A review and comparison of surface incident shortwave radiation from multiple data sources: satellite retrievals, reanalysis data and GCM simulations

Figures & data

Table 1. The detailed information of various R_s products used in this study.

Category	Dataset	Spatial and temporal resolution	Time range	References
Ground measurements	BSRN	N/A(station) daily	1992–2015	Ohmura et al. (1998)
	GEBA	N/A(station) monthly	2001–2008	Gilgen and Ohmura (1999)
	CMA	N/A(station) daily	1961–2010	https://data.cma.cn/
	Buoys	N/A(station) daily	1991–2018	http://www.pmel.noaa.gov/tao/disdel/frames/main.html
	GC-NET	N/A(station) daily	1995–2009	Konrad et al. (2020)
Satellite retrievals	GLASS	0.05 × 0.05° daily	1983.07–2018.12	Zhang et al. (2019)
	GEWEX-SRB	1 × 1° monthly	1983.07–2017.06	Pinker and Laszlo (1992)
	CERES-EBAF	1 × 1° monthly	2001.01–2018.12	Kato et al. (2013)
Reanalysis	ERA5	0.25 × 0.25° monthly	1983.01–2018.12	Hersbach et al. (2020)
	MERRA2	0.5 × 0.625° monthly	1983.01–2018.12	Gelaro et al. (2017)
	CFSR	0.3125 × 0.3125° monthly	1979.01–2010.12	Saha et al. (2010)
GCM simulations	CMIP6	0.7 × 0.7° −2.8 × 2.8° monthly	1983.01–2014.12	Eyring et al. (2016)

Table 2. The detailed information of CMIP6 GCMs used in this study.

ID	Model	Spatial resolution	Time series
1	ACCESS-CM2	1.25° × 1.875°	1980.01–2014.12
2	ACCESS-ESM1-5	1.24° × 1.875°	1980.01–2014.12
3	AWI-CM-1-1-MR	0.9375° × 0.9375°	1980.01–2014.12
4	AWI-ESM-1-1-LR	1.875° × 1.875°	1980.01–2014.12
5	BCC-CSM2-MR	1.125° × 1.125°	1980.01–2014.12
6	BCC-ESM1	2.8125° × 2.8125°	1980.01–2014.12
7	CAMS-CSM1-0	1.125° × 1.125°	1980.01–2014.12
8	CanESM5	2.8125° × 2.8125°	1980.01–2014.12
9	CAS-ESM2-0	1.41° × 1.41°	1980.01–2014.12
10	CESM2	0.9375° × 1.25°	1980.01–2014.12
11	CESM2-FV2	1.875° × 2.5°	1980.01–2014.12
12	CESM2-WACCM	0.9375° × 1.25°	1980.01–2014.12
13	CESM2-WACCM-FV2	1.875° × 2.5°	1980.01–2014.12
14	CIESM	0.9375° × 1.25°	1980.01–2014.12
15	CMCC-CM2-HR4	0.9375° × 1.25°	1980.01–2014.12
16	CMCC-CM2-SR5	0.9375° × 1.25°	1980.01–2014.12
17	CMCC-ESM2	0.9375° × 1.25°	1980.01–2014.12
18	E3SM-1-0	1° × 1°	1980.01–2014.12
19	E3SM-1-1	1° × 1°	1980.01–2014.12
20	E3SM-1-1-ECA	1° × 1°	1980.01–2014.12
21	EC-Earth3	0.7° × 0.7°	1980.01–2014.12
22	EC-Earth3-AerChem	0.7° × 0.7°	1980.01–2014.12
23	EC-Earth3-CC	0.7° × 0.7°	1980.01–2014.12
24	EC-Earth3-Veg	0.7° × 0.7°	1980.01–2014.12
25	EC-Earth3-Veg-LR	1.125° × 1.125°	1980.01–2014.12
26	FGOALS-f3-L	1° × 1.25°	1980.01–2014.12
27	FGOALS-g3	2.25° × 2°	1980.01–2016.12
28	FIO-ESM-2-0	0.9375° × 1.25°	1980.01–2014.12
29	GFDL-ESM4	1° × 1.25°	1980.01–2014.12
30	GISS-E2-1-G	2° × 2.5°	1980.01–2014.12
31	GISS-E2-1-G-CC	2° × 2.5°	1980.01–2014.12
32	GISS-E2-1-H	2° × 2.5°	1980.01–2014.12
33	GISS-E2-2-H	2° × 2.5°	1980.01–2014.12
34	IITM-ESM	1.91° × 1.875°	1980.01–2014.12
35	INM-CM4-8	1.5° × 2°	1980.01–2014.12
36	INM-CM5-0	1.5° × 2°	1980.01–2014.12
37	IPSL-CM5A2-INCA	1.875° × 3.75°	1980.01–2014.12
38	IPSL-CM6A-LR	1.26° × 2.5°	1980.01–2014.12
39	IPSL-CM6A-LR-INCA	1.26° × 2.5°	1980.01–2014.12
40	KACE-1-0-G	1.25° × 1.875°	1980.01–2014.12
41	KIOST-ESM	1.875° × 1.875°	1980.01–2014.12
42	MIROC6	1.41° × 1.41°	1980.01–2014.12
43	MPI-ESM-1-2-HAM	1.875° × 1.875°	1980.01–2014.12
44	MPI-ESM1-2-HR	0.9375° × 0.9375°	1980.01–2014.12
45	MPI-ESM1-2-LR	1.875° × 1.875°	1980.01–2014.12
46	MRI-ESM2-0	1.125° × 1.125°	1980.01–2014.12
47	NESM3	1.875° × 1.875°	1980.01–2014.12
48	NorCPM1	1.875° × 2.5°	1980.01–2029.12
49	NorESM2-LM	1.875° × 2.5°	1980.01–2014.12
50	NorESM2-MM	0.9375° × 1.25°	1980.01–2014.12
51	SAM0-UNICON	0.9375° × 1.25°	1980.01–2014.12
52	TaiESM1	0.9375° × 1.25°	1980.01–2014.12

