scholarly journals Microclimate and radiant energy measurements using a novel device for natural resource monitoring

2016 ◽  
Author(s):  
Taylor Thomas ◽  
Adam Wolf
Keyword(s):  
Relative Humidity ◽  
Air Temperature ◽  
Radiant Energy ◽  
Barometric Pressure ◽  
Net Radiation ◽  
Resource Monitoring ◽  
Energy Monitoring ◽  
Active Radiation ◽  
Novel Device ◽  
Natural Resource Monitoring

ABSTRACTA novel device for microclimate and radiant energy monitoring of natural resources was compared to known reference instruments and sensors to gauge relative performance under field conditions in Nebraska and New Jersey, USA during summer 2016. For all measurements tested, including air temperature, relative humidity, barometric pressure, four component net radiation, and photosynthetically active radiation, the device reported values near or within the accuracy limits as stated by the reference instrument / sensor manufacturer.

scholarly journals Microclimate under different shading screens in greenhouses cultivated with bromeliads

2012 ◽  
Vol 16 (8) ◽  
pp. 858-863 ◽  
Author(s):  
Ester Holcman ◽  
Paulo C. Sentelhas
Keyword(s):  
Relative Humidity ◽  
Solar Radiation ◽  
Air Temperature ◽  
Photosynthetically Active Radiation ◽  
External Condition ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Net Radiation ◽  
Active Radiation ◽  
Incoming Solar Radiation

This study had as its objective the evaluation of the influence of shading screens of different colors on the different microclimate variables in a greenhouse covered with transparent low-density polyethylene (LDPE). The experiment was conducted with five treatments: thermo-reflective screen (T1); a control - without screen (T2); red screen (T3); blue screen (T4); and black screen (T5), all of them with 70% of shading. An automatic micrometeorological station was installed in each treatment, measuring air temperature (T), relative humidity (RH), incoming solar radiation (Rg), photosynthetically active radiation (PAR) and net radiation (Rn) continuously. The control (T2) and red screen (T3) treatments promoted the highest solar radiation transmissivity, respectively 56.3 and 27%. The black screen (T5) had the lowest solar radiation transmissivity (10.4%). For PAR and Rn the same tendency was observed. The highest temperature was observed under blue screen (T4) treatment, which was 1.3 °C higher than external condition. Blue screen (T4) treatment also presented the highest relative humidity difference between inside and outside conditions.

Ranking Potential Evapotranspiration Models in the Prediction of Maize Water Requirements in the PortHarcourt Area of Nigeria

2003 ◽  
Vol 32 (1) ◽  
pp. 51-56 ◽  
Author(s):  
M.J. Ayotamuno
Keyword(s):  
Relative Humidity ◽  
Air Temperature ◽  
Meteorological Factors ◽  
Potential Evapotranspiration ◽  
Empirical Models ◽  
Geographical Region ◽  
Net Radiation ◽  
Temperature Elevation ◽  
Water Requirements

It has been observed that many of the empirical models used to estimate evapotranspiration, although simple, are not sufficiently sensitive in those areas where the temperature is relatively constant but other meteorological factors that promote evapotranspiration vary (Michael, 1978; Hashemi and Haliban, 1979). It is therefore important to verify, or even recalibrate these models when they are used within a new geographical region or climatic area (eg PortHarcourt, Nigeria) if account is to be taken of relational changes between meteorological factors such as net radiation, air temperature, elevation, advection and relative humidity.

scholarly journals A New Index Assessing the Viability of PAR Application Projects Used to Validate PAR Models

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 470
Author(s):  
Francisco Ferrera-Cobos ◽  
Jose M. Vindel ◽  
Rita X. Valenzuela
Keyword(s):  
Neural Networks ◽  
Artificial Neural Networks ◽  
Relative Humidity ◽  
Air Temperature ◽  
Satellite Data ◽  
Solar Zenith Angle ◽  
The Other ◽  
Clearness Index ◽  
Active Radiation ◽  
Climatic Regions

