Arctic Cloud Fraction and Radiative Fluxes in Atmospheric Reanalyses

Abstract Arctic radiative fluxes, cloud fraction, and cloud radiative forcing are evaluated from four currently available reanalysis models using data from the North Slope of Alaska (NSA) Barrow site of the Atmospheric Radiation Measurement Program (ARM). A primary objective of the ARM–NSA program is to provide a high-resolution dataset of direct measurements of Arctic clouds and radiation so that global climate models can better parameterize high-latitude cloud radiative processes. The four reanalysis models used in this study are the 1) NCEP–NCAR global reanalysis, 2) 40-yr ECMWF Re-Analysis (ERA-40), 3) NCEP–NCAR North American Regional Reanalysis (NARR), and 4) Japan Meteorological Agency and Central Research Institute of Electric Power Industry 25-yr Reanalysis (JRA25). The reanalysis models simulate the radiative fluxes well if/when the cloud fraction is simulated correctly. However, the systematic errors of climatological reanalysis cloud fractions are substantial. Cloud fraction and radiation biases show considerable scatter, both in the annual mean and over a seasonal cycle, when compared to those observed at the ARM–NSA. Large seasonal cloud fraction biases have significant impacts on the surface energy budget. Detailed comparisons of ARM and reanalysis products reveal that the persistent low-level cloud fraction in summer is particularly difficult for the reanalysis models to capture creating biases in the shortwave radiation flux that can exceed 160 W m−2. ERA-40 is the best performer in both shortwave and longwave flux seasonal representations at Barrow, largely because its simulation of the cloud coverage is the most realistic of the four reanalyses. Only two reanalyses (ERA-40 and NARR) capture the observed transition from positive to negative surface net cloud radiative forcing during a 2–3-month period in summer, while the remaining reanalyses indicate a net warming impact of Arctic clouds on the surface energy budget throughout the entire year. The authors present a variable cloud radiative forcing metric to diagnose the erroneous impact of reanalysis cloud fraction on the surface energy balance. The misrepresentations of cloud radiative forcing in some of the reanalyses are attributable to errors in both simulated cloud amounts and the models’ radiative response to partly cloudy conditions.

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A transitioning Arctic surface energy budget: the impacts of solar zenith angle, surface albedo and cloud radiative forcing

Climate Dynamics ◽

10.1007/s00382-010-0937-5 ◽

2010 ◽

Vol 37 (7-8) ◽

pp. 1643-1660 ◽

Cited By ~ 117

Author(s):

Joseph Sedlar ◽

Michael Tjernström ◽

Thorsten Mauritsen ◽

Matthew D. Shupe ◽

Ian M. Brooks ◽

...

Keyword(s):

Surface Energy ◽

Energy Budget ◽

Zenith Angle ◽

Radiative Forcing ◽

Solar Zenith Angle ◽

Surface Albedo ◽

Surface Energy Budget ◽

Cloud Radiative Forcing ◽

Arctic Surface

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Sensitivity of the surface energy budget to drifting snow as simulated by MAR in coastal Adelie Land, Antarctica

10.5194/tc-2020-329 ◽

2020 ◽

Author(s):

Louis Le Toumelin ◽

Charles Amory ◽

Vincent Favier ◽

Christoph Kittel ◽

Stefan Hofer ◽

...

Keyword(s):

