Altitude Difference Research Articles

Heatwaves in Southern Armenia in the context of climate change

AbstractThe quantitative and qualitative evaluations of long‐term trends and spatial distribution of heatwaves (HW) are carried out in Southern Armenia (Syunik province). For this purpose, the daily average maximum air temperature data (𝑇max) from four meteorological stations (Sisian, Goris, Kapan, and Meghri) are studied for the 1936–2019 period. The HW catchment algorithm and a new concept of HW (which is called potential HWs [PHWs]) are developed. The presence of trends and their significance for different HW measures are assessed utilizing linear and exponential trends, Sen's slope, and Mann–Kendall (MK) trend test. The results show that HWs become increasingly frequent and intense. Moreover, they have extended duration, as they emerge earlier and fade later in Syunik province. Significant variation trends of HW are observed (e.g., the frequency of HWs increased up to five times), especially after the 1990s in southern and central parts of the province. Contrary to this, relatively weaker or no trends occurred in the northern parts. Our methodological approach successfully determines the HW measures' trends in the province based on the relief features and altitude differences. The outcomes highlight their notable impact on the progression of HW. Overall, this study provides significant insights into understanding HW's variations and their transformation in the mountainous areas.

Stochastic Approach for Optimal Positioning of Pumps As Turbines (PATs)

A generic water system consists of a series of works that allow the collection, conveyance, storage and finally the distribution of water in quantities and qualities such as to satisfy the needs of end users. In places characterized by high altitude differences between the intake works and inhabited centres, the potential energy of the water is very high. This energy is attributable to high pressures, which could compromise the functionality of the pipelines; it is therefore necessary to dissipate part of this energy. A common alternative to dissipation is the possibility of exploiting this energy by inserting a hydraulic turbine. The present study aims to evaluate the results obtained from a stochastic approach for the solution of the multi-objective optimization problem of PATs (Pumps As Turbines) in water systems. To this end, the Bayesian Monte Carlo optimisation method was chosen for the optimization of three objective functions relating to pressure, energy produced and plant costs. The case study chosen is the Net 3 literature network available in the EPANET software manual. The same problem was addressed using the NSGA-III (Nondominated Sorting Genetic Algorithm) to allow comparison of the results, since the latter is more commonly used. The two methods have different peculiarities and therefore perform better in different contexts.

Increased Reliance on Carbohydrates for Aerobic Exercise in Highland Andean Leaf-Eared Mice, but Not in Highland Lima Leaf-Eared Mice

Exercise is an important performance trait in mammals and variation in aerobic capacity and/or substrate allocation during submaximal exercise may be important for survival at high altitude. Comparisons between lowland and highland populations is a fruitful approach to understanding the mechanisms for altitude differences in exercise performance. However, it has only been applied in very few highland species. The leaf-eared mice (LEM, genus Phyllotis) of South America are a promising taxon to uncover the pervasiveness of hypoxia tolerance mechanisms. Here we use lowland and highland populations of Andean and Lima LEM (P. andium and P. limatus), acclimated to common laboratory conditions, to determine exercise-induced maximal oxygen consumption (O2max), and submaximal exercise metabolism. Lowland and highland populations of both species showed no difference in O2max running in either normoxia or hypoxia. When run at 75% of O2max, highland Andean LEM had a greater reliance on carbohydrate oxidation to power exercise. In contrast, highland Lima LEM showed no difference in exercise fuel use compared to their lowland counterparts. The higher carbohydrate oxidation seen in highland Andean LEM was not explained by maximal activities of glycolytic enzymes in the gastrocnemius muscle, which were equivalent to lowlanders. This result is consistent with data on highland deer mouse populations and suggests changes in metabolic regulation may explain altitude differences in exercise performance.

