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 Evidence for elevation-dependent warming from the Chinese Tianshan Mountains

2020 ◽  
Author(s):  
Lu Gao ◽  
Haijun Deng ◽  
Xiangyong Lei ◽  
Jianhui Wei ◽  
Yaning Chen ◽  
...  
Keyword(s):  
Time Scales ◽  
Air Temperature ◽  
Tianshan Mountains ◽  
Swiss Alps ◽  
Maximum Temperature ◽  
High Mountains ◽  
Chinese Tianshan Mountains ◽  
Chinese Tianshan ◽  
Warming Rate ◽  
Different Time Scales

Abstract. The phenomenon that 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 the melting of snow, which would have significant impacts on regional ecological environment. Owing to the lack of high-density ground observations in the high mountains, there is a widespread controversy on the existence of the EDW. Current evidences are mainly derived from some typical high mountains such as the Swiss Alps, the Colorado Rocky Mountains, the Tropical Andes and the Tibetan Plateau/Himalayas. Rare evidences in other mountains have been reported, especially in arid regions. In this study, EDW features in the Chinese Tianshan Mountains (CTM) are detected using a unique high-resolution (1 km, 6-hourly) air temperature data set (CTMD). The results showed that there are significant EDW signals at different altitudes on different time scales. The warming rate of the minimum temperature in winter shows significant elevation dependence, especially above 4000 m. The greatest altitudinal gradient in the warming rate of maximum temperature is found above 2500 m in April. For the mean temperature, the warming rates in January, February and March show prominent EDW features but with different significances. Within the CTM, the Tolm Mountains, the eastern part of the Borokoonu Mountains, the Bogda Mountains and the Balikun Mountains are the representative regions that show significant EDW features on different time scales. This new evidence partly explains the accelerated melting of glaciers in spring in the CTM.

scholarly journals Contemporary Warming and Daily Values of Temperature (on the Example of Warsaw)

2004 ◽  
Vol 11 (1) ◽  
pp. 119-126
Author(s):  
Urszula Kossowska-Cezak
Keyword(s):  
Air Temperature ◽  
Minimum Temperature ◽  
Daily Temperature ◽  
Maximum Temperature ◽  
Absolute Maximum ◽  
Absolute Minimum ◽  
Mean Temperature ◽  
The Mean ◽  
Minimum Daily Temperature ◽  
Warming Process

Abstract This paper aims at presenting changes in everyday air temperature values, triggered by the contemporary warming process. The analysis has been based on the mean, maximum, and minimum daily temperature values measured in Warsaw between 1951 – 2003. The mean daily temperature in that period was between −24.6 and 28.4°C, absolute minimum temperature was −30.7°C, absolute maximum temperature amounted to 36.4°C. Calculations indicate that the number of days with mean temperature ≤ −5.0°C (minimum < 0.0°C, maximum < 0.0°C) in the last several years decreased. This trend slowed down at the beginning of 21st century, nevertheless, the number of days with mean daily temperature > 20.0°C and maximum temperature > 25.0°C was growing, particularly in the 1990’s and even more so in early 2000’s. Also since 1990’s, there has been increasingly more nights with minimum temperature > 15.0°C, which has been particularly apparent in 2001. Contemporary warming is then marked with an increasing frequency of the hottest days and decreasing frequency of the coldest days. These changes were asymmetrical beyond 1950’s, yet, in late 1990’s they coincided.

scholarly journals Prediction of maximum or minimum air temperature in a coastal location in West Bengal