Relative Humidity ◽

Surface Energy ◽

Energy Budget ◽

Radiative Forcing ◽

Climate Models ◽

Surface Energy Budget ◽

Near Surface ◽

Surface Atmosphere ◽

Drifting Snow ◽

The Impact

Abstract. In order to understand the evolution of the climate of Antarctica, dominant processes that control surface and low-atmosphere meteorology need to be accurately captured in climate models. We used the regional climate model MAR (v3.11) at 10 km horizontal resolution, forced by ERA5 reanalysis over a 9-year period (2010–2018), to study the impact of drifting snow (designing here the wind-driven transport of snow particles below and above 2 m) on the near-surface atmosphere and surface in Adelie Land, East Antarctica. Two model runs were performed, respectively with and without drifting snow, and compared to half-hourly in situ observations at D17, a coastal and windy location of Adelie Land. We show that sublimation of drifting-snow particles in the atmosphere drives the difference between model runs and is responsible for significant impacts on the near-surface atmosphere. By cooling the low atmosphere and increasing its relative humidity, drifting snow also reduces sensible and latent heat exchanges at the surface (−5.9 W m−2 on average). Moreover, large and dense drifting-snow layers act as near-surface cloud by interacting with incoming radiative fluxes, enhancing incoming longwave radiations and reducing incoming shortwave radiations in summer (net radiative forcing: 5.9 W m−2). Even if drifting snow modifies these processes involved in surface-atmosphere interactions, the total surface energy budget is only slightly modified by introducing drifting snow, because of compensating effects in surface energy fluxes. The drifting-snow driven effects are not prominent near the surface but peak higher in the boundary layer (fifth vertical level, 38 m) where drifting snow sublimation is the most pronounced. Accounting for drifting snow in MAR generally improves the comparison at D17, more especially for the representation of relative humidity (mean bias reduced from −11.1 % to 2.9 %) and incoming longwave radiation (mean bias reduced from −7.6 W m−2 to −1.5 W m−2). Consequently, our results suggest that a detailed representation of drifting-snow processes is required in climate models to better capture the near–surface meteorology and surface–atmosphere interactions in coastal Adelie Land.

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Dust radiative forcing and its impact on surface energy budget over West Africa

Scientific Reports ◽

10.1038/s41598-020-69223-4 ◽

2020 ◽

Vol 10 (1) ◽

Cited By ~ 3

Author(s):

Abdoul Aziz Saidou Chaibou ◽

Xiaoyan Ma ◽

Tong Sha

Keyword(s):

Surface Energy ◽

West Africa ◽

Energy Budget ◽

Radiative Forcing ◽

Surface Energy Budget

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Relationship between cloud radiative forcing, cloud fraction and cloud albedo, and new surface-based approach for determining cloud albedo

Atmospheric Chemistry and Physics ◽

10.5194/acp-11-7155-2011 ◽

2011 ◽

Vol 11 (14) ◽

pp. 7155-7170 ◽

Cited By ~ 26

Author(s):

Y. Liu ◽

W. Wu ◽

M. P. Jensen ◽

T. Toto

Keyword(s):

Radiative Forcing ◽

Climate Models ◽

Cloud Fraction ◽

Shortwave Radiation ◽

Cloud Radiative Forcing ◽

Analytical Expression ◽

Cloud Albedo ◽

Annual Variations ◽

Hourly Data ◽

Radiation Parameterizations

Abstract. This paper focuses on three interconnected topics: (1) quantitative relationship between surface shortwave cloud radiative forcing, cloud fraction, and cloud albedo; (2) surface-based approach for measuring cloud albedo; (3) multiscale (diurnal, annual and inter-annual) variations and covariations of surface shortwave cloud radiative forcing, cloud fraction, and cloud albedo. An analytical expression is first derived to quantify the relationship between cloud radiative forcing, cloud fraction, and cloud albedo. The analytical expression is then used to deduce a new approach for inferring cloud albedo from concurrent surface-based measurements of downwelling surface shortwave radiation and cloud fraction. High-resolution decade-long data on cloud albedos are obtained by use of this surface-based approach over the US Department of Energy's Atmospheric Radiaton Measurement (ARM) Program at the Great Southern Plains (SGP) site. The surface-based cloud albedos are further compared against those derived from the coincident GOES satellite measurements. The three long-term (1997–2009) sets of hourly data on shortwave cloud radiative forcing, cloud fraction and cloud albedo collected over the SGP site are analyzed to explore the multiscale (diurnal, annual and inter-annual) variations and covariations. The analytical formulation is useful for diagnosing deficiencies of cloud-radiation parameterizations in climate models.

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Influence of Subfacet Heterogeneity and Material Properties on the Urban Surface Energy Budget

Journal of Applied Meteorology and Climatology ◽

10.1175/jamc-d-13-0286.1 ◽

2014 ◽

Vol 53 (9) ◽

pp. 2114-2129 ◽

Cited By ~ 23

Author(s):

Prathap Ramamurthy ◽

Elie Bou-Zeid ◽

James A. Smith ◽

Zhihua Wang ◽

Mary L. Baeck ◽

...

