scholarly journals Temperature and humidity conditions of Macocha Abyss

2012 ◽  
Vol 42 (3) ◽  
pp. 227-242
Author(s):  
Tomáš Litschmann ◽  
Jaroslav Rožnovský ◽  
Tomáš Středa ◽  
Hana Středová ◽  
Jiří Hebelka

Abstract The paper deals with the evaluation of temperature and humidity measurements in the vertical profile of Macocha Abyss (Moravian Karst, South Moravia, Czech Republic). The measuring profile on a rock wall is made up of seven HOBO-PRO sensors. Two other meteorological stations are installed at the bottom and near the upper edge of the abyss. The evaluation was designed separately for warm season (June 1, 2008 to August 31, 2008) and cold season (November 1, 2008 to February 28, 2009). In the warm season, distribution of inverse temperatures dominated in the abyss. Temperature differences between the bottom of the abyss and its upper edge reached about 10 ◦ C. At the bottom of the abyss, the minimum temperatures proved to be higher than at its upper edge and in its vicinity. Thermal circulation is evident to the depth of about 60 m. The highest temperatures were observed in the deeper layers of the abyss in the warm period at around 10 a.m. of Central European Summer Time. Towards the upper edge of the abyss, the hour of daily maximum temperature shifts to 2 to 4 p.m. In the cold season, the minimum temperature was observed between 6 and 7 a.m. of Central European Time. A decrease in the accumulation of cold air (cold-air pool formation) was not found in the lower floors of the abyss. This phenomenon does not occur even during clear nights. The depth of 60 m from the upper edge of the area maintains a high relative humidity (above 95%) in the warm season. However, humidity decreases from this depth towards the top of the abyss. In the cold season, the whole abyss is filled with air with relative humidity of 90 to 95%.

2016 ◽  
Vol 48 (4) ◽  
pp. 915-931 ◽  
Author(s):  
H. C. L. O'Neil ◽  
T. D. Prowse ◽  
B. R. Bonsal ◽  
Y. B. Dibike

A large portion of the freshwater in western Canada originates as snowpack from the northern Rocky Mountains. Temperature and precipitation in the region control the amount of snow accumulated and stored throughout the winter, and the intensity and timing of melt during the spring freshet. Therefore, trends in temperature, precipitation, snow accumulation, and snowmelt over western Canada are examined using the Mann-Kendall non-parametric test and an original geographic information system (GIS)-based approach to trend analysis on a newly produced high-resolution gridded climate dataset for the period 1950–2010. Temporal and spatial analyses of these hydroclimatic variables reveal that daily minimum temperature has increased more than daily maximum temperature, particularly during the cold season, and at higher elevations, contributing to earlier spring melt. Precipitation has decreased throughout the cold season and increased in the warm season, particularly in the northern half of the study area. Snow accumulation has decreased through all months of the year while snowmelt results indicate slight increases in mid-winter melt events and an earlier onset of the spring freshet. This study provides a summary of detected trends in key hydroclimatic variables across western Canada regarding the effects these changes can have on the spring freshet and streamflow throughout the region.


2021 ◽  
Vol 21 (4) ◽  
pp. 23-30
Author(s):  
Ji Yoon Kang ◽  
Bong-Chur Park ◽  
Jongbae Heo ◽  
Keewook Kim

Damage caused by heatwaves has been increasing recently worldwide. As climate change led by global warming progresses, heatwaves are projected to cause the most damage. Thus, it is very important to issue an appropriate heatwave advisory so that one can be prepared for it. Considering that the degree of heat experienced by people differs depending on the difference in humidity between regions with similar summer temperatures, it is necessary to evaluate whether the issuance of a heatwave warning using only the daily maximum temperature is appropriate. This study intends to examine the applicability of the heat index considering both temperature and humidity for effective heatwave response. First, the agreement between the occurrences of heatwaves and heat-related illness, where the occurrence is decided by the daily maximum temperature and daily maximum heat index, was evaluated. The results show that when the daily maximum heat index was applied as a criterion for issuing a heatwave warning, the coincidence with the occurrence of heat-related illness was more than two times higher than when the daily maximum temperature was applied. Next, on evaluating the prediction accuracy of the heat index according to the prediction-related leading time, the accuracy of the heat index was noted to be higher than that of the temperature for all the leading times; the highest accuracy was shown at the leading time of 10 hours (NSE = 0.7196; CORR = 0.8698). Based on the results of this study, it is necessary to consider using a heat index that contains both temperature and humidity elements to issue a heatwave warning. Furthermore, to establish regional standards for heatwave warnings, the relationship between heatwave characteristics and meteorological factors should be first analyzed using long-term data from various observation points.


