Sentences with phrase «stratospheric water vapour»

The contributions of stratospheric water vapour and ozone, volcanic eruptions, and organic and black carbon are small.»
Many models have large biases in lower stratospheric water vapour (Gettelman et al., 2010), which could have implications for surface temperature change (Solomon et al., 2010).
However, ozone reponses to climate changes are quite sensitive to the initial base state (how much stratospheric water vapour was there?
Surface albedo, contrails and stratospheric water vapour RFs are included in the total curve but not in the others.
Based on chemical transport model studies, the RF from the increase in stratospheric water vapour due to oxidation of CH4 is estimated to be +0.07 [± 0.05] W m — 2, with a low level of scientific understanding.
If that isn't enough Marotzke says, «However, climate models do not illustrate stratospheric water vapour very well, the prognoses thus remain vague.»
* The GWP for methane includes indirect effects of tropospheric ozone production and stratospheric water vapour production.
A change in stratospheric water vapour because of the increase in methane over the industrial period would be a forcing of the climate (and is one of the indirect effects of methane we discussed last year), but a change in the tropopause flux is a response to other factors in the climate system.
Stratospheric water vapour comes from two sources — the uplift of tropospheric water through the very cold tropical tropopause (both as vapour and as condensate), and the oxidation of methane in the upper stratosphere (CH4 +2 O2 — > CO2 + 2H2O NB: this is just a schematic, the actual chemical pathways are more complicated).
Second, this is a discussion about stratospheric water vapour (10 to 15 km above the surface), not water vapour in general.
Methane enhances its own lifetime through changes in the OH concentration: it leads to changes in tropospheric ozone, enhances stratospheric water vapour levels, and produces CO2.
Recent studies have shown a doubling of stratospheric water vapour, likely from increasing atmospheric heights due to global warming, overshooting thunderstorm tops from stronger tropical cyclones and mesoscale convective systems etc...
If the lower stratospheric water vapour (LSWV) is relaxing back to some norm after the 1997/1998 El Nino, then what we are seeing would be internal variability in the system which might have some implications for feedbacks to increasing GHGs, and my estimate of that would be that this would be an amplifying feedback (warmer SSTs leading to more LSWV).
Plugging the changes in water vapour into a climate model that looks at the way different substances absorb and emit infrared radiation, they conclude that between 2000 and 2009 a drop in stratospheric water vapour of less than one part per million slowed the rate of warming at the Earth's surface by about 25 %.
I would assume that the increase in stratospheric water vapour would make for a thicker vail of sulfuric acid given a large volcanic eruption.
Forster, P.M. de F., and K.P. Shine, 2002: Assessing the climate impact of trends in stratospheric water vapour.
The forcings illustrated here are from the well mixed greenhouse gases (GHGs)(CO2, CH4, N2O, CFCs), tropospheric and stratospheric O3, direct aerosol effects (from sulphates, nitrates, organic and black carbon), land use change, solar irradiance, volcanic aerosols, and various indirect effects (on clouds, stratospheric water vapour, snow albedo etc.).
Such a small change in stratospheric water vapour can have such a large effect precisely because the stratosphere is already dry.
The Met Office held a briefing for the press to explain that the reduction in warming might be natural variation, or could be accounted for by a mixture of a decrease in stratospheric water vapour and the cooling bias introduced by new methodology.
Stratospheric water vapour?
On the other hand, as well as being a powerful GHG it is a source of tropospheric ozone and stratospheric water vapour, both of which add to the basic forcing from methane.
... there is little quantification of the stratospheric water vapour change attributable to different causes.
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