scholarly journals Possible Biogeophysical Effects of Cultivated Land Conversion in Northeast China in 2010–2030

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Haiming Yan ◽  
Jinyan Zhan ◽  
Juan Huang ◽  
Tengteng Zhai
Keyword(s):  
Heat Flux ◽  
Northeast China ◽  
Sensible Heat Flux ◽  
Wrf Model ◽  
Cultivated Land ◽  
Land Change ◽  
Theoretical Support ◽  
Changing Trends ◽  
The Future ◽  
Flux Increase

There will be substantial cultivated land change in China as the society strives to meet the growing food demands, which will greatly influence the future climate. This study analyzed the possible biogeophysical effects of cultivated land change on the climate in Northeast China during 2010–2030 on the basis of simulation with the Weather Research and Forecast (WRF) model. Scenario analysis was first carried out on the possible changing trends of cultivated land. Then the climate effects of the cultivated land change were analyzed on the basis of the simulation with the WRF model. The simulation results indicate that the total cultivated land area in Northeast China will decrease during 2010–2030, mainly converting into urban and built-up land and forests due to the urbanization and governmental policies. Besides, the cultivated land change will lead to the increase of the sensible heat flux in the regions where a lot of cultivated land will change into urban and built-up land, while it will make the latent heat flux increase in the regions where the cultivated land will be mainly converted into forests through influencing the evapotranspiration. All these results can provide theoretical support for implementing the future land management in Northeast China.

scholarly journals Possible Influence of the Cultivated Land Reclamation on Surface Climate in India: A WRF Model Based Simulation

2013 ◽  
Vol 2013 ◽  
pp. 1-9
Author(s):  
Yi Qu ◽  
Feng Wu ◽  
Haiming Yan ◽  
Bangrong Shu ◽  
Xiangzheng Deng
Keyword(s):  
Climate Change ◽  
Heat Flux ◽  
Simulation Analysis ◽  
Land Reclamation ◽  
Global Climate ◽  
Regional Climate ◽  
Sensible Heat Flux ◽  
Wrf Model ◽  
Cultivated Land ◽  
The Impact

Land use/cover change (LUCC) has become one of the most important factors for the global climate change. As one of the major types of LUCC, cultivated land reclamation also has impacts on regional climate change. Most of the previous studies focused on the correlation and simulation analysis of historical LUCC and climate change, with few explorations for the impacts of future LUCC on regional climate, especially impacts of the cultivated land reclamation. This study used the Weather Research and Forecasting (WRF) model to forecast the changes of energy flux and temperature based on the future cultivated land reclamation in India and then analyzed the impacts of cultivated land reclamation on climate change. The results show that cultivated land reclamation will lead to a large amount of land conversions, which will overall result in the increase in latent heat flux of regional surface as well as the decrease in sensible heat flux and further lead to changes of regional average temperature. Furthermore, the impact on climate change is seasonally different. The cultivated land reclamation mainly leads to a temperature decrease in the summer, while it leads to a temperature increase in the winter.

scholarly journals Impacts of Cultivated Land Reclamation on the Climate and Grain Production in Northeast China in the Future 30 Years

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Qingling Shi ◽  
Yingzhi Lin ◽  
Enpei Zhang ◽  
Haiming Yan ◽  
Jinyan Zhan
Keyword(s):  
Climate Change ◽  
Food Security ◽  
Northeast China ◽  
Land Reclamation ◽  
Wrf Model ◽  
Cultivated Land ◽  
Climatic Effects ◽  
Global Food Security ◽  
Temperature And Precipitation ◽  
Theoretical Support

China, as a large agricultural country as well as a major country with great demand for grain, has played a more and more important role in the international grain market. As Northeast China is one of the major commodity grain bases in China as well as one of the regions with the highest intensity of human activities, it plays an important role in influencing the global food security. This study first generally analyzed the cultivated land reclamation and the climate change of temperature and precipitation in Northeast China during 2000–2010. Then, on the basis of these data, the climatic effects of cultivated land reclamation in Northeast China during 2030–2040 were simulated by the weather research forecast (WRF) model. Finally, the possible effects of the climate change on the grain yield and the potential influence on the food security were analyzed. The simulation result indicated that the temperature in Northeast China would be increasing on the whole, while the precipitation would be decreasing. The result of this study can provide some theoretical support to the agricultural economic development in Northeast China and serve the national macropolicy and food security strategy of the whole China.

