScris: Lun Apr 01, 2013 6:14 pm 
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Membru din: Mar Mar 26, 2013 8:42 pm
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In acest topic vom vedea raportul vaporilor de apa si al norilor, variatia acestora.
La diferite altitudini vom vedea variatia acestor parametri nori-umezeala, in decursul timpului, atat la nivel global cat si in diferite segmente, nu intamplator studiate.
Imagine
In imaginea de mai sus ma intriga liniile ce depasesc 100...
Poate ma ajuta cineva sa inteleg?

In alta ordine de idei, atasez aici un text in care se arata o influenta a radiatiei cosmice asupra norilor josi...
Galactic cosmic rays (GCR) are energetic particles originating from space that impinge on Earth's atmosphere. Almost 90% of all the incoming cosmic ray particles are protons, about 9% are helium nuclei (alpha particles) and about 1% are electrons (beta minus particles). The term "ray" is a misnomer, as cosmic particles arrive individually, not in the form of a ray or beam of particles.

The flux of galactic cosmic rays varies inversely with the solar cycle. Svensmark and Friis-Christensen (1997) suggested that galactic cosmic rays enhance low cloud formation, explaining variations on the order of 3 percent global total cloud cover over a solar cycle. A 3 percent cloud cover change corresponds to a radiative net change of about 0.5 W/m2, which may be compared with the IPCC 2007 estimate of 1.6 W/m2 for the total effect of all recognized climatic drivers 1750-2006, including release of greenhouse gasses from the burning of fossil fuels.


Desigur, cand soarele este mai slab patrund mai multe radiatii cosmice.
Voi reveni cu diverse materiale.


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 Subiectul mesajului: Re: Vaporii de apa si norii versus clima
MesajScris: Mar Apr 02, 2013 4:11 pm 
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The new hypothesis on cloud formation being influenced by the intensity of galactic cosmic rays has been exposed to critique (Kristjánsson et al. 2002; Kristjánsson et al. 2004). Later, however, new experiments demonstrated that cosmic rays may indeed produce cloud condensation nuclei (CCN's). By way of the SKY experiment in Copenhagen was demonstrated how electrons set free in the air by passing cosmic rays help to assemble building blocks for CCN's (Svensmark et al. 2006, Svensmark 2007).

As more experiments are carried out and longer and improved dataseries on cloud cover, cosmic rays, atmospheric water vapour, the amount of atmospheric aerosols, etc. are established, knowledge on cloud cover formation will improve. Until all processes controlling cloud formation are thoroughly understood, any attempt of modelling future climate change may well prove in vain.
Imagine
Imagine
Imagine

Deci e ca naiba...daca inteleg bine unu la mana creste umiditatea in atmosfera joasa, apoi vor creste radiatiile cosmice odata cu slabirea Soarelui (vezi diagrama din topicul cu Soarele) si automat vor creste norii josi. Deci factori ce duc la racire, pe langa slabirea in sine a Soarelui.


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 Subiectul mesajului: Re: Vaporii de apa si norii versus clima
MesajScris: Sâm Apr 06, 2013 6:31 pm 
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Imagine
cu albastru nori global, cu rosu nori intre 15 grade nord si sud de Ecuator.
(medie si anomalie)


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 Subiectul mesajului: Re: Vaporii de apa si norii versus clima
MesajScris: Lun Apr 15, 2013 5:01 pm 
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Climate Change Blog
February 8, 2012
“A significant measure of negative feedback to global warming”Filed under: Climate Forcings —
A new paper just published in Geophysical Research Letters by Roger Davies and Mathew Molloy of the University of Auckland finds that over the past decade the global average effective cloud height has declined and that “If sustained, such a decrease would indicate a significant measure of negative cloud feedback to global warming.”

Davies and Molloy are quick to point out that part of the decline from 2000 to 2010 in cloud height is due to the timing and variability of El Niño/La Niña events over the same period, however, there still seems to be evidence that at least part of the decline may remain even when El Niño/La Niña variability is accounted for.
Imagine
Figure 1 shows the history of the effective cloud height, as determined by Davies and Molloy from satellite observations, from March 2000 through February 2010. The dotted line is the linear trend through the data as determined by Davies and Molloy and has a value of -44 meters per decade (+/- 22m). However, clearly the trend is influenced by the large negative departure centered around the beginning of 2008 that was related to a moderate La Niña event in the Pacific Ocean. To avoid the influence of the this event, Davies and Molloy calculate the difference between the cloud heights during the first and last years of their record and still find a decline of 31 m/dec (+/- 11m). Although this latter technique doesn’t fully account for the El Niño/La Niña signal in the record, it does at least give some indication of the influence of the large negative departures in the latter half of the record, and indicates that the overall decline is not simply an artifact of a single event.


