CERES Surface Validation Update Uncertainty Study · Langley%Research%Center%Science%Directorate%...

CERES Science Team Mee.ng – Sep 26-‐28 2017, Goddard, MD Langley Research Center Science Directorate

CERES Surface Validation Update &

Uncertainty StudyDavid Rutan1, Seiji Kato2, Fred Rose1, David Doelling2

Bill Smith2, Tom Caldwell1, Cristian Mitrescu1

1 SSAI, Hampton, VA2 NASA Langley Research Ctr, Hampton, VA

•  Show how to access valida.on data. •  Summarize SYN1Deg & EBAF –surface results. •  Describe a study determining sensi.vity of uncertainty

(RMS) to spa.al variability of surface sites.

(All biases are based on Calcula.on – Observa.on)


h"ps://ceres-‐tool.larc.nasa.gov/ord-‐tool CERES Data Access


h"p://ceres-‐iprod.larc.nasa.gov/cave2

Sfc LW Down Bias Sfc SW Up EBAF-‐sfc LW

Down ObservaFon EBAF-‐sfc Ed2.8

MERRA EBAF-‐sfc Ed2.8 MERRA

EBAF-‐surface & MERRA ValidaFon Access


Available Surface ValidaFon Sites

Surface ValidaFon Summary


Longwave Surface Irradiance Down (SYN1Deg Ed4) (2000/02 -‐ 2016/12)

Hourly

Monthly

Land

Land

Buoy

Buoy


Hourly

Shortwave Surface Irradiance Down (SYN1Deg Ed4 ) (2000/02 -‐ 2016/12)

Monthly

Land Buoy

Buoy Land


Surface Irradiance Down (EBAF-‐Surface Ed4) Land Sites (2000/02 -‐ 2016/12)

Shortwave Surface Bias (EBAF-Observation)

-40 -20 0 20 40Delta SW (Calc-Obs) (W/m2)

0

200

400

600

Coun

t

Obs Mean: 183.4Bias EBAF Ed2.8: -0.87Bias EBAF Ed4: -0.80RMS Ed2.8: 11.51RMS Ed4: 11.54N: 4959.

EBAF Ed4 EBAF Ed2.8

/SCF2/CERES/sarb/rose/maf/data/PRODUCT/V201507/SFC_EBAF.Ed28.V3.A006.V201507.200003-201502.hdf/SCF2/CERES/sarb/rose/Ed4_SFC_EBAF/data/PRODUCT/LM9/SFC_EBAF.Ed4.LM9.200003-201602.hdf

Longwave Surface Bias (EBAF-Observation)

-40 -20 0 20 40Delta LW (Calc-Obs) (W/m2)

0

100

200

300

400

500

Coun

t

Obs Mean: 317.9Bias EBAF Ed2.8: 0.82Bias EBAF Ed4: -0.04RMS Ed2.8: 10.00RMS Ed4: 9.75N: 5114.

EBAF Ed4EBAF Ed2.8

/homedir/drutan/EBAF-val/ami:/homedir/drutan/EBAF-val/pltebf3n4.pro Mon Sep 25 15:04:34 2017

EBAF Ed2.8 & EBAF Ed4 LM9 "Land" Group, 36 Sites


Surface Irradiance Down (EBAF-‐Surface Ed4) Land Sites (2000/02 -‐ 2016/12)

SW Surface Down Deseasonalized Anomalies

2000 2002 2004 2006 2008 2010 2012 2014 2016Year/Month

-20

-10

0

10

20

SW A

nom

alie

s (W

m-2

)

0

10

20

30

40

# Sites Used Per Month

ρ Ed4 & Obs: 0.98ρ Ed4 & #sites: 0.04

ObservationsEBAF Ed4

LW Surface Down Deseasonalized Anomalies

2000 2002 2004 2006 2008 2010 2012 2014 2016Year/Month

-20

-10

0

10

20

LW A

nom

alie

s (W

m-2

)

0

10

20

30

40


ρ Ed4 & Obs: 0.98ρ Ed4 & #sites: 0.50


"Land" Group, 36 Possible Sites

/homedir/drutan/EBAF-val/pltebf4ts Fri Jun 30 08:31:45 2017


Surface Irradiance Down EBAF-‐Surface Ed4 Buoys (2000/02 -‐ 2016/12)



0

50

100

150

200

250

300

Coun

t

Obs Mean: 230.2Bias EBAF Ed2.8: 3.53Bias EBAF Ed4: 4.68RMS Ed2.8: 11.37RMS Ed4: 11.61N: 3145.