Vertical Distribution of Aerosols and Hazes Over Jupiter's Great Red Spot and Its Surroundings in 2016 From HST/WFC3 Imaging

AbstractIn this work, we have analyzed images provided by the Hubble Space Telescope's Wide Field Camera 3 (HST/WFC3) in December 2016, with a spectral coverage from the ultraviolet to the near infrared. We have obtained the spectral reflectivity of the GRS and its surroundings, with particular emphasis on selected, dynamically interesting regions. A spectral characterization of the GRS area is performed following two different procedures: (a) in terms of Altitude/Opacity and Color Indices (AOI and CI); (b) by means of automatic spectral classification. We used the NEMESIS radiative transfer suite to retrieve the main atmospheric parameters (e.g., particle vertical and size distributions, refractive indices) that are able to explain the observed spectral reflectivity. The optimal a priori model atmosphere used for the retrievals is obtained from a grid of about 12,000 different atmospheric models, and choosing the one that best fits South Tropical Zone (STrZ) spectra and its observed limb‐darkening. We conclude that the spectral reflectivity of the GRS area is well reproduced with the following layout: (a) a stratospheric haze with its base near the 100 mbar level, with optical depths at 900 nm of the order of unity and particles with a size of 0.3 μm; (b) a more vertically extended tropospheric haze, with τ (900 nm) ∼10 down to 500 mbar and micron sized particles. Both haze layers show a stronger short wavelength absorption, and thus both act as chromophores. The altitude difference between clouds tops in the GRS and surrounding areas is ∼10 km.

A Manual for Monitoring Wild Boars (Sus scrofa) Using Thermal Infrared Cameras Mounted on an Unmanned Aerial Vehicle (UAV)

This study proposes monitoring methods of wild boars in plains or mountain forest areas using unmanned aerial vehicles (UAVs) equipped with infrared cameras. It is recommended to monitor in winter when the canopy layer is thin and the temperature difference between the ambient temperature and the body temperature of the wild boar is distinct, so that the infrared camera can better detect the wild boars. In flat land, the plane movement of the UAV can be easily monitored using the line transect, the point count survey, the plot sampling method, and the belted transect. In the mountain forest, there are variations in elevation due to slopes. Therefore, we introduced the WAYPOINT function to reflect the difference in altitude. After the investigator designates the waypoint, various information can be modified according to the terrain, and the WAYPOINT can be transmitted to other UAVs, so the utilization is high. In this method, once a route is created using the WAYPOINT, there is no need for additional operation after the start of the flight, and it helps to re-monitor the site by using the WAYPOINT record repeatedly. Therefore, this technical note provides a more repeatedly sustainable and scalable monitoring method than the conventional UAV method.

Digital inclusive finance and rural consumption structure – evidence from Peking University digital inclusive financial index and China household finance survey

PurposeThis paper examines the impact and mechanism of China's digital inclusive finance on rural consumption upgrade. First, the impact of the development of digital inclusive finance on the upgrading of rural household consumption structure is to be theoretically analyzed and empirically tested. Secondly, in terms of heterogeneity analysis, it pays attention to the age heterogeneity of users that digital inclusive finance influencing rural residents' developmental consumption upgrade, which is related to the issue of intergenerational “digital gap”. Thirdly, the mechanism of digital inclusive finance in promoting rural consumption upgrade is to be investigated. Finally, how to promote the role of digital inclusive finance in upgrading the structure of rural consumption to a developmental demand level will be showed.Design/methodology/approachFrom the perspective of the micro-household, this study is conducted by using the instrumental variable (IV) method, with 2SLS model and IV-Tobit model, based on the matched city-level data of Digital Inclusive Financial Index (DIFI) with the Chinese Household Financial Survey (CHFS). “The relief degree of land surface” is an ideal instrumental variable of digital inclusive finance, for including regional altitude difference and terrain factors of regional area, has theoretical influence on the development of digital inclusive finance, and is not affected by other economic variables.FindingsThe conclusions show that the digital inclusive finance plays a significant role in promoting the rural households' developmental consumption, but has no significant effect on the rural households' survival-type consumption and hedonistic consumption. Furthermore, this paper examines the impact and mechanism of China's digital inclusive finance on rural consumption upgrade. First, the impact of the development of digital inclusive finance on the upgrading of rural household consumption structure is to be theoretically analyzed and empirically tested. Secondly, it is discovered that digital inclusive finance is age heterogeneous in promoting the upgrade of consumption structure of rural household, and its effect on the elderly is weaker than that on the young for the intergenerational “digital gap”. Thirdly, these conclusions reveal that the digital inclusive finance does affect the consumption of rural residents through three mechanisms: increasing income and wealth, easing liquidity constraints and facilitating payment methods. Finally, how to promote the role of digital inclusive finance in upgrading the structure of rural consumption to a developmental demand level will be showed.Originality/valueThe current research on the relationship between digital inclusive finance and rural consumption only stays at the level of total rural consumption and has not stressed the structural problems of rural consumption. Can digital inclusive finance promote the upgrade of rural consumption structure? To what level can digital inclusive finance promote the upgrading of rural consumption structure? Therefore, it is of great theoretical value to study the upgrading of rural consumption structure from the micro level. Can the current digital inclusive finance benefit the elderly and help break the vulnerability of the elderly to enjoy finance? In this regard, evidence of heterogeneity remains to be provided.

