Applications of future GEO advanced IR sounder for high impact weather forecasting demonstration with regional OSSE

Transcription

1 Applications of future GEO advanced IR sounder for high impact weather forecasting demonstration with regional OSSE Jun Tim Schmit &, Zhenglong Feng Pei Agnes and Robert Atlas C, University of Wisconsin-Madison s so * AOS, University of Wisconsin-Madison &Center for Satellite Applications and Research, NESDIS, NOAA, Madison %AOML, OAR/NOAA The Fifth Asia/Oceanic Meteorological Satellite Users Conference November 2014 Shanghai, China Acknowledgement: This work is supported by NOAA Sandy Supplemental Project 1

2 Outline Rationale for GEO advanced sounders Potential applications i on high h impact weather nowcasting and forecasting Quick regional OSSE demonstration on GEO sounder impact Summary 2

3 Geo orbit uniquely monitors time evolution LEO data have limitation on monitoring due to orbital gap and low temporal resolution. Why GEO Sounder? High temporal resolution is unique aspect of GEO measurements A geostationary hyper-spectral sounder could provide nearly full disk coverage rather than the partial coverage available with polar orbiting sounders. 3

4 Top two reasons for GEO Sounder (1) To forecasters, information on water vapor transportation t ti both horizontally and vertically is key to forecasting severe storms (deep convective, tornadic storms) over CONUS. Only advanced sounding mission from GEO orbit can provide this needed high temporal and high spatial resolution 4-D moisture information. (2) High spatial and temporal moisture profile observations are critical for storm prediction through assimilating into regional or storm scale NWP models over CONUS. For example, forecasts in regional NWP are more sensitive to initialization than microphysics schemes (Wicker et al. 2014) 4

5 TPW LI Improved moisture flux over GOES Sounder Lifted Index indicates: 0< LI stable -3< LI <0 marginally unstable -6< LI <-3 moderately unstable -9< LI <-6 very unstable LI <-9 extreme instability TPW (cm) before storm Storm Period LI (K) before storm LI <-6 Best chances of a severe storm Storm Period 5 GOES Sounder and HES results (preliminary) are based on vertical resolution function analysis

6 FY2E Ch 4 (6.8 um) FY2E BT observations; 15:02 UTC Initialization impact on storm forecasts in regional NWP (Lu et al. 2014) Forecasted FY2E 6.8 µm brightness temperature (BT) images (lower two panels) and observation (upper left panel), yellowcolor indicates drier air. BT (C) Forecasts with GFS analysis as background; 15:00 UTC forecasts Forecasts with GFS as background and simulated GEO moisture soundings from EC analysis; 15:00 UTC forecasts 6

7 Observing System Simulation Experiment t(osse) Current systems Future systems 3DVAR 4DVAR EnKF or combined 7

8 Radiance simulation from ECMWF T um Simulation Observation 144 h i 10/27/ UTC 144 hours since 10/27/ UTC Qualitative validation of simulated radiances from NR with GOES 13 Imager observations, retrievals are also generated Bufr files created for both GEO/LEO AIRS radiances Prepburf files created for both GEO/LEO AIRS sounding retrievals 8

9 About EC nature run ECMWF T1279 (hourly, 15 km resolution) Large scale features are reasonably simulated, even for 108 h forecasts Smallscale features are less reasonable, especially small convective clouds over Amazon River. Ice clouds aretoo cold Too much water cloud 9

10 Hurricane Sandy from T1279 NR Track SLP EC nature run is a little slow for tracking Sandy SPD EC nature run is weak for Sandy intensity 10

11 Orbit comparison: GEO VS LEO GEO AIRS has more usable observations Better coverage Better refresh rate UWRTM: SARTA + cloudy model RAOB: vertical correlative errors considered d Loop is shown in steps of 1 hour for a period of 72 hours for Hurricane Sandy. All simulated from the ECMWF T1279 NR 11

12 Quick rosse design Forecast Model: WRF ARW V3.6.1 Assimilation System: GSI V3.3 Model Domain Horizontal resolution: 16 km Vertical levels: 75 levels Model Top: 10 hpa Time step: 50s Physics Scheme Microphysics: WSM6 scheme Longwave Radiation: RRTMG scheme Shortwave Radiation: RRTMG scheme Planetary Boundary layer: Yonsei University scheme Cumulus Parameterization: Grell scheme Experiment time period: 54 hours: 10/25 18z to 10/28 00z,

13 Experiment design cont Control Run : GTS + Leo AIRS retrievals Experiment: GTS + Geo AIRS retrievals ti Assimilation : 10/27 00 z to 10/27 12 z Forecast: 10/27 12 z to 10/30 12 z Using retrievals in this rosse: (1) Equivalence between radiance assimilation and retrieval assimilation (Migliorini 2012) (2) To avoid technical issues when assimilating GEO AIRS radiances with current assimilation systems used by operational centers 2618z 6h cyc1 3h cyc2 3h cyc3 3h cyc4 3h cyc5 72h forecast Data Data Data Data Data Window time: 1.5hr to +1.5hr Data assimilated il d3 hourly 13

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15 Summary GEO soundings are very useful for high impact weather nowcasting and forecasting EC nature run simulates Hurricane Sandy (2012) track reasonable well although a little slow, but intensity is weak for regional OSSE Preliminary results show improved impact from GEO IR sounder over LEO IR sounder on track forecasts Future work includes more experiments on understanding the better use of high temporal sounding information, especially the moisture sounding information in regional NWP 15