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    The difference between surface and 1000mb geopotential height

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    • vujacicmV
      vujacicm @Gkikas LGPZ
      last edited by vujacicm

      @Gkikas-LGPZ Does this mean that also on Mount Everest can be 1000mb?

      Is here reason, why temperature in Windy is lower then station shows, because is 1142m high?

      Maybe I have troublle to understand difference between pressure and geopotential height. This mean that on top od the mountain can be 1000mb geopotential height, but not 1000mb pressure.

      1 Reply Last reply Reply Quote 0
      • vujacicmV
        vujacicm @Gkikas LGPZ
        last edited by vujacicm

        @Gkikas-LGPZ Looks like that air pressure and geopotential height is not the same thing. This mean that on top of Mounth Eversr can ne 1000mb geopotential heights, but not air pressure.

        If I am right, air pressure tells you, how away you are from sea level and geopotential height, how away you are from surface.

        CaefixC 1 Reply Last reply Reply Quote 0
        • CaefixC
          Caefix @vujacicm | Premium
          last edited by

          @vujacicm https://en.wikipedia.org/wiki/Geopotential_height
          https://en.wikipedia.org/wiki/Pressure_altimeter

          vujacicmV 1 Reply Last reply Reply Quote 0
          • vujacicmV
            vujacicm @Caefix
            last edited by

            @Caefix Here is the map of Himalayas.

            Surface -13 Celzius
            1000005921.jpg

            850mb 17 Celzius
            1000005922.jpg

            How everywhere higher then Himalayas surface temperature can be higher then on surface?

            idefix37I 2 Replies Last reply Reply Quote 0
            • idefix37I
              idefix37 Sailor Moderator @vujacicm
              last edited by

              @vujacicm
              The temperature at surface is the temperature at ground level (about 2m). The temperature variation is important, the sun heating the soil during the day and the soil cooling during the night due to radiative effect.
              The temperature at 850hPa is the air mass temperature at this elevation i.e. in free atmosphere. The variation during one day is not so important.

              vujacicmV 1 Reply Last reply Reply Quote 0
              • vujacicmV
                vujacicm @idefix37
                last edited by vujacicm

                @idefix37 It's not 18 degress too hot for 9000m elevation or even higher?

                1 Reply Last reply Reply Quote 0
                • idefix37I
                  idefix37 Sailor Moderator @vujacicm
                  last edited by

                  @vujacicm said in The difference between surface and 1000mb geopotential height:

                  850mb 17 Celzius

                  850hPa is not 9000m, only 1500m !
                  By the way, here we are on the forum community of windy.com. So why all your posts show screenshots from another weather app ?!

                  vujacicmV 1 Reply Last reply Reply Quote 0
                  • vujacicmV
                    vujacicm @idefix37
                    last edited by vujacicm

                    @idefix37 Mounth Everest is 9000m height. How can there be 850mb on 1500m?

                    On Windy is simillar

                    Surface -5
                    1000005940.jpg

                    850mb 20
                    1000005941.jpg

                    On Meteoblue I can show the temperature on the point, on Windy I can only show temperature with colours.

                    idefix37I 2 Replies Last reply Reply Quote 0
                    • idefix37I
                      idefix37 Sailor Moderator @vujacicm
                      last edited by idefix37

                      @vujacicm
                      See what is the vertical structure of the grid points in a weather model

                      https://community.windy.com/topic/5014/windspeed-and-direction-different-heights/2?_=1724610259822

                      vujacicmV 1 Reply Last reply Reply Quote 0
                      • idefix37I
                        idefix37 Sailor Moderator @vujacicm
                        last edited by idefix37

                        @vujacicm
                        In Windy, you can see precisely the temperature of a point.

                        C2709D9C-EFBA-45F5-BEF7-EA535AB71649.jpeg

                        vujacicmV 1 Reply Last reply Reply Quote 0
                        • vujacicmV
                          vujacicm @idefix37
                          last edited by vujacicm

                          @idefix37 I am to slow with screenshot. It's gone, before I scan.

                          1 Reply Last reply Reply Quote 0
                          • vujacicmV
                            vujacicm @idefix37
                            last edited by

                            @idefix37 You are showing me the winds. What about temperature? Does 20 degress on 850mb still cross surface of Mounth Everest?

                            idefix37I 1 Reply Last reply Reply Quote 0
                            • idefix37I
                              idefix37 Sailor Moderator @vujacicm
                              last edited by idefix37

                              @vujacicm
                              The winds ? The title of my screenshot is Temperature and -7°C is not a wind speed !

                              vujacicmV 1 Reply Last reply Reply Quote 0
                              • vujacicmV
                                vujacicm @idefix37
                                last edited by vujacicm

                                @idefix37 This, what you give me, is about winds

                                https://community.windy.com/topic/5014/windspeed-and-direction-different-heights/2?_=1724610259822

                                I see that understanding geopotential height is not easy, that's reason, why a lot of questions.

                                idefix37I 1 Reply Last reply Reply Quote 0
                                • idefix37I
                                  idefix37 Sailor Moderator @vujacicm
                                  last edited by idefix37

                                  @vujacicm
                                  I should have only shown this graph.

                                  A145EAC6-BC6A-4400-84C2-ECE8EEA6D692.jpeg

                                  It should allow you to understand what is the temperature at 850hPa above Mount Everest.
                                  Note also there is sometime a big difference between the real elevation and the model elevation.

                                  vujacicmV 1 Reply Last reply Reply Quote 0
                                  • vujacicmV
                                    vujacicm @idefix37
                                    last edited by vujacicm

                                    @idefix37 So, model elevation shows that there is 18 Celzius let's say 500m above Mount Everest surface?

                                    idefix37I 1 Reply Last reply Reply Quote 0
                                    • idefix37I
                                      idefix37 Sailor Moderator @vujacicm
                                      last edited by idefix37

                                      @vujacicm

                                      In the mountains, global models are wrong because their orography model is too coarse compared to the reality of the terrain.
                                      It is exactly what @Gkikas-LGPZ explained to you in his post here Bové
                                      You should therefore not try to focus on high mountains with global models.

                                      vujacicmV 3 Replies Last reply Reply Quote 0
                                      • vujacicmV
                                        vujacicm @idefix37
                                        last edited by vujacicm

                                        @idefix37 What I see on 850mb, I can say that on that level the surface of this mountain is adiabaticaly heated on this level. If this is not true, then is really just wrong, how you say.

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                                        • vujacicmV
                                          vujacicm @idefix37
                                          last edited by

                                          @idefix37 It looks like you are right, if geopotential is lower then mountain, it will not show right

                                          https://www.theweatherprediction.com/charts/850/

                                          1 Reply Last reply Reply Quote 0
                                          • vujacicmV
                                            vujacicm @idefix37
                                            last edited by

                                            @idefix37 Situation is like this. I live in area, where mountains around are lower then 3000m. So, I can only use surface or 700mb geopotential. Lower will show wrong.

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