Atmospheric circulation and its effect on Arctic sea ice ...
Atmospheric data for Arctic modeling
description
Transcript of Atmospheric data for Arctic modeling
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:
1) Routine measurements for input to NWP models
2) Special observing networks
3) Short-duration field campaigns
Three categories of atmospheric observations:
1) Routine measurements for input to NWP models
2) Special observing networks
3) 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
Surface ship and ocean buoy reports
7-days
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
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
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
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= 26PROCN= 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.
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= 203PROCN= 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.
PrepBUFR dataQuality Control Flags
0) Keep (always assimilate)1) Good2) Neutral or not checked (default) -- e.g.,
IAOBP T and P obs are flagged as QC=23) Suspect4) 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.)
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)
Tiksi, Russia
Alert, Canada
Barrow, Alaska
Eureka, Canada
Summit, Greenland
Ny-Alesund, Svalbard
IASOA Target Observatories
IASAO
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