Seasonal Effects of High-Altitude Forest Travel on Cardiovascular Function: An Overlooked Cardiovascular Risk of Forest Activity.

Cardiovascular physiological responses involving hypoxemia in low temperature environments at high altitude have yet to be adequately investigated. This study aims to demonstrate the health effects of hypoxemia and temperature changes in cardiovascular functions (CVFs) by comparing intra-individual differences as participants ascend from low (298 m, 21.9 °C) to high altitude (2729 m, 9.5 °C). CVFs were assessed by measuring the arterial pressure waveform according to cuff sphygmomanometer of an oscillometric blood pressure (BP) device. The mean ages of participants in winter and summer were 43.6 and 41.2 years, respectively. The intra-individual brachial systolic, diastolic BP, heart rate, and cardiac output of participants significantly increased, as participants climbed uphill from low to high altitude forest. Following the altitude increase from 298 m to 2729 m, with the atmosphere gradually reducing by 0.24 atm, the measured average SpO2 of participants showed a significant reduction from 98.1% to 81.2%. Using mixed effects model, it is evident that in winter, the differences in altitude affects CVFs by significantly increases the systolic BP, heart rate, left ventricular dP/dt max and cardiac output. This study provides evidence that cardiovascular workload increased significantly among acute high-altitude travelers as they ascend from low to high altitude, particularly in winter.

Comparison of roughness index for Kitka and Koznica wind farms

<span lang="EN-US">Kosovo has limited renewable energy resources and its power generation sector is based on fossil fuels. Such a situation emphasizes the importance of active research and efficient use of renewable energy potential. According to the analysis of meteorological data for Kosovo, it can be concluded that among the most attractive potential wind power sites are the locations known as Kitka (42° 29' 41" N and 21° 36' 45" E) and Koznica (42° 39′ 32″ N, 21° 22′30″E). The two terrains in which the analysis was carried out are mountain areas, with altitudes of 1142 m (Kitka) and 1230 m (Koznica). the same measuring height, about 84 m above the ground, is obtained for these average wind speeds: Kitka 6,667 m/s and Koznica 6,16 m/s. Since the difference in wind speed is quite large versus a difference in altitude that is not being very large, analyses are made regarding the terrain characteristics including the terrain relief features. In this paper it will be studied how much the roughness of the terrain influences the output energy. Also, that the assumption to be taken the same as to how much they will affect the annual energy produced.</span>

Variations in Morphology and Anatomy of Breadfruit (Artocarpus altilis) Based on Differences in Altitude