Photosynthetically active radiation (PAR) is a useful variable to estimate the growth of biomass or microalgae. However, it is not always feasible to access PAR measurements; in this work, two sets of nine hourly PAR models were developed. These models were estimated for mainland Spain from satellite data, using multilinear regressions and artificial neural networks. The variables utilized were combinations of global horizontal irradiance, clearness index, solar zenith angle cosine, relative humidity, and air temperature. The study territory was divided into regions with similar features regarding PAR through clustering of the PAR clearness index (kPAR). This methodology allowed PAR modeling for the two main climatic regions in mainland Spain (Oceanic and Mediterranean). MODIS 3 h data were employed to train the models, and PAR data registered in seven stations across Spain were used for validation. Usual validation indices assess the extent to which the models reproduce the observed data. However, none of those indices considers the exceedance probabilities, which allow the assessment of the viability of projects based on the data to be modeled. In this work, a new validation index based on these probabilities is presented. Hence, its use, along with the other indices, provides a double and thus more complete validation.

scholarly journals Modeling Regional Vegetation NPP Variations and Their Relationships with Climatic Parameters in Wuhan, China

2013 ◽  
Vol 17 (4) ◽  
pp. 1-20 ◽  
Author(s):  
Lunche Wang ◽  
Wei Gong ◽  
Yingying Ma ◽  
Miao Zhang
Keyword(s):  
Air Temperature ◽  
Photosynthetically Active Radiation ◽  
Vegetation Index ◽  
Climatic Factors ◽  
Global Radiation ◽  
Air Pressure ◽  
Stress Factors ◽  
Net Radiation ◽  
Active Radiation ◽  
Sunshine Hours

Abstract Net primary productivity (NPP) is an important component of the carbon cycle and a key indicator of ecosystem performance. The aim of this study is to construct a more accurate regional vegetation NPP estimation model and explore the relationship between NPP and climatic factors (air temperature, rainfall, sunshine hours, relative humidity, air pressure, global radiation, and surface net radiation). As a key variable in NPP modeling, photosynthetically active radiation (PAR) was obtained by finding a linear relationship between PAR and horizontal direct radiation, scattered radiation, and net radiation with high accuracy. The fraction of absorbed photosynthetically active radiation (FPAR) was estimated by enhanced vegetation index (EVI) instead of the widely used normalized difference vegetation index (NDVI). Stress factors of temperature/humidity for different types of vegetation were also considered in the simulation of light use efficiencies (LUE). The authors used EVI datasets of Moderate Resolution Imaging Spectroradiometer (MODIS) from 2001 to 2011 and geographic information techniques to reveal NPP variations in Wuhan. Time lagged serial correlation analysis was employed to study the delayed and continuous effects of climatic factors on NPP. The results showed that the authors’ improved model can simulate vegetation NPP in Wuhan effectively, and it may be adopted or used in other regions of the world that need to be further tested. The results indicated that air temperature and air pressure contributed significantly to the interannual changes of plant NPP while rainfall and global radiation were major climatic factors influencing seasonal NPP variations. A significant positive 32-day lagged correlation was observed between seasonal variation of NPP and rainfall (P < 0.01); the influence of changing climate on NPP lasted for 64 days. The impact of air pressure, global radiation, and net radiation on NPP persisted for 48 days, while the effects of sunshine hours and air temperature on NPP only lasted for 16 and 32 days, respectively.

scholarly journals Influence of different protected cultivation structures on performance of cucumber (Cucumis sativus L.) in Indian hot arid region

2021 ◽  
Vol 23 (3) ◽  
pp. 265-271
Author(s):  
P.S. KHAPTE ◽  
H.M. MEENA ◽  
PRADEEP KUMAR ◽  
UDAY BURMAN ◽  
ANURAG SAXENA ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Plant Growth ◽  
Air Temperature ◽  
Arid Region ◽  
Arid Regions ◽  
Physiological Activity ◽  
Cucumis Sativus L ◽  
Active Radiation ◽  
Protected Cultivation ◽  
Greenhouse Cucumber

The performance of gynoecious cucumber (cv. Terminator) was evaluated under three protected structures viz., naturally ventilated polyhouse (NVP), insect proof net house (INH) and shade net house (SNH) at Jodhpur, Rajasthan in hot arid region of India. The photosynthetically active radiation (PAR) inside these structures during cropping period ranged from 154-842 μmol m-2 s-1 which was much lower than the outside. Among structures, air temperature was 1.2°C and 0.7°C lower while relative humidity (RH) was 17 and 4 per cent higher in NVP and SNH respectively as compared to INH. Relatively low air as well as soil temperature, coupled with high RH and optimal radiation in NVP led to better plant growth and physiological activity which resulted in 42 and 142per cent higher yield than INH and SNH, respectively. Hence, it can be recommended that NVP is the best low-tech protected structure which modifies the microclimate favouring successful cultivation of greenhouse cucumber in Indian hot arid regions.

