Assessing the Impact of Urban Hydrological Processes on the Summertime Urban Climate in Nanjing Using the WRF Model

2019 ◽  
Vol 124 (23) ◽  
pp. 12683-12707 ◽  
Author(s):  
Xueyuan Wang ◽  
Shiguang Miao ◽  
Hongnian Liu ◽  
Jianning Sun ◽  
Ning Zhang ◽  
...  
Keyword(s):  
Urban Climate ◽  
Wrf Model ◽  
Hydrological Processes ◽  
The Impact

scholarly journals Assessing the Impact of Enhanced Hydrological Processes on Urban Hydrometeorology with Application to Two Cities in Contrasting Climates

2016 ◽  
Vol 17 (4) ◽  
pp. 1031-1047 ◽  
Author(s):  
Jiachuan Yang ◽  
Zhi-Hua Wang ◽  
Matei Georgescu ◽  
Fei Chen ◽  
Mukul Tewari
Keyword(s):  
Water Cycle ◽  
Wrf Model ◽  
Single Layer ◽  
Urban Canopy ◽  
Field Measurements ◽  
Green Roofs ◽  
The United States ◽  
Climatic Conditions ◽  
Hydrological Processes ◽  
The Impact

Abstract To enhance the capability of models in better characterizing the urban water cycle, physical parameterizations of urban hydrological processes have been implemented into the single-layer urban canopy model in the widely used Weather Research and Forecasting (WRF) Model. While the new model has been evaluated offline against field measurements at various cities, its performance in online settings via coupling to atmospheric dynamics requires further examination. In this study, the impact of urban hydrological processes on regional hydrometeorology of the fully integrated WRF–urban modeling system for two major cities in the United States, namely, Phoenix and Houston, is assessed. Results show that including hydrological processes improves prediction of the 2-m dewpoint temperature, an indicative measure of coupled thermal and hydrological processes. The implementation of green roof systems as an urban mitigation strategy is then tested at the annual scale. The reduction of environmental temperature and increase of humidity by green roofs indicate strong diurnal and seasonal variations and are significantly affected by geographical and climatic conditions. Comparison with offline studies reveals that land–atmosphere interactions play a crucial role in determining the effect of green roofs.

Variational Assimilation of Cloud Liquid/Ice Water Path and Its Impact on NWP

2015 ◽  
Vol 54 (8) ◽  
pp. 1809-1825 ◽  
Author(s):  
Yaodeng Chen ◽  
Hongli Wang ◽  
Jinzhong Min ◽  
Xiang-Yu Huang ◽  
Patrick Minnis ◽  
...  
Keyword(s):  
Data Assimilation ◽  
Liquid Water ◽  
Weather Prediction ◽  
Wrf Model ◽  
Liquid Water Path ◽  
Cloud Liquid Water ◽  
Water Path ◽  
Ice Water Path ◽  
Ice Water ◽  
The Impact

AbstractAnalysis of the cloud components in numerical weather prediction models using advanced data assimilation techniques has been a prime topic in recent years. In this research, the variational data assimilation (DA) system for the Weather Research and Forecasting (WRF) Model (WRFDA) is further developed to assimilate satellite cloud products that will produce the cloud liquid water and ice water analysis. Observation operators for the cloud liquid water path and cloud ice water path are developed and incorporated into the WRFDA system. The updated system is tested by assimilating cloud liquid water path and cloud ice water path observations from Global Geostationary Gridded Cloud Products at NASA. To assess the impact of cloud liquid/ice water path data assimilation on short-term regional numerical weather prediction (NWP), 3-hourly cycling data assimilation and forecast experiments with and without the use of the cloud liquid/ice water paths are conducted. It is shown that assimilating cloud liquid/ice water paths increases the accuracy of temperature, humidity, and wind analyses at model levels between 300 and 150 hPa after 5 cycles (15 h). It is also shown that assimilating cloud liquid/ice water paths significantly reduces forecast errors in temperature and wind at model levels between 300 and 150 hPa. The precipitation forecast skills are improved as well. One reason that leads to the improved analysis and forecast is that the 3-hourly rapid update cycle carries over the impact of cloud information from the previous cycles spun up by the WRF Model.

