Frost damage to Hemerocallis esculenta in a mire: relationship between flower bud height and air temperature profile during calm, clear nights

2004 ◽  
Vol 82 (3) ◽  
pp. 409-419 ◽  
Author(s):  
Masahito Yamada ◽  
Hidenori Takahashi
Keyword(s):  
Temperature Profile ◽  
Air Temperature ◽  
Minimum Temperature ◽  
Frost Damage ◽  
Flower Bud ◽  
Vegetation Height ◽  
Meteorological Observations ◽  
Lower Height ◽  
First Time ◽  
Sarobetsu Mire

As air temperature near the ground changes with height, the present study investigates the effect of those changes and their role on the relationship between frost damage and flower bud height of Hemerocallis esculenta Koidzumi during scape elongation in the Sarobetsu Mire, Hokkaido, Japan. Meteorological observations near the ground and flower bud height of H. esculenta were measured from April to August in 2001, 2002, and 2003. In the present study, the intensity and duration of low temperature were combined as one variable instead of being treated as separate variables, as is usually done in laboratory experiments. In addition, the raised minimum temperature phenomenon was observed for the first time in a mire. The frost damage event occurred during predawn on 15 June 2001, 5 June 2002, and 5 June 2003. The weather during those nights was calm and clear, and the wind was not strong enough to prevent frost damage. The lower height limit of frost damage, observed in 2003, was found to be around 0.10–0.15 m, as buds below this height were protected by their own leaves. The upper height limit of frost damage was 0.34 and 0.43 m for 2001 and 2002, respectively. Frost damage of H. esculenta depended on the air temperature profile, which was affected mainly by vegetation height during scape elongation during calm, clear nights in the Sarobetsu Mire. Other factors that contributed to frost damage were also intensity–duration of low temperatures, which was treated as one variable in the present study, and the raised minimum temperature phenomenon.Key words: air temperature profile, bud height, lethal temperature, raised minimum temperature phenomenon, scape elongation.

scholarly journals Spring Frost Damage to Tea Plants Can Be Identified with Daily Minimum Air Temperatures Estimated by MODIS Land Surface Temperature Products

2021 ◽  
Vol 13 (6) ◽  
pp. 1177
Author(s):  
Peijuan Wang ◽  
Yuping Ma ◽  
Junxian Tang ◽  
Dingrong Wu ◽  
Hui Chen ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Air Temperature ◽  
Land Surface Temperature ◽  
Land Surface ◽  
Frost Damage ◽  
Estimation Model ◽  
Spring Frost ◽  
Tea Plants ◽  
Elevation Model ◽  
Minimum Air Temperature

Tea (Camellia sinensis) is one of the most dominant economic plants in China and plays an important role in agricultural economic benefits. Spring tea is the most popular drink due to Chinese drinking habits. Although the global temperature is generally warming, spring frost damage (SFD) to tea plants still occurs from time to time, and severely restricts the production and quality of spring tea. Therefore, monitoring and evaluating the impact of SFD to tea plants in a timely and precise manner is a significant and urgent task for scientists and tea producers in China. The region designated as the Middle and Lower Reaches of the Yangtze River (MLRYR) in China is a major tea plantation area producing small tea leaves and low shrubs. This region was selected to study SFD to tea plants using meteorological observations and remotely sensed products. Comparative analysis between minimum air temperature (Tmin) and two MODIS nighttime land surface temperature (LST) products at six pixel-window scales was used to determine the best suitable product and spatial scale. Results showed that the LST nighttime product derived from MYD11A1 data at the 3 × 3 pixel window resolution was the best proxy for daily minimum air temperature. A Tmin estimation model was established using this dataset and digital elevation model (DEM) data, employing the standard lapse rate of air temperature with elevation. Model validation with 145,210 ground-based Tmin observations showed that the accuracy of estimated Tmin was acceptable with a relatively high coefficient of determination (R2 = 0.841), low root mean square error (RMSE = 2.15 °C) and mean absolute error (MAE = 1.66 °C), and reasonable normalized RMSE (NRMSE = 25.4%) and Nash–Sutcliffe model efficiency (EF = 0.12), with significantly improved consistency of LST and Tmin estimation. Based on the Tmin estimation model, three major cooling episodes recorded in the "Yearbook of Meteorological Disasters in China" in spring 2006 were accurately identified, and several highlighted regions in the first two cooling episodes were also precisely captured. This study confirmed that estimating Tmin based on MYD11A1 nighttime products and DEM is a useful method for monitoring and evaluating SFD to tea plants in the MLRYR. Furthermore, this method precisely identified the spatial characteristics and distribution of SFD and will therefore be helpful for taking effective preventative measures to mitigate the economic losses resulting from frost damage.