scholarly journals Effect of shelterbelt on the microclimate of the gram (Cicer arietinum) crop

MAUSAM ◽  
2021 ◽  
Vol 47 (2) ◽  
pp. 173-178
Author(s):  
RAJ SINGH ◽  
O. P. BISHNOI ◽  
V. U. M. RAO ◽  
DIWAN SINGH
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Cicer Arietinum ◽  
Air Temperature ◽  
Photosynthetically Active Radiation ◽  
Minimum Temperature ◽  
Radiation Absorption ◽  
Active Radiation ◽  
Maximum Reduction

The shelterbelt influence on the microclimate of gram crop in different intercropping systems comprising of four treatment, viz., pure gram, 1 : 1, 2 : 1 and 4 : 1 gram and raya, was quantified. Albedo varied from 14.8 to 22.6 percent in various treatments with highest value fo 18.3 percent in pure gram treatment, whereas, photosynthetically active radiation absorption was highest in  2 : 1 gram treatment (76%). Maximum reduction (69.2 per cent) in wind speed was observed in  1 : 1 intercropping system at 4h distance from the edge of the shelterbelt in comparison to pure gram field. Relative humidity was 8 to 15 percent less in the sheltered gram as compare to the pure gram, whereas, the average air temperature increased by 1 to 2 C in the sheltered crop over that of the pure gram and this increase was in the range of  9.9 to 12.2 per cent at 4h distance from the edge of shelterbelt. The grass minimum temperature was higher by 0.7degree cent grate in 2 : 1 treatment over that of pure gram during the months of January and February.  

scholarly journals Development of Suitable Microclimate Using Low˗tech Greenhouse for Off-Season Production of High Value Crops in Bangladesh

2021 ◽  
Vol 3 (6) ◽  
pp. 95-103
Author(s):  
M. A. Awal ◽  
P. C. Dhar ◽  
M. H. R. Pramanik
Keyword(s):  
Relative Humidity ◽  
Film Thickness ◽  
Air Temperature ◽  
Photosynthetically Active Radiation ◽  
Crop Production ◽  
Active Radiation ◽  
Horticultural Crops ◽  
Season Extension ◽  
Soil Temperatures ◽  
Solar Noon

Low˗tech greenhouses (low˗techs) have been used globally to cultivate horticultural crops since many years, but their utilization in Bangladesh is a recent phenomenon. Moreover, information on altered microclimate inside the low˗tech is hardly reported. An investigation has been conducted in the Crop Botany Field Laboratory, Bangladesh Agricultural University (24o72´N, 90o43´E and 18 masl), Mymensingh during the late autumn to winter seasons from mid-October to mid-February of 2015/16, 2016/17 and 2017/18 years to find out the variation in microclimatic parameters between inside and outside of low˗techs and to evaluate the suitability of altered microclimate inside the low˗techs for off˗season production of high value crops in Bangladesh. Three low˗techs were erected in each year using bamboo frame covered with single inflated polyethylene film (thickness = 0.2 mm). Major microclimatic parameters inside and aside outside the low˗techs were measured with standard devices or techniques. Around 30 percent incoming photosynthetically active radiation (PAR) was cut˗off by low˗tech cover during solar noon when the sun’s zenith gets minimum value (around 0o). However, this cut˗off portion of PAR was gradually increased with the sunrise and sunset when zenith is around 90o. During the daytime, low˗tech retains higher air temperature than that found at outside and the differences in air temperature between inside and outside of low˗techs was gradually increased after sunrise with a peak difference of 7 to 9 oC following the solar noon (i.e., 13:00-14:00 hour). No distinct variation in relative humidity was recorded between inside and outside of the low˗tech. Low˗tech cover retains higher soil temperature than that was recorded in outside. The variation of both air and soil temperatures between inside and outside of low˗techs was higher during the daytime but lower at nighttime or even at daytime when the sky remained overcast. The variation in microclimatic parameters under low˗techs not only protect the growing crops from climate vagaries during autumn, winter and spring seasons but also provide suitable warmer environment for growing many high value crops during that seasons and thus crop production in off˗season and/or season extension benefits can easily be achieved by low˗techs.

scholarly journals Detrended Multiple Cross-Correlation Coefficient applied to solar radiation, air temperature and relative humidity