Toward a Robust Canopy Hydrology Scheme with Precipitation Subgrid Variability

2007 ◽  
Vol 8 (3) ◽  
pp. 439-446 ◽  
Author(s):  
Dagang Wang ◽  
Guiling Wang
Keyword(s):  
Land Surface ◽  
Surface Characteristics ◽  
Hydrological Processes ◽  
Canopy Interception ◽  
Time Step ◽  
Covered Area ◽  
Surface Models ◽  
Physically Based ◽  
Interception Loss ◽  
The Impact

Abstract Representation of the canopy hydrological processes has been challenging in land surface modeling due to the subgrid heterogeneity in both precipitation and surface characteristics. The Shuttleworth dynamic–statistical method is widely used to represent the impact of the precipitation subgrid variability on canopy hydrological processes but shows unwanted sensitivity to temporal resolution when implemented into land surface models. This paper presents a canopy hydrology scheme that is robust at different temporal resolutions. This scheme is devised by applying two physically based treatments to the Shuttleworth scheme: 1) the canopy hydrological processes within the rain-covered area are treated separately from those within the nonrain area, and the scheme tracks the relative rain location between adjacent time steps; and 2) within the rain-covered area, the canopy interception is so determined as to sustain the potential evaporation from the wetted canopy or is equal to precipitation, whichever is less, to maintain somewhat wet canopy during any rainy time step. When applied to the Amazon region, the new scheme establishes interception loss ratios of 0.3 at a 10-min time step and 0.23 at a 2-h time step. Compared to interception loss ratios of 0.45 and 0.09 at the corresponding time steps established by the original Shuttleworth scheme, the new scheme is much more stable under different temporal resolutions.

scholarly journals Nature-based cooling potential: a multi-type green infrastructure evaluation in Toronto, Ontario, Canada

2021 ◽  
Author(s):  
Vidya Anderson ◽  
William A. Gough
Keyword(s):  
Urban Agriculture ◽  
Air Temperature ◽  
Green Infrastructure ◽  
Urban Climate ◽  
Surface Air Temperature ◽  
Green Roofs ◽  
Near Surface ◽  
Green Walls ◽  
The Impact ◽  
Agriculture Systems

AbstractThe application of green infrastructure presents an opportunity to mitigate rising temperatures using a multi-faceted ecosystems-based approach. A controlled field study in Toronto, Ontario, Canada, evaluates the impact of nature-based solutions on near surface air temperature regulation focusing on different applications of green infrastructure. A field campaign was undertaken over the course of two summers to measure the impact of green roofs, green walls, urban vegetation and forestry systems, and urban agriculture systems on near surface air temperature. This study demonstrates that multiple types of green infrastructure applications are beneficial in regulating near surface air temperature and are not limited to specific treatments. Widespread usage of green infrastructure could be a viable strategy to cool cities and improve urban climate.

Examining Terrain Effects on an Upstate New York Tornado Event Utilizing a High-Resolution Model Simulation

2021 ◽  
Author(s):  
Luke J. LeBel ◽  
Brian H. Tang ◽  
Ross A. Lazear
Keyword(s):  
New York ◽  
High Resolution ◽  
Wind Shear ◽  
Model Simulation ◽  
Wrf Model ◽  
Severe Weather ◽  
Streamwise Vorticity ◽  
Low Level ◽  
Severe Convection ◽  
The Impact

AbstractThe complex terrain at the intersection of the Mohawk and Hudson valleys of New York has an impact on the development and evolution of severe convection in the region. Specifically, previous research has concluded that terrain-channeled flow in the Mohawk and Hudson valleys likely contributes to increased low-level wind shear and instability in the valleys during severe weather events such as the historic 31 May 1998 event that produced a strong (F3) tornado in Mechanicville, New York.The goal of this study is to further examine the impact of terrain channeling on severe convection by analyzing a high-resolution WRF model simulation of the 31 May 1998 event. Results from the simulation suggest that terrain-channeled flow resulted in the localized formation of an enhanced low-level moisture gradient, resembling a dryline, at the intersection of the Mohawk and Hudson valleys. East of this boundary, the environment was characterized by stronger low-level wind shear and greater low-level moisture and instability, increasing tornadogenesis potential. A simulated supercell intensified after crossing the boundary, as the larger instability and streamwise vorticity of the low-level inflow was ingested into the supercell updraft. These results suggest that terrain can have a key role in producing mesoscale inhomogeneities that impact the evolution of severe convection. Recognition of these terrain-induced boundaries may help in anticipating where the risk of severe weather may be locally enhanced.

scholarly journals A Case Study of Observed and Modeled Barrier Flow in the Denmark Strait in May 2015

2017 ◽  
Vol 145 (6) ◽  
pp. 2385-2404 ◽  
Author(s):  
Alice K. DuVivier ◽  
John J. Cassano ◽  
Steven Greco ◽  
G. David Emmitt
Keyword(s):  
Wrf Model ◽  
Horizontal Resolution ◽  
Surface Energy Budget ◽  
Vertical Resolution ◽  
Structure Comparison ◽  
Denmark Strait ◽  
Pbl Scheme ◽  
Barrier Jets ◽  
The Impact ◽  
Jet Structure