scholarly journals Evidence of elevation-dependent warming from the Chinese Tian Shan

2021 ◽  
Vol 15 (12) ◽  
pp. 5765-5783
Author(s):  
Lu Gao ◽  
Haijun Deng ◽  
Xiangyong Lei ◽  
Jianhui Wei ◽  
Yaning Chen ◽  
...  
Keyword(s):  
Air Temperature ◽  
Minimum Temperature ◽  
Swiss Alps ◽  
Maximum Temperature ◽  
Current Evidence ◽  
High Mountain ◽  
Regional Warming ◽  
Mean Temperature ◽  
Warming Rate ◽  
Tian Shan

Abstract. The phenomenon in which the warming rate of air temperature is amplified with elevation is termed elevation-dependent warming (EDW). It has been clarified that EDW can accelerate the retreat of glaciers and melting of snow, which can have significant impacts on the regional ecological environment. Owing to the lack of high-density ground observations in high mountains, there is widespread controversy regarding the existence of EDW. Current evidence is mainly derived from typical high-mountain regions such as the Swiss Alps, the Colorado Rocky Mountains, the tropical Andes and the Tibetan Plateau–Himalayas. Rare evidence in other mountain ranges has been reported, especially in arid regions. In this study, EDW features (regional warming amplification and altitude warming amplification) in the Chinese Tian Shan (CTM) were detected using a unique high-resolution (1 km, 6-hourly) air temperature dataset (CTMD) from 1979 to 2016. The results showed that there were significant EDW signals at different altitudes on different timescales. The CTM showed significant regional warming amplification in spring, especially in March, and the warming trends were greater than those of continental China with respect to three temperatures (minimum temperature, mean temperature and maximum temperature). The significance values of EDW above different altitude thresholds are distinct for three temperatures in 12 months. The warming rate of the minimum temperature in winter showed a significant elevation dependence (p<0.01), especially above 3000 m. The greatest altitudinal gradient in the warming rate of the maximum temperature was found above 4000 m in April. For the mean temperature, the warming rates in June and August showed prominent altitude warming amplification but with different significance above 4500 m. Within the CTM, the Tolm Mountains, the eastern part of the Borokoonu Mountains, the Bogda Mountains and the Balikun Mountains are representative regions that showed significant altitude warming amplification on different timescales. This new evidence could partly explain the accelerated melting of snow in the CTM, although the mechanisms remain to be explored.

scholarly journals Estudo de Frequência da Ocorrência de Rajada de Vento e seu Papel na Segurança das Operações Aéreas no Aeródromo Internacional de Belém-PA (Wind Occurrence Frequency Study and Its Importance in Air Operations Security on Belém's International Aerodrome)

2015 ◽  
Vol 7 (6) ◽  
pp. 1110
Author(s):  
Ingrid Monteiro Peixoto de Souza ◽  
Thiago Melo Souza ◽  
José Danilo Costa Souza Filho ◽  
Maria do Carmo Felipe de Oliveira ◽  
Dimitrie Nechet
Keyword(s):  
Air Temperature ◽  
Atmospheric Pressure ◽  
Occurrence Frequency ◽  
Equatorial Atlantic ◽  
Flight Operations ◽  
Equatorial Atlantic Ocean ◽  
Meteorological Observations ◽  
Maximum Temperatures ◽  
Meteorological Elements ◽  
Wind Intensity

Este trabalho teve como objetivo estudar a freqüência de ocorrência de rajada de vento e sua importância na segurança das operações aéreas, uma vez que estas apresentam significativas variações de intensidade do vento, podendo ocasionar, inúmeros riscos para a aviação, desde desconforto durante o voo, até perdas de vidas humanas. Os dados foram obtidos no Aeródromo Internacional de Belém do Pará, no período de 2009 a 2012, onde foram realizadas análises estatísticas, bem como, estudos das correlações dos percentuais de ocorrências com os elementos meteorológicas de superfície (temperatura do ar e pressão atmosférica), extraídas de observações meteorológicas horárias da localidade em estudo. Os resultados mostram, que nos últimos anos, a ocorrência de rajada de vento no aeródromo de Belém-Pa, vem aumentando, onde o maior registro dessa ocorrência dentro do período foi no ano de 2012. A maior frequência de eventos de rajada por intervalos de velocidade foi de 21 a 30 KT. A maior distribuição sazonal do registro de rajadas de vento ocorreu no período mais chuvoso da região, dezembro a maio, influenciadas pela nebulosidade, formada no Oceano Atlântico Equatorial, devido a atuação da ZCIT. As maiores quantidades de registros de rajadas de ventos correspondem ao período de máximas temperaturas, sugerindo uma correlação entre o aquecimento e a ocorrência de rajadas próximas a superfície terrestre. A distribuição de rajada de vento, de acordo com a orientação do vento indica predominância dos ventos de leste, de 60º a 120º.  ABSTRACT This paper aimed to study the wind occurrence frequency and its importance on the safety of flight operations, since these are significant variations in wind intensity, causing many risks to aviation, from discomfort during flight to even loss of lifes. The data were obtained from the International Aerodrome of Belém do Pará, in the period from 2009 to 2012, where statistical analyzes were performed, as well as studies of correlations of the percentage of occurrences with surface meteorological elements (air temperature and atmospheric pressure), extracted from hourly meteorological observations from the study site. The results show that in recent years, the occurrence of gust of wind at the airfield of Belém-Pa, is increasing, where the highest record of this occurrence within the period was in 2012. The higher frequency of events per burst speed intervals was 21-30 KT. The largest seasonal distribution record wind gusts occurred in the rainy season in the region, from December to May, influenced by clouds formed in the Equatorial Atlantic Ocean, due to tripping of the ITCZ​. The largest amounts of records gusty winds correspond to the period of maximum temperatures, suggesting a correlation between warming and the occurrence of near Earth's surface bursts. The distribution of wind, according to the orientation of the wind indicates predominance of winds east 60 º to 120 º.   Keywords: Wind direction, air temperature, atmospheric pressure.  

