# Presentation: 118065

## CERES: Aqua Review

- NASA HQ, Aug 7, 2006

## CERES Level 1 Requirements: Products

**"Two scanning broadband radiometers providing radiant flux at the Top of the Atmosphere"**
**One instrument for spatial scanning, one for new angular distribution models of earth's anisotropy fields.  Successful on both.  **
**" Level 1 Radiances"**
**Successful, now on Edition 2.  Edition 3 in early 2007.**
**"Level 2 Instantaneous geophysical parameters (TOA Flux)**
**Successful, including new angular models, now Ed2.  Ed3 in late 07.**
**"Level 3 Averaged geophysical parameters, possibly from mulitple instruments"**
**Successful, ERBE-Like now Ed2, SRBAVG in Sept 2006, AVG in 2007.**
**"After launch ... data calibration and validation of standard data products"**
**Successful, merged MODIS/CERES on Aqua, CERES on Aqua/Terra****next is MODIS/CERES/geostationary/Terra/Aqua in 2006 & 2007.**
**"As needed ... calibration updates, algorithmic improvements arising from improved validation, and for improving processing efficiencies"**
**Underway for in orbit contamination correction (~ 1%), A-train. **

## Slide 3

## CERES Level 1 Requirements: Products

**Data Processing and Testing: Climate Data Record Focus**
**Products merge global data from CERES crosstrack and rotating azimuth scanners, MODIS, GEOS-4 weather assimilation, MATCH aerosol assimilation, microwave snow and sea-ice, 5 geostationary imagers.  Up to 11 instruments on 7 spacecraft (including Terra).**
**Products include levels 1 through 3 gridded products and include ERBE-like products as well as more advanced CERES products.**
**TOA monthly biases at 1 to 2 W m****-2**** level (vs. ~ 5 W m****-2**** for ERBE), as required for climate change studies. Surface flux biases at 5-10 W m****-2 ****(vs 20 W m****-2****). Instrument stability at 0.1 to 0.5% level. **
**Aqua Angular Distribution Models (ADMs) developed from 2 years of data are now available.  ADMs were developed with data from before the loss of the FM-4 SW channel. Aqua ADMs perform better than Terra ADMs, especially in the polar regions.**
**Merged CERES and 3-hourly geosynchronous (GEO) data validated and released for Terra in spring 2006 and scheduled for Aqua in fall 2006.  Merged Terra/Aqua radiation diurnal cycles in 2007.**
**CERES eliminates geo 5% calibration errors to 0.1% global, <1% regional.   **

## Notable Recent CERES Science

**Investigation of “Earthshine” albedo study (6 W m****-2**** increase in shortwave flux 2000-2003) versus CERES (< 0.5 W m****-2**** decrease). Terra and Aqua albedo anomalies agree that there was a dip in global albedo of about 0.5% in 2003, but a return to values near 2000-2002 in 2004.**
**CERES Terra albedo variations (2000-2005) show <1% de-seasonalized variability and are highly correlated with MODIS-derived cloud fraction changes.  Cloud fraction dominates but aerosol correlation suggests some aerosol indirect effect as well.**
**CERES Global Net Radiation interannual anomalies agree to within 0.4 Wm****-2 ****(1********)**** ****of independent ocean heat flux data.**
**Six years of Terra/Aqua data show interannual variations in global radiation require 15-25 years of overlapped 0.3%/decade stability to constrain cloud feedback and climate sensitivity to +/- 25%.**
**Radiative column closure in deep convection optically thick cloud limit over tropical ARM sites: 2% consistency, TOA to Surface.**
**100,000 Terra and Aqua overpasses of 40 surface flux sites from equator to poles show consistency of 0.5 Wm****-2 ****for interannual anomalies in SW, and 1.0 Wm****-2**** in LW downward surface flux.  **

