


In-situ report Precipitation Surface Temperature and humidity Temperature and humidity profiles AMDAR GPS ZTD Lidar Bertrand Calpiniwith input from, Roger Saunders,Richard Assmann, Stewart Taylor, Gemma Bennitt
1. Rainfall Intensity • Final report on the WMO CIMO webpage
Field Intercomparison of Thermometer Screens/Shields and Humidity Measuring Instruments (17*2 screens) LBOM VROT SDAV LCOC LLAN VYOU VTHY SCAE VDAV SYOU VEIG SSOC
Field Intercomparison of Thermometer Screens/Shields and Humidity Measuring Instruments
Field Intercomparison of Thermometer Screens/Shields and Humidity Measuring Instruments Differences in the time of occurrence of daily maximum temperatures
Gardaia Results • Even some low-cost screen appear with very good performance • Consequences for climate services: • Maximum daily temperature delay: up to 3hrs • Maximum temperature error: up to 1.5deg • Final report on the WMO CIMO webpage
3. Radiosonde 8th WMO International Radiosonde Comparison. Yangjiang, Guangdong, China 12 July – 3 August 2010 Participants: 11 manufacturers from China, Finland, France, Germany, Japan, Korea, South Africa, Switzerland, USA
Tropical/subtropical moist conditions Tropopause & 16km Temperature >> -90deg
Yangjiang Results • Unprecedented performances achieved with QRS • No pressure sensor needed anymore for GPS radiosonde with a direct impact on lowering the cost of radiosonde • Intercomparison results used to facilitate selection of systems for national purposes, minimizing additional performance testing on a national level (WTO procedures). • Recommendations on vendors to improve their operational radiosonde >>> Final report on the WMO CIMO webpage
What is GRUAN? • GCOS Reference Upper Air Network • Network for ground-based reference observations for climate in the free atmosphere in the frame of GCOS • Initially 15 stations, envisaged to be a network of 30-40 sites across the globe • See www.gruan.org for more detail
GRUAN goals • Maintain observations over several decades for accurately estimating climate variability and change • Focus on characterizing observational biases, including complete estimates of measurement uncertainty • Ensure traceability of measurements by comprehensive metadata collection and documentation • Ensure long-term stability by managing instrumental changes • Tie measurements to SI units or internationally accepted standards • Measure a large suite of co-related climate variables with deliberate measurement redundancy Priority 1: Water vapor, temperature, (pressure and wind) Priority 2: Ozone, clouds, …
Monitoring with GPS-RO Vaisala RS92: (COSMIC - RS92)/RS92 SIPPICAN (USA): (COSMIC – SIPP)/SIPP Co-located COSMIC and radiosonde refractivity (3 hrs, 300 km) Very small bias Sonde’s understimate humidity
E-AMDAR: Network Developments 1. 1st Nov 2010 - EZY fleets providing data over UK domain and selected European airports. Software installed on BAW A319 (LCY – SNN – JFK). But when a volcano erupts coverage is reduced! 26
AMDAR reports from Alaskan Airlines received from 25 March 2011 an extra 110 aircraft reporting ~10% increase in AMDAR reports globally 230 dropsonde reports over North Pacific during March 2011 – good quality 57% reduction of Canadian AMDARs over 2 years, but levelled-off recently New Canadian ADS data received from 4 March 2011 over western North Atlantic Some stats
Ground-based GPSObservations available from E-GVAP http://egvap.dmi.dk
Ground-based GPS NAE and UK models: • ~18 000 zenith total delay (ZTD) observations assimilated into NAE model per day, ~1400 in UK models. • Recent study focusing on heavy rainfall events with UK4 model showed 10.9% increase in ETS for 6 hour precip accumulation when ZTDs assimilated. Global model: • Trials of assimilating ZTD into global NWP model underway • Met Office and Czech republic now produce global near real-time ZTD observations (not yet available on GTS)
Met office Observation Monitoring – some notable events 2010/11 Volcanic ash episode in April 2010: few AMDARs, but more TEMPs - looked for changes in temperature bias at TEMP stations (as biased AMDARs removed) - no significant changes seen Loss of ~40% Canadian sonde winds due to demise of Loran-C on 1/08/10 - impact minimised by CMC producing winds at either 00Z or 12Z at nearby stations Antarctic Concordiasi campaign Sep-Nov 2010 - 560 dropsondes received and assimilated at the Met Office - >50000 balloon winds + temps received/assimilated from 19 gondola balloons AMDAR data over UK increased by 65% on 1/11/10 due to EasyJet data (for a 6-month trial period) - quality similar to other E-AMDAR data E-AMDAR processing problems 28-29 Nov 2010 - few AMDARs on 28 Nov, but old data queued & sent on 29 Nov, resulting in rms o-b vector wind 50% higher (10% for assim’d data) than usual in 12UTC run & probable degradation in forecast 2Greenland stations’ TEMP reports corrupted since January 2011 - - data missing 700-100hPa from stations 04220 & 04270 at Met Office (& MeteoFrance) due to coding errors in reports Winds from 102 European wind profilers/weather radars now assimilated at Met Office - Norwegian WRWP wind quality improved in spring 2010, but Spanish WRWP quality still poor (no Finnish winds assimilated 2 Nov – 8 Dec 2010, as profiles received in reverse height order)
Issues for NWP • Transition to BUFR for radiosondes provide new opportunities • Global GPS total zenith delay • In-situ soil moisture and temp • Common format for precip radar data • To improve estimates of solid precipitation and develop guidance on the accuracy and temporal resolution of solid precipitation parameters • New observations needed for mesoscale
DAOS-WG statement on need for additional in-situ observations There is increasing evidence based upon results from A-TREC, TPARC, AMMA (in the form of OSEs, adjoint-based observation impact studies, and analysis uncertainty estimates) to recommend, if feasible, increases in observations from: • Commercial aircraft over the N. Pacific, N. Atlantic, and the S. Hemisphere in general. • Additional soundings from certain coastal radiosondes, including those in eastern Siberia, and perhaps selected stations in polar regions, Africa, and South America. to improve NWP forecasts in the 2-5 day timeframe.