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Andrea de Almeida Brito ◽  
Heráclio Alves de Araújo ◽  
Gilney Figueira Zebende
Keyword(s):  
Relative Humidity ◽  
Solar Radiation ◽  
Solar Energy ◽  
Correlation Coefficient ◽  
Air Temperature ◽  
Cross Correlation ◽  
Global Solar Radiation ◽  
Meteorological Variables ◽  
Hourly Data ◽  
Cross Correlations

AbstractDue to the importance of generating energy sustainably, with the Sun being a large solar power plant for the Earth, we study the cross-correlations between the main meteorological variables (global solar radiation, air temperature, and relative air humidity) from a global cross-correlation perspective to efficiently capture solar energy. This is done initially between pairs of these variables, with the Detrended Cross-Correlation Coefficient, ρDCCA, and subsequently with the recently developed Multiple Detrended Cross-Correlation Coefficient, $${\boldsymbol{DM}}{{\boldsymbol{C}}}_{{\bf{x}}}^{{\bf{2}}}$$DMCx2. We use the hourly data from three meteorological stations of the Brazilian Institute of Meteorology located in the state of Bahia (Brazil). Initially, with the original data, we set up a color map for each variable to show the time dynamics. After, ρDCCA was calculated, thus obtaining a positive value between the global solar radiation and air temperature, and a negative value between the global solar radiation and air relative humidity, for all time scales. Finally, for the first time, was applied $${\boldsymbol{DM}}{{\boldsymbol{C}}}_{{\bf{x}}}^{{\bf{2}}}$$DMCx2 to analyze cross-correlations between three meteorological variables at the same time. On taking the global radiation as the dependent variable, and assuming that $${\boldsymbol{DM}}{{\boldsymbol{C}}}_{{\bf{x}}}^{{\bf{2}}}={\bf{1}}$$DMCx2=1 (which varies from 0 to 1) is the ideal value for the capture of solar energy, our analysis finds some patterns (differences) involving these meteorological stations with a high intensity of annual solar radiation.

scholarly journals Effects of trees, gardens, and nature trails on heat index and child health: design and methods of the Green Schoolyards Project

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Kevin Lanza ◽  
Melody Alcazar ◽  
Deanna M. Hoelscher ◽  
Harold W. Kohl
Keyword(s):  
Physical Activity ◽  
United States ◽  
Relative Humidity ◽  
Air Temperature ◽  
The United States ◽  
Heat Index ◽  
Activity Levels ◽  
Natural Setting ◽  
Physical Activity Levels ◽  
Nature Trails

Abstract Background Latinx children in the United States are at high risk for nature-deficit disorder, heat-related illness, and physical inactivity. We developed the Green Schoolyards Project to investigate how green features—trees, gardens, and nature trails—in school parks impact heat index (i.e., air temperature and relative humidity) within parks, and physical activity levels and socioemotional well-being of these children. Herein, we present novel methods for a) observing children’s interaction with green features and b) measuring heat index and children’s behaviors in a natural setting, and a selection of baseline results. Methods During two September weeks (high temperature) and one November week (moderate temperature) in 2019, we examined three joint-use elementary school parks in Central Texas, United States, serving predominantly low-income Latinx families. To develop thermal profiles for each park, we installed 10 air temperature/relative humidity sensors per park, selecting sites based on land cover, land use, and even spatial coverage. We measured green features within a geographic information system. In a cross-sectional study, we used an adapted version of System for Observing Play and Recreation in Communities (SOPARC) to assess children’s physical activity levels and interactions with green features. In a cohort study, we equipped 30 3rd and 30 4th grade students per school during recess with accelerometers and Global Positioning System devices, and surveyed these students regarding their connection to nature. Baseline analyses included inverse distance weighting for thermal profiles and summing observed counts of children interacting with trees. Results In September 2019, average daily heat index ranged 2.0 °F among park sites, and maximum daily heat index ranged from 103.4 °F (air temperature = 33.8 °C; relative humidity = 55.2%) under tree canopy to 114.1 °F (air temperature = 37.9 °C; relative humidity = 45.2%) on an unshaded playground. 10.8% more girls and 25.4% more boys interacted with trees in September than in November. Conclusions We found extreme heat conditions at select sites within parks, and children positioning themselves under trees during periods of high heat index. These methods can be used by public health researchers and practitioners to inform the redesign of greenspaces in the face of climate change and health inequities.

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