Local Air Temperature Research Articles

Effects of Occupants and Local Air Temperatures as Sources of Stochastic Uncertainty in District Energy System Modeling

Input uncertainty is one of the major obstacles urban building energy models (UBEM) must tackle. The aim of this paper was to quantify the effects of two of the main sources of stochastic uncertainty, namely building occupants and urban microclimate, on electrical and thermal supply system sizing at the district scale. In order to analyze the effects of the former, three different methods of occupant modeling were implemented in a UBEM. The effects of the urban heat island on system sizing were studied through the use of measured temperature data from a weather station in the case study district compared to measured data from a national weather station. The methods developed were used to assess the sizing and costs of centralized and decentralized technologies for a case study in central Zurich, Switzerland. The choice of occupant modeling approach was found to affect the district’s total annualized costs for space heating and cooling by ±5%, whereas for the costs of electricity the variation was ±8%. Regarding outdoor temperature, the effects on the heating demands proved be negligible, however the costs of the cooling alternatives were found to vary by about 4% at the district scale due to the effect of urban climate, for individual buildings this deviation was as high as 40%.

Topography modulates near-ground microclimate in the Mediterranean Fagus sylvatica treeline

Understanding processes controlling forest dynamics has become particularly important in the context of ongoing climate change, which is altering the ecological fitness and resilience of species worldwide. However, whether forest communities would be threatened by projected macroclimate change or unaffected due to the controlling effect of local site conditions is still a matter for debate. After all, forest canopy buffer climate extremes and promote microclimatic conditions, which matters for functional plant response, and act as refugia for understory species in a changing climate. Yet precisely how microclimatic conditions change in response to climate warming will depend on the extent to which vegetation structure and local topography shape air and soil temperature. In this study, we posited that forest microclimatic buffering is sensitive to local topographic conditions and canopy cover, and using meteorological stations equipped with data-loggers we measured this effect during 1 year across a climate gradient (considering aspect as a surrogate of local topography) in a Mediterranean beech treeline growing in contrasting aspects in southern Italy. During the growing season, the below-canopy near-ground temperatures were, on average, 2.4 and 1.0 °C cooler than open-field temperatures for south and north-west aspects, respectively. Overall, the temperature offset became more negative (that is, lower under-canopy temperatures at the treeline) as the open-field temperature increased, and more positive (that is, higher under-canopy temperatures at the treeline) as the open-field temperature decreased. The buffering effect was particularly evident for the treeline on the south-facing slope, where cooling of near-ground temperature was as high as 8.6 °C for the maximum temperature (in August the offset peaked at 10 °C) and as high as 2.5 °C for the average temperature. In addition, compared to the south-facing slope, the northern site exhibited less decoupling from free-air environment conditions and low variability in microclimate trends that closely track the free-air biophysical environment. Although such a decoupling effect cannot wholly isolate forest climatic conditions from macroclimate regional variability in the south-facing treeline, it has the potential to partly offset the regional macroclimatic warming experienced in the forest understory due to anthropogenic climate change.

Observed impacts of utility-scale photovoltaic plant on local air temperature and energy partitioning in the barren areas

Rapid progress of solar photovoltaic (PV) technology has caused growing interest in understanding interactions between large scale PV plants and near-surface atmosphere. However few attempts have been made to quantify the impact of PV modules on surface radiative forcing and energy partitioning process. Here, this issue is explored experimentally and analytically in the two adjacent sites located at the PV plant and the natural barren field respectively in Wujiaqu in Xinjiang of China. The results showed that the physical effect of PV panels is not symmetrical in the whole day. During the daytime, compared with the reference site, net shortwave radiative forcing increases 8%, a warming effect on the integrated underlying surface (0.1 K) and a cooling effect (∼-2.6 K) on the ground surface were found in the PV plant. 9.2% of the net radiation (NR) was converted into electric energy (PE), sensible heat flux (H) increased by 30.6% hence resulted in the convection heating effects of 0.64 K and 0.32 K on the near-surface air temperature at the height of 2 m and 10 m respectively, while latent heat flux (LE) and ground surface heat flux (GS) decreased by 49% and 3% respectively related to the reference site. At night, PV panels produce a cooling effect of −0.2 K and −2.3 K on the ground and integrated underlying surface respectively, and less GS is released in the PV plant which contribute to the cooling effects of −0.24 K and −0.08 K on the air temperature at the height of 2 m and 10 m respectively related to the reference site. In the whole day, in the PV plant, H increased by 27.6%, LE and GS decreased by 47.4% and 6.7% respectively, air temperature increased by 0.16 K and 0.1 K at 2 m and 10 m respectively.

