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Atmospheric data for Arctic modeling. John Walsh International Arctic Research Center University of Alaska, Fairbanks Arctic System Modeling Workshop, Montreal, July 2009. Three categories of atmospheric observations:. Routine measurements for input to NWP models
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Atmospheric data for Arctic modeling John Walsh International Arctic Research Center University of Alaska, Fairbanks Arctic System Modeling Workshop, Montreal, July 2009
Three categories of atmospheric observations: • Routine measurements for input to NWP models 2) Special observing networks • Short-duration field campaigns
Three categories of atmospheric observations: • Routine measurements for input to NWP models 2) Special observing networks • Short-duration field campaigns + Value-added products: reanalyses gridded fields (e.g., CRU) Polar Pathfinder products
Routine measurements – in some respects, the Arctic is well-covered • surface synoptic network • rawinsonde network • buoy, ship reports • aircraft reports • satellite measurements (profiles of T, q, wind) • Archived in reanalysis ingest data banks (e.g., PREPBUFR files at NCAR)
Surface station observations Upper-air rawinsonde observations
Reports from commercial, military, and reconnaissance sources 7-days: 01/01/2003 - 01/07/2003
Satellite-derived temperatures 7-days Winds derived from satellite observed cloud drift analysis 7-days
01/01/2003 00Z 6-hour accumulated observations: red: surface station slate blue: upper-air yellow: sat. temp. green: sat. wind violet: aircraft sky blue: ship
01/01/2003 06Z 6-hour accumulated observations: red: surface station slate blue: upper-air yellow: sat. temp. green: sat. wind violet: aircraft sky blue: ship
01/01/2003 12Z 6-hour accumulated observations: red: surface station slate blue: upper-air yellow: sat. temp. green: sat. wind violet: aircraft sky blue: ship
01/01/2003 18Z 6-hour accumulated observations: red: surface station slate blue: upper-air yellow: sat. temp. green: sat. wind violet: aircraft sky blue: ship
Sample PrepBUFR observations: SID=48582 , YOB= 82.85, XOB=194.99, ELV= 0, DHR= 1.883, RPT= 19.883, TCOR=0, TYP=180, TSB=*, T29=562, ITP=99, SQN= 203 PROCN= 2, SAID=*** PMO=******, PMQ=** ---------------------------------------------------------------------------------------------- level 1 obs qmark qc_step rcode fcst anal oberr category ---------------------------------------------------------------------------------------------- PRESSURE (MB) 988.2 2. PREPRO ***** 987.6 987.4 1.6 0. SP HUMIDITY(MG/KG) ******** ****** ***** 234.0 239.0 ******** 0. TEMPERATURE (C) -33.3 2. PREPRO ***** -32.8 -32.8 2.5 0. HEIGHT (METERS) 0.0 2. PREPRO ***** -4.0 -5.0 ******** 0. SID=BAW269 , YOB= 60.00, XOB=340.00, ELV=10058, DHR=-0.550, RPT= 17.450, TCOR=0, TYP=130, TSB=0, T29= 41, ITP=99, SQN= 26 PROCN= 0, SAID=*** RCT= 18.08, PCAT=*****, POAF=***, DGOT=*** ---------------------------------------------------------------------------------------------- level 1 obs qmark qc_step rcode fcst anal oberr category ---------------------------------------------------------------------------------------------- PRESSURE (MB) 262.0 2. PREPRO ***** ******** ******** ******** 6. SP HUMIDITY(MG/KG) ******** ****** ***** 35.0 35.0 ******** 6. TEMPERATURE (C) -62.0 1. PREPACQC 17. -61.1 -60.9 1.7 6. TEMPERATURE (C) -62.0 2. PREPRO ***** -61.1 -60.9 1.7 6. HEIGHT (METERS) 10058.0 2. PREPRO ***** 9708.0 9724.0 ******** 6. U-COMP WIND (M/S) 4.4 1. PREPACQC 17. -2.3 1.8 3.6 6. U-COMP WIND (M/S) 4.4 2. PREPRO ***** -2.3 1.8 3.6 6. V-COMP WIND (M/S) 2.6 1. PREPACQC 17. 4.8 2.1 3.6 6. V-COMP WIND (M/S) 2.6 2. PREPRO ***** 4.8 2.1 3.6 6. WIND DIR (DEG) 240.0 ****** PREPRO ***** ******** ******** ******** 6. WIND SPEED (KNOTS) 10.0 ****** PREPRO ***** ******** ******** ******** 6.
PrepBUFR data 0) Keep (always assimilate) • Good • Neutral or not checked (default) -- e.g., IAOBP T and P obs are flagged as QC=2 • Suspect • Rejected (don’t assimilate) ** Rejected obs. have an additional flag layer indicating justification (e.g., conflicts with a pre-existing QC=0; threshold test failure, etc.) Quality Control Flags
2) Examples of special observing networks • International Arctic Buoy Network ( + Russian NP stations) • Greenland automated weather stations • Trace gas/chemical sampling (NOAA CMDL) • Baseline Surface Radiation Network (BSRN), ARM • International Arctic System for Observing the Atmosphere (IASAO)
IASAO Tiksi, Russia Barrow, Alaska Eureka, Canada Alert, Canada Ny-Alesund, Svalbard Summit, Greenland IASOA Target Observatories
IASAO: International Arctic System for Observing the Atmosphere
3) Short-duration field programs-- process studies for algorithm development, model validation • SHEBA • ATLAS, LAII Flux Study • ARM field campaigns • OASIS • IPY cruises … others
Problem areas • Precipitation, especially solid precip (snowfall, depth, water equivalent) • Clouds • Aerosols • … others