Figure 1. Spatial distributions of the observation stations.

Figure 2. Evaluation results of monthly R_s estimates from seven products against the ground measurements from BSRN, CMA, GEBA, GC-NET and buoys.

Table 3. Summary of performance statistics for surface measurements of five networks and seven monthly R_s estimates from 2001 to 2010. The units of Bias and RMSE are W/m².

Dataset	Measures	BSRN	CMA	GEBA	GC-NET	Buoy	All networks
GLASS	R	0.98	0.95	0.97	0.89	0.88	0.96
	Bias	−4.28	1.27	2.54	−23.54	−7.14	0.48
	RMSE	19.51	18.89	19.46	68.36	17.76	21.11
GEWEX-SRB	R	0.98	0.94	0.97	0.90	0.93	0.96
	Bias	2.03	8.80	8.01	−4.40	1.90	7.03
	RMSE	17.32	22.41	21.10	60.01	13.48	21.94
CERES-EBAF	R	0.99	0.95	0.97	0.91	0.94	0.97
	Bias	3.78	7.57	5.91	1.42	4.14	5.90
	RMSE	14.07	20.46	19.70	55.68	12.91	20.28
ERA5	R	0.99	0.93	0.97	0.91	0.90	0.96
	Bias	8.77	21.23	12.02	−1.71	1.94	12.66
	RMSE	16.81	30.78	22.54	56.80	15.07	24.77
MERRA2	R	0.98	0.90	0.96	0.91	0.78	0.93
	Bias	14.52	36.63	22.59	−12.56	−13.04	21.27
	RMSE	23.70	45.99	32.80	59.56	31.14	36.14
CFSR	R	0.98	0.90	0.95	0.91	0.54	0.94
	Bias	9.07	25.49	14.89	1.53	34.83	18.43
	RMSE	22.15	38.15	30.17	56.79	49.91	34.49
CMIP6	R	0.98	0.91	0.95	0.91	0.69	0.94
	Bias	4.85	18.02	9.04	−6.73	6.37	10.22
	RMSE	19.21	31.18	26.64	58.45	25.94	28.13

Figure 3. Spatial distributions of RMSEs of (a) GLASS; (b) ERA5; (c) GEWEX-SRB; (d) MERRA2; (e) CERES-EBAF; (f) CFSR; (g) CMIP6 R_s against ground measurements on monthly scale.

Figure 4. Spatial distributions of biases of (a) GLASS; (b) ERA5; (c) GEWEX-SRB; (d) MERRA2; (e) CERES-EBAF; (f) CFSR; (g) CMIP6 R_s against ground measurements on monthly scale.

Figure 5. Spatial distribution of ten-year (2001–2010) mean R_s of (a) GLASS; (b) ERA5; (c) GEWEX-SRB; (d) MERRA2; (e) CERES-EBAF; (f) CFSR; (g) CMIP6.