Background: Breadfruit [Artocarpus altilis (Parkinson ex F.A.Zorn) Fosberg] is a versatile plant that can be used by humans. Breadfruit has morphological variations that are thought to be related to anatomical variations that are formed as an adaptation mechanism to survive in a different area. This plant has the ability to live in different altitude ranges, from coastal areas to upland areas. This research was conducted for eight months in areas with altitude ranges of <350 masl, 350-700 masl, and >700 masl in Banyumas, Purbalingga, and Cilacap Regencies. Sampling of plants was carried out randomly selected (purposive random sampling), then described their morphological characteristics. Furthermore, the leaves are made for anatomical preservation to determine the anatomical character. Breadfruit plants that grow at an altitude of less than 350 m above sea level have the characteristics of a higher, larger diameter stem, have a tighter branching, more sap production, a higher number of fruit and have a larger fruit size. The anatomical characteristics of breadfruit plants that grow at an altitude of less than 350 masl have stomata characters that are wider and longer than those of 350-700 masl and > 700 masl. The highest stomata and trichomata density at an altitude > 700 masl. The highest mean cuticle thickness, epidermis, palisade ratio and mesophyll thickness were highest in breadfruit leaves at altitudes <350 masl.

Pressure comparative analysis study through the Venture pipe with the difference diameter of the pipe.

The interesting phenomenon of a fluid flow in the venturimeter that has a different diameter of cappilaries pipe is that of a difference in fluid altitude, the velocity of flow in a pipe, as well as pressure. The study aims to analyze the relationship between the diameter of the capillaries pipe and the flow velocity, the height of the liquid and the pressure. The method in this research is experiment. After experiment, it is continued by calculating some variables using formulas and analyzing them. The conclution of this research is that if the diameter of the capillaries pipe is enlarged, the flow velocity becomes small, the level of the water's surface increases, and the pressure also increases. It corresponds to Bernoulli's equation.

Observational study to compare the effect of altitude on cardiopulmonary reserves of different individuals staying more than 6 weeks at 10,000 ft and 15,000 ft

BackgroundThe variation in heights beyond high altitude has different effects on the cardiorespiratory profile of individuals because of variation in oxygen density with every thousand feet. This study was planned to analyze and compare the effects of difference in altitudes on cardiorespiratory profile from anesthesiologist's point of view. MethodsA multicenter observational study was done involving two different groups of 600 patients at 10,000 ft (Group A) and 15,000 ft (Group B). Observation and comparison of oxygen saturation, 6-min walk test, and breath holding time was carried out. ResultsFifty-five percent of subjects in Group A had oxygen saturation of more than 93% in comparison to 5.5% in Group B. This was statistically significant (P < 0.001). Two percent of subjects in Group A in comparison to 63.5% of Group B had oxygen saturation of less than 88% (P < 0.001). Percentage increase of more than 15% of heart rate was found to be statistically significant in all the age groups. Overall, 3.8% of individuals in Group A had breath holding time less than 15 s in comparison to 16.6% of individuals in Group B (P value < 0.001). ConclusionThe study demonstrates that there is a significant fall in oxygen saturation, significant rise in the heart rate in 6-min walk test, and significant fall in the breath holding time in the group located at 15,000 ft. Heights beyond 10,000 ft should be restricted to life and limb saving surgeries, and logistics should be focused more on “scoop and run” than “stay and play” policy.

Downhill hiking improves low-grade inflammation, triglycerides, body weight and glucose tolerance

Exercise is a well-established tool for cardiovascular risk reduction. Particularly eccentric exercise, which essentially means walking downwards could favour more people becoming physically active. With the present controlled study, we tested the hypothesis that eccentric exercise can improve insulin sensitivity, triglyceride handling, body mass index, glucose tolerance and inflammation. We allocated 127 healthy sedentary individuals to one of two groups: (i) an active group of 102 individuals walking downwards a predefined route three to five times per week over two months, covering a difference in altitude of 540 m; for the upward route a cable car was used, for which adherence was recorded electronically and (ii) a matched control group of 25 individuals who stayed sedentary. Fasting and postprandial metabolic profiles were obtained at baseline and after two months. Compared to baseline, eccentric exercise significantly improved HOMA insulin resistance (1.94 ± 1.65 vs. 1.71 ± 1.36 (µU−1 ml) × ((mmol/l)−122.5); p = 0.038) and resulted in a decrease in fasting glucose (97 ± 15 vs. 94 ± 9 mg dl−1; p = 0.025) and glucose tolerance (238 ± 50 vs. 217 ± 47 mg dl−1 h−1; p < 0.001), whereas these parameters did not change significantly in the control group. Eccentric exercise significantly improved triglyceride tolerance (1923 ± 1295 vs. 1670 ± 1085 mg dl−1 h−1; p = 0.003), whereas triglyceride tolerance remained unchanged in the control group (p = 0.819). Furthermore, body mass index (27.7 ± 4.3 vs. 27.4 ± 4.3 kg m−2; p = 0.003) and C-reactive protein (0.27 ± 0.42 vs. 0.23 ± 0.25 mg dl−1; p = 0.031) were significantly lowered in the eccentric exercise group but not in the control group. Downhill walking, a type of exercise is a promising unusual exercise modality with favorable effects on body mass index, insulin action, on postprandial glucose and triglyceride handling and on C-reactive protein.ClinicalTrials.gov Identifier: NCT00386854.