Irreversibility Analysis Related to Heterogeneous Airflow and Heat Transfer during Room Cooling of Postharvest Apples

Room cooling is traditionally used for postharvest products and is always involved with heterogeneous airflow and heat transfer. Despite the current evaluation of such heterogeneity, the irreversibility parameters are still not considered to evaluate the corresponding characteristics. Furthermore, the relationships between the irreversibility and the heterogeneous airflow and heat transfer should be also analyzed. To this end, based on the numerical simulation using an experimentally validated model, the distribution characteristics of air velocity, local mean air age, temperature, local volumetric rates of entropy generation, and entransy dissipation during the room cooling process for postharvest apples are respectively discussed. The relationships between the irreversibility parameters and apparent heterogeneity are further analyzed. The results show that higher local mean air age and temperature inside bins are resulted by lower air velocity nearby, and significant local volumetric rates of entropy generation and entransy dissipation at the surfaces of bins are also obtained for longer duration in the room cooling process. The irreversibility parameters, including local volumetric rates of entropy generation and entransy dissipation, are related to local mean air age with the Pearson’s coefficients of between 0.60 and 0.80 and better related to temperature with the Pearson’s coefficients of above 0.80.

A theoretical framework for classifying occupant-centric data streams on indoor climate using a physiological and cognitive process hierarchy

New and pervasive information and communication technologies have made it possible to capture a large range of continuous data from, or close to, each individual building occupant. These occupant-centric data streams may include subjective votes, evaluations, complaints, control actions, physiological measurements such as heart rate or pupil size, physical measurements of skin temperature or local draft and air temperature measurements, and much more. Currently, considerable resources are put into studies that focus on the development and potential uses of such systems, while the origin and nature of the collected information which is embedded in the data is poorly investigated. In this paper, we propose a taxonomy for the classification of occupant-centric data streams, developed through the application of established theories and categories in environmental and market psychology. The proposed framework organises five data source categories and links them to four levels of physiological and cognitive processes, making an explicit connection between data and embedded information attributes. The framework, originally developed to classify continuous occupant centric data in the domain of indoor climate, can also bring insights that might help explain known gaps and challenges in different models and theories that aim at predicting individual satisfaction with indoor climate conditions.

Assessment of global warming in Al Buraimi, sultanate of Oman based on statistical analysis of NASA POWER data over 39 years, and testing the reliability of NASA POWER against meteorological measurements

We performed a number of statistical analysis methods on the historical data for the air temperature at 2 m above the ground and its range, as reported by the database of NASA known as POWER, which stands for Prediction Of Worldwide Energy Resources. The point of analysis is the University of Buraimi, located in Al Buraimi Governate, in the Northwest of the Sultanate of Oman, near its border with United Arab Emirates (UAE). The data is in the form of a value per day, for every day in the year. The data analyzed span the period from January 3rd, 1981 (earliest day available) to December 31st, 2019 (latest end-of-year available).The statistical analysis methods include: simple linear regression, F-test: two-sample for variances, analysis of variance (ANOVA): single factor, and t-test: two-sample assuming equal variances (pooled).The results show that the mean of the local 2-meter air temperature is increasing at a rate of about 0.039 °C per year, starting from an estimated value of 27.4 °C in 1980.For the standard deviation of the 2-meter air temperature, and the mean and standard deviation of its range; although a linear regression analysis suggests a decline over time, the regression coefficient is not significant. On the other hand, the analysis of variance for the 9 years 1981, 1985, 1990, 1995, 2000, 2005, 2010, 2015, 2019 suggests existence of statistical difference among them collectively, for the 2-meter air temperature and its range.In the second part of this work, NASA POWER data for the air temperature at 2 m above the ground, the atmospheric pressure, the relative humidity at 2 m above the ground, and the daily precipitation were compared with recorded sensor measurements at Manah meteorological station, located in Al Dakhiliyah Governate, in the Northeast of the Sultanate of Oman over all days of years 2011, 2012, 2015, and 2016. The statistical analysis and visual inspection suggest that NASA POWER data are reliable for the 2-meter air temperature, while showing about 2.1 kPa constant shift (underestimation) for the atmospheric pressure. The data show mild inaccuracy for the 2-meter relative humidity, but are largely unreliable for the precipitation, with significantly exaggerated values compared to real recordings.