Abstract Mesoscale barrier jets in the Denmark Strait are common in winter months and have the capability to influence open ocean convection. This paper presents the first detailed observational study of a summertime (21 May 2015) barrier wind event in the Denmark Strait using dropsondes and observations from an airborne Doppler wind lidar (DWL). The DWL profiles agree well with dropsonde observations and show a vertically narrow (~250–400 m) barrier jet of 23–28 m s−1 near the Greenland coast that broadens (~300–1000 m) and strengthens farther off coast. In addition, otherwise identical regional high-resolution Weather Research and Forecasting (WRF) Model simulations of the event are analyzed at four horizontal grid spacings (5, 10, 25, and 50 km), two vertical resolutions (40 and 60 levels), and two planetary boundary layer (PBL) parameterizations [Mellor–Yamada–Nakanishi–Niino, version 2.5 (MYNN2.5) and University of Washington (UW)] to determine what model configurations best simulate the observed jet structure. Comparison of the WRF simulations with wind observations from satellites, dropsondes, and the airborne DWL scans indicate that the combination of both high horizontal resolution (5 km) and vertical resolution (60 levels) best captures observed barrier jet structure and speeds as well as the observed cloud field, including some convective clouds. Both WRF PBL schemes produced reasonable barrier jets with the UW scheme slightly outperforming the MYNN2.5 scheme. However, further investigation at high horizontal and vertical resolution is needed to determine the impact of the WRF PBL scheme on surface energy budget terms, particularly in the high-latitude maritime environment around Greenland.

scholarly journals First Evidence of Human's Influence on Climate of Prague and Brno

Geografie ◽  
1994 ◽  
Vol 99 (1) ◽  
pp. 14-19
Author(s):  
Jan Munzar
Keyword(s):  
Air Quality ◽  
Urban Environment ◽  
Urban Climate ◽  
Quality Deterioration ◽  
New Knowledge ◽  
The Creation ◽  
The Impact

The paper brings some new knowledge on air quality deterioration as a part of urban environment in Prague and Brno in the end of the 18th and in the 19th centuries. The impact of man-induced processes on the creation of specific features of urban climate is documented.

scholarly journals A plea for a novel kind of ecohydrology: the interaction between hydrological processes and - endangered or not - wildlife

2020 ◽  
Author(s):  
Jasper Griffioen ◽  
Martin Wassen ◽  
Joris Cromsigt
Keyword(s):  
Climate Change ◽  
Surface Water ◽  
Ecosystem Engineer ◽  
Sewage Water ◽  
Water Systems ◽  
Nature Reserves ◽  
Hydrological Processes ◽  
Groundwater Levels ◽  
Nature Restoration ◽  
The Impact

<p>Ecohydrology usually refers to the effects of hydrological processes on the occurrence, distribution and patterns of plants. Here, we emphasize a new kind of ecohydrology in which the effects of hydrological processes on the occurrence of – endangered or not - wildlife become addressed via the threat of its habitat or, oppositely, where the occurrence of wildlife leads to a threat of endangered fauna. We present three examples to illustrate this.</p><p>First, the habitat of the tiger in the Terai Arc Landscape (TAL) at the foot of the Himalayas seems to increasingly become threatened by changes in the hydrological conditions. Grasslands in floodplains are an important part of the tiger habitat as these are the grounds where the tiger preferably hunts for deer as his prey. Disturbances of the water systems such as gravel and sand extraction from the river beds, intake of water for irrigation and hydropower production are increasingly happening and climate change may further alter the Himalayan water systems. This seems to disturb the grasslands in their hydrological and hydromorphological dynamics, which may negatively impact the density of deer, which may put additional pressure on the tiger populations in the nature reserves of the TAL.</p><p>Second, ungulates are important mammals in the grasslands and savannah of southern Africa. The water availability for these animals may alter upon climate change, including higher frequencies of droughts. Research suggests that the community composition of ungulates may alter by this. Here, the larger water-dependent grazers may be replaced by smaller, less water-dependent species.</p><p>Third, the beaver is well-known as hydrological ecosystem engineer. The beaver, therefore, has obtained some attention within the context of ecohydrology. The impact of the beaver as ecosystem engineer is, however, peculiar for nature reserves at the Belgian-Dutch border. Surface water with poor quality due to lack of appropriate sewage water treatment is running along nature reserves. The reintroduction of the beaver causes a rise in the surface and groundwater levels due to its dam-building activities. This induces an introduction of polluted surface water into the Dutch wetlands which contain a less eutrofied ecosystem than the Belgian ones that were fed by the polluted surface water. Nature restoration may thus go on the expense of nature degradation.</p><p>These examples show that the ecohydrology of wildlife is as fascinating and diverse as classical ecohydrology is.</p>

The Impact of Vineyard Abandonment on Soil Properties and Hydrological Processes

2017 ◽  
Vol 16 (12) ◽  
pp. vzj2017.05.0096 ◽  
Author(s):  
Jesús Rodrigo Comino ◽  
Igor Bogunovic ◽  
Hadis Mohajerani ◽  
Paulo Pereira ◽  
Artemi Cerdà ◽  
...  
Keyword(s):  
Soil Properties ◽  
Hydrological Processes ◽  
The Impact
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