2021 ◽  
pp. 097206342110116
Author(s):  
Suresh K. Rathi ◽  
P. R. Sodani ◽  
Suresh Joshi

A considerable association between temperature and all-cause mortality has been documented in various studies. Further insights can be obtained from studying the impact of temperature and heat index (HI) for Jaipur city’s all-cause mortality. The objective of this work was to assess the association between the extreme heat (daily maximum temperature, daily minimum temperature, daily mean temperature, relative humidity and HI) and all-cause mortality for summer months (March to June) from 2006 to 2015 for urban population of Jaipur. For summer months, we collected the data on various temperature and all-cause mortality parameters for at least 10 years. The student’s t-test and ANOVA were used to analyse variations in mean temperature, maximum temperature and HI. The Pearson correlation coefficient was used to study the relationship between ambient heat and lag time effect all-cause mortality. A total of 75,571 deaths (all-cause mortality) for 1,203 summer days (2006–2015) were analysed in relation to temperature and relative humidity. The mean daily all-cause mortality has been estimated at 62.8 ± 15.2 for the study period. There is a significant increase of 39% per day all-cause mortality at the maximum temperature of 45 °C and above. However only 10% rise per day all-cause mortality for extreme danger days (HI > 54 °C). The mean daily all-cause mortality shows a significant association with daily maximum temperature ( F = 34.6, P < .0001) and HI (discomfort index) from caution to extreme danger risk days ( F = 5.0, P < .0019). The lag effect of extreme heat on all-cause mortality for the study period (2006 to 2015) was at a peak period on the same day of the maximum temperature ( r = 0.245 at P < .01) but continues up to four days. The study concludes that the effect of ambient heat on all-cause mortality increase is clearly evident (rise of 39% deaths/day). Accordingly, focus should be put on developing adaptation measures against ambient heat. This analysis may satisfy policy makers’ needs. Extreme heat-related mortality needs further study to reduce adverse effects on health among Jaipur’s urban population.


Author(s):  
Benlin Shi ◽  
Xinyu Zhu ◽  
Hongzhong Li ◽  
Yunchuan Hu ◽  
Yi Zhang

Abstract. Climate change is exerting significant impacts on global agricultural production. Climatic variations adversely affect crop production and, thus tend to impose a key constraint of agricultural production, primarily on how to cont inuously enhance the winter wheat yields worldwide. The high uncertainties in predicting the effects of climate change on wheat production are most likely due to rare understanding on the responses of wheat production to extreme climatic factors, e.g. high temperatures, low humidity as well as high wind speed. Dry-hot wind hazard represents one of the main natural disasters for Chinese winter wheat production, especially for the Huang-huai-hai plain. However, high uncertainties of the effects of dry-hot wind hazard on winter wheat production still exist, mainly due to the gaps of long-term observations. Therefore, we selected Shangqiu as the case study area to determine the occurrence regularity of dry-hot wind hazard on winter wheat production in Huang-huai-hai plain. We analyzed regional meteorological data with daily resolution in the later growth stage of winter wheat during the period of 1963 to 2012. In accordance with the meteorological industry standards of “Disaster Grade of Dry-hot Wind for Wheat” by the China Meteorological Administration, we synthesized analyzed the distribution of annual average days of dry-hot wind in winter wheat growing seasons and the associated responses to the climate change. Hence the relationships between dry-hot wind times and winter wheat yields were also discussed. The results showed that the annual average days of light and severe dry-hot wind exhibited tended to decline in the recent 50 years. Great inter-annual variations of light and severe dry-hot wind were observed. The significant inter-annual variations were related with the corresponding meteorological conditions of temperature, moisture and wind speed. The most serious damages of light and severe dry-hot wind both occurred in 1960s while the damages appeared less in the 1980s and the last decade, which could be also explained by the corresponding temperature, moisture and wind speed conditions. From 1963 to 2012, a climatic mutation point of daily maximum temperature was found near 1972, but insignificantly (p>0.05). The wind speed at 2:00 pm and the relative humidity at 2:00 pm were closely related to the hazard conspicuously. A climatic mutation point of the wind speed at 2:00 pm was found near 1984, and climatic mutation of the relative humidity at 2:00 pm was found near 1981 (p<0.05). Daily maximum temperature, wind speed at 2:00 pm and the relative humidity at 2:00 pm played a major role in decreasing trend of dry-hot wind disaster, and the significantly decreased of wind speed at 2:00 pm constituted a main factor in Shangqiu. Dry-hot wind hazard is very sensitive to climate change. Yields of winter wheat were negatively correlated with annual average days of dry-hot wind in Shangqiu (p<0.05). In actual practices, great concerns should be paid on the defense of dry-hot wind for winter wheat production. Thus the most effective practices have to be taken for enhancing the resistance of winter wheat to dry-hot wind hazard through improving filed microclimate condition.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Emily J. Wilkins ◽  
Peter D. Howe ◽  
Jordan W. Smith