Impact Analysis of Urban Morphology on Residential District Heat Energy Demand and Microclimate Based on Field Measurement Data

In this work, we focus on investigating the relationship between urban morphology parameters and residential building space heating energy performance, comparing microclimate conditions of existing residential blocks with central heating supply. Firstly, a dataset composed of district morphological parameters that measured heat energy consumption was established. Then, effects of morphological indicators including cover ratio, average building height, and floor area ratio on building space heating energy efficiency were assessed specifically. Analysis results show that a larger floor area ratio induced a reduction in heating energy consumption density, the observed effect is notable at an initial increase of floor area ratio. Thirdly, the case study shows that the heating load of residential districts with a high built density is more sensitive to solar radiation. To further assess how and to what extent urban forms alter microclimates, on-site measurement investigated detailed changes in the thermal environment of selected residential districts before and after the operational stage of central heating supply. Analysis results demonstrate that heat energy delivered by a central heating supply could dampen the variations of local outdoor air temperatures, more notable for residential districts with a higher floor area ratio during the night period. Findings from this work would be useful for urban planners considering energy-efficient design practices.

Increasing temperature elevates the variation and spatial differentiation of pesticide tolerance in a plant pathogen.

Climate change and pesticide resistance are two of the most imminent challenges human society is facing today. Knowledge of how the evolution of pesticide resistance may be affected by climate change such as increasing air temperature on the planet is important for agricultural production and ecological sustainability in the future but is lack in scientific literatures reported from empirical research. Here, we used the azoxystrobin‐Phytophthora infestans interaction in agricultural systems to investigate the contributions of environmental temperature to the evolution of pesticide resistance and infer the impacts of global warming on pesticide efficacy and future agricultural production and ecological sustainability. We achieved this by comparing azoxystrobin sensitivity of 180 P. infestans isolates sampled from nine geographic locations in China under five temperature schemes ranging from 13 to 25°C. We found that local air temperature contributed greatly to the difference of azoxystrobin tolerance among geographic populations of the pathogen. Both among‐population and within‐population variations in azoxystrobin tolerance increased as experimental temperatures increased. We also found that isolates with higher azoxystrobin tolerance adapted to a broader thermal niche. These results suggest that global warming may enhance the risk of developing pesticide resistance in plant pathogens and highlight the increased challenges of administering pesticides for effective management of plant diseases to support agricultural production and ecological sustainability under future thermal conditions.

Extensive Urban Green Roof Shows Consistent Annual Net Uptake of Carbon as Documented by 5 Years of Eddy‐Covariance Flux Measurements

AbstractVegetated roofs or green roofs may supply a number of different urban ecosystem services such as thermal regulation of local air temperature by evaporative cooling or climate change mitigation by sequestration of CO2. However, knowledge about the annual and seasonal variations of green roof carbon uptake due to changes in meteorological conditions and water availability remains scarce. We studied the annual variation of net ecosystem exchange (NEE) by eddy‐covariance flux measurements during a 5‐year period from 2014 to 2019 on a large and unirrigated green roof at the Berlin‐Brandenburg airport (BER) in Berlin, Germany. The roof vegetation was dominated by Sedum species and herbs. The BER green roof showed net uptake of carbon in each of the 5 study years with an average uptake of −141.1 g C m−2 y−1 and an average measurement uncertainty of ±15.5 g C m−2 y−1. The NEE, however, was characterized by significant interannual variation in which the maximum annual uptake of −189 g C m−2 y−1 in a year with above average precipitation roughly doubles the minimum uptake of −95 g C m−2 y−1 in a dry year. The variation of NEE was a function of the annual amount of precipitation and the frequency of rainfall, that is, the number of dry days per year (DDY). The roof might lose its carbon uptake function in a warmer future climate with an increasing number of DDY. Sustainable irrigation of the roof (e.g., rainwater harvesting) could help to maintain the carbon uptake function of the green roof vegetation.