scholarly journals A new method to derive middle atmospheric temperature profiles using a combination of Rayleigh lidar and O<sub>2</sub> airglow temperatures measurements

2012 ◽  
Vol 30 (1) ◽  
pp. 27-32 ◽  
Author(s):  
A. Taori ◽  
A. Jayaraman ◽  
K. Raghunath ◽  
V. Kamalakar
Keyword(s):  
Temperature Profile ◽  
Atmospheric Temperature ◽  
New Method ◽  
Temperature Profiles ◽  
Vertical Temperature ◽  
Lidar System ◽  
Mesospheric Temperature ◽  
Simultaneous Measurements ◽  
Rayleigh Lidar ◽  
First Time

Abstract. The vertical temperature profiles in a typical Rayleigh lidar system depends on the backscatter photon counts and the CIRA-86 model inputs. For the first time, we show that, by making simultaneous measurements of Rayleigh lidar and upper mesospheric O2 temperatures, the lidar capability can be enhanced to obtain mesospheric temperature profile up to about 95 km altitudes. The obtained results are compared with instantaneous space-borne SABER measurements for a validation.

scholarly journals Non-stationary temporal characterization of the temperature profile of a soil exposed to frost in south-eastern Canada

2008 ◽  
Vol 15 (3) ◽  
pp. 409-416 ◽  
Author(s):  
F. Anctil ◽  
A. Pratte ◽  
L. E. Parent ◽  
M. A. Bolinder
Keyword(s):  
Time Series ◽  
Soil Temperature ◽  
Temperature Profile ◽  
Air Temperature ◽  
Soil Depth ◽  
Time Lag ◽  
Power Spectra ◽  
Temperature Time Series ◽  
Soil Temperatures ◽  
Temperature Time

Abstract. The objective of this work was to compare time and frequency fluctuations of air and soil temperatures (2-, 5-, 10-, 20- and 50-cm below the soil surface) using the continuous wavelet transform, with a particular emphasis on the daily cycle. The analysis of wavelet power spectra and cross power spectra provided detailed non-stationary accounts with respect to frequencies (or periods) and to time of the structure of the data and also of the relationships that exist between time series. For this particular application to the temperature profile of a soil exposed to frost, both the air temperature and the 2-cm depth soil temperature time series exhibited a dominant power peak at 1-d periodicity, prominent from spring to autumn. This feature was gradually damped as it propagated deeper into the soil and was weak for the 20-cm depth. Influence of the incoming solar radiation was also revealed in the wavelet power spectra analysis by a weaker intensity of the 1-d peak. The principal divergence between air and soil temperatures, besides damping, occurred in winter from the latent heat release associated to the freezing of the soil water and the insulation effect of snowpack that cease the dependence of the soil temperature to the air temperature. Attenuation and phase-shifting of the 1-d periodicity could be quantified through scale-averaged power spectra and time-lag estimations. Air temperature variance was only partly transferred to the 2-cm soil temperature time series and much less so to the 20-cm soil depth.

scholarly journals Air temperature profile and air/sea temperature difference measurements by infrared and microwave scanning radiometers

Radio Science ◽  
2003 ◽  
Vol 38 (3) ◽  
pp. n/a-n/a ◽  
Author(s):  
D. Cimini ◽  
J. A. Shaw ◽  
E. R. Westwater ◽  
Y. Han ◽  
V. Irisov ◽  
...  
Keyword(s):  
Temperature Profile ◽  
Air Temperature ◽  
Temperature Difference ◽  
Sea Temperature

scholarly journals Modelling of room air temperature profile with displacement ventilation