EBAF Ed4 EBAF Ed2.8

/SCF2/CERES/sarb/rose/maf/data/PRODUCT/V201507/SFC_EBAF.Ed28.V3.A006.V201507.200003-201502.hdf/SCF2/CERES/sarb/rose/Ed4_SFC_EBAF/data/PRODUCT/LM9/SFC_EBAF.Ed4.LM9.200003-201602.hdf



0

50

100

150

200

250

Coun

t

Obs Mean: 393.4Bias EBAF Ed2.8: -0.80Bias EBAF Ed4: 0.74RMS Ed2.8: 5.74RMS Ed4: 5.55N: 1201.

EBAF Ed4EBAF Ed2.8

/homedir/drutan/EBAF-val/pltebf3n4 Mon Sep 25 15:06:05 2017

EBAF Ed2.8 & EBAF Ed4 LM9 Buoy Group, 46 Sites


Surface Irradiance Down EBAF-‐Surface Ed4 Buoys (2000/02 -‐ 2016/12)

SW Surface Down Deseasonalized Anomalies

2000 2002 2004 2006 2008 2010 2012 2014 2016Year/Month

-30

-20

-10

0

10

20

30

SW A

nom

alie

s (W

m-2

)

0

05

10

15

20

25

30


ρ Ed4 & Obs: 0.83ρ Ed4 & #sites: 0.32


LW Surface Down Deseasonalized Anomalies

2000 2002 2004 2006 2008 2010 2012 2014 2016Year/Month

-30

-20

-10

0

10

20

30

LW A

nom

alie

s (W

m-2

)

0

05

10

15

20

25

30


ρ Ed4 & Obs: 0.94ρ Ed4 & #sites: 0.25


Buoy Group, 46 Possible Sites

/homedir/drutan/EBAF-val/pltebf4ts Thu Jul 6 08:35:42 2017


SYN1Deg Longwave Shortwave

All in Wm-‐2 Land Buoy Land Buoy Ed3 Ed4 Ed3 Ed4 Ed3 Ed4 Ed3 Ed4

Observed Mean 317 396 183 235 Bias -‐3.1 1.3 -‐1.9 2.9 1.9 -‐1.2 3.7 -‐1.2 RMS 10.7 10.3 5.0 5.8 11.8 11.2 10.4 9.9 N (Months) 5125 943 5125 2295

EBAF-‐surface Longwave Shortwave All in Wm-‐2 Land Buoy Land Buoy

Ed2.8 Ed4 Ed2.8 Ed4 Ed2.8 Ed4 Ed2.8 Ed4 Observed Mean 318 393 183 230 Bias 0.8 -‐0.0 -‐0.8 0.7 -‐0.9 -‐0.8 3.5 4.7 RMS 10.0 9.8 5.7 5.6 11.5 11.5 11.4 11.6 N (Months) 5114 1201 4959 3145

Monthly Mean Bias/RMS for SYN1deg & EBAF-Surface


Spatial Uncertainty Analysis of Surface Validation




0

50

100

150

Coun

t

Obs Mean: 308.8Bias EBAF: -2.30RMS EBAF: 9.43N: 1283.Avg Mean: 309.2Avg Bias: -2.28Avg RMS: 3.41Avg N: 192.0

EBAFAvg Sites 1st

/homedir/drutan/EBAF-val/pltha4cstm Mon Sep 25 15:43:16 2017



0

50

100

150

200

Coun

t

Obs Mean: 183.2Bias EBAF: -3.78RMS EBAF: 8.46N: 1289.Avg Mean: 183.6Avg Bias: -3.76Avg RMS: 4.73Avg N: 192.0

EBAFAvg Sites 1st

/SCF2/CERES/sarb/rose/Ed4_SFC_EBAF/data/PRODUCT/LM9/SFC_EBAF.Ed4.LM9.200003-201609.hdf

EBAF & Regional Avg EBAF NOAA SURFRAD Group, 07 Sites

At times assume a group of sites represent a larger area: drives down the RMS.

EBAF Avg

Mean 308 309

Bias -‐2 -‐2

RMS 9 3

N 1283 192

-180 -135 -90 -45 0 45 90 135 180Longitude

-90

-60

-30

0

30

60

90

Latit

ude

/Users/rutan/cave/web/map4cstm2017 Mon Sep 25 15:53:04 2017

EBAF Avg

Mean 183 184

Bias -‐4 -‐4

RMS 9 5

N 1289 192

NOAA GMD Surfrad Sites




0

10

20

30

40

50

60

Coun

t

Obs Mean: 167.6Bias EBAF: 3.23RMS EBAF: 12.06N: 661.0Avg Mean: 169.2Avg Bias: 3.48Avg RMS: 6.37

