Reply by the author to C. J. Swain

Geophysics ◽  
1984 ◽  
Vol 49 (9) ◽  
pp. 1563-1564
Author(s):  
John H. Karl

As Dr. Swain observes, my 4πγ[Formula: see text] effect results from a global average, and as such says nothing about the vertical gradient at any given location. That’s my point. If my average value is correct (no one has disagreed with that) and measured values agree with the normal gradient, then there must be anomalies that are even larger than 4πγ[Formula: see text] somewhere. It is likely that these anomalous values occur in mountainous regions—just the place where the elevation correction is most important.

1985 ◽  
Vol 59 (3) ◽  
pp. 860-868 ◽  
Author(s):  
D. P. Schuster ◽  
M. A. Mintun ◽  
M. A. Green ◽  
M. M. Ter-Pogossian

We have measured with positron emission tomography (PET) the regional distribution of extravascular lung water (EVLW) and hematocrit (HctL) in normal supine dogs. H2(15)O and C15O were used as total lung water (TLW) and intravascular water (IVW) compartment labels, respectively. An additional plasma volume label (68Ga-transferrin) was used to determine regional HctL. EVLW was calculated as the difference between TLW and IVW. In 13 dogs, EVLW was relatively constant along a gravity-dependent vertical gradient, although values in the most anterior regions were statistically less (P less than 0.05) than those in more posterior ones. The average value for EVLW (13 dogs) was 14.4 +/- 2.5 ml H2O/100 ml lung. When EVLW was compared with IVW on a regional basis, the EVLW/IVW ratio decreased significantly in a gravity-dependent direction from 1.95 +/- 0.28 to 0.88 +/- 0.18. In 7 dogs, no significant difference between HctL and systemic hematocrit (average ratio 1.01 +/- 0.08) was found nor was any significant variation of HctL within the lung detected. Thus, in contrast to gravimetric techniques, a hematocrit correction does not appear to be necessary when regional EVLW is studied by PET.


Geophysics ◽  
1986 ◽  
Vol 51 (7) ◽  
pp. 1505-1508 ◽  
Author(s):  
T. R. LaFehr ◽  
Kwok C. Chan

In his reply to C. J. Swain’s (1984) discussion Karl states that no one has disagreed with his proposed (0.265 mGal/m) “average value” for the normal gravity gradient and that his global terrain model can be used to challenge the validity of the traditional approach to data reduction. Our investigations show that Karl is in error on both counts, and we hope that the following analyses will help toward a clearer understanding of this question.


Author(s):  
Binh Tran Quoc ◽  
Pham Thanh Xuan ◽  
Pham Le Tuan ◽  
Le Phuong Thuy ◽  
Nguyen Xuan Linh ◽  
...  

Currently, the legal area of a land parcel in cadastral map is defined as the projected area of the parcel on a map plane. However, in practice, the real surface area of parcels plays important role for land use. In plain regions, the differences between real and legal areas of parcels are negligible, but in hilly and mountainous regions, these differences are significant and must be accounted in land management. In this paper, the authors had proposed a method for calculating real surface area of land parcels using GIS and data extracted from digital elevation models. The method was verified against Vietnam’s standard on cadastral map by using a simulated land parcel that is a part of a sphere, and got positive results. The method is then applied for calculating surface area of more than 2000 land parcels in Tien Xuan Commune, Thach That District, Hanoi City. The obtained results showed that the differences between real and legal areas of land parcels can reach a value of 23% for forestry land at mountain side with slope of more than 30o. In whole Tien Xuan Commune, these differences have an average value of 2.4%.


2021 ◽  
Vol 13 (19) ◽  
pp. 3839
Author(s):  
Yong Zhou ◽  
Yi Liu ◽  
Jiandong Qiao ◽  
Mingjie Lv ◽  
Zhitao Du ◽  
...  

The trapping layer refers to the atmospheric layer with vertical gradient of atmospheric refractivity less than −157 N-Units/km or vertical gradient of atmospheric modified refractivity 0 M-unit/km, which has a significant impact on radar and radio communication systems. Based on COSMIC and other radio occultation data, we show the statistical characteristics of the global trapping layer during 2005–2020.The statistical results show that the occurrence rate of the trapping layers is mainly concentrated between 50°S and 50°N, and higher occurrences of the trapping layers with more than 50% mainly occur in the boundary area between ocean and land, such as the northwest coastal area of Mexico, the west coastal area of Africa, the Mediterranean Sea, the Red Sea and the Arabian Sea, and the northwest area of Australia, etc. The altitude of the trapping layer is lower near the land and increases with the distance away from the coastline. The intensity is mainly between 6 M-unit and 24 M-unit (an M-unit is the unit of atmospheric modified refractivity), and the average value in some regions is above 24 M-unit, such as in the Arabian Sea area. In addition, the thickness of the trapping layer is between 50 and 240 m, and is generally larger over the ocean than over the land. These results reveal that the generation of the trapping layer is the result of the interaction of various background environmental factors such as radiation band migration, trade winds, monsoons, solar radiation heating, sea–land breezes and so on.


10.37236/7702 ◽  
2019 ◽  
Vol 26 (4) ◽  
Author(s):  
Corey Vorland

J. Propp and T. Roby isolated a phenomenon in which a statistic on a set has the same average value over any orbit as its global average, naming it homomesy. They proved that the cardinality statistic on order ideals of the product of two chains poset under rowmotion exhibits homomesy. In this paper, we prove an analogous result in the case of the product of three chains where one chain has two elements. In order to prove this result, we generalize from two to n dimensions the recombination technique that D. Einstein and Propp developed to study homomesy. We see that our main homomesy result does not fully generalize to an arbitrary product of three chains, nor to larger products of chains; however, we have a partial generalization to an arbitrary product of three chains. Additional corollaries include refined homomesy results in the product of three chains and a new result on increasing tableaux. We conclude with a generalization of recombination to any ranked poset and a homomesy result for the Type B minuscule poset cross a two element chain.


