scholarly journals Contribution of Land Use Changes to Near-Surface Air Temperatures during Recent Summer Extreme Heat Events in the Phoenix Metropolitan Area

2010 ◽  
Vol 49 (8) ◽  
pp. 1649-1664 ◽  
Author(s):  
Susanne Grossman-Clarke ◽  
Joseph A. Zehnder ◽  
Thomas Loridan ◽  
C. Sue B. Grimmond

Abstract The impact of 1973–2005 land use–land cover (LULC) changes on near-surface air temperatures during four recent summer extreme heat events (EHEs) are investigated for the arid Phoenix, Arizona, metropolitan area using the Weather Research and Forecasting Model (WRF) in conjunction with the Noah Urban Canopy Model. WRF simulations were carried out for each EHE using LULC for the years 1973, 1985, 1998, and 2005. Comparison of measured near-surface air temperatures and wind speeds for 18 surface stations in the region show a good agreement between observed and simulated data for all simulation periods. The results indicate consistent significant contributions of urban development and accompanying LULC changes to extreme temperatures for the four EHEs. Simulations suggest new urban developments caused an intensification and expansion of the area experiencing extreme temperatures but mainly influenced nighttime temperatures with an increase of up to 10 K. Nighttime temperatures in the existing urban core showed changes of up to ∼2 K with the ongoing LULC changes. Daytime temperatures were not significantly affected where urban development replaced desert land (increase by ∼1 K); however, maximum temperatures increased by ∼2–4 K when irrigated agricultural land was converted to suburban development. According to the model simulations, urban landscaping irrigation contributed to cooling by 0.5–1 K in maximum daytime as well as minimum nighttime 2-m air temperatures in most parts of the urban region. Furthermore, urban development led to a reduction of the already relatively weak nighttime winds and therefore a reduction in advection of cooler air into the city.

2016 ◽  
Vol 17 (10) ◽  
pp. 2713-2726 ◽  
Author(s):  
Trent W. Ford ◽  
Justin T. Schoof

Abstract Extreme heat events have been connected with antecedent soil moisture in many global regions, such that dry soils increase sensible heat content of the near-surface atmosphere and impede precipitation through boundary layer growth. However, negative soil moisture–temperature feedbacks (dry soils = higher temperatures) are founded on investigations of maximum temperature that neglect the potentially important latent heating component provided by soil moisture. In this study, the association of spring soil moisture and subsequent summer oppressive heat events is quantified, defined by equivalent temperature. The advantage of equivalent temperature over maximum temperature is that it accounts for both the temperature and moisture components of atmospheric heat content. Quantile regression and composite analysis are used to determine the association between spring soil moisture and summer oppressive heat events using a 25-yr station observation record in Illinois. A consistent response of summer oppressive heat events to antecedent 5-cm soil moisture anomalies is found at all four stations. The frequency of oppressive summer equivalent temperature events is significantly increased following spring seasons with wetter-than-normal soils compared with spring seasons with dry soils. This provides evidence of a possible positive soil moisture–temperature feedback. Further, it is found that oppressive heat events correspond with the combination of wetter-than-normal spring soils and persistent summertime upper-level ridging to the northeast of the region, thereby leading to the conclusion that abundant-to-surplus spring soil moisture is necessary but not sufficient for the occurrence of oppressive heat in Illinois.


1971 ◽  
Vol 1 (3) ◽  
pp. 27-32
Author(s):  
W.L.F. Brinkmann ◽  
M.N. Goes Ribeiro

Abstract Maximum and minimum air temperatures were taken weekley at 10 different sites about 2 cm above ground level during the period of June 15th, 1968 to January 26th, 1970. Three temperature types were observed each of which has a specific ecological effect on land-use in Central Amazonia.


2021 ◽  
pp. 1-49
Author(s):  
John Turner ◽  
Hua Lu ◽  
John King ◽  
Gareth J. Marshall ◽  
Tony Phillips ◽  
...  