2019 ◽  
Vol 19 (2) ◽  
pp. 112-126 ◽  
Author(s):  
Natalia Lastovets ◽  
Risto Kosonen ◽  
Panu Mustakallio ◽  
Juha Jokisalo ◽  
Angui Li
Keyword(s):  
Temperature Profile ◽  
Air Temperature ◽  
Displacement Ventilation

scholarly journals Surface turbulent fluxes over pack ice inferred from TOVS observations

1997 ◽  
Vol 25 ◽  
pp. 393-399
Author(s):  
R.W. Lindsay ◽  
J. A. Francis ◽  
P. O. G. Persson ◽  
D. A. Roterock ◽  
A.J. Schweiger
Keyword(s):  
Boundary Layer ◽  
Wind Speed ◽  
Air Temperature ◽  
Sensible Heat Flux ◽  
Turbulent Fluxes ◽  
Layer Model ◽  
Radiative Fluxes ◽  
Mean Values ◽  
Boundary Layer Model ◽  
Meteorological Observations

A one-dimensional, atmospheric boundary-layer model is coupled to a thermodynamic ice model to estimate the surface turbulent fluxes over thick sea ice. The principal forcing parameters in this time-dependent model are the air temperature, humidity, and wind speed at a specified level (either at 2 m or at 850 mb) and the down-welling surface radiative fluxes, The free parameters are the air temperature, humidity, and wind-speed profiles below the specified level, the surface skin temperature and ice-temperature profile, and the surface turbulent fluxes. The goal is to determine how well we can estimate the turbulent surface heat and momentum fluxes using forcing parameters from atmospheric temperatures and radiative fluxes retrieved Irom the TlROS-N Operational Vertical Sounder TOVS) data.Meteorological observations from the Lead Experiment (LeadEx, April 1992) ice camp are used to validate turbulent fluxes computed with the surface observations, and the results are used to compare with estimates based on radiosonde observations or with estimates based on TOVS data. We and that the TOVS-based estimates of the stress are significantly more accurate than those found with a constant geostrophic drag coefficient, with a rool mean square error about half as large. This improvement is due to stratification effects included in the boundary-layer model. The errors in the sensible heat flux estimates, however, are large compared Io the small mean values observed during the field experiment.

Effects of climatic change on trees from cool and temperate regions: an ecophysiological approach to modelling of bud burst phenology

1995 ◽  
Vol 73 (2) ◽  
pp. 183-199 ◽  
Author(s):  
Heikki Hänninen
Keyword(s):  
Air Temperature ◽  
Elevated Temperatures ◽  
Day Treatment ◽  
Strong Support ◽  
Frost Damage ◽  
Minor Effect ◽  
Bud Burst ◽  
Natural Conditions ◽  
Short Day ◽  
Rest Break

A framework is presented for modelling bud burst phenology of trees from the cool and temperate regions. Three ecophysiological aspects affecting the timing of bud burst are considered: (i) effects of environmental factors on the rest status of the bud, (ii) effect of rest status on the ability for bud burst, and (iii) direct effect of air temperature on the rate of development towards bud burst. Any model for bud burst phenology can be presented within the framework with three submodels, each of them addressing one of the corresponding three ecophysiological aspects. A total of 96 hypothetical models were synthesized by combining submodels presented in the literature. The models were tested in two experiments with saplings of Pinus sylvestris L. growing in experimental chambers at their natural site in eastern Finland. In the first experiment, air temperature and (or) concentration of atmospheric CO2 was elevated. Elevation of the air temperature hastened bud burst, whereas elevation of the concentration of CO2 did not affect it. Several models accurately predicted the timing of bud burst for natural conditions but too early for bud burst at the elevated temperatures. This finding suggests that (i) the risk of a premature bud burst with subsequent frost damage, as a result of climatic warming, was overestimated in a recent simulation study, and (ii) bud burst observations in natural conditions alone are not sufficient for the testing of these mechanistic models. Several models did predict the timing of bud burst accurately for all treatments, but none of them obtained sufficiently strong support from the findings to stand out as superior or uniquely correct. In the second experiment a photoperiod submodel for rest break was tested by exposing the saplings to short-day conditions. The short-day treatment had only a minor effect on the timing of bud burst. These results demonstrated the importance of the concept of model realism: the accuracy of a model can be lost in new conditions (e.g., global warming), unless the model correctly addresses the essential ecophysiological aspects of the regulation of timing of bud burst. Key words: annual cycle of development, chilling, dormancy, field test, photoperiod, rest break.

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