scholarly journals Shortwave radiation budget of the northern hemisphere using International Satellite Cloud Climatology Project and NCEP/NCAR climatological data

1999 ◽  
Vol 104 (D20) ◽  
pp. 24401-24421 ◽  
Author(s):  
N. Hatzianastassiou ◽  
I. Vardavas
Keyword(s):  
Northern Hemisphere ◽  
Radiation Budget ◽  
Shortwave Radiation ◽  
Climatological Data

Evaluation of net shortwave radiation over China with a regional climate model

2020 ◽  
Vol 80 (2) ◽  
pp. 147-163
Author(s):  
X Liu ◽  
Y Kang ◽  
Q Liu ◽  
Z Guo ◽  
Y Chen ◽  
...  
Keyword(s):  
Regional Climate Model ◽  
Climate Model ◽  
Regional Climate ◽  
Radiant Energy ◽  
Energy System ◽  
Radiation Budget ◽  
Shortwave Radiation ◽  
Monsoon Region ◽  
Clear Sky ◽  
Sky Conditions

The regional climate model RegCM version 4.6, developed by the European Centre for Medium-Range Weather Forecasts Reanalysis, was used to simulate the radiation budget over China. Clouds and the Earth’s Radiant Energy System (CERES) satellite data were utilized to evaluate the simulation results based on 4 radiative components: net shortwave (NSW) radiation at the surface of the earth and top of the atmosphere (TOA) under all-sky and clear-sky conditions. The performance of the model for low-value areas of NSW was superior to that for high-value areas. NSW at the surface and TOA under all-sky conditions was significantly underestimated; the spatial distribution of the bias was negative in the north and positive in the south, bounded by 25°N for the annual and seasonal averaged difference maps. Compared with the all-sky condition, the simulation effect under clear-sky conditions was significantly better, which indicates that the cloud fraction is the key factor affecting the accuracy of the simulation. In particular, the bias of the TOA NSW under the clear-sky condition was <±10 W m-2 in the eastern areas. The performance of the model was better over the eastern monsoon region in winter and autumn for surface NSW under clear-sky conditions, which may be related to different levels of air pollution during each season. Among the 3 areas, the regional average biases overall were largest (negative) over the Qinghai-Tibet alpine region and smallest over the eastern monsoon region.

The Total Meridional Heat Flux and Its Oceanic and Atmospheric Partition

2005 ◽  
Vol 18 (21) ◽  
pp. 4374-4380 ◽  
Author(s):  
Carl Wunsch
Keyword(s):  
Northern Hemisphere ◽  
Energy Transport ◽  
Atmospheric Model ◽  
Heat Fluxes ◽  
Radiation Budget ◽  
Meridional Heat Transport ◽  
Atmospheric Flux ◽  
Oceanic Surface ◽  
Earth Radiation Budget ◽  
Estimated Error

Abstract Atmospheric meridional heat transport is inferred as a residual from the Earth Radiation Budget Experiment (ERBE) data and in situ oceanic estimates. Reversing the conventional approach of computing the ocean as an atmospheric model residual is done to permit calculation of a preliminary uncertainty estimate for the atmospheric flux. The structure of the ERBE errors is itself an important uncertainty. Total energy transport is almost indistinguishable from a hemispherically antisymmetric analytic function, despite the great asymmetry of the oceanic heat fluxes. ERBE data appear sufficiently noisy so that a considerable range of atmospheric transports remains possible: the maximum atmospheric value lies between 3 and 5 PW in the Northern Hemisphere, at one standard deviation, although the values are sensitive to the noise assumptions made here. The Northern Hemisphere ocean and atmosphere carry comparable poleward heat fluxes to about 28°N where the oceanic flux drops rapidly, but does not actually vanish until the oceanic surface area goes to zero. Within the estimated error bars, there is a remarkable antisymmetry about the equator of the combined ocean and atmospheric transports, despite the marked oceanic transport asymmetry.

Impact of Clouds on the Shortwave Radiation Budget of the Surface-Atmosphere System for Snow-Covered Surfaces

1994 ◽  
Vol 7 (4) ◽  
pp. 579-585 ◽  
Author(s):  
Seth Nemesure ◽  
Robert D. Cess ◽  
Ellsworth G. Dutton ◽  
John J. Deluisi ◽  
Zhanqing Li ◽  
...  
Keyword(s):  
Radiation Budget ◽  
Shortwave Radiation ◽  
Surface Atmosphere ◽  
Atmosphere System

scholarly journals Climatological and radiative properties of midlatitude cirrus clouds derived by automatic evaluation of lidar measurements

2016 ◽  
Vol 16 (12) ◽  
pp. 7605-7621 ◽  
Author(s):  
Erika Kienast-Sjögren ◽  
Christian Rolf ◽  
Patric Seifert ◽  
Ulrich K. Krieger ◽  
Bei P. Luo ◽  
...  
Keyword(s):  
Radiative Forcing ◽  
Cirrus Clouds ◽  
Radiative Properties ◽  
Radiation Budget ◽  
Shortwave Radiation ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Data Set ◽  
Detection Scheme ◽  
Lidar Measurements