MAUSAM ◽  
2021 ◽  
Vol 64 (4) ◽  
pp. 671-680
Author(s):  
SUKUMAR LALAROY ◽  
SANJIB BANDYOPADHYAY ◽  
SWETA DAS
Keyword(s):  
Solar Radiation ◽  
Air Temperature ◽  
Minimum Temperature ◽  
West Bengal ◽  
Global Solar Radiation ◽  
Maximum Temperature ◽  
Accurate Estimation ◽  
Radiation Data ◽  
Sunshine Hour ◽  
Minimum Air Temperature

bl 'kks/k i= dk mÌs'; Hkkjrh; rVh; LFkku vFkkZr~ if'peh caxky ds vyhiqj ¼dksydkrk½ esa izsf{kr HkweaMyh; lkSj fofdj.k dh enn ls gjxzhCl fofdj.k QkWewZyk ls rkjh[kokj la'kksf/kr KRS irk djuk gS ftlls fd vkxs ;fn U;wure rkieku ¼Tmin½ Kkr gks rks vf/kdre rkieku ¼Tmax½ dk iwokZuqeku nsus esa vFkok blds foijhr] mi;ksx fd;k tk ldsA HkweaMyh; lkSj fofdj.k ds chp lglaca/k dh x.kuk rkjh[kokj fd, x, /kwi ds ?kaVkokj  vk¡dM+ksa ds vkSlr ds mi;ksx ftlesa vkaXLVªkse izsLdkWV QkewZyk ls izkIr fu;rkad  as = 0-25 vkSj bs = 0-5 gS] ls dh xbZZ gSA blesa izsf{kr fd, x, HkweaMyh; lkSj fofdj.k vkadM+ksa dk v/;;u fd;k x;k gSA ;g fuf'pr :i  ls dgk tkrk gS fd vkaxLVªkse izsldkWV QkewZyk HkweaMyh; lkSj fofdj.k dk lVhd vkdyu djrk gS vkSj ;g lgh ik;k tkrk gSA bl 'kks/k i= esa gjxzhCl fofdj.k QkewZyk ¼ftles KRS = 0-19 fy;k x;k gS½ ls rkjh[kokj izkIr fd, x, vf/kdre rkiekuksa rFkk U;wure rkiekuksa ds vkSlr ¼vkadM+s Hkkjr ekSle foKku foHkkx ds vyhiqj] dksydkrk ftyk & 24 ijxuk ds dk;kZy; ls izkIr½ dk mi;ksx djds HkweaMyh; lkSj fofdj.k ds chp lglaca/k dh x.kuk dh xbZ gS vkSj bldk v/;;u izsf{kr HkweaMyh; lkSj fofdj.k ds lkFk Hkh fd;k x;k gSA rkjh[kokj la'kksf/kr KRS dh x.kuk gjxzhCl fofdj.k QkewZyk ls dh xbZA blesa HkweaMyh; lkSj fofdj.k ds izsf{kr vkadM+ksa] rkjh[kokj vf/kdre rkiekuksa vkSj U;wure rkiekuksa ds vkSlr mi;ksx esa fy, x, gSaA bls fdlh LVs'ku ds vf/kdre rkiekuksa  vkSj U;wure rkieku vkadMksa ds rkjh[kokj KRS  ds mi;ksx ds }kjk vkl ikl ds {ks=ksa ds ok"iksRltZu ds fy, HkweaMyh; lkSj fofdj.k dk vkdyu djus ds fy, Hkh mi;ksx esa yk;k tk ldrk gSA  The objective of this study is to find the date wise corrected KRS from the Hargreaves Radiation formula with the help of observed global solar radiation for the Indian coastal location namely Alipore (Kolkata) in West Bengal so that subsequently it can be used for predicting maximum temperature Tmax if minimum temperature Tmin is known or vice-versa. The correlation between the global solar radiation calculated by using date wise average sunshine hour data with constants as = 0.25 and bs = 0.5, from Angstrom Prescott formula with the observed global solar radiation data was studied. The assertion that the Angstrom Prescott formula gives nearly accurate estimation of global solar radiation has been found to be correct. Correlation between the global solar radiation calculated by using date wise average of Tmax and Tmin (sourced from IMD located at Alipore, Kolkata, District - South 24 parganas) from Hargreaves Radiation formula (taking KRS  = 0.19 ) with the observed global solar radiation data was also  studied. Date wise corrected  KRS by Hargreaves Radiation formula was computed using the observed data of global solar radiation, date wise average of maximum temperature Tmax and minimum temperature Tmin. The date wise corrected KRS can be used for better prediction of Tmax and Tmin. Also it can be used for estimation of global solar radiation for reference evapo-transpiration of the neighbourhood areas by utilizing the date wise KRS with the Tmax and Tmin of the station.