## What Didn't Work on CERES Aqua as Planned?

**CERES Mirror Attenuator Mosaic solar diffusers showed coating degradations in first two years on orbit.  Weakened initial stability confirmation.  *****Improve coatings on FM-5.***
**CERES FM-4 SW channel failed March 30, 2005.  Total and Window channels remain nominal.  Obtained primary second instrument data requirement: > 2 years of rotating azimuth.  *****But if CERES FM-3 fails, will need to derive CERES SW on FM-4 using MODIS/CERES merged at night for LW, and then apply in daytime for Total - LW = SW.  ***
**All CERES instruments have shown SW optics transmission loss when in rotating azimuth mode (1 to 2% over 5 years).  *****Physical model in testing, Rev1 released to correct all-sky and clear-ocean.  Edition 3 in 2007 will begin more rigorous correction for all scene types.  All CERES instruments now in crosstrack to eliminate further changes.***
***Data fusion more difficult than anticipated: climate accuracy ***

## Next Steps

**Beta 3-hourly SYN/AVG products running off-line now, in production for Oct 23-27, 2006 Science Team meeting**
**joint meeting with GERB at UKMO in Exeter.**
**GERB Edition 1 30-minute time resolution for Meteosat view for broadband validation of diurnal cycles**
**Cloud/Sfc/Atm Flux and cloud validation using CALIPSO/Cloudsat.  Keys: multilayer, polar, # samples.**
**Participating in GEWEX Radiative Flux Assessment of Decadal changes in surface and TOA radiation budget**
**April 2003 - Oct 2005 Terra SRBAVG in beta testing: Edition 2D out in fall.  Aqua will follow.**
**Edition 3 will correct SW/LW cal by scene type, improved cloud, aerosol, ADMs, GEOS 5, global net, Atmos fluxes, merged Terra/Aqua for advanced fusion data products.**
**SW/HW conversions from SGI to clusters, automation **

## Amount of change for a factor of 6 in climate model sensitivity (2K to 12K for doubling CO2) 

- Murphy et al.
-  Nature, 2004

***Weather = dynamics, Climate = energetics***
***Need Climate Change OSSEs, Climate Obs. Reqmts***

***Dynamics***
***variables not***
***very sensitive***

***Cloud, Radiation, Sea Ice variables very sensitive***

## Global Surface Temperature Change AR4 Climate Models

-  Weak ability to distinguish climate sensitivity until after 2030
-  Early temperature response similar because more sensitive   climate models have a stronger ocean response delay.

*** ******Must determine ***
*** ******climate sensitivity ****** and therefore ****** cloud feedback ****** well before ***
*** ******temperature signals ****** show sensitivity:****** can't wait to after 2030***

## Cloud Radiative Forcing AR4 Climate Models

*B. Soden, Pers.*
*Comm. 7/06*

- -  Noise likely dominated by ocean heat storage variability
-   Cloud Feedback linear in change of cloud radiative forcing
-    but because of clear sky changes even negative CRF    change is a slight positive feedback.

* **Strong Positive *
*  **Cloud Feedback*
* **Weak Positive *
*  **Cloud Feedback*

## CERES Net Radiation vs Global Ocean Heat Storage

*Wong et al. 2006*
*J.Climate, in press*

***We will need to carefully unscramble cloud feedback and natural ***
***variability in ocean heat storage: a fusion of ocean/atmosphere data***

## SW TOA Flux Interannual Variability: Tropical Ocean

***Shows consistent calibration stability at < 0.3 Wm******-2 ******per decade (95% conf)***
***Unfortunately only works for tropical mean ocean (nband vs bband issues)***
***Regional trends differ by +2 to -5 Wm******-2******/decade SeaWiFS vs CERES***

*Loeb et al. 2006*
*JGR, in press*

- 0.21 Wm-2

## CERES Shortwave TOA Reflected Flux Changes: 

**CERES Shortwave TOA Reflected Flux Changes: **
**Ties to Changing Cloud Fraction**

***Unscrambling climate signal cause and effect requires complete parameter set at climate accuracy.  For e.g.****** for forcing/response energetics: radiation, aerosol, cloud, land, snow/ice, temperature, humidity, precipitation ***