Figure 1. Deseasonalized anomalies of global effective cloud-top height from the 10-year mean. Solid line: 12-month running mean of 10-day anomalies. Dotted line: linear regression. Gray error bars indicate the sampling error (±8 m) in the annual average (source: Davies and Molloy, 2012).


The average global cloud height is linked to the average global temperature—generally, the higher the average cloud height, the higher the average surface temperature, and vice versa. The tie-in is related to the height in the atmosphere from which clouds radiate long-wave radiation to space. The higher up they are, the cooler they are, and thus the less radiation they lose to space, which means the surface stays warmer.

Davies and Molloy calculate that on a decadal basis, the radiative forcing from increasing greenhouse gases is the same as that caused by either a decrease in the total global cloud amount of ~0.3% (which would allow more short wave radiation from the sun to hit the earth’s surface) or an increase in the global average cloud height of ~19 meters (about 62 feet). All to say, that clouds play a major role in the earth’s climate and that small changes in cloud characteristics can add to (via positive feedbacks) or offset (via negative feedbacks) the warming pressure put on the climate from increasing greenhouse gases. A point well-recognized by Davies and Molloy when they write “Changes in cloud properties in response to rising surface temperatures represent some of the strongest, yet least understood, feedback processes in the climate system. “

Davies and Molloy hoped to better our understanding of cloud behavior by quantifying changes in cloud heights as determined from data obtained from the Multiangle Imaging SpectroRadiometer (MISR) carried aboard the Terra satellite. The MISR data provides stereo imaging that can be used to determine the heights of clouds. The MISR data is not perfect, as it misses very thin clouds (like high level cirrus) and very homogeneous clouds (like some cirrus from thunderstorm anvils), but perhaps its biggest shortcoming is that the period of available data is still pretty short (i.e., only begins February 2000). Nevertheless, an investigation of what data is available from the MISR instrument can provide some insight as to the variability of cloud heights and their relationship to the earth’s climate.

Which was the main purpose of the work of Davies and Molloy.

In full recognition of the limitations of the data, here is how Davies and Molloy conclude their paper, in their own words:

Finally, we note that the climate data record of [effective cloud height] anomalies may ultimately indicate a measure of long-term cloud feedback that may be quite separate from the correlations discussed above [i.e., correlations with El Niña/La Niña]. Ten years is unfortunately too short a span for any definitive conclusion, as the linear trend in global cloud height of -44 +/- 22 m over the last decade is partly influenced by the La Niña event, and may prove ephemeral. The difference between the first and last year of the decade, not directly affected by the La Niña event, is -31 +/- 11 m. If sustained, such a decrease would indicate a significant measure of negative cloud feedback to global warming, as lower cloud heights reduce the effective altitude of emission of radiation to space with a corresponding cooling effect on equilibrium surface temperature. Given the precision of the MISR measurements, we look forward to the extension of this climate data record with great interest.

According to the calculations of Davies and Molloy, the negative climate forcing from a decrease in the average global cloud amount during the past 10 years has more than offset the positive forcing from an increase in greenhouse gases from human activities. It is little wonder that the rate of global temperature rise during this period has been so paltry!

Davies and Molloy write that they “look forward to the extension of this climate data record with great interest.” We want to be the first to second that sentiment.
http://www.worldclimatereport.com/index.php/2012/02/08/a-significant-measure-of-negative-feedback-to-global-warming/#more-527


Adaug eu: Ar putea fi de fapt cu totii in eroare (din pacate sau din fericire) daca in realitate temperatura globala a scazut in aceeasi perioada....personal nu pot crede ca incalzirea poate duce la un feedback negativ de acest gen. Pare absurd.
Cred ca au demonstrat exact contrariul. E logic doar: cand vine caldura, norii se inalta tot mai sus. Simt ca temperatura globala a avut un usor trend negativ in perioada studiata.


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 Subiectul mesajului: Re: Vaporii de apa si norii versus clima
MesajScris: Vin Apr 19, 2013 5:17 pm 
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http://isccp.giss.nasa.gov/climanal1.html

Foarte multe date climatice despre nori si nu numai...

Si: Cloud Climatology...

http://isccp.giss.nasa.gov/role.html


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 Subiectul mesajului: Re: Vaporii de apa si norii versus clima
MesajScris: Sâm Iun 22, 2013 11:50 am 
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FOARTE TARE!
One would not assume that cloud cover over Antactica’s Southern Ocean could cause rainfall in Zambia or the tropical island of Java. New research from the University of Washington, however, finds that a phantom band of rainfall just south of the equator that does not occur in reality is caused by poor simulation of the cloud cover thousands of miles farther to the south. This illusionary band of rainfall is one of the most persistent biases in global climate models.

Atmospheric scientists at Washington hope that their results will help explain why global climate models duplicate the inter-tropical convergence zone, a band of heavy rainfall in the northern tropics, on the other side of the equator by mistake.