Correlation Between Local Air Temperature and the COVID-19 Pandemic in Hubei, China.

Objective: To clarify the correlation between temperature and the COVID-19 pandemic in Hubei.Methods: We collected daily newly confirmed COVID-19 cases and daily temperature for six cities in Hubei Province, assessed their correlations, and established regression models.Results: For temperatures ranging from −3.9 to 16.5°C, daily newly confirmed cases were positively correlated with the maximum temperature ~0–4 days prior or the minimum temperature ~11–14 days prior to the diagnosis in almost all selected cities. An increase in the maximum temperature 4 days prior by 1°C was associated with an increase in the daily newly confirmed cases (~129) in Wuhan. The influence of temperature on the daily newly confirmed cases in Wuhan was much more significant than in other cities.Conclusion: Government departments in areas where temperatures range between −3.9 and 16.5°C and rise gradually must take more active measures to address the COVID-19 pandemic.

INFLUENCE OF URBAN FORESTATION ON THE THERMAL COMFORT OF RESIDENTS OF JARDIM IRACEMA, FORTALEZA, CEARÁ

Urban forestation has an important connotation in the cities, being essential to contribute to the well-being of the population. The present study aimed to analyze the relationship between urban forestation and thermal comfort in an urban neighborhood of Fortaleza / CE. As specific objectives: to evaluate the influence of afforestation on microclimate factors, to compare different areas (with and without afforestation) in the Jardim Iracema neighborhood in Fortaleza / CE, and to understand the importance of trees for the population. This research was carried out in two stages: preliminary survey of the locality with subsequent application of a questionnaire with 40 people from the community and measurement of temperature and humidity in 8 different points, 4 of which are wooded and 4 not wooded. The results demonstrate that local air temperature and humidity are influenced by the presence of air. As for the environmental perception, 65% of the population is dissatisfied with the local urban forestation and they like places with trees because they bring shade (95%) and reduce the temperature (85%). However, they address harm such as interference with public lighting and the power grid. Most of the interviewees believe that the trees used do not resemble those of the caatinga domain and do not have an opinion about the pruning. Another important point is that half of the interviewees do not collaborate with the local urban forestation and believe that the public agencies must have responsibility on it. Public agencies must create strategies aimed at sensitizing the population about the importance of urban forestation and its maintenance, promoting environmental education.

Influence of glacial turbidity and climate on diatom communities in two Fjord Lakes (British Columbia, Canada)

Inputs of glacial meltwater and changes in climate can profoundly influence lake ecosystems. Anderson and Seton lakes, two morphologically and chemically similar fjord lakes within the Fraser River Basin, British Columbia, experience a common biogeoclimatic setting, yet contrasting turbid-water influences from a hydroelectric development which diverts glacially-turbid water into Seton Lake, but not Anderson Lake. We conducted a comparative paleolimnological study of these two lakes to infer climatic and hydro-system influences affecting the freshwater algal community over the past ~ 200 years. Paleolimnological analysis of multiple cores for sedimentary diatom assemblages from Seton Lake revealed substantial diversion-related reductions in diatom concentrations and fluxes following the completion of the Bridge River Diversion (ca. 1950). Diatom compositional changes in Seton Lake were consistent with decreased light penetration due to increased turbidity. These changes did not occur in Anderson Lake, indicating the changes in the Seton Lake cores were likely driven by inflow of the glacially-turbid waters. Both lakes exhibited diatom compositional changes ca. 1980, with a rise in Lindavia comensis coincident with significant increases in local mean annual air temperatures and presumably associated limnological changes. Modern phytoplankton data, collected as part of this study, provides support for the occurrence of different L. comensis morphs throughout the sampling period (May–October) in Anderson Lake and in the fall in Seton Lake. The rise of L. comensis in both Anderson and Seton lakes is conceivably linked to the recent ice-free conditions enabling this taxon to persist throughout the year.

