GLOBAL CLIMATE OBSERVING SYSTEM
ESSENTIAL CLIMATE VARIABLE - Earth radiation budget |
| Domain | Atmospheric | Description | The primary observations related to the Earth’s radiation budget are of solar irradiance, the external driver of the climate system, and of the almost compensating reflected solar and emitted longwave radiation that leaves the atmosphere. The observations are made from space, and continuity and stability of measurement are essential for detecting fluctuations and change. Imbalance between incoming and outgoing fluxes is estimated from the increase in heat content of the oceans to be about 0.6 Wm-2, about 0.2% of the input from solar irradiance. This is smaller than the uncertainty of several Wm-2 in the measurements of outgoing radiation, which arises largely from uncertainty in absolute calibration. Measuring the variability of fluxes over the globe and over time nevertheless provides insight into the overall behaviour of the climate system, and provides data for the evaluation and improvement of climate models. This includes diurnal variations that can be used to identify biases in the radiation fields of numerical weather prediction models, contributing to the improvements of parameterizations for use in models in general. [GCOS-195 4.5.5] |
| Sub-domain | Upper-air |
| Full Name | Earth radiation budget |
| Satellite Signficant Contribution | Yes  |
|
| GCOS Actions |
Action
Status* | Description | Who | Time Frame | Performance Indicator | Cost Implications |
A14
Cat-C | Ensure continued long-term operation of the BSRN and expand the network to obtain globally more representative coverage. Establish formal analysis infrastructure. | Parties’ national services and research programmes operating BSRN sites in cooperation with AOPC and the WCRP GEWEX Radiation Panel. | Ongoing (network operation and extension); by 2012 (analysis infrastructure). | The number of BSRN stations regularly submitting data to International Data Centres; | 1-10M US$ (20% in non-Annex-I Parties). |
A25
Cat-B | Ensure continuation of Earth Radiation Budget observations, with at least one dedicated satellite mission operating at any one time. | Space agencies. | Ongoing | Long-term data availability at archives. | 30-100M US$ (Mainly by Annex-I Parties). |
*GCOS-195 Status Categories:
Category A: Action completed, perhaps exceeding reasonable expectations. Very good progress on ongoing tasks.
Category B: Action largely completed according to expectation. Good progress on ongoing tasks.
Category C: Moderate progress overall, although progress may be good for some part of the action.
Category D: Limited progress overall, although progress may be moderate or good for some part of the action.
Category E: Very little or no progress, or deterioration rather than progress.
|
|
| GCOS Products | |
|
| CEOS Response | [A25 (A.7.1, A.7.2)]
2015 Update: The Total Solar Irradiance Calibration Transfer Experiment (TCTE) measures total solar irradiance (TSI), or the total light coming from the Sun at all wavelengths, in order to monitor changes in the incident sunlight at the top of Earth’s atmosphere. The mission mitigates a potential and likely upcoming gap in an otherwise continuous 34-year climate data record following the loss of the NASA Glory mission in 2011. TCTE was successfully launched on November 19, 2013.
Planned: ISS/TSIS with launch in 2017 and continued follow-on missions (from TSIS Performance Requirements)
TSI accuracy 0.01% (0.14 W/m2) and stability 0.01%/decade (0.14 W/m2/decade)
SSI accuracy 0.2% and Stability 0.5%/decade for wavelengths <400 nm and 0.1%/decade at wavelengths >400nm
Solar irradiance:
In the frame of CEOS WGCV the solar irradiance spectrum is under reevaluation since 2014 in cooperation between the CEOS WGCv subgroups for Atmospheric Composition (ACSG) and Infrared and Visible Optical Sensors (IVOS). The activity aims to identify the most suitable solar irradiance spectrum in terms of retrieval, calibration, and validation.
Activity updates on solar irradiance measurements:- ESA’s SoHO/VIRGO (TSI) functioning since 1996
- NASA’s ACRIMSat/ACRIM3 (TSI) ceased operations in Nov. 2013
- NASA’s SORCE/TIM (TSI) continuing since 2003 and achieving target requirements above
- NASA’s SORCE/SIM (SSI) continuing since 2003 but not achieving target requirements above
- CNES Picard/PREMOS (TSI) 2010-2014 achieved accuracy target requirements above
- NOAA’s STP-Sat3/TCTE/TIM (TSI) launched Nov. 2013 and achieving target requirements above
- NORSAT1/CLARA (TSI) planned for 2016 launch
- NOAA’s ISS/TSIS (TSI & SSI) planned for 2017 launch to achieve target and exceed planned requirements given in table above
Earth radiation budget:
CERES FM6 will fly on JPSS-1 in the 2016 timeframe Broadband Radiometer (BBR) is scheduled to fly on EarthCARE in late 2015.
Responsibility for continuity of Earth radiation observations in the United States has been transferred back to NASA from NOAA. NASA is currently developing the next generation Radiation Budget Instrument (RBI) and it will fly on JPSS-2 in the 2021 timeframe.
|
|
|