Presentation on theme: "1 September 11, 2011 WWRP MWFR Meeting, FU Berlin, Germany The Convective and Orographically-induced Precipitation Study (COPS) Goal: Advance the quality."— Presentation transcript:
1 September 11, 2011 WWRP MWFR Meeting, FU Berlin, Germany The Convective and Orographically-induced Precipitation Study (COPS) Goal: Advance the quality of forecasts of orographically-induced convective precipitation by 4D observations and modeling of its life cycle quality Quantitative Precipitation Forecasting (QPF) and verification Probabilistic QPF (PrQPF): - Uncertainty - Predictability forecasts Focus on: - Nowcasting to short-range QPF - High-spatial and temporal resolution (extensive research on convection-permitting models) and Research at the interface of observations and modeling using the key tool data assimilation: - Model initialization for case studies - Observing system impact studies - Advanced (ensemble) reanalyses for investigation of model physics and predictive skill - Predictability Implementation and test of a stochastic EnKF at IPM convective Field phase throughout summer from June to August 2007 4D observations Synergy of state-of-the-art remote sensing and in-situ instruments: - Densified obs., e.g., Joint COPS-D-PHASE (JDC) data set - Upstream and regional observations by 9 aircraft - 5-min Rapid Scan Service of MSG-8 by EUMETSAT - Unique multi-wavelength passive-active sensor synergy - 9-month operation of the ARM Mobile Facility (AMF) - Demonstration of new observing systems, particularly scanning lidar -> Data set allows in-depth analysis of process chain -> Open data policy, available for international research, see www.uni-hohenheim.de/cops with further linkswww.uni-hohenheim.de/cops modeling of its life cycle Unique collaboration with forecast centers, e.g., DWD, Météo- France, Meteo Swiss, UK Met Office, and research centers: - Real-time, multi-model ensemble runs coordinated via WWRP Forecast Demonstration Project D-PHASE - Case studies with operational and research models orographically-induced Low-mountain area: - Located in southwestern Germany/eastern France - Characteristic for the landscape in middle Europe - Area with extreme precipitation prone to flooding and thunderstorms - Characterized by poor forecast skill
2 COPS QJRMS Special Issue See http://onlinelibrary.wiley.com/doi/10.1002/qj.v137.1s/issuetoc (21 papers)http://onlinelibrary.wiley.com/doi/10.1002/qj.v137.1s/issuetoc The COPS Overview Paper (Wulfmeyer et al. QJRMS 2011) has been identified as New Hot Paper in Geosciences (see http://sciencewatch.com/dr/nhp/2011/11sepnhp/11sepnhpWulf)http://sciencewatch.com/dr/nhp/2011/11sepnhp/11sepnhpWulf Next COPS Workshop tentatively planned from March 28-30, 2012. Title: „The predictability of convective precipitation in orographic terrain.“ Email sent to ISSC Final report in preparation in collaboration with ISSC. Delivery at end of 2011.
3 September 11, 2011 WWRP MWFR Meeting, FU Berlin, Germany Major COPS Results and Conclusions 1) Logistics: Surface data collection, harmonization, and quality control GRIB1 Tigge+ table for CP models, common visualization tools Common lidar and radar data formats Air traffic control Data base
4 September 11, 2011 WWRP MWFR Meeting, FU Berlin, Germany Major COPS Results and Conclusions 2)Processes: Evapotranspiration nearly independent of soil moisture, thus mainly controlled by vegetation. CAPE higher (moisture convergence), CIN lower over mountain ranges. Thermodynamically-induced flow decisive for convection initiation and modification of frontal systems under all forcing conditions. Diurnal cycle of precipitation is likely due to a preconditioning of lower troposphere by shallow convection leading to more severe and less to mountain flow-coupled convection in the late afternoon.
