A Comparison of Measured Upper Air Temperatures and Temperatures Derived using the Lapse Rate of the US Standard Atmosphere

1977 ◽  
Author(s):  
Spence E. Peters ◽  
Jr
Keyword(s):  
Lapse Rate ◽  
Standard Atmosphere ◽  
Air Temperatures ◽  
The Us

scholarly journals Suitability of a constant air temperature lapse rate over an Alpine glacier: testing the Greuell and Böhm model as an alternative

2013 ◽  
Vol 54 (63) ◽  
pp. 120-130 ◽  
Author(s):  
Lene Petersen ◽  
Francesca Pellicciotti ◽  
Inge Juszak ◽  
Marco Carenzo ◽  
Ben Brock
Keyword(s):  
Air Temperature ◽  
Surface Air Temperature ◽  
Ambient Air ◽  
Lapse Rate ◽  
Spatial And Temporal Variability ◽  
Near Surface ◽  
Alpine Glacier ◽  
Temperature Lapse Rate ◽  
Boundary Layer Height ◽  
Air Temperatures

AbstractNear-surface air temperature, typically measured at a height of 2 m, is the most important control on the energy exchange and the melt rate at a snow or ice surface. It is distributed in a simplistic manner in most glacier melt models by using constant linear lapse rates, which poorly represent the actual spatial and temporal variability of air temperature. In this paper, we test a simple thermodynamic model proposed by Greuell and Böhm in 1998 as an alternative, using a new dataset of air temperature measurements from along the flowline of Haut Glacier d’Arolla, Switzerland. The unmodified model performs little better than assuming a constant linear lapse rate. When modified to allow the ratio of the boundary layer height to the bulk heat transfer coefficient to vary along the flowline, the model matches measured air temperatures better, and a further reduction of the root-mean-square error is obtained, although there is still considerable scope for improvement. The modified model is shown to perform best under conditions favourable to the development of katabatic winds – few clouds, positive ambient air temperature, limited influence of synoptic or valley winds and a long fetch – but its performance is poor under cloudy conditions.

scholarly journals Thermodynamic model for a pilot balloon

2021 ◽  
Author(s):  
Vicent Favà ◽  
Juan José Curto ◽  
Alba Gilabert
Keyword(s):  
Thermodynamic Model ◽  
Ground Level ◽  
Atmospheric Temperature ◽  
Lapse Rate ◽  
Temperature Lapse Rate ◽  
Ascent Rate ◽  
Pilot Balloon ◽  
The Us ◽  
Optical Theodolite

Abstract. In the early part of the 20th century, tracking a pilot balloon from the ground with an optical theodolite was one of the few methods that was able to provide information from the upper air. One of the most significant sources of error with this method, however, was involved in calculating the balloon height as a function of time, a calculation dependent on the ascent rate which was traditionally taken to be constant. This study presents a new thermodynamic model which allows us to compute the thermal jump between the surrounding environment and the lifting gas as a function of different parameters such as the atmospheric temperature lapse rate or the physical characteristics of the balloon. The size of the thermal jump and its effect on the ascent rate is discussed for a 30 g pilot balloon, which was the type used at the Ebro Observatory (EO) between 1952 and 1963. The meridional and zonal components of the wind profile from ground level up to 10 km altitude were computed by applying the model using EO digitized data for a sample of this period. The obtained results correlate very well with those obtained from the ERA5 reanalysis. A very small thermal jump with a weak effect on the computed ascent rate was found. This ascent rate is consistent with the values assigned in that period to the balloons filled with hydrogen used at the Ebro Observatory and to the 30 g balloons filled with helium used by the US National Weather Service.

Spatial and temporal variation of surface air temperature at different altitude zone in recent 30 years over Nepal

MAUSAM ◽  
2021 ◽  
Vol 68 (3) ◽  
pp. 417-428
Author(s):  
JANAK LAL NAYAVA ◽  
SUNIL ADHIKARY ◽  
OM RATNA BAJRACHARYA
Keyword(s):  
Air Temperature ◽  
Surface Air Temperature ◽  
Temperature Data ◽  
Lapse Rate ◽  
Spatial And Temporal Variation ◽  
Mountain Regions ◽  
Temperature Lapse Rate ◽  
Air Temperatures ◽  
Long Term Trend

This paper investigates long term (30 yrs) altitudinal variations of surface air temperatures based on air temperature data of countrywide scattered 22 stations (15 synoptic and 7 climate stations) in Nepal. Several researchers have reported that rate of air temperature rise (long term trend of atmospheric warming) in Nepal is highest in the Himalayan region (~ 3500 m asl or higher) compared to the Hills and Terai regions. Contrary to the results of previous researchers, however this study found that the increment of annual mean temperature is much higher in the Hills (1000 to 2000 m asl) than in the Terai and Mountain Regions. The temperature lapse rate in a wide altitudinal range of Nepal (70 to 5050 m asl) is -5.65 °C km-1. Warming rates in Terai and Trans-Himalayas (Jomsom) are 0.024 and 0.029 °C/year respectively.  

scholarly journals Daily air temperature estimation on glacier surfaces in the Tibetan Plateau using MODIS LST data