Have you noticed a surge in heatwaves in the last decade? Heatwaves are becoming more common and so are their negative effects. So how do we alleviate these negative impacts? Most answers to this question involve using water directly or indirectly. European cities, for example, adopt a variety of water-dependent strategies such as greening streets and roofs to adapt to

With climate change comes more climatic extremes, and a higher chance of them happening simultaneously. But they are currently being studied in isolation. Together, drought and heatwaves prompted an exceptionally dangerous wildfire season in the Western U.S. in 2020 and 2021. We show that dry-AND-hot extreme events are increasing in intensity, frequency and spatial extent in the U.S. - submission by Mojtaba Sadegh, Mohammad Reza Alizadeh

Baffin Bay sea ice extent and synoptic moisture transport drive water vapor isotope (<i>δ</i><sup>18</sup>O, <i>δ</i><sup>2</sup>H, and deuterium excess) variability in coastal northwest Greenland

Abstract. At Thule Air Base on the coast of Baffin Bay (76.51∘ N, 68.74∘ W), we continuously measured water vapor isotopes (δ18O, δ2H) at a high frequency (1 s−1) from August 2017 through August 2019. Our resulting record, including derived deuterium excess (dxs) values, allows an analysis of isotopic–meteorological relationships at an unprecedented level of detail and duration for high Arctic Greenland. We examine isotopic variability across multiple temporal scales from daily to interannual, revealing that isotopic values at Thule are predominantly controlled by the sea ice extent in northern Baffin Bay and the synoptic flow pattern. This relationship can be identified through its expression in the following five interacting factors: (a) local air temperature, (b) local marine moisture availability, (c) the North Atlantic Oscillation (NAO), (d) surface wind regime, and (e) land-based evaporation and sublimation. Each factor's relative importance changes based on the temporal scale and in response to seasonal shifts in Thule's environment. Winter sea ice coverage forces distant sourcing of vapor that is isotopically light from fractionation during transport, while preventing isotopic exchange with local waters. Sea ice breakup in late spring triggers a rapid isotopic change at Thule as the newly open ocean supplies warmth and moisture that has ∼10 ‰ and ∼70 ‰ higher δ18O and δ2H values, respectively, and ∼10 ‰ lower dxs values. Sea ice retreat also leads to other environmental changes, such as sea breeze development, that radically alter the nature of relationships between isotopes and many meteorological variables in summer. On synoptic timescales, enhanced southerly flow promoted by negative NAO conditions produces higher δ18O and δ2H values and lower dxs values. Diel isotopic cycles are generally very small as a result of a moderated coastal climate and the counteracting isotopic effects of the sea breeze, local evaporation, and convection. Future losses in Baffin Bay's sea ice extent will likely shift mean annual isotopic compositions toward more summer-like values, and local glacial ice could potentially preserve isotopic evidence of past reductions. These findings highlight the influence that the local environment can have on isotope dynamics and the need for dedicated, multiseason monitoring to fully understand the controls on water vapor isotope variability.

A comparison of photovoltaic models for estimating power generation: a case study of Brazilian data

This paper presents photovoltaic (PV) generation models used to predict the power output injected into the grid, taking into account the relevant environmental variables, such as irradiance and ambient air temperature. The purpose is to identify the models that have the necessary degree of accuracy and simplicity to be used in studies of technical impacts of connecting PV generation plants to power systems. The paper focuses on semi-empirical models that adopt analytical expressions based on empirical equations and information provided by manufacturers. Using time series of ground measured irradiance and local ambient air temperature, five models are used to generate power output time series in minutely and hourly resolution, which are then compared with actual power measurements using statistical metrics.

