Je ziet de dikte/hoogtewaarden toch van de troposfeer?

Bericht van: Wim (Oudewater) , 17-01-2013 00:30 

Polaire waarden boven NL afgelopen dagen. Verklaring voor het type sneeuw, stuif/poeder/poolsneeuw lijkt me. Ook lijkt het mij dat als de huidige wintersetting weinig slagkracht zou hebben, de invloeden van de oceaan al lang en breed gezorgd zouden hebben voor ruime dikke dooi.
Ergens kan ik dus natuurlijk twijfels over modeloutput voor de aankomende 7 en de dagen erna en over het wel of niet aanhouden van het winterweer best voorstellen.

At latitudes above 60° , the tropopause is less than 9 -10 km above sea level; the lowest is less than 8 km high, above Antarctica and above Siberia and northern Canada in winter. The highest average tropopause is over the oceanic warm pool of the western equatorial Pacific, about 17.5 km high, and over Southeast Asia, during the summer monsoon, the tropopause occasionally peaks above 18 km. In other words, cold conditions lead to a lower tropopause, obviously because of less convection.

Deep convection (thunderstorms) in the Intertropical Convergence Zone, or over mid-latitude continents in summer, continuously push the tropopause upwards and as such deepen the troposphere. This is because thunderstorms mix the tropospheric air at a moist adiabatic lapse rate. In the upper troposphere, this lapse rate is essentially the same as the dry adiabatic rate of 10K/km. So a deepening by 1 km reduces the tropopause temperature by 10K. Therefore, in areas where (or at times when) the tropopause is exceptionally high, the tropopause temperature is also very low, sometimes below -80 C. Such low temperatures are not found anywhere else in the Earth's atmosphere, at any level, except in the winter stratosphere over Antarctica.

On the other hand, colder regions have a lower tropopause, obviously because convective overturning is limited there, due to the negative radiation balance at the surface. In fact, convection is very rare in polar regions; most of the tropospheric mixing at middle and high latitudes is forced by frontal systems in which uplift is forced rather than spontaneous (convective). This explains the paradox that tropopause temperatures are lowest where the surface temperatures are highest.

Bericht laatst bijgewerkt: 17-01-2013 01:36
Don't be pushed by your problems, be led by your dreams!

Tropopauze geopot analyse animatie Januari   ( 608)
Wim (Oudewater) -- 17-01-2013 00:11
En?   ( 271)
Wallie (Lelystad) -- 17-01-2013 00:08
Je ziet de dikte/hoogtewaarden toch van de troposfeer?   ( 333)
Wim (Oudewater) -- 17-01-2013 00:30
Het gaat allemaal wel wat snel   ( 190)
Wallie (Lelystad) -- 17-01-2013 00:41
  Ik heb iets aangevuld in mijn vorige bericht.  
Wim (Oudewater) -- 17-01-2013 00:43
Ja, ik zie het. Stukje van november 1997 (zie link)   ( 172)
Wallie (Lelystad) -- 17-01-2013 00:48
  Nou, ik ga meer eens naar bed denk ik, trusten 🙂  
Wallie (Lelystad) -- 17-01-2013 00:52
  Insgelijks  
Wim (Oudewater) -- 17-01-2013 01:01
Precies 2 pvu is zo ongeveer de onderkant daarvan (niets is   ( 207)
Wallie (Lelystad) -- 17-01-2013 00:40