1 Status of ARM Best Estimate Product CrIS EDR Cal/Val Telecon 7-May-2013 L. Borg, D. Tobin, R. Knuteson, N. R. Nalli with support from our ARM partners.

1

Status of ARM Best Estimate Product

CrIS EDR Cal/Val Telecon7-May-2013

L. Borg, D. Tobin, R. Knuteson, N. R. Nalli

with support from our ARM partners …

Donna Holdridge, Jenni Kyrouac, Jim Mather, Douglas Sisterson

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ARM Best Estimate Sonde Product

Overview:ARM data is being collected at NSA, SGP, & TWP-Manus to validate NPP CrIMSS EDRs

• NSA & SGP: sondes launched 45 minutes prior and 5 minutes prior to overpass• TWP: single sonde launched 15 minutes prior to overpass

Zeroth Order Processing:• Sondes are interpolated onto common pressure grid• MWR PWV scaling applied to sonde RHs & WV mixing ratios• Sondes interpolated to overpass time• Data written to netcdf

Time [UTC}

Example Sonde Pair Launch Timing

Pres

sure

[hPa

]Primary ARM data products used:• sondewnpn: RS-92 balloon-borne sounding

system: Vaisala-processed• mwrlos: microwave radiometer: water liq, &

vapor along los path

Status Phase-1 Sonde Launches

ARM-NSA ARM-SGP ARM-TWPLocation Barrow, Alaska, USA Ponca City,

Oklahoma, USAManus Island, Papua New Guinea

Regime Polar Continent Midlatitude Continent, Rural

Tropical Pacific Warm Pool, Island

Planned N 180 180 90

Launched n1 90 89 78

Launched n2 90 89 ---

Time Frame Jul - Dec 2012 Jul 2012 - Jan 2013 Jul 2012 – May 2013

• Sondes completed at NSA & SGP, but ongoing at TWP-Manus

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Temperature [K]

Pres

sure

[mb]

NSA

Temperature [K]

SGP

Pres

sure

[mb]

Temperature [K]

TWP-Manus

Pres

sure

[mb]

Sonde Profiles

H2O[g/kg]

Pres

sure

[mb]

Approximate Overpass Times•13:00 UTC (04:00 AKST)•21:00 UTC (12:00 AKST)

H2O[g/kg]

Pres

sure

[mb]

Approximate Overpass Times• 08:00 UTC (02:00 CST)• 19:00 UTC (13:00 CST)

• Limited collection sites, but representing a wide range of climatic conditions• Highly accurate measurements

4H2O[g/kg]

Pres

sure

[mb]

Approximate Overpass Times• 03:00 UTC (13:00 PGT)• 15:00 UTC (01:00 PGT)

Pres

sure

[mb]

Altit

ude

[km

]

Interpolated Sondes

5

NSA

5

Sample MWR Measurements: NSA

Time [UTC]

Pres

sure

[mb]

NSA Overpass: 29-Jul-2012 21:31:26 UTC

Time [UTC]

pwv

[cm

]lw

p [c

m]

MWR Data

Time [UTC]

Time [UTC] versus MWR Scale Factor at NSA: mean_mwrsf = 1.018

mwr scale factor

mean=1.018

mwr scale factor

mean=1.0348

mwr scale factor

mean=1.0239

Time [UTC]

mw

r sca

le fa

ctor

NSA

Time [UTC]

mw

r sca

le fa

ctor

SGP

Time [UTC]

mw

r sca

le fa

ctor

TWP

MWR Scale Factors

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• Mean MWR scale factors are close to 1

meanstdev

H2O Difference [g/kg] H2O Difference [g/kg]

Temperature Difference [K]Temperature Difference [K]

Pres

sure

[mb]

NSA SGP

Pres

sure

[mb]

Pres

sure

[mb]

Pres

sure

[mb]

Differences Between Sonde Pairs

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• This analysis does not follow the official 1km/2km layering methodology for reporting statistics

• SGP - The variability in temperature that occurs within 45 minutes is 1°K

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CrIMSS GDAS

CrIMSS and GDAS Matchup

H2O [g/kg]

Pres

sure

[mb]

• This analysis does not follow the official 1km/2km layering methodology for reporting statistics

Pres

sure

[mb]

Temperature [K]

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CrIMSS GDAS

Temperature [K]

Pres

sure

[mb]

RH [%]

Pres

sure

[mb]

CrIMSS and GDAS Matchup

• This analysis does not follow the official 1km/2km layering methodology for reporting statistics

meanstdev

ARMBE Comparisons with CrIMSS & GDAS

Temperature Difference [K]

Pres

sure

[mb]

NSA

ARMBE-CrIMSS

Temperature Difference [K]

Pres

sure

[mb]

ARMBE-GDAS

Temperature Difference [K]

SGP

Pres

sure

[mb]

ARMBE-CrIMSS

Pres

sure

[mb]

Temperature Difference [K]

ARMBE-GDAS

TWP

Temperature Difference [K]

ARMBE-CrIMSS

Pres

sure

[mb]

Temperature Difference [K]

ARMBE-GDAS

Pres

sure

[mb]

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• Analysis uses CrIMSS EDRs with MX Version 5.3 - 6.5• This analysis does not follow the official 1km/2km layering methodology for reporting

statistics

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Next Steps

• ARMBE v0p0 product was distributed internally December 26, 2012

• ARMBE v0p1 product will be distributed to team within the week• Zeroth Order ARMBE product including recent TWP-Manus sondes• Updated sonde averaging scheme• Updated figures• Additional variables saved to netcdf

• ARMBE v1 product under development • Use gdas data in sonde interpolation and to account for scene spatial

variability• Perform vertical averaging and resolution reduction using official 1km/2km

methodology• Use CrIMSS EDRs with more recent MX versions• Include cloud height information

• We recommend that Phase-2 of the sonde launches begin