scholarly journals Identifying Spatial and Temporal Characteristics of Land Surface Albedo Using GF-1 WFV Data

2021 ◽  
Vol 13 (20) ◽  
pp. 4070
Author(s):  
Zhe Wang ◽  
Hongmin Zhou ◽  
Huawei Wan ◽  
Qian Wang ◽  
Wenrui Fan ◽  
...  
Keyword(s):  
Temporal Variation ◽  
Energy Budget ◽  
Land Surface ◽  
Surface Albedo ◽  
Surface Energy Budget ◽  
Spatial And Temporal Variation ◽  
Wide Field ◽  
Characteristic Analysis ◽  
Variation Characteristics ◽  
Precipitation And Temperature

Land surface albedo (LSA) is an important parameter that affects surface–air interactions and controls the surface radiation energy budget. The spatial and temporal variation characteristics of LSA reflect land surface changes and further influence the local climate. Ganzhou District, which belongs to the middle of the Hexi Corridor, is a typical irrigated agricultural and desert area in Northwest China. The study of the interaction of LSA and the land surface is of great significance for understanding the land surface energy budget and for ground measurements. In this study, high spatial and temporal resolution GF-1 wide field view (WFV) data were used to explore the spatial and temporal variation characteristics of LSA in Ganzhou District. First, the surface albedo of Ganzhou District was estimated by the GF-1 WFV. Then, the estimated results were verified by the surface measured data, and the temporal and spatial variation characteristics of surface albedo from 2014 to 2018 were analyzed. The interaction between albedo and precipitation or temperature was analyzed based on precipitation and temperature data. The results show that the estimation of surface albedo based on GF-1 WFV data was of high accuracy, which can meet the accuracy requirements of spatial and temporal variation characteristic analysis of albedo. There are obvious geographic differences in the spatial distribution of surface albedo in Ganzhou, with the overall distribution characteristics being high in the north and low in the middle. The interannual variation in annual average surface albedo in Ganzhou shows a trend of slow fluctuations and gradual increases. The variation in annual albedo is characterized by “double peaks and a single valley”, with the peaks occurring from December to February at the end and beginning of the year, and the valley occurring from June to August. Surface albedo was negatively correlated with precipitation and temperature in most areas of Ganzhou.

scholarly journals Impact of stratospheric aerosol intervention geoengineering on surface air temperature in China: A surface energy budget perspective

2021 ◽  
Author(s):  
Zhaochen Liu ◽  
Xianmei Lang ◽  
Dabang Jiang
Keyword(s):  
Spatial Pattern ◽  
Air Temperature ◽  
Land Surface ◽  
Surface Albedo ◽  
Surface Air Temperature ◽  
Stratospheric Aerosol ◽  
Surface Energy Budget ◽  
Shortwave Radiation ◽  
Surface Cooling ◽  
Temperature Changes

Abstract. Stratospheric aerosol intervention (SAI) geoengineering is a rapid, effective, and promising means to counteract anthropogenic global warming, but the climate response to SAI, with great regional disparities, remains uncertain. In this study, we use Geoengineering Model Intercomparison Project G4 experiment simulations from three models (HadGEM2-ES, MIROC-ESM, and MIROC-ESM-CHEM) that offset anthropogenic forcing under medium-low emissions (RCP4.5) by injecting a certain amount of SO2 into the stratosphere every year, to investigate the surface air temperature response to SAI geoengineering over China. It has been shown that the SAI leads to surface cooling over China over the last 40 years of injection simulation (2030–2069), which varies among models, regions and seasons. The spatial pattern of SAI-induced temperature changes over China is mainly due to net surface shortwave radiation changes. We find that changes in solar radiation modification strength, surface albedo, atmospheric water vapor and cloudiness affect surface shortwave radiation. In summer, the increased cloud cover in some regions reduces net surface shortwave radiation, causing strong surface cooling. In winter, both the strong cooling in all three models and the abnormal warming in MIROC-ESM are related to surface albedo changes. Our results suggest that cloud and land surface processes in models may dominate the spatial pattern of SAI-induced surface air temperature changes over China.

Effect of forest canopy structure on wintertime Land Surface Albedo: Comparing CLM5 simulations to in-situ observations

2020 ◽  
Author(s):  
Johanna Malle ◽  
Nick Rutter ◽  
Clare Webster ◽  
Giulia Mazzotti ◽  
Leanne Wake ◽  
...  
Keyword(s):  
Snow Cover ◽  
Land Surface ◽  
Surface Albedo ◽  
Canopy Structure ◽  
Surface Energy Budget ◽  
Area Index ◽  
Albedo Feedback ◽  
Snow Albedo ◽  
Snow Cover Extent ◽  
Wide Range

<p>Seasonal snow massively impacts the surface energy budget through its high reflectivity and is therefore an important component of land-atmosphere models. It affects climate through Snow Albedo Feedback (SAF), a positive feedback mechanism between a reduced snow cover extent due to climate warming and the corresponding increase of shortwave absorption, which provokes a further reduction in snow cover extent. SAF has been shown to be the largest climate feedback over the extratropical Northern Hemisphere (NH) during the snow melt period. Yet, large biases in SAF projections are linked to snow-vegetation interactions.</p><p>This study aims at investigating uncertainties associated with the representation of wintertime Land Surface Albedo (LSA) of forested environments in global climate models, which is an essential aspect when studying SAF. UAV-based observations of LSA were used to assess corresponding LSA simulations in CLM5, the land component of the NCAR Community Earth System Model. Our measurements capture a wide range of forest structure and species found in seasonally snow covered environments, spanning from Swiss sub-alpine to Finnish boreal forests, and show a strong dependency of LSA on solar angle and canopy density. CLM5 simulations failed to capture a realistic range in LSA and shortcomings were identified particularly with regards to simulations at sparsely forested sites. In these environments, Leaf Area Index as the main descriptor of canopy structure was unable to explain observed LSA differences in space and time. This study emphasizes the need to improve the representation of canopy structure in land surface models with critical implications for simulations of Snow Albedo Feedback strength over the NH extratropics.</p>

Evaporation and land surface energy budget at the Salar de Atacama, Northern Chile

2005 ◽  
Vol 310 (1-4) ◽  
pp. 236-252 ◽  
Author(s):  
Stephanie K. Kampf ◽  
Scott W. Tyler ◽  
Cristián A. Ortiz ◽  
José F. Muñoz ◽  
Paula L. Adkins
Keyword(s):  
Surface Energy ◽  
Energy Budget ◽  
Land Surface ◽  
Surface Energy Budget ◽  
Northern Chile
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