Keyword(s):

Surface Energy ◽

Energy Budget ◽

Material Properties ◽

Sensible Heat Flux ◽

Role Reversal ◽

Surface Energy Budget ◽

Urban Surface ◽

Urban Site ◽

Peak Time ◽

Sensible Heat

AbstractUrban facets—the walls, roofs, and ground in built-up terrain—are often conceptualized as homogeneous surfaces, despite the obvious variability in the composition and material properties of the urban fabric at the subfacet scale. This study focuses on understanding the influence of this subfacet heterogeneity, and the associated influence of different material properties, on the urban surface energy budget. The Princeton Urban Canopy Model, which was developed with the ability to capture subfacet variability, is evaluated at sites of various building densities and then applied to simulate the energy exchanges of each subfacet with the atmosphere over a densely built site. The analyses show that, although all impervious built surfaces convert most of the incoming energy into sensible heat rather than latent heat, sensible heat fluxes from asphalt pavements and dark rooftops are 2 times as high as those from concrete surfaces and light-colored roofs. Another important characteristic of urban areas—the shift in the peak time of sensible heat flux in comparison with rural areas—is here shown to be mainly linked to concrete’s high heat storage capacity as well as to radiative trapping in the urban canyon. The results also illustrate that the vegetated pervious soil surfaces that dot the urban landscape play a dual role: during wet periods they redistribute much of the available energy into evaporative fluxes but when moisture stressed they behave more like an impervious surface. This role reversal, along with the direct evaporation of water stored over impervious surfaces, significantly reduces the overall Bowen ratio of the urban site after rain events.

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Surface energy budget over the central Arctic Ocean during late summer and early freeze-up

Journal of Geophysical Research Atmospheres ◽

10.1029/2000jd900083 ◽

2001 ◽

Vol 106 (D23) ◽

pp. 32187-32205 ◽

Cited By ~ 18

Author(s):

E. Douglas Nilsson ◽

Üllar Rannik ◽

Måns Håkansson

Keyword(s):

Surface Energy ◽

Arctic Ocean ◽

Energy Budget ◽

Late Summer ◽

Surface Energy Budget ◽

Central Arctic Ocean

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Measuring the impact of a new snow model using surface energy budget process relationships

10.1002/essoar.10502951.1 ◽

2020 ◽

Author(s):

Jonathan Day ◽

Gabriele Arduini ◽

Irina Sandu ◽

Linus Magnusson ◽

Anton Beljaars ◽

...

Keyword(s):

Surface Energy ◽

Energy Budget ◽

Surface Energy Budget ◽

Budget Process ◽

Snow Model ◽

The Impact

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Projected Changes in Soil Temperature and Surface Energy Budget Components over the Alps and Northern Italy

Water ◽

10.3390/w10070954 ◽

2018 ◽

Vol 10 (7) ◽

pp. 954 ◽

Cited By ~ 2

Author(s):

Claudio Cassardo ◽

Seon Park ◽

Sungmin O ◽

Marco Galli

Keyword(s):

Heat Flux ◽

Surface Energy ◽

Soil Temperature ◽

Energy Budget ◽

Regional Climate ◽

Northern Italy ◽

Surface Energy Budget ◽

Future Climate ◽

Radiative Properties ◽

The Alps

This study investigates the potential changes in surface energy budget components under certain future climate conditions over the Alps and Northern Italy. The regional climate scenarios are obtained though the Regional Climate Model version 3 (RegCM3) runs, based on a reference climate (1961–1990) and the future climate (2071–2100) via the A2 and B2 scenarios. The energy budget components are calculated by employing the University of Torino model of land Processes Interaction with Atmosphere (UTOPIA), and using the RegCM3 outputs as input data. Our results depict a significant change in the energy budget components during springtime over high-mountain areas, whereas the most relevant difference over the plain areas is the increase in latent heat flux and hence, evapotranspiration during summertime. The precedence of snow-melting season over the Alps is evidenced by the earlier increase in sensible heat flux. The annual mean number of warm and cold days is evaluated by analyzing the top-layer soil temperature and shows a large increment (slight reduction) of warm (cold) days. These changes at the end of this century could influence the regional radiative properties and energy cycles and thus, exert significant impacts on human life and general infrastructures.

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