scholarly journals Sensitivity Analysis of Surface Energy Budget to Albedo Parameters in Seoul Metropolitan Area Using the Unified Model

Atmosphere ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 120 ◽  
Author(s):  
Jieun Wie ◽  
Seon-Ok Hong ◽  
Jae-Young Byon ◽  
Jong-Chul Ha ◽  
Byung-Kwon Moon
Keyword(s):  
Surface Energy ◽  
Energy Budget ◽  
Metropolitan Area ◽  
Large Population ◽  
Unified Model ◽  
Surface Energy Budget ◽  
Sensible Heat ◽  
Surface Cooling ◽  
Sensitivity Experiments ◽  
Seoul Metropolitan Area

The large population growth has significantly altered the thermal characteristics of the atmosphere, including decreased albedo and increased heat capacity; thus, urban areas experience unique climatic phenomena. We conducted sensitivity experiments using Unified Model Local Data Assimilation and Prediction-Met-Office-Reading Urban Surface Exchange Scheme (LDAPS-MORUSES) to investigate the response of surface energy budget to albedo changes in the Seoul Metropolitan Area. We compared 1.5-m temperature at 56 automatic weather station (AWS) sites and showed underestimations of approximately 0.5–2 K, but the diurnal cycle was well simulated. We changed the wall and road albedo parameters by ±50% from the default values for sensitivity experiments. With increasing albedo, 1.5-m temperature decreased by approximately 0.06 °C and 0.01 °C in urban and suburban areas, respectively. These changes are responses to decreased net radiation and sensible heat during daytime, whereas sensible heat mainly contributes to the surface cooling during nighttime. Furthermore, the decrease in albedo leads to altered vertical structure of potential temperature and atmospheric circulations at altitudes of 300–1000 m. Results show that albedo modification can affect not only surface temperature but also the entire urban boundary layer.

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

2014 ◽  
Vol 53 (9) ◽  
pp. 2114-2129 ◽  
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.

scholarly journals Near-surface climate and surface energy budget of Larsen C ice shelf, Antarctic Peninsula

2012 ◽  
Vol 6 (2) ◽  
pp. 353-363 ◽  
Author(s):  
P. Kuipers Munneke ◽  
M. R. van den Broeke ◽  
J. C. King ◽  
T. Gray ◽  
C. H. Reijmer
Keyword(s):  
Surface Energy ◽  
Antarctic Peninsula ◽  
Energy Budget ◽  
Heat Fluxes ◽  
Surface Energy Budget ◽  
Shortwave Radiation ◽  
Sensible Heat ◽  
Ice Shelf ◽  
Near Surface ◽  
The Impact

Abstract. Data collected by two automatic weather stations (AWS) on the Larsen C ice shelf, Antarctica, between 22 January 2009 and 1 February 2011 are analyzed and used as input for a model that computes the surface energy budget (SEB), which includes melt energy. The two AWSs are separated by about 70 km in the north–south direction, and both the near-surface meteorology and the SEB show similarities, although small differences in all components (most notably the melt flux) can be seen. The impact of subsurface absorption of shortwave radiation on melt and snow temperature is significant, and discussed. In winter, longwave cooling of the surface is entirely compensated by a downward turbulent transport of sensible heat. In summer, the positive net radiative flux is compensated by melt, and quite frequently by upward turbulent diffusion of heat and moisture, leading to sublimation and weak convection over the ice shelf. The month of November 2010 is highlighted, when strong westerly flow over the Antarctic Peninsula led to a dry and warm föhn wind over the ice shelf, resulting in warm and sunny conditions. Under these conditions the increase in shortwave and sensible heat fluxes is larger than the decrease of net longwave and latent heat fluxes, providing energy for significant melt.

scholarly journals Near-surface climate and surface energy budget of Larsen C ice shelf, Antarctic Peninsula

2011 ◽  
Vol 5 (5) ◽  
pp. 2665-2697
Author(s):  
P. Kuipers Munneke ◽  
M. R. van den Broeke ◽  
J. C. King ◽  
T. Gray ◽  
C. H. Reijmer
Keyword(s):  
Surface Energy ◽  
Antarctic Peninsula ◽  
Energy Budget ◽  
Heat Fluxes ◽  
Surface Energy Budget ◽  
Shortwave Radiation ◽  
Sensible Heat ◽  
Ice Shelf ◽  
Near Surface ◽  
The Impact

Abstract. Data collected by two automatic weather stations (AWS) on the Larsen C ice shelf, Antarctica, between 22 January 2009 and 1 February 2011 are analyzed and used as input for a model that computes the surface energy budget (SEB), including melt energy. The two AWSs are separated by about 70 km in the north-south direction, and both the near-surface meteorology and the SEB show similarities, although small differences in all components (most notably the melt flux) can be seen. The impact of subsurface absorption of shortwave radiation on melt and snow temperature is significant, and discussed. In winter, longwave cooling of the surface is entirely compensated by a downward turbulent transport of sensible heat. In summer, the positive net radiative flux is compensated by melt, and quite frequently by upward turbulent diffusion of heat and moisture, leading to sublimation and weak convection over the ice shelf. The month of November 2010 is highlighted, when strong westerly flow over the Antarctic Peninsula led to a dry and warm föhn wind over the ice shelf, resulting in warm and sunny conditions. Under these conditions the increase in shortwave and sensible heat fluxes is larger than the reduction of net longwave and latent heat fluxes, providing energy for significant melt.