scholarly journals Impacts of High-Resolution Urban Canopy Parameters within the WRF Model on Dynamical and Thermal Fields over Guangzhou, China

2019 ◽  
Vol 58 (5) ◽  
pp. 1155-1176
Author(s):  
Chong Shen ◽  
Xiaoyang Chen ◽  
Wei Dai ◽  
Xiaohui Li ◽  
Jie Wu ◽  
...  
Keyword(s):  
Heat Flux ◽  
Wind Speed ◽  
Sensible Heat Flux ◽  
Wrf Model ◽  
Urban Canopy ◽  
Urban Morphology ◽  
Meteorological Model ◽  
Thermal Fields ◽  
Ground Heat Flux ◽  
Surface Skin Temperature

AbstractOn urban scales, the detailed characteristics of land-use information and building properties are vital to improving the meteorological model. The WRF Model with high-spatial-resolution urban fraction (UF) and urban morphology (UM) is used to study the impacts of these urban canopy parameters (UCPs) on dynamical and thermal meteorological fields in two representative seasons in Guangzhou. The results of two seasons are similar and as follows. 1) The impacts of updated UF and UM are obvious on wind speed but minor on temperature and humidity. In the urban environment, the results with updated UF and UM are more consistent with observations compared with the default UCPs, which means the performance of the model has been improved. 2) The dynamical factors associated with wind speed are analyzed. Turbulent kinetic energy (TKE) is significantly affected by UM but little by UF. And both UF and UM are found to influence friction velocity U*. The UM and greater UF attained larger U*. 3) In addition, the thermal fields are analyzed. The UM and increased UF induce higher surface skin temperature (TSK) and ground heat flux in the daytime, indicating that more heat is transported from the surface to the soil. At night, more heat is transported from the soil to the surface, producing higher TSK. For sensible heat flux (HFX), greater UF induces larger HFX during the daytime. But the effects of UM are complex, which makes HFX decrease during the daytime and increase at night. Finally, larger UF attains lower latent heat in the daytime.

scholarly journals Regional Climate Variability Responses to Future Land Surface Forcing in the Brazilian Amazon

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Tao Zhang ◽  
Jinyan Zhan ◽  
Feng Wu ◽  
Jiao Luo ◽  
Juan Huang
Keyword(s):  
Heat Flux ◽  
Surface Temperature ◽  
Land Surface ◽  
Regional Climate ◽  
Sensible Heat Flux ◽  
Wrf Model ◽  
Brazilian Amazon ◽  
Close Link ◽  
Study Results ◽  
Surface Changes

Tropical deforestation could destabilize regional climate changes. This paper aimed to model the potential climatological variability caused by future forest vulnerability in the Brazilian Amazon over the 21th century. The underlying land surface changes between 2005 and 2100 are first projected based on the respectable output produced by Hurtt et al. Then the weather research and forecasting (WRF) model is applied to assess the impacts of future deforestation on regional climate during 2090–2100. The study results show that the forests in the Brazilian Amazon will primarily be converted into dryland cropland and pasture in the northwest part and into cropland/woodland mosaic in the southeast part, with 5.12% and 13.11%, respectively. These land surface changes will therefore lead to the significant reduction of the sum of sensible heat flux and latent heat flux and precipitation and the increase of the surface temperature. Furthermore, the variability of surface temperature is observed with close link to the deforested areas.

scholarly journals Doppler lidar observations of sensible heat flux and intercomparisons with a ground-based energy balance station and WRF model output

2009 ◽  
Vol 18 (2) ◽  
pp. 155-162 ◽  
Author(s):  
Jenny Davis ◽  
Christopher G. Clare Collier ◽  
Fay Davies ◽  
Guy N. Pearson ◽  
Ralph Burton ◽  
...  
Keyword(s):  
Heat Flux ◽  
Energy Balance ◽  
Sensible Heat Flux ◽  
Wrf Model ◽  
Model Output ◽  
Doppler Lidar ◽  
Sensible Heat ◽  
Lidar Observations

scholarly journals A New Land-Use Dataset for the Weather Research and Forecasting (WRF) Model