scholarly journals Prediction of solar radiation with air temperature data in a coastal location in Tamilnadu

MAUSAM ◽  
2021 ◽  
Vol 62 (1) ◽  
pp. 85-90
Author(s):  
A. MUGRAPAN ◽  
SUBBARAYAN SIVAPRAKASAN ◽  
S. MOHAN
Keyword(s):  
Solar Radiation ◽  
Air Temperature ◽  
Minimum Temperature ◽  
Reference Evapotranspiration ◽  
Temperature Data ◽  
Maximum Temperature ◽  
Adjustment Coefficient ◽  
Meteorological Observatory ◽  
Daily Sunshine ◽  
Sunshine Hour

The objective of this study is to evaluate the performance of the Hargreaves’ Radiation formula in estimating daily solar radiation for an Indian coastal location namely Annamalainagar in Tamilnadu State. Daily solar radiation by Hargreaves’ Radiation formula was computed using the observed data of maximum temperature, Tmax and minimum temperature, Tmin, sourced from the India Meteorological Observatory located at Annamalainagar and employing the adjustment coefficient KRS of 0.19. Daily solar radiation was also computed using Angstrom-Prescott formula with the measured daily sunshine hour data. The differences between the daily solar radiation values computed using the formulae were more pronounced in year around. Hence, the adjustment coefficient KRS is calibrated for the study location under consideration so that the calibrated KRS could be used to better predict daily solar radiation and hence better estimation of reference evapotranspiration.

Thermal Signatures of Peri-Urban Landscapes

2020 ◽  
Vol 59 (9) ◽  
pp. 1443-1452 ◽  
Author(s):  
William A. Gough
Keyword(s):  
Surface Temperature ◽  
Minimum Temperature ◽  
Maximum Temperature ◽  
Urban Landscapes ◽  
Cold Surface ◽  
Historical Climate ◽  
Mean Temperature ◽  
Climate Records ◽  
Urban Rural ◽  
Rural Sites

AbstractA new thermal metric is examined that is based on the ratio of day-to-day warm and cold surface temperature transitions. Urban and rural sites in Canada are examined using this new metric for the minimum temperature, maximum temperature, and mean temperature of the day. A distinctive signature emerges for “peri-urban” landscapes—landscapes at the urban–rural interface—and thus may provide a useful and relatively easy way to detect such environments using the current and historical climate records. A climatological basis for the presence of these distinct thermal signatures in peri-urban landscapes is proposed.

scholarly journals Treeline dynamics with climate change at the central Nepal Himalaya

2014 ◽  
Vol 10 (4) ◽  
pp. 1277-1290 ◽  
Author(s):  
N. P. Gaire ◽  
M. Koirala ◽  
D. R. Bhuju ◽  
H. P. Borgaonkar
Keyword(s):  
Climate Change ◽  
Minimum Temperature ◽  
Plant Density ◽  
Elevation Gradient ◽  
Age Distribution ◽  
Maximum Temperature ◽  
High Mountain ◽  
Nepal Himalaya ◽  
Central Nepal ◽  
The Impact