The results of the study appear in a recent issue of Proceedings of the National Academy of Sciences (PNAS).

“There have been tons of efforts to get the tropical precipitation right, but they have looked in the tropics only,†said Yen-Ting Hwang, a UW doctoral student in atmospheric sciences who found the culprit in one of the most remote areas of the planet.

“What we found, and that was surprising to us, is the models tend to be not cloudy enough in the Southern Ocean so too much sunlight reaches the ocean surface and it gets too hot there,†Hwang said. “People think of clouds locally, but we found that these changes spread into the lower latitudes.â€

Prior studies examined tropical sea-surface temperatures, or better ways to represent tropical winds and clouds. None managed to correctly stimulate rainfall in the tropics, however, which is an important region for global climate models since small shifts in rainfall patterns can have huge effects on climate and agriculture.

“The rain bands are very sharp in this area,†commented Dargan Frierson, a UW associate professor of atmospheric sciences. “You go from some of the rainiest places on Earth to some of the driest in [less than a few hundred miles].â€

Recent theories have suggested that tropical rainfall might be linked to global processes. The new research looked for possible connections to ocean temperatures, air temperatures, winds and cloud cover.

“For the longest time we were expecting that it would be a combination of different factors,†Frierson said, “but this one just stood out.â€

Cloud biases over the Southern Ocean are the primary contributor to the phantom double rain band problem existing in most modern climate models, the research showed.

“It almost correlates perfectly,†Hwang said in a statement. “The models that are doing better in tropical rainfall are the ones that have more cloud cover in the Southern Ocean.â€

Hwang will present the findings at the World Climate Research Programme (WCRP) in April. The findings have also been submitted for inclusion in the fifth report of the Intergovernmental Panel on Climate Change (IPCC).

The team found that most modern climate models do not generate enough low-level clouds over the perpetually stormy Southern Ocean, allowing heat to accumulate in the Southern Hemisphere.

“Basically hot air rises, and it rains where air rises. So it´s kind of obvious that the rain is going to be over warmer ocean temperatures,†Frierson said. “Our new thinking is that the heat spreads – it´s the warmth of the entire hemisphere that affects tropical rainfall.â€

Climatologists can look for ways to improve the models to increase cloud cover over the Southern Ocean in the short term. Eventually, however, more powerful computers may permit models that are able to create accurate simulations of global cloud coverage.

“We have confidence in climate predictions outside the tropics, but tropical rainfall forecasts are much less certain,†Frierson said. “We hope this work will lead to better rainfall forecasts in regions like equatorial Africa, where it´s so important to have accurate predictions of future patterns.â€


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 Subiectul mesajului: Re: Vaporii de apa si norii versus clima
MesajScris: Mar Aug 20, 2013 12:26 pm 
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Formarea norilor si a precipitatiilor, induse de un dispozitiv solar artificial. (Ghessem Rain System)


http://www.bgu.ac.il/bidr/research/phys/remote/Papers/2008-Brening_Cloud-formation_GPh_08.pdf

Ohohooo!

Nota personala.

Acest rezultat ar fi aparut inevitabil la instalarea marilor ferme solare...
Daca sunt amplasate strategic (bariere) rezultatele pot fi uimitoare, de doua ori beneficii. Electricitate plus clima mai buna.
Oricum erau proiecte si ar trebui sa tina seama de asta.


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 Subiectul mesajului: Re: Vaporii de apa si norii versus clima
MesajScris: Dum Sep 22, 2013 1:02 am 
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http://www.meteogiornale.it/notizia/21246-1-raggi-cosmici-e-global-warming


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 Subiectul mesajului: Re: Vaporii de apa si norii versus clima
MesajScris: Mar Sep 24, 2013 8:24 pm 
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http://www.drroyspencer.com/
http://www.meteogiornale.it/notizia/16818-1-il-campo-magnetico-solare-e-la-nuvolosita-terrestre


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 Subiectul mesajului: Re: Vaporii de apa si norii versus clima
MesajScris: Sâm Oct 05, 2013 11:41 pm 
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http://stiintasitehnica.com/stiri/infuen-eaza-razele-cosmice-clima-da-nu-poate/index.html


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 Subiectul mesajului: Re: Vaporii de apa si norii versus clima
MesajScris: Sâm Oct 19, 2013 5:52 pm 
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http://www.atmos.washington.edu/CloudMap/Publications/WarrenEtal2007_CloudSurvey.pdf


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 Subiectul mesajului: Re: Vaporii de apa si norii versus clima
MesajScris: Sâm Oct 19, 2013 5:55 pm 
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Winter cloudiness variability over Northern Eurasia related to the Siberian High during
1966–2010

http://iopscience.iop.org/1748-9326/8/4/045012/pdf/1748-9326_8_4_045012.pdf


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