Husk mig
▼ Indhold

Den nyeste forskning viser....



Side 24 af 24<<<222324
17-06-2016 00:17
christian-roskilde
★★★☆☆
(562)
Kjeld Jul skrev:
John-
en interessant undersøgelse,som viser,hvor dårlige klimamodellerne er.

Her mere om vekselvirkningen mellem aerosoller og skyer.

http://www.cato.org/blog/climate-alarm-death-knell-sound-again?utm_medium-twitter&utm_source=twitterfeed

http://blogs.reading.ac.uk/weather-and-climate-at-reading/2016/1053/


Nir shaviv:

Klimamodellerne overvurdere effekten af vulkansk aktivitet på klimaet, hvor simuleringerne viser et større temperaturfald end man har observeret.



Kilde til grafen er fra denne artikkel.

http://www.sciencebits.com/FittingElephants

Med i mente vi især ikke kender skyernes betydning ordenligt, bør klimamodellerne efter min mening tages med forbehold.

Mvh.
01-07-2016 14:17
Kjeld Jul
★★★★☆
(1870)
Nyt studie af meteorolog Marc Salzmann,UNI Leipzig viser,at GW indtil nu ikke har indvirket på den globale gennemsnitlige nedbørsmængde.
Dette skyldes hovedsageligt den kølende virkning af SO2 aerosoler.
Den globale nedbørsmængde aftager ved aerosol-køling med ca. 3 til 4% pr. C,hvor CO2 øger nedbørsmængden med ca. 1,5 til 2% pr. gr. C.

http://advances.sciencemag.org/content/2/6/e1501572
19-08-2016 14:46
kristofferszilas
★★★☆☆
(852)
Bourgeois et al. (2016). Ubiquity and impact of thin mid-level clouds in the tropics. Nature Communications 7.

Abstract
Clouds are crucial for Earth's climate and radiation budget. Great attention has been paid to low, high and vertically thick tropospheric clouds such as stratus, cirrus and deep convective clouds. However, much less is known about tropospheric mid-level clouds as these clouds are challenging to observe in situ and difficult to detect by remote sensing techniques. Here we use Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) satellite observations to show that thin mid-level clouds (TMLCs) are ubiquitous in the tropics. Supported by high-resolution regional model simulations, we find that TMLCs are formed by detrainment from convective clouds near the zero-degree isotherm. Calculations using a radiative transfer model indicate that tropical TMLCs have a cooling effect on climate that could be as large in magnitude as the warming effect of cirrus. We conclude that more effort has to be made to understand TMLCs, as their influence on cloud feedbacks, heat and moisture transport, and climate sensitivity could be substantial.

Et populærvidenskabeligt sammendrag kan findes her:
Thin clouds at about 5 km altitude are more ubiquitous in the tropics than previously thought and they have a substantial cooling effect on climate, report researchers. The cooling effect of mid-level clouds is currently missing in global climate models.
...
Clouds cover about 70% of Earth's surface at any time. Different types of clouds affect Earth's climate differently: low liquid clouds, such as the cotton-like cumulus, cool Earth while high altitude ice clouds, such as the wispy cirrus, warm the climate. Overall, clouds cool the climate by about 20 W m-2. In contrast, Earth receives on average about 340 W m-2 energy from the sun every day and our current emissions of anthropogenic greenhouse gases warm the climate by about 3 W m-2.
26-08-2016 09:57
kristofferszilas
★★★☆☆
(852)
Svenskmark et al. (2016). The response of clouds and aerosols to cosmic ray decreases. Journal of Geophysical Research (in press).

Abstract
A method is developed to rank Forbush Decreases (FDs) in the galactic cosmic ray radiation according to their expected impact on the ionization of the lower atmosphere. Then a Monte Carlo bootstrap based statistical test is formulated to estimate the significance of the apparent response in physical and micro-physical cloud parameters to FDs. The test is subsequently applied to one ground based and three satellite based datasets. Responses (> 95%) to FDs are found in the following parameters of the analyzed datasets. AERONET: Ångström exponent (cloud condensation nuclei changes), SSM/I: liquid water content, ISCCP: total, high and middle, IR detected clouds over the oceans, MODIS: cloud effective emissivity, cloud optical thickness, liquid water, cloud fraction, liquid water path, liquid cloud effective radius. Moreover, the responses in MODIS are found to correlate positively with the strength of the FDs, and the signs and magnitudes of the responses agree with model based expectations. The effect is mainly seen in liquid clouds. An impact through changes in UV driven photo chemistry is shown to be negligible and an impact via UV absorption in the stratosphere is found to have no effect on clouds. The total solar irradiance has a relative decrease in connection with FDs of the order of 10−3, which is too small to have a thermodynamic impact on timescales of a few days. The results demonstrate that there is a real influence of FDs on clouds probably through ions.
26-08-2016 14:16
Morten Riber
★★★★☆
(1785)
kristofferszilas skrev:
Svenskmark et al. (2016). The response of clouds and aerosols to cosmic ray decreases. Journal of Geophysical Research (in press).