Abstract. Cirrus, i.e., high, thin clouds that are fully glaciated, play an important role in the Earth's radiation budget as they interact with both long- and shortwave radiation and affect the water vapor budget of the upper troposphere and stratosphere. Here, we present a climatology of midlatitude cirrus clouds measured with the same type of ground-based lidar at three midlatitude research stations: at the Swiss high alpine Jungfraujoch station (3580 m a.s.l.), in Zürich (Switzerland, 510 m a.s.l.), and in Jülich (Germany, 100 m a.s.l.). The analysis is based on 13 000 h of measurements from 2010 to 2014. To automatically evaluate this extensive data set, we have developed the Fast LIdar Cirrus Algorithm (FLICA), which combines a pixel-based cloud-detection scheme with the classic lidar evaluation techniques. We find mean cirrus optical depths of 0.12 on Jungfraujoch and of 0.14 and 0.17 in Zürich and Jülich, respectively. Above Jungfraujoch, subvisible cirrus clouds (τ < 0.03) have been observed during 6 % of the observation time, whereas above Zürich and Jülich fewer clouds of that type were observed. Cirrus have been observed up to altitudes of 14.4 km a.s.l. above Jungfraujoch, whereas they have only been observed to about 1 km lower at the other stations. These features highlight the advantage of the high-altitude station Jungfraujoch, which is often in the free troposphere above the polluted boundary layer, thus enabling lidar measurements of thinner and higher clouds. In addition, the measurements suggest a change in cloud morphology at Jungfraujoch above ∼ 13 km, possibly because high particle number densities form in the observed cirrus clouds, when many ice crystals nucleate in the high supersaturations following rapid uplifts in lee waves above mountainous terrain. The retrieved optical properties are used as input for a radiative transfer model to estimate the net cloud radiative forcing, CRFNET, for the analyzed cirrus clouds. All cirrus detected here have a positive CRFNET. This confirms that these thin, high cirrus have a warming effect on the Earth's climate, whereas cooling clouds typically have cloud edges too low in altitude to satisfy the FLICA criterion of temperatures below −38 °C. We find CRFNET = 0.9 W m−2 for Jungfraujoch and 1.0 W m−2 (1.7 W m−2) for Zürich (Jülich). Further, we calculate that subvisible cirrus (τ < 0.03) contribute about 5 %, thin cirrus (0.03 < τ < 0.3) about 45 %, and opaque cirrus (0.3 < τ) about 50 % of the total cirrus radiative forcing.

scholarly journals The net radiation budget of the northern hemisphere

1999 ◽  
Vol 104 (D22) ◽  
pp. 27341-27359 ◽  
Author(s):  
N. Hatzianastassiou ◽  
I. Vardavas
Keyword(s):  
Northern Hemisphere ◽  
Radiation Budget ◽  
Net Radiation

scholarly journals Five years of shortwave radiation budget measurements at a continental land site in southeastern Australia

1998 ◽  
Vol 103 (D20) ◽  
pp. 26093-26106 ◽  
Author(s):  
A. J. Prata ◽  
I. F. Grant ◽  
R. P. Cechet ◽  
G. F. Rutter
Keyword(s):  
Radiation Budget ◽  
Shortwave Radiation ◽  
Southeastern Australia ◽  
Land Site

scholarly journals Can a coupled meteorology–chemistry model reproduce the historical trend in aerosol direct radiative effects over the Northern Hemisphere?

2015 ◽  
Vol 15 (17) ◽  
pp. 9997-10018 ◽  
Author(s):  
J. Xing ◽  
R. Mathur ◽  
J. Pleim ◽  
C. Hogrefe ◽  
C.-M. Gan ◽  
...  
Keyword(s):  
Northern Hemisphere ◽  
Climate Models ◽  
Global Climate ◽  
Eastern China ◽  
Global Climate Models ◽  
Shortwave Radiation ◽  
Historical Trend ◽  
Clear Sky ◽  
Northern Pacific ◽  
Central Atlantic

Abstract. The ability of a coupled meteorology–chemistry model, i.e., Weather Research and Forecast and Community Multiscale Air Quality (WRF-CMAQ), to reproduce the historical trend in aerosol optical depth (AOD) and clear-sky shortwave radiation (SWR) over the Northern Hemisphere has been evaluated through a comparison of 21-year simulated results with observation-derived records from 1990 to 2010. Six satellite-retrieved AOD products including AVHRR, TOMS, SeaWiFS, MISR, MODIS-Terra and MODIS-Aqua as well as long-term historical records from 11 AERONET sites were used for the comparison of AOD trends. Clear-sky SWR products derived by CERES at both the top of atmosphere (TOA) and surface as well as surface SWR data derived from seven SURFRAD sites were used for the comparison of trends in SWR. The model successfully captured increasing AOD trends along with the corresponding increased TOA SWR (upwelling) and decreased surface SWR (downwelling) in both eastern China and the northern Pacific. The model also captured declining AOD trends along with the corresponding decreased TOA SWR (upwelling) and increased surface SWR (downwelling) in the eastern US, Europe and the northern Atlantic for the period of 2000–2010. However, the model underestimated the AOD over regions with substantial natural dust aerosol contributions, such as the Sahara Desert, Arabian Desert, central Atlantic and northern Indian Ocean. Estimates of the aerosol direct radiative effect (DRE) at TOA are comparable with those derived by measurements. Compared to global climate models (GCMs), the model exhibits better estimates of surface-aerosol direct radiative efficiency (Eτ). However, surface-DRE tends to be underestimated due to the underestimated AOD in land and dust regions. Further investigation of TOA-Eτ estimations as well as the dust module used for estimates of windblown-dust emissions is needed.

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