AbstractDaily weather affects total visitation to parks and protected areas, as well as visitors’ experiences. However, it is unknown if and how visitors change their spatial behavior within a park due to daily weather conditions. We investigated the impact of daily maximum temperature and precipitation on summer visitation patterns within 110 U.S. National Park Service units. We connected 489,061 geotagged Flickr photos to daily weather, as well as visitors’ elevation and distance to amenities (i.e., roads, waterbodies, parking areas, and buildings). We compared visitor behavior on cold, average, and hot days, and on days with precipitation compared to days without precipitation, across fourteen ecoregions within the continental U.S. Our results suggest daily weather impacts where visitors go within parks, and the effect of weather differs substantially by ecoregion. In most ecoregions, visitors stayed closer to infrastructure on rainy days. Temperature also affects visitors’ spatial behavior within parks, but there was not a consistent trend across ecoregions. Importantly, parks in some ecoregions contain more microclimates than others, which may allow visitors to adapt to unfavorable conditions. These findings suggest visitors’ spatial behavior in parks may change in the future due to the increasing frequency of hot summer days.


2021 ◽  
Vol 13 (10) ◽  
pp. 1884
Author(s):  
Jingjing Hu ◽  
Yansong Bao ◽  
Jian Liu ◽  
Hui Liu ◽  
George P. Petropoulos ◽  
...  

The acquisition of real-time temperature and relative humidity (RH) profiles in the Arctic is of great significance for the study of the Arctic’s climate and Arctic scientific research. However, the operational algorithm of Fengyun-3D only takes into account areas within 60°N, the innovation of this work is that a new technique based on Neural Network (NN) algorithm was proposed, which can retrieve these parameters in real time from the Fengyun-3D Hyperspectral Infrared Radiation Atmospheric Sounding (HIRAS) observations in the Arctic region. Considering the difficulty of obtaining a large amount of actual observation (such as radiosonde) in the Arctic region, collocated ERA5 data from European Centre for Medium-Range Weather Forecasts (ECMWF) and HIRAS observations were used to train the neural networks (NNs). Brightness temperature and training targets were classified using two variables: season (warm season and cold season) and surface type (ocean and land). NNs-based retrievals were compared with ERA5 data and radiosonde observations (RAOBs) independent of the NN training sets. Results showed that (1) the NNs retrievals accuracy is generally higher on warm season and ocean; (2) the root-mean-square error (RMSE) of retrieved profiles is generally slightly higher in the RAOB comparisons than in the ERA5 comparisons, but the variation trend of errors with height is consistent; (3) the retrieved profiles by the NN method are closer to ERA5, comparing with the AIRS products. All the results demonstrated the potential value in time and space of NN algorithm in retrieving temperature and relative humidity profiles of the Arctic region from HIRAS observations under clear-sky conditions. As such, the proposed NN algorithm provides a valuable pathway for retrieving reliably temperature and RH profiles from HIRAS observations in the Arctic region, providing information of practical value in a wide spectrum of practical applications and research investigations alike.All in all, our work has important implications in broadening Fengyun-3D’s operational implementation range from within 60°N to the Arctic region.


2014 ◽  
Vol 53 (9) ◽  
pp. 2148-2162 ◽  
Author(s):  
Bárbara Tencer ◽  
Andrew Weaver ◽  
Francis Zwiers

AbstractThe occurrence of individual extremes such as temperature and precipitation extremes can have a great impact on the environment. Agriculture, energy demands, and human health, among other activities, can be affected by extremely high or low temperatures and by extremely dry or wet conditions. The simultaneous or proximate occurrence of both types of extremes could lead to even more profound consequences, however. For example, a dry period can have more negative consequences on agriculture if it is concomitant with or followed by a period of extremely high temperatures. This study analyzes the joint occurrence of very wet conditions and high/low temperature events at stations in Canada. More than one-half of the stations showed a significant positive relationship at the daily time scale between warm nights (daily minimum temperature greater than the 90th percentile) or warm days (daily maximum temperature above the 90th percentile) and heavy-precipitation events (daily precipitation exceeding the 75th percentile), with the greater frequencies found for the east and southwest coasts during autumn and winter. Cold days (daily maximum temperature below the 10th percentile) occur together with intense precipitation more frequently during spring and summer. Simulations by regional climate models show good agreement with observations in the seasonal and spatial variability of the joint distribution, especially when an ensemble of simulations was used.


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