On the incident solar radiation in CMIP5 models

Zhou, Linjiong; Zhang, Minghua; Bao, Qing; Liu, Yimin

doi:10.1002/2015gl063239

Cited by 14 publications

(20 citation statements)

References 7 publications

(8 reference statements)

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“…In the case of 0 , which scales the TOA incoming solar radiation, calculating 0 at the center of the radiation time step leads to fluctuations in the time-mean incoming solar radiation around a latitude circle [Zhou et al, 2015]. We find that it is important to treat separately the two uses of the cosine of this angle, which we denote as 0 and 0m in (1).…”

Section: Discussionmentioning

confidence: 99%

“…Despite the fact that fluctuations of this magnitude will not impact weather forecasts, the use of an averaged 0 across the model time step has now been implemented in the ECMWF model following the suggestion of Zhou et al [2015]. The red lines in Figure 2 confirm that this removes the erroneous fluctuations and is applicable for any model time step.…”

Section: Incoming Solar Radiationmentioning

confidence: 92%

“…To reproduce the fluctuations found by Zhou et al [2015], Figure 2 depicts the 1 year mean of the incoming solar flux around the equator from free-running 13 month T255 (around 75 km) resolution atmosphere-only model simulations (ECMWF model cycle 41R2) with the radiation scheme called every 3 h. The simulations were started on 1 August 2000, and the annual mean was computed starting on 1 September. With a 1 h model time step, the wavenumber 24 of amplitude around 1 W m −2 is very similar to that reported by Zhou et al [2015] for EC-Earth, which also uses a 1h model time step [Hazeleger et al, 2011].…”

Section: Incoming Solar Radiationmentioning

confidence: 99%

“…Climate models with a 3h radiation time step include ACCESS [Bi et al, 2013], EC-Earth [Hazeleger et al, 2011], GFDL [Anderson et al, 2004], HadGEM3 [Walters et al, 2014] and INM-CM4 [Zhou et al, 2015]. Climate models with a 3h radiation time step include ACCESS [Bi et al, 2013], EC-Earth [Hazeleger et al, 2011], GFDL [Anderson et al, 2004], HadGEM3 [Walters et al, 2014] and INM-CM4 [Zhou et al, 2015].…”

Section: Introductionmentioning

confidence: 99%

“…Morcrette [2000] described the method currently used in the ECMWF model and others [e.g., Yang and Slingo, 2001] as follows: when the shortwave radiation scheme is called at the beginning of a radiation time step, the TOA incoming solar flux into a horizontal plane is set to unity in order that the computed net shortwave flux profile is normalized. Zhou et al [2015] stressed the importance of using the average value of 0 across the time interval rather than the centered time value; this explained their finding that the incoming solar radiation in 8 out of the 28 climate models they examined had erroneous fluctuations in the annual mean as a function of longitude around the equator. This approach is illustrated by the schematic in Figure 1 and hereafter is referred to as the Morcrette method.…”

Section: Introductionmentioning

confidence: 99%

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Effect of solar zenith angle specification in models on mean shortwave fluxes and stratospheric temperatures

Hogan

Hirahara

2016

Geophysical Research Letters

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Many weather and climate models call their radiation schemes only every 3 h, which we show can lead to a stratospheric temperature overestimate of 3–5 K and wavenumber 8 fluctuations in top‐of‐atmosphere (TOA) net shortwave flux around the tropics of amplitude 1.6 W m−2. Solving this problem while retaining a 3h radiation time step requires careful treatment of the cosine of the solar zenith angle, μ0, which appears twice in the calculation of shortwave fluxes, scaling the following: (1) TOA incident flux and (2) the path length of the direct solar beam through the atmosphere. If μ0 is calculated as the average over the radiation time step, rather than at the central time, then the fluctuations are removed, but the stratosphere is still too warm by 2–3 K. It is only if the second μ0 is averaged only over the sunlit part of the radiation time step that the temperature bias is removed.