## Using CERES to Determine Length of Climate Data Record Needed to Constrain Cloud Feedback

***Given climate variability, 15 to 20 years is required to first detect climate trends at cloud feedback level with 90% confidence,***
***and 18 to 25 years to constrain to +/- 25% in climate sensitivity***

***Half of***
***Anthrop***
***Forcing of 0.6 Wm******-2***
***/decade***

## Future Issues

***Current IPCC AR4 climate model predictions/papers show ***
***global air sfc temperature change not discriminating next few decades for climate sensitivity (sensitive: more ocean delay)***
***uncertainty in climate sensitivity low clouds (Bony, GRL 2005)***
***climate sensitivity linear in cloud radiative forcing (Soden and Held, Jclim 2006)***
***CERES the only global cloud forcing observation demonstrated at the accuracy required (e.g. Loeb et al. 2006)***
***NPOESS has just eliminated the CERES follow on sensor called ERBS.  ***
***The last remaining CERES sensor (FM-5) is currently scheduled on NPOESS C2 in 2013/14: but gap risk is large: greatly reduce if change to NPP in 2010.***
***Cost estimates the same for NPP and NPOESS use of FM-5***
***Would delay the most serious gap issue to 2015.***
***Still need a plan for broadband global data 2015-2025.***

## The EOS Afternoon Satellite Constellation

*(artwork by Alex McClung)*

**Key A-train Science:****	****Cloud, Aerosol and Aerosol Indirect Effect Processes**
**Largest IPCC Climate Sensitivity and Anthropogenic Forcing Uncertainties**
**Unprecedented Data Fusion: e.g. NEWS CERES/CALIPSO/Cloudsat/MODIS**
**Full vertical profiles: link aerosol to source, aerosol/cloud, multilayer & polar cloud**

## CERES Backup Slides

**HQ Aqua Review**
**August 7, 2006**

## TOA Flux Errors vs Time/Space Scale

|  | Global
Interannual
Cld Rad Fcing
Trend/decade | Zonal
Eqtr - Pole
Gradient
Monthly | 1 deg region
Monthly
(1 ) | 20km fov
Instantaneous
(1 )
(So = 1000) |
| --- | --- | --- | --- | --- |
| Dominant
Error Sources | Calibration Stability | Angle
Sampling
Twilight | Calibration
Time Sampling | Angle Sampling |
| TOA SW Flux | 0.3 Wm-2
Terra Rev1 | 3.5 Wm-2 | 3.0 Wm-2 | 10 Wm-2 |
| TOA LW Flux | 0.5 Wm-2
Terra Rev1 | 2.0 Wm-2 | 1.5 Wm-2 | 5 Wm-2 |
| TOA Net Flux | 0.6 Wm-2
Terra Rev1 | 4.0 Wm-2 | 3.5 Wm-2 | 11 Wm-2 |
| Science Rqmt | 0.15 Wm-2
25% feedback | 1 - 3 Wm-2 | 2 - 5 Wm-2 | 10 Wm-2 |

## Global Net Flux Balance Error Budget(out of 1365/ 4 = 341.25 Wm-2 = SW + LW)

**Error Source (white = heating)****	****  ****	****SW****	****  LW****	****  Net**
**Solar Constant (1361 vs 1365)****	****	****+ 1.0****	****  0.0****	****+ 1.0**
**Absolute Calibration****	****	****    ****	****   1.0****	****  1.0****	****   2.0**
**Spectral Correction ****	****	****   ****	****   0.5****	****   0.3****	****   0.8**
**Spatial Sampling****	****	****	****< 0.1****	****< 0.1****	****< 0.1**
**Angle Sampling (ADMs)****	****	****+ 0.2****	****-  0.1****	****+ 0.1**
**Time Sampling (diurnal)****	****	****< 0.2****	****< 0.2****	****< 0.2**
**Reference Altitude (20km)****	****	****   0.1****	****   0.2****	****   0.3**
**Twilight SW Flux (= 0.25 Wm****-2****)****	****< 0.1****	****   0.0****	****< 0.1**
**Near Terminator SW Flux ****	****	**** ****+ 0.7****	****   0.0****	****+ 0.7**
**3-D Cloud ********vis**** bias on ********(********o****)****	****              ****+ 0.7****	****  0.0      ****+ 0.7**
**Ocean Heat Storage****	****	****	****         ****	****          ****+ 0.4 - 1.0**
**Expected Global Net Range:****	****	****          ****	****           0 to ****+ 6.5**
**CERES SRBAVG Ed2D Global Net****	****	****	**** ****+ 6.4**
***Will provide community with advice for optimal global "closure" ***