Abstract. Treeline shifting in tandem with climate change has widely been reported from various parts of the world. In Nepal, several impacts of climate change on the physical environment have been observed, but study on the biological impacts is lacking. This dendrochronological study was carried out at the treeline in the high mountain slope of Kalchuman Lake (3750–4003 m a.s.l.) area of Manaslu Conservation Area in the central Nepal Himalaya to explore the impact of climate change on the treeline dynamic. Two belt transect plots (size: 20 m wide, > 250 m long) were laid which included treeline as well as tree species limit. Ecological mapping of all individuals of dominant trees Abies spectabilis and Betula utilis was done and their tree cores were collected. Stand character and age distribution revealed an occurrence of more matured B. utilis (max. age 198 years) compared to A. spectabilis (max. age 160 years). A. spectabilis contained an overwhelmingly high population (89%) of younger plants (< 50 years) indicating its high recruitment rate. Population age structure along the elevation gradient revealed an upward shifting of A. spectabilis at the rate of 2.61 m year-1 since AD 1850. The upper distribution limit of B. utilis was found to be stagnant in the past few decades. An increment in plant density as well as upward shifting in the studied treeline ecotones was observed. The temporal growth of A. spectabilis was correlated negatively with the monthly mean and minimum temperature of June to September of the current and previous year. The regeneration of A. spectabilis, on the other hand, was positively correlated with August precipitation and monthly maximum temperature of the month of the current year. The growth and regeneration of A. spectabilis was more sensitive to maximum and minimum temperature rather than average temperature. The growth of the B. utilis was mainly limited by moisture stress during the pre-monsoon season. As these two species presented species-specific responses to climate change with differential pattern in regeneration condition, much wider differences are anticipated in their population status as climate continues to change throughout the century.

scholarly journals Effects of vernal equinox solar eclipse on temperatures and wind directions in Switzerland

2017 ◽  
Author(s):  
Werner Eugster ◽  
Carmen Emmel ◽  
Sebastian Wolf ◽  
Nina Buchmann ◽  
Joseph P. McFadden ◽  
...  
Keyword(s):  
Air Temperature ◽  
Solar Eclipse ◽  
Wind Direction ◽  
Temperature Drop ◽  
Swiss Alps ◽  
Maximum Temperature ◽  
Small Scale ◽  
Near Surface ◽  
Vernal Equinox ◽  
Cold Air

Abstract. The vernal equinox total solar eclipse of 20 March 2015 produced a maximum occultation of 65.8 to 70.1 % over Switzerland during the morning hours (09:22 to 11:48 CET). Skies were generally clear over the Swiss Alps due to a persistent high-pressure band between the UK and Russia associated with a rather weak pressure gradient over the continent. To assess the effects of penumbral shading on near-surface meteorology across Switzerland, air temperature data measured at 10-minute intervals at 184 MeteoSwiss weather stations that reported air temperature at 10-minute intervals were used. Wind speed and direction data were available from 165 of these stations. Additionally, six Swiss FluxNet eddy covariance flux (ECF) sites provided turbulent measurements at 20 Hz resolution. During maximum occultation the temperature drop was up to 5.8 K at a mountain site where cold air can pool in the topographic depression of the weather station. The bootstrapped average of the maximum temperature drops of all 184 MeteoSwiss sites during the solar eclipse was 1.51 ± 0.02 K (mean ± SE). A detailed comparison with literature values since 1834 showed a temperature decrease by 2.6 ± 1.7 K (average of all reports) with extreme values up to 11 K. On fair weather days under weak larger scale pressure gradients, local thermo-topographic wind systems develop that are driven by small-scale pressure and temperature gradients. At one ECF site, the penumbral shading delayed the morning transition from down-valley to up-valley wind conditions, and at another site, it prevented this transition from occurring at all. Data from the 165 MeteoSwiss sites measuring wind direction did not show a consistent pattern of wind direction response to the passing of the penumbral shadow. These results suggest that the local topographic setting had an important influence on the temperature drop and the wind flow patterns during the eclipse. Still, results tend to lend support to a recent theory that the anticyclonic cold-air outflow from the center of the eclipse only extends ≈ 1600 km outwards, with cyclonic flow beyond that distance. This contrasts with an earlier theory that the anticyclonic outflow should reach as far as ≈ 2400 km from the center of the eclipse, which would have included all of Switzerland during the 2015 eclipse. Nevertheless, a significant cyclonic effect of the passing penumbral shadow was found in the elevation range ≈ 1700–2700 m a.s.l., but not at lower elevations of the Swiss Plateau. Thus, measurable effects of penumbral shading on the local wind system could be even found at ≈ 2000 km from the path of the eclipse (that is, Switzerland during the 2015 eclipse).

