How are the coastal breezes affected by changes in the land surface? Analysis from a case study using WRF

Author(s):  
Roberto Mulero-Martinez ◽  
Carlos Román-Cascón ◽  
Marie Lothon ◽  
Fabienne Lohou ◽  
Carlos Yagüe ◽  
...  

<p>Sea breezes are common and recurrent thermally-driven wind circulations formed in coastal areas under conditions of weak synoptic forcing. The different heat capacity between the land and the sea causes the thermal contrast needed for their formation. Therefore, the temperature changes at the surface of both the sea and the land influence the breezes characteristics. In this work, we investigate how sensitive are the sea breezes to changes in land cover and soil moisture, which may have a direct impact on the surface temperature inland. This is done through the design of different sensitivity experiments performed with the Weather Research and Forecasting (WRF) model, where we tested the effect of the land use and soil moisture modification. This was done through the simulation of a typical sea-breeze case study in the coastal area of the southwest of the Iberian Peninsula (Gulf of Cádiz). The differences among the experiments are compared spatially and confronted with observations from different meteorological towers at the coast and inland. A special emphasis is made on the changes observed in the area of the National Park of Doñana. This area is characterised by large shallow marshes with varying seasonal status and extensive rice crops. Thus, contrasting conditions of the surface are typically observed, which also depend on the previous hydrological conditions. Preliminary results highlight the importance of the correct representation of the surface inland to obtain a proper simulation of the sea-breeze system. Besides, new lines of research emerge to analyse the impacts caused by other potential modifications in the surface conditions of the land and the ocean (e.g., global change, urbanization, crop modification, changes in precipitation regimes or sea surface temperature, etc).</p>

2006 ◽  
Vol 134 (11) ◽  
pp. 3174-3189 ◽  
Author(s):  
Christian Sutton ◽  
Thomas M. Hamill ◽  
Thomas T. Warner

Abstract Current generation short-range ensemble forecast members tend to be unduly similar to each other, especially for components such as surface temperature and precipitation. One possible cause of this is a lack of perturbations to the land surface state. In this experiment, a two-member ensemble of the Advanced Research Weather Research and Forecasting (WRF) model (ARW) was run from two different soil moisture analyses. One-day forecasts were conducted for six warm-season cases over the central United States with moderate soil moistures, both with explicit convection at 5-km grid spacing and with parameterized convection at 20-km grid spacing. Since changing the convective parameterization has previously been demonstrated to cause significant differences between ensemble forecast members, 20-km simulations were also conducted that were initialized with the same soil moisture but that used two different convective parameterizations as a reference. At 5 km, the forecast differences due to changing the soil moisture were comparable to the differences in 20-km simulations with the same soil moisture but with a different convective parameterization. The differences of 20-km simulations from different soil moistures were occasionally large but typically smaller than the differences from changing the convective parameterization. Thus, perturbing the state of the land surface for this version of WRF/ARW was judged to be likely to increase the spread of warm-season operational short-range ensemble forecasts of precipitation and surface temperature when soil moistures are moderate in value, especially if the ensemble is comprised of high-resolution members with explicit convection.


Urban Science ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 27
Author(s):  
Lahouari Bounoua ◽  
Kurtis Thome ◽  
Joseph Nigro

Urbanization is a complex land transformation not explicitly resolved within large-scale climate models. Long-term timeseries of high-resolution satellite data are essential to characterize urbanization within land surface models and to assess its contribution to surface temperature changes. The potential for additional surface warming from urbanization-induced land use change is investigated and decoupled from that due to change in climate over the continental US using a decadal timescale. We show that, aggregated over the US, the summer mean urban-induced surface temperature increased by 0.15 °C, with a warming of 0.24 °C in cities built in vegetated areas and a cooling of 0.25 °C in cities built in non-vegetated arid areas. This temperature change is comparable in magnitude to the 0.13 °C/decade global warming trend observed over the last 50 years caused by increased CO2. We also show that the effect of urban-induced change on surface temperature is felt above and beyond that of the CO2 effect. Our results suggest that climate mitigation policies must consider urbanization feedback to put a limit on the worldwide mean temperature increase.


2021 ◽  
Author(s):  
Gaetana Ganci ◽  
Annalisa Cappello ◽  
Giuseppe Bilotta ◽  
Giuseppe Pollicino ◽  
Luigi Lodato

<p>The application of remote sensing for monitoring, detecting and analysing the spatial and extents and temporal changes of waste dumping sites and landfills could become a cost-effective and powerful solution. Multi-spectral satellite images, especially in the thermal infrared, can be exploited to characterize the state of activity of a landfill.  Indeed, waste disposal sites, during the period of activity, can show differences in surface temperature (LST, Land Surface Temperature), state of vegetation (estimated through NDVI, Normalized Difference Vegetation Index) or soil moisture (estimated through NDWI, Normalized Difference Water Index) compared to neighboring areas. Landfills with organic waste typically show higher temperatures than surrounding areas due to exothermic decomposition activities. In fact, the biogas, in the absence or in case of inefficiency of the conveying plants, rises through the layers of organic matter and earth (landfill body) until it reaches the surface at a temperature of over 40 ° C. Moreover, in some cases, leachate contamination of the aquifers can be identified by analyzing the soil moisture, through the estimate of the NDWI, and the state of suffering of the vegetation surrounding the site, through the estimate of the NDVI. This latter can also be an indicator of soil contamination due to the presence of toxic and potentially dangerous waste when buried or present nearby. To take into account these facts, we combine the LST, NDVI and NDWI indices of the dump site and surrounding areas in order to characterize waste disposal sites. Preliminary results show how this approach can bring out the area and level of activity of known landfill sites. This could prove particularly useful for the definition of intervention priorities in landfill remediation works.</p>


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