5 September 11, 2011 WWRP MWFR Meeting, FU Berlin, Germany The COPS Summer in Perspective Diurnal cycle in good agreement with climatology. Phase shift between CI and precipitation maximum amounts to about 10 h (Wulfmeyer et al. QJRMS 2011). Diurnal cycle of convection initiation (Weckwerth et al. QJRMS 2011). Diurnal cycle of precipitation for June, July, and August, as well as average.
6 September 11, 2011 WWRP MWFR Meeting, FU Berlin, Germany IOP4b, June 20, 2007: Meteorological Conditions Movie of radar, GPS, MSG composite, resolution: 15 min
7 September 11, 2011 WWRP MWFR Meeting, FU Berlin, Germany Major COPS Results and Conclusions 3) Model performance and verification: Indications that models overestimate transpiration at low soil moisture (root depth, root water uptake). Boundary layer to deep over mountains, probably too strong vertical mixing. Thermodynamically-induced flows partly resolved, vertical wind too low in convergence zones Windward-lee effect due to incorrect simulation of flow distorsion in low-mountain regions and resulting displacement of convergence zone triggering CI at wrong locations. Clear improvement of diurnal cycle of precipitation and QPF by CP models. Main remaining systematic errors in QPF due to deficiencies of aerosol-cloud-precip microphysics?
8 September 11, 2011 WWRP MWFR Meeting, FU Berlin, Germany Major COPS Results and Conclusions Comparison between water vapor DIAL and D-PHASE models
9 September 11, 2011 WWRP MWFR Meeting, FU Berlin, Germany Meteo Swiss COSMO7 with parameterization of deep convection, 7-km grid resolution Meteo Swiss COSMO2 without parameterization of deep convection, 2.2 km grid resolution COPS Precipitation Statistics COPS precipitation climatology (June to August, 2007). 3-month integrated precipitation of model - observations. Convection-permitting models reduce the windward-lee effect and improve the simulation of the diurnal cycle of precipitation.
10 September 11, 2011 WWRP MWFR Meeting, FU Berlin, Germany The COPS Summer in Perspective Diurnal cycle of precipitation (Bauer et al. QJRMS 2011).
11 September 11, 2011 WWRP MWFR Meeting, FU Berlin, Germany First COPS Verification Study of Convection- Permitting (CP) Models FSS shows consistent superior performance of convection- permitting (CP) COSMO2 over COSMO7 but no clear signal for COSMO-DE (Bauer et al. QJRMS 2011). Forecast initial time: 0 UTC Verification time period: 6-18 UTC The Fractions Skill Score (FSS, Roberts and Lean MWR 2008) is an example of a fuzzy verification score useful for high-resolution models. CP
12 September 11, 2011 WWRP MWFR Meeting, FU Berlin, Germany Major COPS Results and Conclusions 4) Demonstration of new Obs.: Water-vapor and temperature lidar provided previously unachieved vertical and temporal resolution as well as accuracy. GPS STD and tomography very useful for studying moisture variability. VERA and C-band Doppler radar (partly dual-Doppler) applied for detection of convergence zones. Combination of ground-based and airborne sensors investigated aerosol-cloud microphysics. Lidar aerosol data improved the simulation of precipitation during Saharian dust outbreak over COPS area. Much more can be exploited with the COPS data set, emphasis should be set on studying ABL and microphysics. New lidar technology available for long-term operational measurements.
13 Major COPS Results and Conclusions 5) Data assimilation and predictability: Positive impact of the assimilation of GPS STD on QPF. Positive impact of Doppler radar and reflectivity. 3DVAR provides benchmark for DA systems on the CP scale Orography can increase the predictability of convection. The lead time is not limited by the lifetime of convective cells but by the lifetime of the forcing conditions leading to convection. Multi-model ensemble provided improved simulation of convective cells (14 h lead time). COPS and D-PHASE data can be used as DA testbed and IMRE but test and comparison of different DA techniques still open. More impact studies possible. COPS-D-PHASE data set unique for verification studies.