scholarly journals The annual surface energy budget of a high-arctic permafrost site on Svalbard, Norway

2009 ◽  
Vol 3 (2) ◽  
pp. 245-263 ◽  
Author(s):  
S. Westermann ◽  
J. Lüers ◽  
M. Langer ◽  
K. Piel ◽  
J. Boike
Keyword(s):  
Heat Flux ◽  
Surface Energy ◽  
Latent Heat ◽  
Energy Budget ◽  
Sensible Heat Flux ◽  
Surface Energy Budget ◽  
Wave Radiation ◽  
Sensible Heat ◽  
Near Surface ◽  
Ground Heat Flux

Abstract. Independent measurements of radiation, sensible and latent heat fluxes and the ground heat flux are used to describe the annual cycle of the surface energy budget at a high-arctic permafrost site on Svalbard. During summer, the net short-wave radiation is the dominant energy source, while well developed turbulent processes and the heat flux in the ground lead to a cooling of the surface. About 15% of the net radiation is consumed by the seasonal thawing of the active layer in July and August. The Bowen ratio is found to vary between 0.25 and 2, depending on water content of the uppermost soil layer. During the polar night in winter, the net long-wave radiation is the dominant energy loss channel for the surface, which is mainly compensated by the sensible heat flux and, to a lesser extent, by the ground heat flux, which originates from the refreezing of the active layer. The average annual sensible heat flux of −6.9 Wm−2 is composed of strong positive fluxes in July and August, while negative fluxes dominate during the rest of the year. With 6.8 Wm−2, the latent heat flux more or less compensates the sensible heat flux in the annual average. Strong evaporation occurs during the snow melt period and particularly during the snow-free period in summer and fall. When the ground is covered by snow, latent heat fluxes through sublimation of snow are recorded, but are insignificant for the average surface energy budget. The near-surface atmospheric stratification is found to be predominantly unstable to neutral, when the ground is snow-free, and stable to neutral for snow-covered ground. Due to long-lasting near-surface inversions in winter, an average temperature difference of approximately 3 K exists between the air temperature at 10 m height and the surface temperature of the snow. As such comprehensive data sets are sparse for the Arctic, they are of great value to improve process understanding and support modeling efforts on the present-day and future arctic climate and permafrost conditions.

scholarly journals The annual surface energy budget of a high-arctic permafrost site on Svalbard, Norway

2009 ◽  
Vol 3 (2) ◽  
pp. 631-680 ◽  
Author(s):  
S. Westermann ◽  
J. Lüers ◽  
M. Langer ◽  
K. Piel ◽  
J. Boike
Keyword(s):  
Heat Flux ◽  
Surface Energy ◽  
Latent Heat ◽  
Energy Budget ◽  
Sensible Heat Flux ◽  
Surface Energy Budget ◽  
Wave Radiation ◽  
Sensible Heat ◽  
Near Surface ◽  
Ground Heat Flux

Abstract. Independent measurements of radiation, sensible and latent heat fluxes and the ground heat flux are used to describe the annual cycle of the surface energy budget at a high-arctic permafrost site on Svalbard. During summer, the net short-wave radiation is the dominant energy source, while well developed turbulent processes and the heat flux in the ground lead to a cooling of the surface. About 15% of the net radiation is consumed by the seasonal thawing of the active layer in July and August. The Bowen ratio is found to vary between 0.25 and 2, depending on water content of the uppermost soil layer. During the polar night in winter, the net long-wave radiation is the dominant energy loss channel for the surface, which is mainly compensated by the sensible heat flux and, to a lesser extent, by the ground heat flux, which originates from the refreezing of the active layer. The average annual sensible heat flux of −6.9 Wm−2 is composed of strong positive fluxes in July and August, while negative fluxes dominate during the rest of the year. With 6.8 Wm−2, the latent heat flux more or less compensates the sensible heat flux in the annual average. Strong evaporation occurs during the snow melt period and particularly during the snow-free period in summer and fall. When the ground is covered by snow, latent heat fluxes through sublimation of snow are recorded, but are insignificant for the average surface energy budget. The near-surface atmospheric stratification is found to be predominantly unstable to neutral, when the ground is snow-free, and stable to neutral for snow-covered ground. Due to long-lasting near-surface inversions in winter, an average temperature difference of approximately 3 K exists between the air temperature at 10 m height and the surface temperature of the snow.

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

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

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

Water ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 954 ◽  
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.

scholarly journals The Surface Energy Budget at Gale Crater during the first 2500 sols of the Mars Science Laboratory mission

2021 ◽  
Author(s):  
G. M. Martínez ◽  
A. Vicente‐Retortillo ◽  
A. R. Vasavada ◽  
C. E. Newman ◽  
E. Fischer ◽  
...  
Keyword(s):  
Surface Energy ◽  
Energy Budget ◽  
Surface Energy Budget ◽  
Science Laboratory ◽  
Mars Science Laboratory ◽  
Gale Crater
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