2018 ◽  
Vol 64 (243) ◽  
pp. 132-147 ◽  
Author(s):  
HONGBO ZHANG ◽  
FAN ZHANG ◽  
GUOQING ZHANG ◽  
YAOMING MA ◽  
KUN YANG ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Air Temperature ◽  
Lapse Rate ◽  
The Tibetan Plateau ◽  
Mean Square ◽  
Night Time ◽  
Glacier Surface ◽  
Temperature Estimation ◽  
Air Temperatures ◽  
Air Temperature Estimation

ABSTRACTThe MODerate resolution Imaging Spectroradiometer (MODIS) land surface temperature (LST) data have been widely used for air temperature estimation in mountainous regions where station observations are sparse. However, the performance of MODIS LST in high-elevation glacierized areas remains unclear. This study investigates air temperature estimation in glacierized areas based on ground observations at four glaciers across the Tibetan Plateau. Before being used to estimate the air temperature, MODIS LST data are evaluated at two of the glaciers, which indicates that MODIS night-time LST is more reliable than MODIS daytime LST data. Then, linear models based on each of the individual MODIS LST products from two platforms (Terra and Aqua) and two overpasses (night-time and daytime) are built to estimate daily mean, minimum and maximum air temperatures in glacierized areas. Regional glacier surface (RGS) models (mean /-mean-square differences: 3.3, 3.0 and 4.8°C for daily mean, minimum and maximum air temperatures, respectively) show higher accuracy than local non-glacier surface models (mean root-mean-square differences: 4.2, 4.7 and 5.7°C). In addition, the RGS models based on MODIS night-time LST perform better to estimate daily mean, minimum and maximum air temperatures than using temperature lapse rate derived from local stations.

An exercise in modelling using the US Standard Atmosphere

2006 ◽  
Vol 42 (1) ◽  
pp. 76-80 ◽  
Author(s):  
Michael C LoPresto ◽  
Diane A Jacobs
Keyword(s):  
Standard Atmosphere ◽  
The Us

Testing the Doran summer climate rules in Upper Wright Valley, Antarctica

2015 ◽  
Vol 27 (4) ◽  
pp. 411-415 ◽  
Author(s):  
Christopher P. McKay
Keyword(s):  
Temperature Gradient ◽  
High Elevation ◽  
Lapse Rate ◽  
Dry Valleys ◽  
Average Difference ◽  
Degree Days ◽  
Monthly Average ◽  
Summer Climate ◽  
Air Temperatures ◽  
Direct Measurements

AbstractBased on data from low elevation lake sites, previous studies have suggested three quantitative relationships related to summer (December, January and February) air temperatures in the Dry Valleys of Antarctica: i) decrease with altitude at the dry lapse rate of 9.8°C km-1, ii) increase with distance from the coast at a rate of 0.09°C km-1, and iii) degree-days above freezing during the summer months is logarithmically proportional to the maximum summer air temperature. Here, we tested the first two of these rules at high elevation sites in Upper Wright Valley. Direct measurements confirmed that the summer lapse rate followed the dry lapse rate. For the three furthest stations, Tyrol Valley, Mount Fleming and Horseshoe Crater, the average difference between the measurements and the predicted summer monthly averages are -2.1±1.4°C, -0.5±1.0°C and -0.4±0.9°C, respectively. By contrast, at Linnaeus Terrace (54 km from the coast) the monthly average is warmer than predicted by several degrees: +4.3±1.3°C. The inland temperature gradient at these high elevation sites may result from sunlight effects rather than coastal wind as previously shown for the lower valleys. The warm conditions observedc. 50 km from the coast may reflect a zone affected by both sunlight and coastal wind.

scholarly journals Using daily air temperature thresholds to evaluate snow melting occurrence and amount on Alpine glaciers by <i>T</i>-index models: the case study of the Forni Glacier (Italy)

2014 ◽  
Vol 8 (5) ◽  
pp. 1921-1933 ◽  
Author(s):  
A. Senese ◽  
M. Maugeri ◽  
E. Vuillermoz ◽  
C. Smiraglia ◽  
G. Diolaiuti
Keyword(s):  
Air Temperature ◽  
Energy Budget ◽  
Snow Depth ◽  
Lapse Rate ◽  
Positive Energy ◽  
Temperature Threshold ◽  
Snow Melting ◽  
Air Temperatures ◽  
Temperature Thresholds ◽  
The Mean

