Institute of Meteorology and Climatology University of HannoverEGS Nice, April 2003 Christoph Leifeld ADWICE Advanced Diagnosis and Warning system for aircraft ICing Environments C. Leifeld, T. Hauf Institute of Meteorology and Climatology (IMUK) University of Hannover, Germany A. Tafferner DLR Oberpfaffenhofen, Institute of Atmospheric Physics Wessling, Germany H. Leykauf DWD, German Weather Service, Business Unit Aviation Offenbach, Germany

Institute of Meteorology and Climatology University of HannoverEGS Nice, April 2003 Christoph Leifeld Aircraft icing – a severe threat in aviation Icing is caused by supercooled liquid water drops cloud water drops  <50  m freezing drizzle  50  m – 500  m freezing rain  >500  m supercooled liquid drops hit and freeze on wings, propellers, etc. ice accretion rates up to several mm per minute are observed, ice accretion depends on atmospheric and aircraft parameters  severe reduction of aircraft performance is possible

Institute of Meteorology and Climatology University of HannoverEGS Nice, April 2003 Christoph Leifeld Ice accretion DLR research aircrafts

Institute of Meteorology and Climatology University of HannoverEGS Nice, April 2003 Christoph Leifeld Minimizing the icing hazard Ice removal: Technical anti-icing systems: heating the leading edges and using inflatable boots Ice avoidance: Meteorologists have to diagnose and forecast clouds and precipitation with icing potential supercooled liquid water (SLW) and its constituents –cloud drops, –drizzle and –rain. Ice removal: Technical anti-icing systems: heating the leading edges and using inflatable boots Ice avoidance: Meteorologists have to diagnose and forecast clouds and precipitation with icing potential supercooled liquid water (SLW) and its constituents –cloud drops, –drizzle and –rain.

Institute of Meteorology and Climatology University of HannoverEGS Nice, April 2003 Christoph Leifeld How to forecast hazardous icing clouds ? Current NWP models do not forecast the SLWC with sufficient accuracy  Nowcasting systems like IIDA (NCAR) and ADWICE (IMUK, DLR, DWD) are under development. They rely on instant observations and modelling data. ADWICE uses the Local Model (LM) of the German Weather Service (DWD) full domain 325  325 grid points; 35 levels 7 km horizontal grid spacing humidity, temperature model data and parameterisation of moist convection observation data (SYNOP, METAR, RADAR)  Using empirical relationships between the data, ADWICE calculates location, intensity and type of icing. Current NWP models do not forecast the SLWC with sufficient accuracy  Nowcasting systems like IIDA (NCAR) and ADWICE (IMUK, DLR, DWD) are under development. They rely on instant observations and modelling data. ADWICE uses the Local Model (LM) of the German Weather Service (DWD) full domain 325  325 grid points; 35 levels 7 km horizontal grid spacing humidity, temperature model data and parameterisation of moist convection observation data (SYNOP, METAR, RADAR)  Using empirical relationships between the data, ADWICE calculates location, intensity and type of icing.

Institute of Meteorology and Climatology University of HannoverEGS Nice, April 2003 Christoph Leifeld satellite data LWC... Icing Volumes Location (3D) Type (e.g. drops  ) Intensity (LWC) model humidity radar data SYNOP & METAR model temperature Nowcasting system ADWICE convection „Tiedtke“

Institute of Meteorology and Climatology University of HannoverEGS Nice, April 2003 Christoph Leifeld ADWICE schedule Start ADWICE PIA 00 UTC Start LM Start ADWICE Prognostic Icing Algorithm (PIA) PIP Start LM Prognostic Icing Product (PIP) PIP Actual time: 03:15 UTC

Institute of Meteorology and Climatology University of HannoverEGS Nice, April 2003 Christoph Leifeld Prognostic Icing Algorithm (ADWICE PIA) freezingconvectivestratiformgeneral Search/check model data for criteria for icing clouds of different types Prognostic Icing Product (PIP) ADWICE PIP FL UTC model data temperature relative humidity convection „Tiedtke“

Institute of Meteorology and Climatology University of HannoverEGS Nice, April 2003 Christoph Leifeld ADWICE schedule Start ADWICE PIA 00 UTC Start LM Start ADWICE Prognostic Icing Algorithm (PIA) PIP Start LM Prognostic Icing Product (PIP) PIP DIP Start ADWICE Diagnostic Icing Algorithm (DIA) Available data at 06UTC: PIP, SYNOP, METAR, RADAR Diagnostic Icing Product (DIP) Actual time: 06:00 UTC

Institute of Meteorology and Climatology University of HannoverEGS Nice, April 2003 Christoph Leifeld Diagnostic Icing Algorithm (ADWICE DIA) observation data SYNOP/METAR RADAR give information about possible atmospheric structures with icing clouds (cloud/weather/icing types)... model data temperature relative humidity convection „Tiedtke“ Search/check model data for typical structure (observation data) to get more detailed information Compare with PIP

Institute of Meteorology and Climatology University of HannoverEGS Nice, April 2003 Christoph Leifeld ADWICE PIP is confirmed, rejected, changed or icing type is set Check cloud cover cloud base Correction of 3D cloud/icing position reject cloud/icing set cloud/icing freezingconvectivestratiformgeneral ADWICE Diagnostic Icing Product (DIP) with four different icing types: Four different icing types: freezing convective stratiform general ADWICE DIP FL UTC

Institute of Meteorology and Climatology University of HannoverEGS Nice, April 2003 Christoph Leifeld SYNOP UTC N  4

Institute of Meteorology and Climatology University of HannoverEGS Nice, April 2003 Christoph Leifeld Icing at UTC ADWICE DIP FL40ADWICE PIP FL40 Four different icing types: freezing convective stratiform general

Institute of Meteorology and Climatology University of HannoverEGS Nice, April 2003 Christoph Leifeld PIREPS – important data source for validation Deficiencies of PIREPs Reporting and event time may differ, location and flight level very often are not precisely given, coding errors. Problems with validation of ADWICE Number of european PIREPs is too small For more information and other methods to validate ADWICE see poster „Methods of validating ADWICE“ AS11-1MO4P-0862 Deficiencies of PIREPs Reporting and event time may differ, location and flight level very often are not precisely given, coding errors. Problems with validation of ADWICE Number of european PIREPs is too small For more information and other methods to validate ADWICE see poster „Methods of validating ADWICE“ AS11-1MO4P-0862

Institute of Meteorology and Climatology University of HannoverEGS Nice, April 2003 Christoph Leifeld Conclusions The current version of ADWICE uses model data, SYNOP, METAR and radar data. Detection of cloudy and cloud free regions Improvement in forecasting and diagnosing clouds with SLWC Validation of ADWICE is done in single cases only because of lack of PIREPS. More PIREPS are needed. Currently ADWICE is in preoperational use at the DWD and provides helpful information. The current version of ADWICE uses model data, SYNOP, METAR and radar data. Detection of cloudy and cloud free regions Improvement in forecasting and diagnosing clouds with SLWC Validation of ADWICE is done in single cases only because of lack of PIREPS. More PIREPS are needed. Currently ADWICE is in preoperational use at the DWD and provides helpful information.