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http://www.ncas.ac.uk This is the footer Modelling of deep convective clouds and orographic triggering of convection during the COPS experiment Ralph Burton, NCAS (Leeds) Alan Gadian, NCAS (Leeds) Victoria Smith, ICAS, (Leeds) Stephen Mobbs, NCAS (Leeds)
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http://www.ncas.ac.uk 1. 15 th July – deep convection. 2. 12 th August – outflows and convergence. 3. Summary. Outline of talk. How well does WRF simulate these cases?
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http://www.ncas.ac.uk Note the location and orientation (SW-NEish) of the storm cloud 15 th July: isolated deep convective cloud From the Science Directory (Evelyne Richard) Summary
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http://www.ncas.ac.uk Observation of convective cloud, 15 th July 15 th July: isolated deep convective cloud From the Science Directory (Evelyne Richard) Summary
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http://www.ncas.ac.uk WRF convective cloud, 15 th July 15 th July: isolated deep convective cloud?
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http://www.ncas.ac.uk WRF: inner domain: 700m resolution Outer domain 6.3km 1 st nest 2.1km
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http://www.ncas.ac.uk Run #MicrophysicsCu Param.Vert. levelsCloud? 1FerrierBetts-Miller81 2FerrierKain-Fritsch121 3FerrierBetts-Miller121 4ThompsonKain-Fritsch121 Sensitivity Tests
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http://www.ncas.ac.uk Ferrier; Betts-Miller WRF: sensitivity tests – CAPE and wind vectors: 15Z
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http://www.ncas.ac.uk WRF: skew-t and wind vectors: 15Z Cloud is quite shallow Isosurface of cloud water mixing ratio = 1E-4 kg/kg
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http://www.ncas.ac.uk Comparison with observational data: AWS locations.
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http://www.ncas.ac.uk Comparison with observational data: 2m temperatures. Many thanks to Simon Hölzl and Alex Göhm Black = obs.; red = WRF temperature time of day
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http://www.ncas.ac.uk 1156m 1000m 669m 798m 842m 962m 507m 667m 928m Many thanks to Simon Hölzl and Alex Göhm Comparison with observational data: 2m temperatures. Black = obs.; red = WRF temperature time of day
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http://www.ncas.ac.uk 1156m 669m Comparison with observational data: 2m RH. Many thanks to Simon Hölzl and Alex Göhm Black = obs.; red = WRF relative humidity time of day
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http://www.ncas.ac.uk Comparison with observational data: vertical profiles. OBS WRF
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http://www.ncas.ac.uk OBSGRID – Objective analysis. Boundary layer RH, outer domain. 06Z, 15 th July With thanks to Cindy Bruyere, NCAR Achern and Hornisgrinde Radiosonde data Objective analysis: forcing the analysis with observations.
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http://www.ncas.ac.uk Orographic triggering: 12 th August Case.
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http://www.ncas.ac.uk Rain water, 2m temps., wind vectors. 1145Z 12 th August
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http://www.ncas.ac.uk Cloud, 2m temps., wind vectors. 1145Z 12 th August
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http://www.ncas.ac.uk Rain water, wind vectors, orogrpahy. 1300Z 12 th August.
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http://www.ncas.ac.uk Relatively cool area Note this cold area is over a roughly 2-D slope 2m temps., wind vectors, orogrpahy. 1300Z 12 th August.
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http://www.ncas.ac.uk Area of high(er) CAPE in the region of the “cloud” location. Zone of convergence at the cloud location. BUT Sensitivity to model Cu and microphysics Other sensitivities… GFS analysis appears to be too dry. WRF does not seem to agree with obs. at higher elevations ( > ~ 850-900m) quite so well: under-predicts the 2m temp and over-predicts the RH: evaporative cooling? ECMWF T799 analysis – ready to try! Objective analysis Conclusions 15 th July
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http://www.ncas.ac.uk Outflow from clouds in model Outflows appear to convergence, and cloud formed as a result Good comparison with remote sensing data Again, model agrees with obs. at lower elevations better than at higher elevations. Need higher temporal resolution runs (output every minute) to isolate the mechanisms of triggering. 12 th August
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