scholarly journals Spatial and Temporal Variations of Temperature in the Punjab Province, Pakistan

2021 ◽  
Vol 12 (1) ◽  
pp. 67-75
Author(s):  
Sohail Abbas ◽  
Safdar Ali Shirazi ◽  
Nausheen Mazhar ◽  
Kashif Mahmood ◽  
Ashfak Ahmad Khan
Keyword(s):  
Climate Change ◽  
Temperature Change ◽  
Minimum Temperature ◽  
Temporal Variations ◽  
Maximum Temperature ◽  
Punjab Province ◽  
Mean Temperature ◽  
Increasing Trend ◽  
Slope Estimator ◽  
Level Of Significance

Identifying the temperature change at a regional level is one of the essential parameters to determine the intensity of climate change. The current investigation provides an examination of changing trends of temperature in the Punjab province from 1970 to 2019. Sen's slope estimator method is applied to monthly data of mean temperature (Tmean), maximum temperature (Tmax), and minimum temperature (Tmin) to calculate the rate of temperature change. Statistical methods were used to find out the level of significance in terms of negative or positive trends to examine the variability among various weather observatories. Moreover, predicted values have also been observed for a detailed analysis of temperature variability and trends. Significant and pronounced changes in the mean temperature (T mean) are distinguished all over the Punjab regions with an increasing trend from North to South Punjab. In the case of maximum temperature (Tmax), a faster rate of rising in temperature is observed over the Southern and Western regions of Punjab. In contrast, the minimum temperature (Tmin) shows an increasing trend in Central Punjab. The findings provide detailed insight to policymakers for the planning of mitigating efforts and adaptation strategies in response to climate change.

scholarly journals Relationship between mean annual temperatures and precipitation sums in Montenegro between 1951-1980 and 1981-2010 periods

2018 ◽  
Vol 98 (1) ◽  
pp. 31-48 ◽  
Author(s):  
Dragan Buric ◽  
Vladan Ducic ◽  
Jovan Mihajlovic
Keyword(s):  
Air Temperature ◽  
21St Century ◽  
Minimum Temperature ◽  
Temperature Fluctuations ◽  
Annual Precipitation ◽  
Maximum Temperature ◽  
Mean Annual Precipitation ◽  
Temperature And Precipitation

In the second half of the 20th and by the beginning of the 21st century the area of Montenegro was dominated by positive air temperature fluctuations and negative precipitation sums. This paper analyses a 60-year period (1951-2010), with the aim to determine air temperature and precipitation deviation between the two 30-year periods: 1951-1980 and 1981-2010. Calculations of mean, mean maximum and mean minimum temperature have been done, as well as annual values of precipitation sums. All three temperature parameters, particularly maximum values, show that the 1981-2010 period was significantly warmer in relation to previous three decades. Significant changes in mean annual precipitation sums between the two observation periods have been recorded on the coast and, locally, in the western part of the country. The results also showed that there was a significant increase in positive deviations of mean maximum temperature in most parts of Montenegro during the 1981-2010 period in relation to the 1951-1980 period, while changes of this type in other observation parameters were mostly minor.

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

2021 ◽  
Vol 8 ◽  
Author(s):  
Cheng-yi Hu ◽  
Lu-shan Xiao ◽  
Hong-bo Zhu ◽  
Hong Zhu ◽  
Li Liu
Keyword(s):  
Air Temperature ◽  
Minimum Temperature ◽  
Regression Models ◽  
Hubei Province ◽  
Daily Temperature ◽  
Maximum Temperature ◽  
Influence Of Temperature ◽  
Influence Of Temperature On ◽  
Almost All

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.

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