Presentación realizada en la 3rd European Nowcasting Conference, celebrada en la sede central de AEMET en Madrid del 24 al 26 de abril de 2019

Löhnert, Ulrich

Toporov, Maria

English

Agencia Estatal de Meteorología

Maria Toporov (University of Cologne)Ulrich Löhnert (University of Cologne, WWRP DAOS WG co-chair)ENC 2019 | Madrid, Spain  |24.4.2019A new approach for near-real-time monitoring of atmospheric stability, atmospheric water vapor and liquid water https://www.eumetsat.int/ENC 2019 | Madrid, Spain  | M. Toporov, U. Löhnert | 24.4.19Motivation“Seamless Prediction” = nowcasting + short-termWhere will severe convection occur in the next hours?Where is there a high threat for ground fog?Monitor atmospheric stabilityENC 2019 | Madrid, Spain  | M. Toporov, U. Löhnert | 24.4.19Stability Indices (STI)ThunderstormsThunderstormsThunderstormsThunderstormsThunderstormsThunderstormsRadiation FogFog ThreatENC 2019 | Madrid, Spain  | M. Toporov, U. Löhnert | 24.4.19Monitoring of Atmospheric StabilityDemands• Accurate  ABL information• Temporally continuous & good spatial coverage• Clear & cloudy sky• Day / night• Over different land surfacesSEVIRI (MSG, current): • 6 channels• geostationary, „always“ available• ~3 km horiz. Resolution• very limited vertical resolution ENC 2019 | Madrid, Spain  | M. Toporov, U. Löhnert | 24.4.19SEVIRI GII: Global Instability Index SEVIRI IR ImageIndices: KI, KO, Max. Buoyancy, Precip. Water (limited accuracy, only in clear sky conditions)K-IndexENC 2019 | Madrid, Spain  | M. Toporov, U. Löhnert | 24.4.19SEVIRI (MSG, current): • 6 channels• geostationary, „always“ available• ~3 km horiz. res. (nadir)• very limited vertical resolution Expected Improvement with MTG IRS (MTG, from 2021): • 1738 channels with 0.5-0.625 cm-1resolution• geostationary, „always“ available• ~4 km horiz. res. (nadir)• Use 770 channels: CO2 , H2O  absorption and surface sensitivePrincipal Components Analysis use 20 base vectorsENC 2019 | Madrid, Spain  | M. Toporov, U. Löhnert | 24.4.19Further Improvement: Ground-based remote-sensingMicrowave profiler • 14 Channels, 5 elevation angles• High accuracy IWV, LWP• low resolution profiles of T (ABL!) and humidity Evolving network (i.e. E-PROFILE – business case)The prototype Vaisala DIAL system:• Consider 10 humidity levels between 100 and 1900 m• Assumption on absolute humidity uncertainty: 10 % Potential future networkPoint measurements, but network-suitable instruments24/7 unattended, automatic all-weather operationENC 2019 | Madrid, Spain  | M. Toporov, U. Löhnert | 24.4.19ARONCOSMO-REA2COSMO-DE(2 km)COSMO-REA6CORDEX  EUR-11(6.2 km)A virtual Remote sensing Observation Network for continuous, near-real-time monitoring of atmospheric stability(DWD-Extramurale Forschung)High resolution regional reanalysis for Europe and Germany (Bollmeyer et al., 2015)IRS not flying yet, ground-based remote sensing network not yet estbalishedSimulation by using multi-year reanalyses based on COSMO model  (COSMO-REA2)ENC 2019 | Madrid, Spain  | M. Toporov, U. Löhnert | 24.4.19STI-Retrieval for COSMO-REA2 ReanalysisGround-based observationsMWR (Tb)DIAL (q-profile)Geostationary satellite observationsSEVIRI (MSG, 6 channels)IRS (MTG, 20 PCs)COSMO-REA21D, clear & cloudy sky , T, p, q & hydrometeor profilesRetrieval for STI via Neural NetworksRTTOV-gb, RTTOVENC 2019 | Madrid, Spain  | M. Toporov, U. Löhnert | 24.4.19CAPE Times Series in August 2012ENC 2019 | Madrid, Spain  | M. Toporov, U. Löhnert | 24.4.19Contingency Tables, Verfication ParametersRMS=3.32LI_REA2, KLI_NN, KSEVIRIHITSZEROFALSEMISSESHSS – fractional improvement over “chance” forecast; appropriate in case of rare events forecast, when correct forecasts of non-events dominateENC 2019 | Madrid, Spain  | M. Toporov, U. Löhnert | 24.4.19Performance of Single Systems Clear-only Cloudy-onlyIRS & gb sensors alone   ~ 50-75 % skill FT very sensitive to near-surface humidity gradient gb sensors alone outperform IRS ENC 2019 | Madrid, Spain  | M. Toporov, U. Löhnert | 24.4.19Performance of Systems in SynergyCombining sat + gb ~ 80% skillAddition of gbsensors to IRS increase of 5-20 % in skill, FT +40%Clear-onlyENC 2019 | Madrid, Spain  | M. Toporov, U. Löhnert | 24.4.19Performance of Systems in SynergyCloudy-onlyAddition of gbsensors to IRS increase of 20-40 % in skillCombining sat + gb ~ 70-80% skillENC 2019 | Madrid, Spain  | M. Toporov, U. Löhnert | 24.4.19Summary & Outlook• As expected, IRS significantly better than SEVIRI for stability monitoring• Ground-based profilers important for stability monitoring in cloudy cases• IRS can be complemented with ground-based profilers; increased forecast skill 5-40 %  Further questions• Representativeness of ground-based observations?• Required network density to reach which overall accuracy?• Ground-based network vs. even denser near-surface observations?ENC 2019 | Madrid, Spain  | M. Toporov, U. Löhnert | 24.4.19Thank you for your attention!This work was performed within the DWD Extramurale Forschung (EMF) project“A virtual Remote sensing Observation Network for continuous, near-real-time monitoring of atmospheric stability”ENC 2019 | Madrid, Spain  | M. Toporov, U. Löhnert | 24.4.19Ground-based MWRComplementary Weighting FunctionsEbell et.al. 2013MTG – IRS 95% Information below 600 hPawww.eumetsat.intENC 2019 | Madrid, Spain  | M. Toporov, U. Löhnert | 24.4.19Forward model RTTOV-gb• RTTOV: fast RT model developed within NWPSAF• Widely used in the NWP community• Computes brightness temperatures and JacobiansRTTOV ground-based developed by DeAngelis et al. within COST Action TOPROF(http://cetemps.aquila.infn.it/mwrnet/software.html)LBL vs. RTTOV-gbDe Angelis et al., 2016:- Adapting the fast radiative transfer model RTTOV for the assimilation of ground-based microwave radiometer observations, Geosci. Model Dev.RTTOV-gb accuracies better than 0.2 K throughout at zenith observationsENC 2019 | Madrid, Spain  | M. Toporov, U. Löhnert | 24.4.19ACTRIS Cloudnet sites: all equipped with MWRs• Liquid water path• Radiances• Temperature profiles BL• Low-res. humidity profiles

A new approach for near-real-time monitoring of atmospheric stability, atmospheric water vapor and liquid water

https://repositorio.aemet.es/bitstream/20.500.11765/10586/3/OBN7_Toporov_3ENC2019.pdf

A new approach for near-real-time monitoring of atmospheric stability, atmospheric water vapor and liquid water

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