Figure 6. Box plots of ten-year (2001–2010) annual mean R_s in (a) global; (b) land; (c) ocean of the selected seven products. For each box, the blue point is the mean R_s, and the circle is the outliers. The central line represents the median value, while the lower and upper edge symbolize the 25th (v₁) and 75th (v₃) percentiles, respectively. The top line is calculated by [v₃ + 1.5 × (v₃ − v₁)] while the bottom line is [v₁ − 1.5 × (v₃− v₁)].

Table 4. Overview of the maximum, minimum and mean value of R_s over globe, land and ocean of the seven products during 2001–2010 (Units are W/m²).

Data	Global			Land			Ocean
	Max	Min	Mean	Max	Min	Mean	Max	Min	Mean
GLASS	179.9	176.2	177.1	181.8	178.2	179.3	179.2	174.1	175.5
GEWEX-SRB	186.6	185.2	185.8	187.5	185.5	186.3	186.7	184.8	185.6
CERES-EBAF	187.3	185.8	186.8	186.9	185.6	186.5	187.6	185.9	186.8
ERA5	188.4	186.8	188.0	190.6	188.6	189.9	187.8	186.0	187.2
MERRA2	186.6	184.7	185.7	198.2	193.7	196.0	182.7	181.0	181.8
CFSR	193.0	190.0	191.3	192.5	189.6	190.9	193.5	189.9	191.5
CMIP6	187.8	187.1	187.5	190.2	189.5	189.9	186.9	186.1	186.5

Table 5. The average R_s of seven products under different latitude zones during 2001–2010 (Units are W/m²).

Data	60°N–90°N	30°N–60°N	0°N–30°N	0°S–30°S	30°S–60°S	60°S–90°S
GLASS	91.7	151.6	212.9	223.3	142.8	101.9
GEWEX-SRB	103.7	159.4	227.8	233.2	148.3	108.3
CERES-EBAF	100.5	159.1	229.5	232.8	151.3	114.0
ERA5	97.3	164.2	229.5	231.2	154.2	119.9
MERRA2	92.1	169.2	227.2	234.2	146.5	99.4
CFSR	98.2	164.9	244.4	236.3	143.4	122.0
CMIP6	96.0	162.0	231.3	232.7	151.7	114.0

Figure 7. Annual R_s anomaly in (a) globe; (b) land; (c) ocean of the GLASS, GEWEX-SRB, CERES-EBAF, ERA5, MERRA2, CFSR and CMIP6 GCMs.

Table 6. Trend comparison of annual mean R_s from seven products over globe, land and ocean during the whole time series of each product and the period of 2001–2010.

Data	Global		Land		Ocean
	Time range	2001–2010	Time range	2001–2010	Time range	2001–2010
GLASS	−0.23**	−0.25**	−0.15**	−0.24**	−0.31**	−0.31*
GEWEX-SRB	0.06**	−0.04*	0.001	−0.18**	0.08**	0.01
CERES-EBAF	0.03	−0.04*	0.01	−0.06**	0.04	−0.04
ERA5	−0.01	−0.07**	0.06**	−0.06*	−0.05**	−0.07*
MERRA2	−0.17**	−0.15**	−0.07**	−0.36**	−0.21**	−0.07*
CFSR	−0.06**	−0.05	0.05*	−0.23**	−0.11**	0.03
CMIP6	−0.01*	−0.05**	−0.01	−0.05**	−0.02*	−0.05**

Units are W/m² per year.

* represents for the 95% confidence level and ** for 99% confidence level.

Figure 8. Spatial distribution of multi-year (2001–2010) trends of R_s for (a) GLASS; (b) ERA5; (c) GEWEX-SRB; (d) MERRA2; (e) CERES-EBAF; (f) CFSR; (g) CMIP6. The solid dots indicate grids at 95% confidence.

Figure A1. Evaluation results of monthly R_s estimates from seven products against the ground measurements from BSRN.

Figure A2. Evaluation results of monthly R_s estimates from seven products against the ground measurements from CMA.

Figure A3. Evaluation results of monthly R_s estimates from seven products against the ground measurements from GEBA.

Figure A4. Evaluation results of monthly R_s estimates from seven products against the ground measurements from GC-NET.

Figure A5. Evaluation results of monthly R_s estimates from seven products against the ground measurements from buoys.

Ohmura, A., E. G. Dutton, R. Philipona, R. Pinker, C. H. Whitlock, K. Dehne, M. Wild, et al. 1998. “Baseline Surface Radiation Network (BSRN/WCRP): New Precision Radiometry for Climate Research.” Bulletin of the American Meteorological Society 79 (10): 2115–21136. doi:10.1175/1520-0477(1998)079<2115:BSRNBW>2.0.CO;2.