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Section: Discussionmentioning

confidence: 99%

Section: Incoming Solar Radiationmentioning

confidence: 92%

Section: Incoming Solar Radiationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Effect of solar zenith angle specification in models on mean shortwave fluxes and stratospheric temperatures

Hogan

Hirahara

2016

Geophysical Research Letters

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A multisatellite climatology of clouds, radiation, and precipitation in southern West Africa and comparison to climate models

2016

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Southern West Africa (SWA) has a large population that relies on highly variable monsoon rainfall, yet climate models show little consensus over projected precipitation in this region. Understanding of the current and future climate of SWA is further complicated by rapidly increasing anthropogenic emissions and a lack of surface observations. Using multiple satellite observations, the ERA‐Interim reanalysis, and four climate models, we document the climatology of cloud, precipitation, and radiation over SWA in June–July, highlight discrepancies among satellite products, and identify shortcomings in climate models and ERA‐Interim. Large differences exist between monthly mean cloud cover estimates from satellites, which range from 68 to 94%. In contrast, differences among satellite observations in top of atmosphere outgoing radiation and surface precipitation are smaller, with monthly means of about 230 W m−2 of longwave radiation, 145 W m−2 of shortwave radiation, and 5.87 mm d−1 of precipitation. Both ERA‐Interim and the climate models show less total cloud cover than observations, mainly due to underestimating low cloud cover. Errors in cloud cover, along with uncertainty in surface albedo, lead to a large spread of outgoing shortwave radiation. Both ERA‐Interim and the climate models also show signs of convection developing too early in the diurnal cycle, with associated errors in the diurnal cycles of precipitation and outgoing longwave radiation. Clouds, radiation, and precipitation are linked in an analysis of the regional energy budget, which shows that interannual variability of precipitation and dry static energy divergence are strongly linked.

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Evaluation of surface albedo over the Tibetan Plateau simulated by CMIP5 models using in‐situ measurements and MODIS

Meng

Zhao

et al. 2021

Intl Journal of Climatology

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Surface albedo plays a key role in the energy and water cycles, and reasonable parameterizations of surface albedo will be greatly helpful to improve the simulation of radiation partition in climate models. In-situ measurements of albedo from five sites over the Tibetan Plateau (TP) and MODIS albedo product are used to evaluate monthly, annual, and seasonal variations of the surface albedo simulated by 24 Global Climate Models (GCMs) archived by the Coupled Model Intercomparison Project Phase 5 (CMIP5). Potential factors contributing to the bias of simulated albedo were investigated. The results show that the monthly albedo of 24 GCMs varied across models, and the difference among the models was smaller in the June-July-August period than the December-January-February period. The ensemble mean albedo of the 24 GCMs was more consistent with the in-situ measurements than the individual model. The albedo calculated from the BNU-ESM, GFDL-CM3, INM-CM4, MIROC4h, MIROC-ESM, and MIROC-ESM-CHEM models coincided with the observations from June to September, increasing rapidly to above 0.4 from November. However, the annual cycle of surface albedo was insignificant when simulated by some models, such as CanESM2, CSIRO-Mk3.6.0, CMCC-CMS, IPSL-CM5A-MR, and MPI-ESM-MR. Additionally, the surface albedo was overestimated by CMIP5 multi-model ensemble mean-with a smaller amplitude of daily albedo-compared with the values estimated from in-situ observations and MCD43A3. In all 24 models, snow albedo parameterization schemes were found to variably fit the attenuation of snow albedo over time. The cold temperature, relatively more precipitation, fresh snow density, and albedo in these models led to large biases in snow depth and ablation.The surface albedo tends to increase without the influence of blowing snow and withered grass on the model's albedo.

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On the incident solar radiation in CMIP5 models

Cited by 14 publications

References 7 publications

Effect of solar zenith angle specification in models on mean shortwave fluxes and stratospheric temperatures

Effect of solar zenith angle specification in models on mean shortwave fluxes and stratospheric temperatures

A multisatellite climatology of clouds, radiation, and precipitation in southern West Africa and comparison to climate models

Evaluation of surface albedo over the Tibetan Plateau simulated by CMIP5 models using in‐situ measurements and MODIS

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