## Surface SW Flux Validation Noise

***Remarkable consistency for interannual anomalies 0.5 to 1 Wm******-2***

## Surface Downward Flux Errors: 20 - 40 Surface Sites

|  | Global
Interannual
Cld Rad Fcing
Variability | SYN/AVG (est)
Month, 1-deg
Bias, Clr/All
 (1 ) | SRBAVG
Month, 1-deg
Bias All
(1) | CRS 20km fov
Instantaneous
1 Clr/All Sky
(So = 900) |
| --- | --- | --- | --- | --- |
| Dominant
Error Sources | TBD | Aerosol, Tair,
Polar sfc/cld
Site Inhom. | Aerosol, Tair, Param. Site Inhom. | Angle Samp,
Water Vapor
Aerosol, Tair |
| Surface Down SW Flux | 0.5 Wm-2
(40 sites) | 0 / +5 Wm-2
( = 6) | 3  Wm-2
( = 20) | 23 / 20 Wm-2 |
| Surface Down LW Flux | 1.0 Wm-2
(40 Sites) | -7 / -6 Wm-2
( = 8) |  < 1 Wm-2
( = 10) | 12 / 17 Wm-2 |
| Surface Down Total Net Flux | 1.1 Wm-2
(40 Sites) | -7 / -1 Wm-2
( = 9) | 4 Wm-2
( = 22) | 26 / 26 Wm-2 |
| Science Rqmt | TBD | < 5-10 Wm-2 | < 5-10 Wm-2 | < 25 Wm-2 |
| BSRN Acc. | TBD | 5 SW?, 10 LW? | 5 SW, 10 LW | 15 SW, 10 LW |

## Earthshine, ISCCP, CERES: 2000 to 2004

***Loeb et al., AGU 2005***

***Climate accuracy requirements are poorly understood by the community: recent Earthshine 6% changes were published in Science, causing much confusion***

## ISCCP FD versus CERES: 2000 to 2004

***Loeb et al., AGU 2005***

**Tropical 30S-30N**

**Global 90S-90N**

***Meteorological satellite climate data is not accurate or stable enough to determine decadal trends, but very useful for regional studies.***

## Changing Cloud Forcing vs Vertical Velocity15 IPCC AR4 Climate Models: 30S to 30N Ocean

*GRL, 2005*

**Changing Cloud Forcing vs Vertical Velocity****15 IPCC AR4 Climate Models: 30S to 30N Ocean**

***Low Clouds Dominate***
***Cloud Radiative Forcing***
***Changes (SW reflected***
***flux) and Cloud Feedback uncertainty***

**Vertical Velocity (+ = downward motion) **

**Change in Cloud Radiative Forcing/K: Doubled CO****2**

## Climate Sensitivity vs Cloud FeedbackIPCC AR4 Models

*Soden et al. 2006*
*J.Climate*

**Climate Sensitivity vs Cloud Feedback****IPCC AR4 Models**

***Climate sensitivity is essentially linear in cloud feedback***

## Cloud Feedback vs Cloud Radiative ForcingIPCC AR4 Models

*J.Climate*

**Cloud Feedback vs Cloud Radiative Forcing****IPCC AR4 Models**

***Cloud Feedback is essentially linear in cloud radiative forcing change***