Summer Mass Balance and Surface Velocity Derived by Unmanned Aerial Vehicle on Debris-Covered Region of Baishui River Glacier No. 1, Yulong Snow Mountain

Glacier retreat is a common phenomenon in the Qinghai-Tibetan Plateau (QTP) with global warming during the past several decades, except for several mountains, such as the glaciers in the Karakoram and the western Kunlun Mountains. The dynamic nature of glaciers significantly influences the hydrologic, geologic, and ecological systems in the mountain regions. The sensitivity and dynamic response to climate change make glaciers excellent indicators of regional and global climate change, such as glacier melting and retreat with the rise of local air temperature. Long-term monitoring of glacier change is important to understand and assess past, current, and possible future climate environments. Some glacier surfaces are safe and accessible by foot, and are monitored using mass balance stakes and snow pits. Meanwhile, some glaciers with inaccessible termini may be surveyed using satellite remote images and Unmanned Aerial Vehicles (UAVs). Those inaccessible glaciers are generally covered by debris in the southeast QTP, which is hardly accessible due to the wide distribution of crevasses and cliffs. In this paper, we used the UAV to monitor the dynamic features of mass balance and velocity of the debris-covered region of Baishui River Glacier No. 1 (BRG1) on the Yulong Snow Mountain (YSM), Southeast QTP. We obtained the Orthomosaic and DEM with a high resolution of 0.10 m on 20 May and 22 September 2018, respectively. The comparison showed that the elevation of the debris-covered region of the BRG1 decreased by 6.58 m ± 3.70 m on average, and the mean mass balance was −5.92 m w.e. ± 3.33 m w.e. during the summer, correspondingly. The mean displacement of debris-covered glacier surface was 18.30 m ± 6.27 m, that is, the mean daily velocity was 0.14 m/d ± 0.05 m/d during the summer. In addition, the UAV images not only revealed the different patterns of glacier melting and displacement but also captured the phenomena of mass loss due to ice avalanches at the glacier front and the development of large crevasses. This study provides a feasible method for understanding the dynamic features of global debris-covered glaciers which are inaccessible and unobservable by other means.

How to assess ecodistrict resilience to urban heat stress under future heatwaves? A case study for the city of Paris

It is now well-known that the frequency, intensity and duration of heatwaves will strongly increase along the XXIth century, which introduces the urban built environment resilience as a new paradigm. In Paris, the intense 2003 heatwave demonstrated that warm urban temperatures could result in serious adverse health issues. Temperatures were particularly elevated during nighttime, due to the urban heat island effect. Since air-conditioning has not penetrated yet in residential French buildings, studying the potential of combined mitigation strategies at the district and building scale to increase the neighbourhood and buildings resilience in strong urbanized areas under future heatwaves is a key subject matter. The climate change aspect is integrated through a future heatwave weather file, re-assembled from dynamically downscaled multi-year regional climate change projections from the EURO-CORDEX project. The new ecodistrict Clichy-Batignolles in central Paris is chosen as a case study, recognized as innovative for low-energy and environmental solutions. It is composed of high-rise residential and commercial buildings, large green areas, cool surfaces, and reduced anthropogenic sources. We used an Urban Canyon Model (Urban Weather Generator) to model the neighbourhood and different design configurations (building height and density, green and cool surfaces). The designs and measures were evaluated through a sensitivity analysis to analyse their potential to mitigate the urban local microclimate air temperature during the heatwaves. We quantified the neighbourhood resilience and found that the ecodistrict is exposed to a strong urban heat stress under the future intense heatwave. These results highlight how outdoor overheating assessment can be used to evaluate the district mitigation and adaptation strategies. This approach can be used for urban planning, while the modelled future urban heatwaves can be used as an input for building simulations and evaluate the resilience of the buildings to urban heat stress.