Robotics-based vineyard water potential monitoring at high resolution

The purpose of this research is deploying a proximal sensing solution using non-invasive and cost-effective sensors onboard an Autonomous Ground Vehicle (AGV) as a feasible way for building high-resolution maps of water potential in vineyards. The final objective is offering growers a practical system to make decisions about water management, especially for arid climatic conditions. The monitoring AGV was entirely developed within this research context, and as a result, it is a machine specifically designed to endure off-road conditions and harsh environments. The autonomous vehicle served as a massive, non-invasive, and on-the-go data collector robotic platform. The sensors used for measuring the relevant field variables were two spectral reflectance sensors (SRS), an infrared radiometer, and an on-board weather sensor. The collected data were displayed on comprehensible grid maps using the Local Tangent Plane (LTP) coordinate system. The proposed model has a coefficient of determination R2 of 0.69, and results from combining six parameters: the canopy and air temperatures (as the temperature difference), the relative humidity, the altitude difference, the Normalized Difference Vegetation Index (NDVI), and the Photochemical Reflectance Index (PRI). The strongest relationships found in this study were between the temperature difference and PRI, with an R2 of 0.75, and the temperature difference with the leaf water potential with an R2 of 0.61. The practical use of these high-resolution maps includes irrigation scheduling and harvest zoning for sorting grape quality, with a further use as inputs to complex artificial intelligence algorithms considering larger areas or complementing airborne data. Future improvements to make the models more robust and versatile will entail considering additional variables, locations, or grapevine cultivars, and even other crops grown in vertical trellis systems.

Influence of geographic conditions on body length of male newborns in Kyrgyzstan.

Newborn length has been reported by many researchers to be reduced at high altitudes. However, many of these studies lacked adequate control of the ethnic group which may be confounding the altitude differences. In addition, few studies have examined the sources of variation in birth weight at high altitudes that may be related to ethnic group adaptation to the stresses of this hypoxic environment. In our study, we tested the hypotheses that the effect of altitude differences in newborn length depends on ethnic variation. Samples of 3359 healthy male newborns from different areas in Kyrgyzstan between the years 2003 and 2011 were analyzed for altitude and ethnic variation on male newborn length. Our results indicate significant decrease in male newborn length as a latitude increase. It is concluded that ethnic group difference in pregnancy outcome reflects a better state of adaptation to high altitude in this healthy indigenous population and that long-term genetic selection may be the most plausible explanation for these ethnic differences.

Local effects on soil leaf wax hydrogen isotopes along a west to east transect through the Pamirs, Tajikistan