Abstract
A method is developed to rank Forbush Decreases (FDs) in the galactic cosmic ray radiation according to their expected impact on the ionization of the lower atmosphere. Then a Monte Carlo bootstrap based statistical test is formulated to estimate the significance of the apparent response in physical and micro-physical cloud parameters to FDs. The test is subsequently applied to one ground based and three satellite based datasets. Responses (> 95%) to FDs are found in the following parameters of the analyzed datasets. AERONET: Ångström exponent (cloud condensation nuclei changes), SSM/I: liquid water content, ISCCP: total, high and middle, IR detected clouds over the oceans, MODIS: cloud effective emissivity, cloud optical thickness, liquid water, cloud fraction, liquid water path, liquid cloud effective radius. Moreover, the responses in MODIS are found to correlate positively with the strength of the FDs, and the signs and magnitudes of the responses agree with model based expectations. The effect is mainly seen in liquid clouds. An impact through changes in UV driven photo chemistry is shown to be negligible and an impact via UV absorption in the stratosphere is found to have no effect on clouds. The total solar irradiance has a relative decrease in connection with FDs of the order of 10−3, which is too small to have a thermodynamic impact on timescales of a few days. The results demonstrate that there is a real influence of FDs on clouds probably through ions.


Er overskriften ikke misvisende for indholdet i artiklen som udtrykker præcis hvad Svensmark siger i sine foredrag?

At ændringerne i solkonstanten er for lille til at have nogen særlig effekt, men at resultaterne viser at effekten skyldes ændringer i mængden at ioner.

Den evindelige misforståelse af Svensmark er umulig at få bugt med, og hvorfor ved vi jo så udmærket.


Tiden går - mens vi stadig fejlinformeres
24-09-2016 13:16
Kjeld Jul
★★★★☆
(1870)
Når vi taler om CO2 emissionen er det væsentligt at vide,hvorlænge den menneskeskabte CO2 opholder sig i atmosfæren og vi er tilbage på et niveau på fx 300ppm?
AR4 siger,at har man et udslip på 100g vil 50% være væk om 30 år,yderligere 30%om nogle 100 år og resten efter flere tusinde år.
Såfremt vi stoppede al udledning nu,hvordan vil det så se ud i år 2100,hvis vi bruger denne regel?.
Er der kommet nye teorier om opholdstiden?
Er der nogen der kan komme med nogle svar?
24-09-2016 13:42
John Niclasen
★★★★☆
(1718)
Kjeld Jul skrev:
Når vi taler om CO2 emissionen er det væsentligt at vide,hvorlænge den menneskeskabte CO2 opholder sig i atmosfæren og vi er tilbage på et niveau på fx 300ppm?
Er der kommet nye teorier om opholdstiden?
Er der nogen der kan komme med nogle svar?

Hej Kjeld!

Der er noget om dette i den anden tråd Skal vi fejre kuldioxid (CO2)? og her med henvisning til Salby.

Man snakker også om "missing carbon sink". Prøv at søg på dette, og du vil finde mulige svar. Planterne optager og afgiver meget mere pr. år, end os mennesker udleder pr. år. Jeg kan ikke huske det præcise tal.

Nogle måler og vurderer det med isotoper af C. Er det tiden, til isotop-forholdet er tilbage på preindustrielt niveau, man mener, eller er det tiden til koncentrationen af CO2 er tilbage på preindustrielt niveau, man mener? Der er givet forskel på disse to tider.
24-09-2016 13:52
Kjeld Jul
★★★★☆
(1870)
Tak for link John,det vil jeg kigge på.
Side 24 af 24<<<222324





Deltag aktivt i debatten Den nyeste forskning viser....:

Husk mig

Lignende indhold
DebatterSvarSeneste indlæg
Er fri forskning truet?7903-07-2013 18:02
Henrik Svensmarks forskning8609-08-2009 18:29
Artikler
Hvad skal der gøres for at fremme forskning i vedvarende energi og energibesparende teknologi?
NyhederDato
Ny forskning: Skovene kan tilpasse sig15-11-2010 08:21
Meget lidt forskning i klimatilpasning31-03-2009 08:52
▲ Til toppen
Afstemning
Bør der indføres en klimaafgift på oksekød, som foreslået af Etisk Råd?

Ja

Nej

Ved ikke


Tak for støtten til driften af Klimadebat.dk.
Copyright © 2007-2016 Klimadebat.dk | Kontakt | Privatlivspolitik