AbstractWe present the first Antarctic-wide analysis of extreme near-surface air temperatures based on data collected up to the end of 2019 as part of the synoptic meteorological observing programs. We consider temperatures at 17 stations on the Antarctic continent and nearby sub-Antarctic islands. We examine the frequency distributions of temperatures and the highest and lowest individual temperatures observed. The variability and trends in the number of extreme temperatures were examined via the mean daily temperatures computed from the 0, 6, 12 and 18 UTC observations, with the thresholds for extreme warm and cold days taken as the 5th and 95th percentiles. The five stations examined from the Antarctic Peninsula region all experienced a statistically significant increase (p < 0.01) in the number of extreme high temperatures in the late Twentieth Century part of their records, although the number of extremes decreased in subsequent years. For the period after 1979 we investigate the synoptic background to the extreme events using ECMWF ERA-Interim reanalysis fields. The majority of record high temperatures were recorded after the passage of airmasses over high orography, with the air being warmed by the Föhn effect. At some stations in coastal East Antarctica the highest temperatures were recorded after air with a high potential temperature descended from the Antarctic plateau, resulting in an airmass 5-7°C warmer than the maritime air. Record low temperatures at the Antarctic Peninsula stations were observed during winters with positive sea ice anomalies over the Bellingshausen and Weddell Seas.


2013 ◽  
Vol 8 (2) ◽  
pp. 163-175
Author(s):  
Urszula Żukowska ◽  
Grażyna Kalewska

In today's world, when it is so important to use every piece of land for a particular purpose, both economically and ecologically, identifying optimal land use is a key issue. For this reason, an analysis of the optimal land use in a section of the city of Olsztyn, using the L-system Urban Development computer program, was chosen as the aim of this paper. The program uses the theories of L-systems and the cartographic method to obtain results in the form of sequences of productions or maps. For this reason, the first chapters outline both theories, i.e. the cartographic method to identify optimal land use and Lindenmayer grammars (called L-systems). An analysis based on a fragment of the map of Olsztyn was then carried out. Two functions were selected for the analysis: agricultural and forest-industrial. The results are presented as maps and sequences in individual steps.


Author(s):  
Olha Dorosh ◽  
Iryna Kupriyanchik ◽  
Denys Melnyk

The land and town planning legislation concerning the planning of land use development within the united territorial communities (UTC) is considered. It is found that legislative norms need to be finalized. The necessity of updating the existing land management documentation developed prior to the adoption of the Law of Ukraine "On Land Management" and changes in the structure of urban development in connection with the adoption of the Law of Ukraine "On Regulation of Urban Development" was proved as they do not ensure the integrity of the planning process within the territories of these communities through their institutional incapacity (proved by the example of the Palan Unified Territorial Community of the Uman district of the Cherkasy region). The priority of land management and urban planning documents as the most influential tools in planning the development of land use systems in UTC is scientifically grounded and their interdependence established.


Urban Science ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 18
Author(s):  
Ayyoob Sharifi ◽  
Maryam Roosta ◽  
Masoud Javadpoor

As cities are exposed to a portfolio of risks, the concept of resilience has risen to prominence over the past two decades. Consequently, a large volume of research has been published on different aspects of urban resilience. However, urban form resilience is still relatively understudied. As a step toward filling this gap, this study examines resilience of nine selected neighborhoods from Shiraz, an old Iranian city. The selected cases represent three different urban form patterns, namely, traditional, semi-planned, and planned. Different indicators related to the physical configuration of lots, blocks, open and green spaces, and street networks are used to examine resilience of each neighborhood to three major stressors, namely, earthquakes, extreme heat events, and floods. Additionally, a combination of Shannon entropy and the VIKOR (VlseKriterijumska Optimizcija I Kaompromisno Resenje in Serbian) method is used to rank the resilience of each neighborhood to each of the three stressors. Results show that, overall, the physical form of the planned neighborhoods is more conducive to urban resilience. In contrast, the urban form of traditional neighborhoods was found to be less resilient. There were, however, some variations depending on the type of stressor considered. The paper concludes by emphasizing the need to consider social and economic factors in future studies of urban form resilience.


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