Understanding the control mechanisms that affect soil leaf wax hydrogen isotopes is crucial when interpreting these data in the context of paleoclimatic reconstructions. Within a pilot study we aimed to evaluate the regional controls on leaf wax δ2H in the Central Asian Pamir Mountains (Tajikistan), a region characterized by pronounced hydroclimatic gradients. Soil and tap water samples were collected along a ca. 1000 km west-east-gradient, spanning ca. 3100 m of altitude difference. The results give evidence of variable environmental control on soil leaf wax δ2H values in different sub-regions of the study area. In the western and central Pamirs, the plant lipids mirror the signal of a mostly riverine water source, with an isotopic signature mainly controlled by winter and spring precipitation. With ca. –1.3‰ change per 100 m altitude, soil leaf wax derived isotopic lapse rates in these samples are lower than in other Asian high-altitude settings and the global average, which confirms earlier findings from surface water analysis from the Pamirs. In contrast, soil samples from the shielded Karakul basin showed significantly higher δ2H values. Those most likely reflect the more positive isotope signal of a predominant summer precipitation in the arid eastern Pamirs, with potential additional enrichment due to local vapor recycling and soil- and leaf water evapotranspiration. While the predominant water source (precipitation vs river water) plays an important role on a local scale, the results further highlight the significance of regional climate effects on isotopic signals incorporated into leaf waxes.

The dynamics of physiological properties of ebony (Diospyros celebica Bakh) based on crown position and altitude

Knowledge of the physiological properties of tree species is one of the basic requirements in determining the prescription silvicultural treatment of stands in nature. This study aims to analyze the physiological characteristics of the species of ebony (Diospyros celebica Bakh), as one of the potential endemic species of Sulawesi, based on leaf position in the crown and differences in altitude. Leaf sampling locations were in the Hasanuddin University Educational Forest (507 m asl) and Makassar city (16 m asl). The research variables consist of number of stomata, size of stomata, leaf stomata index, and leaf chlorophyll content. The results show that the physiological characteristics of the leaves were influenced by their position in the tree crown and differences in altitude. The highest number of stomata was found in the leaves exposed to the sunlights with 52.900 stomata/mm2 compared to 29.800 stomata/mm2 in shaded leaves. Likewise, the highest chlorophyll content was found in leaves exposed to the sunlights of 0.043 mg/L and shaded leaves of 0.034 mg/L. The difference occurs based on differences in altitude as well. The number of stomata in the lower area was 35.733 stomata/mm2, while in the high area was 42.667 stomata/mm2. The chlorophyll content in the low area was 0.038 mg/L and in the high area it was 0.037 mg/L. The higher a place, the more the number of stomata, this is inversely proportional to the size of the stomata and the stomata index, while the number of chlorophylls is not significantly different.

POSITIVE AND NEGATIVE ROUGHNESS ACCORDING TO LOCAL DIFFERENCES BETWEEN DEM SURFACE AND 3D REFERENCE PLANES

Abstract. The irregularities of the earth’s surface are quantified by means of roughness measurements using Digital Elevation Models (DEM’s). This article presents a roughness measurement method that is based on the calculation of the difference of altitude existing between a plane passing through the centre of a moving window and the altitude of the DEM surface inside this window. This method differs from the measure of the standard deviation and best fit plane, in the sense that it considers all difference values, positives or negatives. The measurement is done in a 3 × 3 or a 5 × 5 moving window and contemplates inside this window the plane which passes through the centre of the window and the highest pixel located in the border or perimeter of this window. According to the 3D configuration of the DEM surface inside the moving window, the sum of all the differences is positive or negative, allowing to discriminate the local morphology independently of the global roughness. The roughness variable which distinguishes negative and positive values allows to classify accurately landscape units such as watersheds, riverbeds, volcanic assemblages as well as landforms associated with tectonic structures.

Response of runoff in the upper reaches of the Minjiang River to climate change

Abstract Climate change affects the water cycle in different regions. The response of annual runoff and seasonal distribution to climate change in the upper reaches of the Minjiang River during 2021–2050 was studied by coupling the Statistical Downscaling Model (SDSM) and the Soil and Water Assessment Tool (SWAT). This model was driven by the second-generation Canadian Earth System Model (CanESM2) under RCP2.6, RCP4.5, and RCP8.5 scenarios. The results show that the runoff in the upper reaches of the Minjiang River has a unique response to climate change. The maximum and minimum temperatures will increase with the increase in emissions, especially in December–January. The daily precipitation shows an upward trend, especially in July–August in the RCP4.5 scenario. The annual runoff shows an upward trend with the increase in emissions. Compared with the current increase of 13–26%, the most prominent period is November–April. Because the study area covers high mountains and gorge landforms, the altitude difference is great, and the influence of evapotranspiration and snow melting processes is more prominent, causing the monthly runoff to decrease in June–July with an increase in precipitation. From April to May, precipitation decreased while runoff increased.