An Integrated Microclimate-Energy Demand Simulation Method for the Assessment of Urban Districts

Rapid urbanization and densification processes are changing microclimatic environments in cities around the world. Even though previous studies have demonstrated the impact of urban microclimate on space cooling and heating demand, modeling tools employed to support the design process largely overlook microclimatic conditions in assessing building energy performance, making use of data from weather stations often located in rural areas. This paper presents a computational approach for the quantitative analysis of building energy demand at the district scale, including interdependent factors such as local air temperature, relative humidity and wind speed, diversity in building geometry and materials. The method, which couples the microclimate model ENVI-met and the district-scale energy simulation tool City Energy Analyst, is applied to a case study in Zurich, Switzerland, in order to analyze the energy performance of the area on a hot summer day. The study contributes to advance a coupling approach between a microclimate simulation and an energy tool at the district scale. The results showed that the coupled assessment approach can deal with complex interactions between geometry, building materials and energy systems. The consideration of local microclimatic conditions led to a 5% increase in the space cooling demand on the selected day, while the simulated peak cooling load for each building was 8% higher on average. The variation in the space cooling demand was found to be mainly due to an increase in latent cooling demand. Moreover, the coupling method allowed a detailed analysis of energy demand variation at the building level showing that, when considering the local climate patterns, the space cooling demand of the individual buildings varied between -5% and +14% on the selected day. The proposed method represents a next step to reflect the mutual interactions between buildings and microclimate in urban districts and aims at supporting decision-making in the design process.

Effects of a Large Dust Storm in the Near‐Surface Atmosphere as Measured by InSight in Elysium Planitia, Mars. Comparison With Contemporaneous Measurements by Mars Science Laboratory

AbstractNASA's InSight landed in Elysium Planitia (~4.5°N,136°E) at Ls ~ 296° (November 2018), right after the decay of the 2018 Global Dust Storm (GDS) and before the onset of the 2019 Large Dust Storm (LDS) at Ls ~ 320° (January 2019). InSight's cameras observed a rise in the atmospheric opacities during the storm from ~0.7 to ~1.9, similarly to contemporaneous measurements by Curiosity in Gale crater. Pressure tides were strongly affected at the locations of InSight and Curiosity. In particular, the diurnal pressure mode experienced an abrupt increase during the onset of the LDS, similar to that measured by Curiosity, most likely due to longitudinally asymmetric dust loading. Later, the dust was redistributed around the planet and the semidiurnal mode evolved according to dust opacity in both missions. Before and after the onset of the storm, the observed wind patterns resulted from the interaction between regional and local slope flows induced by topography, which all produced a diurnal perturbation superimposed on a mean flow, dominated by the Hadley cell but with modifications due to channeling effects from the regional topography. However, the onset of the LDS modified this to a scenario consistent with enhanced tidal flows. The local air temperatures are strongly perturbed by the lander's thermal effects, and their retrieval significantly depends on wind patterns, which changed during the course of the dust storm. Observations suggest a decrease in convective vortices during the dust storm; however, vortex activity remained strong during the storm's onset due to the increase in wind speeds.

Greenery System for Cooling Down Outdoor Spaces: Results of an Experimental Study

Urban green infrastructure (UGI) and nature-based solutions (NBS) are increasingly recognized as strategies to address urban sustainability challenges. These solutions are attracting key scientific and marketing attention thanks to their capability to improve indoor and outdoor thermal comfort and environmental quality of spaces. In urban areas, where most of the population worldwide lives, indoor-outdoor environmental quality is compromised by local and temporary overheating phenomena, air pollution concentration, and impervious surfaces minimizing urban space resilience to climate change related hazards. In this view, the proposed study concerns the analysis of a greenery system for enhancing outdoor thermal conditions and local warming mitigation for pedestrians for the continental Mediterranean climate. The system has the purpose of designing an outdoor “alive” shading system to be applied in open public spaces, with producing physical and societal benefits. The experimental results showed that the implementation of the greenery, characterized by lower surface temperatures and evapotranspiration compared to a simple pergola system, allows the reduction of outdoor air temperature under the shading system and, thus, higher relative humidity in summer. Specifically, the hygrothermal cooling and the additional shading thanks to the presence of greenery provide local air temperature reduction up to 5 °C at pedestrian level.