Atmosphere ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 350
Author(s):  
Huoqing Li ◽  
Hailiang Zhang ◽  
Ali Mamtimin ◽  
Shuiyong Fan ◽  
Chenxiang Ju
Keyword(s):  
Land Use ◽  
Heat Flux ◽  
Sensible Heat Flux ◽  
Wrf Model ◽  
Northwest China ◽  
Specific Humidity ◽  
Weather Research And Forecasting ◽  
United States Geological Survey ◽  
Parameter Values ◽  
Weather Research

The USGS (United States Geological Survey) land-use data used in the Weather Research and Forecasting (WRF) model have become obsolete as they are unable to accurately represent actual underlying surface features. Therefore, this study developed a new multi-satellite remote-sensing land-use dataset based on the latest GLC2015 (Global Land Cover, 2015) land-use data, which had 300 m spatial resolution. The new data were used to update the default USGS land-use dataset. Based on observational data from national meteorological observing stations in Xinjiang, northwest China, a comparison of the old USGS and new GLC2015 land-use datasets in the WRF model was performed for July 2018, where the simulated variables included the sensible heat flux (SHF), latent heat flux (LHF), surface skin temperature (Tsk), two-meter air temperature (T2), wind speed (Winds), specific humidity (Q2) and relative humidity (RH). The results indicated that there were significant differences between the two datasets. For example, our statistical verification results found via in situ observations made by the MET (model evaluation tools) illustrated that the bias of T2 decreased by 2.54%, the root mean square error (RMSE) decreased by 1.48%, the bias of Winds decreased by 10.46%, and the RMSE decreased by 6.77% when using the new dataset, and the new parameter values performed a net positive effect on land–atmosphere interactions. These results suggested that the GLC2015 land-use dataset developed in this study was useful in terms of improving the performance of the WRF model in the summer months.

scholarly journals The efficiency of the Weather Research and Forecasting (WRF) model for simulating typhoons

2014 ◽  
Vol 14 (8) ◽  
pp. 2179-2187 ◽  
Author(s):  
T. Haghroosta ◽  
W. R. Ismail ◽  
P. Ghafarian ◽  
S. M. Barekati
Keyword(s):  
Heat Flux ◽  
Wind Speed ◽  
Model Simulation ◽  
Sensible Heat Flux ◽  
Wrf Model ◽  
Heat Fluxes ◽  
Weather Research And Forecasting ◽  
Data Set ◽  
Wind Speed Prediction ◽  
Weather Research

Abstract. The Weather Research and Forecasting (WRF) model includes various configuration options related to physics parameters, which can affect the performance of the model. In this study, numerical experiments were conducted to determine the best combination of physics parameterization schemes for the simulation of sea surface temperatures, latent heat flux, sensible heat flux, precipitation rate, and wind speed that characterized typhoons. Through these experiments, several physics parameterization options within the Weather Research and Forecasting (WRF) model were exhaustively tested for typhoon Noul, which originated in the South China Sea in November 2008. The model domain consisted of one coarse domain and one nested domain. The resolution of the coarse domain was 30 km, and that of the nested domain was 10 km. In this study, model simulation results were compared with the Climate Forecast System Reanalysis (CFSR) data set. Comparisons between predicted and control data were made through the use of standard statistical measurements. The results facilitated the determination of the best combination of options suitable for predicting each physics parameter. Then, the suggested best combinations were examined for seven other typhoons and the solutions were confirmed. Finally, the best combination was compared with other introduced combinations for wind-speed prediction for typhoon Washi in 2011. The contribution of this study is to have attention to the heat fluxes besides the other parameters. The outcomes showed that the suggested combinations are comparable with the ones in the literature.

scholarly journals Numerical Evaluation of the Impact of Urbanization on Summertime Precipitation in Osaka, Japan

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Hikari Shimadera ◽  
Akira Kondo ◽  
Kundan Lal Shrestha ◽  
Ken Kitaoka ◽  
Yoshio Inoue
Keyword(s):  
Land Use ◽  
Heat Flux ◽  
Urban Areas ◽  
Sensible Heat Flux ◽  
Wrf Model ◽  
Temporal Distribution ◽  
Urban Land Use ◽  
Sensible Heat ◽  
Impact Of Urbanization ◽  
The Impact