EBAFAvg Sites 1st

/homedir/drutan/EBAF-val/pltha4cstm Mon Sep 25 15:44:46 2017



0

50

100

150

Coun

t

Obs Mean: 131.8Bias EBAF: -4.30RMS EBAF: 20.40N: 597.0Avg Mean: 132.7Avg Bias: -4.69Avg RMS: 9.25Avg N: 191.0

EBAFAvg Sites 1st

/SCF2/CERES/sarb/rose/Ed4_SFC_EBAF/data/PRODUCT/LM9/SFC_EBAF.Ed4.LM9.200003-201609.hdf

EBAF & Regional Avg EBAF South Polar Group, 04 Sites

-180 -135 -90 -45 0 45 90 135 180Longitude

-90

-60

-30

0

30

60

90

Lati

tud

e

/Users/rutan/cave/web/map4cstm2017 Mon Sep 25 15:54:39 2017

Four South Polar Sites Represent Antarctica:

EBAF Avg

Mean 168 169

Bias 3 3

RMS 12 4

N 661 192

EBAF Avg

Mean 132 133

Bias -‐4 -‐5

RMS 20 9

N 597 191


∆𝐹↓𝑖𝑙 (𝐾 )= ∆𝐹↓𝑖𝑙(𝑐𝑜𝑚𝑝) (𝐾 )− ∆𝐹↓𝑖𝑙(𝑜𝑏𝑠) (𝐾 )

𝐹↓𝑖𝑙(𝑐𝑜𝑚𝑝;𝑜𝑏𝑠) (𝐾 )= 1/𝐾 ∑1↑𝐾▒𝐹↓𝑖𝑙𝑘  

𝐹↓𝑥,𝑅𝑀𝑆 (𝐾 )= [1/𝑁 ∑1↑𝑁▒1/𝐿 ∑𝑙↑𝐿▒[∆𝐹↓𝑖𝑙 (𝐾) ]↑2   ]↑1/2  

(𝑥=100 𝑟𝑒𝑎𝑙𝑖𝑧𝑎𝑡𝑖𝑜𝑛𝑠)

Simply average over larger and larger groups of sites; randomly select groups 100 times number.

Do land and buoy sites separately.


Figure15:Root–mean-square(RMS)differenceofcomputedandobservedmonthlymeandownwardshortwave(left)andlongwave(right)irradiancesasafunctionofnumberofsetsofcomputedandobservedmonthlymeanirradiancesusedtocomputemonthlymeandifferences(KinEq.11)forocean(closedbluecircles)andland(closedredcircles).SolidlinesarederivedbyfittingclosedcirclesbyEq.(12).

Number of sites per group (K) Number of sites per group (K)

Plot RMS as a function of increasing group size.𝐹↓𝑥,𝑅𝑀𝑆 (𝐾 )↑2 

Shortwave Longwave


Figure15:Root–mean-square(RMS)differenceofcomputedandobservedmonthlymeandownwardshortwave(left)andlongwave(right)irradiancesasafunctionofnumberofsetsofcomputedandobservedmonthlymeanirradiancesusedtocomputemonthlymeandifferences(KinEq.11)forocean(closedbluecircles)andland(closedredcircles).SolidlinesarederivedbyfittingclosedcirclesbyEq.(12).

Number of sites per group (K) Number of sites per group (K)

𝐹↓𝑥,𝑅𝑀𝑆 (𝐾 )↑2 = ∆𝐹↓𝑥,𝑏𝑖𝑎𝑠↑2 + ∆𝐹↓𝑥,𝑟𝑎𝑛𝑑𝑜𝑚↑2 /𝐾 

Plot RMS as a function of increasing group size.

Land (Wm-‐2) Buoy (Wm-‐2)

Shortwave Longwave Shortwave Longwave

∆𝐹↓𝑥,𝑏𝑖𝑎𝑠↑2  3.2 3.1 7.3 4.2

∆𝐹↓𝑥,𝑟𝑎𝑛𝑑𝑜𝑚↑2 

9.6 7.9 5.4 2.0

Shortwave Longwave


h"ps://ceres-‐tool.larc.nasa.gov/ord-‐tool

Summary! CERES EBAF & SYN1Deg along with surface

observation can still be accessed at:

! Overall the new EBAF-sfc Ed4 and SYN1Deg Ed4 surface validation shows little change (good thing).

! Uncertainty due to spatial variability in our surface validation sites shows:! Decrease is rapid for the land indicates higher spatial

variability for these sites! Slower over ocean buoys:

! Sites are primarily in tropics, less spatial variability in general! Fewer site with continuous time series adds to less reliable

relationship.

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CERES Surface Validation Update Uncertainty Study · Langley%Research%Center%Science%Directorate%...

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