Quality assessment of Dobson spectrophotometers for ozone column measurements before and after automation at Arosa and Davos

Abstract. The longest ozone column measurement series are based on the Dobson sun spectrophotometers developed in the 1920s by Gordon B. W. Dobson. These instruments still constitute an important part of the World Meteorological Organization's global network due to their optical qualities and ruggedness. The primary drawback of this instrument is the effort needed for its manual operation. In industrialized and some less developed countries, most stations have made the choice to replace the Dobson by the automated Brewer sun spectrophotometers, but some are still relying on the Dobson instrument. One of them is the Arosa station where both instrument types are run in parallel. Here, an automated version of the Dobson instrument was developed and implemented recently. In the present paper, the results of the analysis of simultaneous measurements from pairs of Dobson instruments that were either collocated at Arosa or Davos or operated one at each location are presented for four distinct time periods: 1992–2012 – manual vs. manual operation of collocated Dobson instruments (MMC); 2012–2013 – manual vs. automated operation of collocated Dobson instruments (MAC); 2012–2019 – automated vs. automated operation of collocated Dobson instruments (AAC); 2016–2019 – automated vs. automated operation of distant Dobson instruments (AAD). The direct comparison of two instruments using the standard operation procedure during the MMC period gives a metric necessary to validate the automated version of Dobson instruments. The direct comparison of two collocated instruments using the standard manual operation procedure reveals random differences of coincident observations with a standard deviation of ∼ 0.45 % and monthly mean differences between −1.0 % and +0.8 %. In most cases the observed biases are not statistically significant. The same analysis of two automated Dobson instruments yields significantly smaller standard deviation of ∼ 0.25 % and biases of between −0.7 % and 0.8 %. This demonstrates that the repeatability has improved with the automation, while the systematic differences are only marginally smaller. The analysis of the AAD period of coincident measurements from the distant sites Arosa and Davos reveals a small positive bias (not significant) compatible with the 250 m altitude difference. The description of the automated data acquisition and control of the Dobson instrument is presented in a separate paper (Stübi et al., 2020).

Population density, genetic diversity and hot spots of Commiphora wightii (Arnott) Bhandari in Rajasthan State

Commiphora wightii (Arnott) Bhandari also known as ‘Guggal’, is a critically endangered medicinal plant species. Natural population of this species is declining due to poor regeneration, over-exploitation and destructive harvesting methods. In present study extensive surveys were conducted in all the guggal occurring forest areas of Rajasthan state with the objectives to study the population density, genetic diversity and its relationship with geographical patterns, distances and agroclimatic zones. Average population density of guggal was 21.9 plants ha−1 in guggal occurrence areas of forests in Rajasthan. The highest density (105.9 plants ha−1) was recorded in Sawai Madhopur and lowest (1.6 plants ha−1) in Jhalawar district. Variation in guggal population density was also observed due to altitude differences. The maximum density (40 plants ha−1) was recorded in altitude range from 301−350 m AMSL mainly in Aravalli range and it reduces at higher (>350 m AMSL) and lower (<301 m AMSL) altitudes.Genetic diversity was studied with 96 genotypes collected from all over Rajasthan using selected six RAPD primers. The genetic distances among these genotypes ranged from 0.000 to 0.732. Statistical analysis indicated low genetic diversity (H = 0.195; I = 0.299), low genetic differentiation (GST = 0.169) and moderate gene flow (Nm = 2.455) between four agroclimatic zone populations. These results indicate that these populations are in process of genetic drift and genetic differentiation. The Mantel test showed statistically significant correlation (R = 0.306; p = 0.000) between pairwise geographical distance and genetic distance.