This study utilized the Weather Research and Forecasting (WRF) model version 3.5.1 to evaluate the impact of urbanization on summertime precipitation in Osaka, Japan. The evaluation was conducted by comparing the WRF simulations with the present land use and no-urban land use (replacing “Urban” with “Paddy”) for August from 2006 to 2010. The urbanization increased mean air temperature by 2.1°C in urban areas because of increased sensible heat flux and decreased mean humidity by 0.8 g kg−1because of decreased latent heat flux. In addition, the urbanization increased duration of the southwesterly sea breeze. The urbanization increased precipitation in urban areas and decreased in the surrounding areas. The mean precipitation in urban areas was increased by 20 mm month−1(27% of the total amount without the synoptic-scale precipitation). The precipitation increase was generally due to the enhancement of the formation and development of convective clouds by the increase in sensible heat flux during afternoon and evening time periods. The urbanization in Osaka changes spatial and temporal distribution patterns of precipitation and evaporation, and consequently it substantially affects the water cycle in and around the urban areas of Osaka.

scholarly journals Reconstruction of the 1979–2006 Greenland ice sheet surface mass balance using the regional climate model MAR

2007 ◽  
Vol 1 (1) ◽  
pp. 21-40 ◽  
Author(s):  
X. Fettweis
Keyword(s):  
Heat Flux ◽  
Mass Balance ◽  
Thermohaline Circulation ◽  
Climate Model ◽  
Sensible Heat Flux ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Surface Mass Balance ◽  
Surface Mass ◽  
The Future

Abstract. Results from a 28-year simulation (1979–2006) over the Greenland ice sheet (GrIS) reveal an increase of solid precipitation (+0.4±2.5 km3 yr−2) and run-off (+7.9±3.3 km3 yr−2) of surface meltwater. The net effect of these competing factors is a significant Surface Mass Balance (SMB) loss of −7.2±5.1 km3 yr−2. The contribution of changes in the net water vapour flux (+0.02±0.09 km3 yr−2) and rainfall (+0.2±0.2 km3 yr−2) to the SMB variability is negligible. The meltwater supply has increased because the GrIS surface has been warming up +2.4°C since 1979. Sensible heat flux, latent heat flux and net solar radiation have not varied significantly over the last three decades. However, the simulated downward infrared flux has increased by 9.3 W m−2 since 1979. The natural climate variability (e.g. the North Atlantic Oscillation) does not explain these changes. The recent global warming, due to the greenhouse gas concentration increase induced by human activities, could be a cause of these changes. The doubling of surface meltwater flux into the ocean over the period 1979–2006 suggests that the overall ice sheet mass balance has been increasingly negative, given the likely meltwater-induced acceleration of outlet glaciers. This study suggests that increased melting overshadows over an increased accumulation in a warming scenario and that the GrIS is likely to keep losing mass in the future. An enduring GrIS melting will probably affect in the future an certain effect on the stability of the thermohaline circulation and the global sea level rise.

scholarly journals The efficiency of the WRF model for simulating typhoons

2014 ◽  
Vol 2 (1) ◽  
pp. 287-313 ◽  
Author(s):  
T. Haghroosta ◽  
W. R. Ismail ◽  
P. Ghafarian ◽  
S. M. Barekati
Keyword(s):  
Heat Flux ◽  
Wind Speed ◽  
Model Simulation ◽  
Sensible Heat Flux ◽  
Wrf Model ◽  
Heat Fluxes ◽  
Data Set ◽  
Wind Speed Prediction ◽  
Speed Prediction ◽  
And Control

Abstract. The Weather Research Forecast (WRF) model includes various configuration options related to physics parameters, which can affect the performance of the model. In this study, different numerical experiments were conducted to determine the best combination of physics parameterization schemes for the simulation of sea surface temperatures, latent heat flux, sensible heat flux, precipitation rate, and wind speed that characterized typhoons. Through these experiments, several physics parameterization options within the WRF model were exhaustively tested for typhoon Noul, which had originated in the South China Sea in November 2008. The model domain consisted of one coarse domain and one nested domain. The resolution of the coarse domain was 30 km, and that of the nested domain was 10 km. In this study, model simulation results were compared with the Climate Forecast System Reanalysis (CFSR) data set. Comparisons between predicted and control data were made through the use of standard statistical measurements. The results facilitated the determination of the best combination of options suitable for predicting each physics parameter. Then, the suggested best combinations were examined for seven other typhoons and the solutions were confirmed. Finally, the best combination was compared with other introduced combinations for wind speed prediction for typhoon Washi (2011). The contribution of this study is to have attention to the heat fluxes besides the other parameters. The outcomes showed that the suggested combinations are comparable with the ones in the literature.

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