Abstract. Glacier melt conditions (i.e., null surface temperature and positive energy budget) can be assessed by analyzing data acquired by a supraglacial automatic weather station (AWS), such as the station installed on the surface of Forni Glacier (Italian Alps). When an AWS is not present, the assessment of actual melt conditions and the evaluation of the melt amount is more difficult and simple methods based on T-index (or degree days) models are generally applied. These models require the choice of a correct temperature threshold. In fact, melt does not necessarily occur at daily air temperatures higher than 0 °C. In this paper, we applied both energy budget and T-index approaches with the aim of solving this issue. We start by distinguishing between the occurrence of snowmelt and the reduction in snow depth due to actual ablation (from snow depth data recorded by a sonic ranger). Then we find the daily average temperature thresholds (by analyzing temperature data acquired by an AWS on Forni Glacier) which, on the one hand, best capture the occurrence of significant snowmelt conditions and, on the other, make it possible, using the T-index, to quantify the actual snow ablation amount. Finally we investigated the applicability of the mean tropospheric lapse rate to reproduce air temperature conditions at the glacier surface starting from data acquired by weather stations located outside the glacier area. We found that the mean tropospheric lapse rate allows for a good and reliable reconstruction of glacier air temperatures and that the choice of an appropriate temperature threshold in T-index models is a very important issue. From our study, the application of the +0.5 °C temperature threshold allows for a consistent quantification of snow ablation while, instead, for detecting the beginning of the snow melting processes a suitable threshold has proven to be at least −4.6 °C.

Pollution of the Atmosphere

2002 ◽  
Keyword(s):  
Water Vapor ◽  
Sea Level ◽  
Temperature Inversion ◽  
Lapse Rate ◽  
Polar Regions ◽  
Average Value ◽  
Standard Atmosphere ◽  
Middle Latitudes ◽  
Air Density ◽  
The Relationship

The earth’s atmosphere consists of 78% (by volume) of N2; 21% O2; about 0.033% CO2; trace amounts of noble gases, NOx, and CH3; and variable amounts of water vapor. At sea level, the amount of water vapor may vary from 0.5 g per kg of air in polar regions to more then 20 g per kg in the tropics. The standard atmosphere is a theoretical set of data that serves as a reference point for calculation of atmospheric changes due to the weather. The values are calculated for sea level conditions and correspond to a pressure of 760 mm of mercury (92.29 in., 1013.25 mbar), an air density of 1.22 kg/m3, and a temperature of 15°C (59 °F). The composition of the air within the troposphere, which is the lowest layer of the atmosphere, does not change with altitude; however, the pressure and temperature decrease with altitude. The relationship between altitude and pressure in the standard atmosphere is shown in Figure 10.1, and the relationship between altitude and temperature is shown in Figure 10.2. The rate of decrease of temperature with altitude (6.49 °C per km) is referred to as the ‘‘standard lapse rate’’. This rate is a strictly theoretical average value because the actual lapse rate varies depending on the weather. Because the air density is proportional to the pressure and inversely proportional to the temperature, it changes at the same rate as the pressure does. The atmosphere is divided into troposphere, stratosphere, mesosphere, and ionosphere. As shown in this figure, the division is based on temperature inversions that occur at the higher altitudes; the altitudes of these inversions vary with the season and with the geographic latitude. Although the general shape of the curves remains the same for all latitudes, the altitudes of the inversions are higher over the equator and lower over the poles; the curves presented in Figure 10.3 refer to middle latitudes. The boundary areas at each temperature inversion are called tropopause, stratopause, and mesopause, respectively. Pollution of the atmosphere is generally the least appreciated of all environmental issues.

scholarly journals Air temperature thresholds to evaluate snow melting at the surface of Alpine glaciers by T-index models: the case study of Forni Glacier (Italy)

2014 ◽  
Vol 8 (2) ◽  
pp. 1563-1587 ◽  
Author(s):  
A. Senese ◽  
M. Maugeri ◽  
E. Vuillermoz ◽  
C. Smiraglia ◽  
G. Diolaiuti
Keyword(s):  
Air Temperature ◽  
Energy Budget ◽  
Snow Water Equivalent ◽  
Lapse Rate ◽  
Positive Energy ◽  
Temperature Threshold ◽  
Weather Station ◽  
Glacier Melt ◽  
Air Temperatures ◽  
The Mean

Abstract. The glacier melt conditions (i.e.: null surface temperature and positive energy budget) can be assessed by analyzing meteorological and energy data acquired by a supraglacial Automatic Weather Station (AWS). In the case this latter is not present the assessment of actual melting conditions and the evaluation of the melt amount is difficult and simple methods based on T-index (or degree days) models are generally applied. These models require the choice of a correct temperature threshold. In fact, melt does not necessarily occur at daily air temperatures higher than 273.15 K. In this paper, to detect the most indicative threshold witnessing melt conditions in the April–June period, we have analyzed air temperature data recorded from 2006 to 2012 by a supraglacial AWS set up at 2631 m a.s.l. on the ablation tongue of the Forni Glacier (Italian Alps), and by a weather station located outside the studied glacier (at Bormio, a village at 1225 m a.s.l.). Moreover we have evaluated the glacier energy budget and the Snow Water Equivalent (SWE) values during this time-frame. Then the snow ablation amount was estimated both from the surface energy balance (from supraglacial AWS data) and from T-index method (from Bormio data, applying the mean tropospheric lapse rate and varying the air temperature threshold) and the results were compared. We found that the mean tropospheric lapse rate permits a good and reliable reconstruction of glacier air temperatures and the major uncertainty in the computation of snow melt is driven by the choice of an appropriate temperature threshold. From our study using a 5.0 K lower threshold value (with respect to the largely applied 273.15 K) permits the most reliable reconstruction of glacier melt.

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