 Web of Science ®Google Scholar

Gilgen, H., and A. Ohmura. 1999. “The Global Energy Balance Archive.” Bulletin of the American Meteorological Society 80 (5): 831–850. doi:10.1175/1520-0477(1999)080<0831:TGEBA>2.0.CO;2.

 Web of Science ®Google Scholar

Konrad, Steffen, Houtz Derek, Vandecrux Baptiste, Abdalati Waleed, Bayou Nicolas, Box Jason, Colgan William, et al. 2020. “Greenland Climate Network (GC-Net) Data.” doi:10.16904/envidat.1.

 Google Scholar

Zhang, Xiaotong, Xiang Zhao, Wenhong Li, Shunlin Liang, Dongdong Wang, Qiang Liu, Yunjun Yao, et al. 2019. “An Operational Approach for Generating the Global Land Surface Downward Shortwave Radiation Product from MODIS Data.” IEEE Transactions on Geoscience and Remote Sensing 57 (7): 4636–4650. doi:10.1109/TGRS.2019.2891945.

 Web of Science ®Google Scholar

Pinker, R. T., and I. Laszlo. 1992. “Modeling Surface Solar Irradiance for Satellite Applications on a Global Scale.” Journal of Applied Meteorology 31 (2): 194–211. doi:10.1175/1520-0450(1992)031<0194:MSSIFS>2.0.CO;2.

 Google Scholar

Kato, Seiji, Norman G. Loeb, Fred G. Rose, David R. Doelling, David A. Rutan, Thomas E. Caldwell, Lisan Yu, and Robert A. Weller. 2013. “Surface Irradiances Consistent with CERES-Derived Top-of-Atmosphere Shortwave and Longwave Irradiances.” Journal of Climate 26 (9): 2719–2740. doi:10.1175/JCLI-D-12-00436.1.

 Web of Science ®Google Scholar

Hersbach, Hans, Bill Bell, Paul Berrisford, Shoji Hirahara, András Horányi, Joaquín Muñoz-Sabater, Julien Nicolas, et al. 2020. “The ERA5 global reanalysis.” Quarterly Journal of the Royal Meteorological Society 146 (730): 1999–2049. doi:10.1002/qj.3803.

 Web of Science ®Google Scholar

Gelaro, Ronald, Will McCarty, Max J. Suárez, Ricardo Todling, Andrea Molod, Lawrence Takacs, Cynthia Randles, et al. 2017. “The Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA-2).” Journal of Climate 30 (14): 5419–5454. doi:10.1175/JCLI-D-16-0758.1.

 Web of Science ®Google Scholar

Saha, Suranjana, Shrinivas Moorthi, Hua-Lu Pan, Xingren Wu, Jiande Wang, Sudhir Nadiga, Patrick Tripp, et al. 2010. “The NCEP Climate Forecast System Reanalysis.” Bulletin of the American Meteorological Society 91 (8): 1015–1058. doi:10.1175/2010BAMS3001.1.

 Web of Science ®Google Scholar

Eyring, Veronika, Sandrine Bony, Gerald A. Meehl, Catherine A. Senior, Bjorn Stevens, Ronald J. Stouffer, and Karl E. Taylor. 2016. “Overview of the Coupled Model Intercomparison Project Phase 6 (CMIP6) Experimental Design and Organization.” Geoscientific Model Development 9 (5): 1937–1958. doi:10.5194/gmd-9-1937-2016.

 Web of Science ®Google Scholar

Data availability statement

The ground measurements collected from BSRN, GEBA, CMA, GC-NET and Buoys in this study are downloaded at https://bsrn.awi.de/, https://geba.ethz.ch/, https://data.cma.cn/, http://cires1.colorado.edu/science/groups/steffen/gcnet/ and https://www.pmel.noaa.gov/tao/drupal/disdel/, respectively. The GEWEX-SRB and CERES-EBAF data are available at https://science.larc.nasa.gov/gewex-srb/ and https://ceres.larc.nasa.gov/data/. The reanalysis datasets are available at https://www.ecmwf.int/en/forecasts/datasets/reanalysis-datasets/era5, https://disc.gsfc.nasa.gov/datasets?project=MERRA-2 and https://climatedataguide.ucar.edu/climate-data/climate-forecast-system-reanalysis-cfsr. The R_s simulations from CMIP6 GCMs are available at https://esgf-node.llnl.gov/search/cmip6/.