Author(s):  
N.N. Voropay ◽  
◽  

Monitoring is a continuous process of observing and registering the parameters of an object, in comparison with specified criteria. In recent decades, questions related to changes in climatic characteristics have been of great interest. Since 2007, microclimatic observations have been carried out automatically in the mountain-depression landscapes of the Baikal region. The correctness of the use of atmospheric-soil measuring systems is shown by comparing the data of automatic measurements and the data of standard meteorological instruments used at the weather stations of Roshydromet. Estimates of the temperature and humidity regime of air and soils were obtained at 72 sites located in different landscapes in the altitude range of 450–2300 m above sea level. The influence of landscape characteristics, primarily altitudinal zonality, is manifested in the monthly and annual values of meteorological characteristics. Calculations of the vertical gradient of air temperature on the slopes of the mountains are carried out. As a result, an assessment was made of the characteristics of temperature inversions, a phenomenon unique in its power in Eastern Siberia. Their intensity, duration, and frequency were estimated. A comparison is made of the temperature regime of soils under natural and anthropogenically disturbed conditions. The obtained measurement data are used to validate the results of climate modeling and remote sensing (satellite images). The best convergence of rows is observed in open, moderately humid areas. Microclimatic observation data make it possible to study in detail the temperature and humidity regime of landscapes, taking into account the altitudinal zonality, exposure and steepness of slopes throughout the year. The observational data obtained make it possible to clarify the climatic description of the study area, which is currently based mainly on the data of weather stations, the network of which does not cover mountainous regions.


2012 ◽  
Vol 16 (12) ◽  
pp. 4661-4673 ◽  
Author(s):  
L. Gao ◽  
M. Bernhardt ◽  
K. Schulz

Abstract. Air temperature controls a large variety of environmental processes, and is an essential input parameter for land surface models, for example in hydrology, ecology and climatology. However, meteorological networks, which can provide the necessary information, are commonly sparse in complex terrains, especially in high mountainous regions. In order to provide temperature data in an adequate temporal and spatial resolution for local scale applications a new elevation correction method has been developed that is able to downscale 3-hourly ERA-Interim temperature data. The scheme is based on model internal vertical lapse rates derived from different ERA-Interim pressure levels and has been validated for twelve meteorological stations in the German and Swiss Alps. The method was also compared with two other statistical, lapse rate based correction approaches. The results indicate that the use of model internal ERA-Interim lapse rates can significantly improve the downscaling performance when compared to the standard procedure of using fixed lapse rates.


2011 ◽  
Author(s):  
J. Rosado ◽  
F. Blanco ◽  
F. Arqueros ◽  
Hiroyuki Sagawa ◽  
Yoshiya Kawasaki ◽  
...  

Geophysics ◽  
1984 ◽  
Vol 49 (9) ◽  
pp. 1563-1563 ◽  
Author(s):  
C. J. Swain

The implication of the author’s hypothesis, that the conventional free‐air correction factor is difficult to justify and can lead to large errors (e.g., 14 mGal from 300 m of topographic relief), would be very serious indeed for many interpretations of gravity data if it were true. He predicts a normal vertical gradient of 0.264 mGal/m near sea level, 14 percent lower than the conventional theoretical value. However, precise measurements of the free‐air gradient near sea level have been reported (Kuo et al., 1969) which differ by less than [Formula: see text] percent from the theoretical value; moreover these differences correlate with small local (isostatic) anomalies. My own observations at Leicester, England (elevation 100 m) and Nairobi (elevation 1 650 m) (made with students) also differ by less than [Formula: see text] percent from the theoretical values and again the differences correlate with small local anomalies. If these values represent the normal free‐air gradient, it would appear that the author’s analysis must be wrong. The formula he derives gives, correctly, the mean vertical gradient at some level over and within the Earth to a good approximation. This can be seen simply by considering the well‐known formulas for the gradient at a point within the Earth where the density is ρ [Formula: see text] and at a point outside the Earth [Formula: see text] and taking averages at this radius. However, the average value has no practical significance. It does not apply to any point on the Earth’s surface; it is merely a mean.


2018 ◽  
Vol 1 (2) ◽  
pp. 57
Author(s):  
Masadah Masadah

Education is a conscious and systematic effort not only to humanize human beings but also for human beings to realize their position as khalifatullah fil ardhi, which in turn will increasingly increase itself to be a pious, faithful, knowledgeable and virtuous man. In general the problems formulated in this research is whether Implementation of Contextual Learning with Learning Community approach can improve student's motivation and achievement in FIQH study field? How Implementation of Contextual Learning has a Learning Community approach that can improve students' motivation and achievement in FIQH? Field. This research was conducted in Mojokerto Regency, precisely at MI Mambaul Hidayah Mengelo Sooko Mojokerto. This research is a classroom action research with collaborative type. This research phase follows a model developed by Kemmis and Taggart, which is a spiral cycle that includes planning activities, action execution, observation, and reflection. The data collection techniques used are: (1) observation; (2) measurement of learning result test; and (3) documentation. Data obtained from the action are then analyzed. Qualitative data consisting of observation and documentation are analyzed qualitatively, while data collected in the form of numbers or quantitative data, simply by using descriptive analysis and visual presentation. Based on the results of research that has been implemented can be concluded that the Implementation of Contextual Learning with Learning Community approach can improve student's motivation and achievement in the field of FIQH study. From the data in the field shows that there is an increase in student learning motivation that the initial average value of pre-test of 20 increased to 24 or about 20% in cycle I, in cycle II more increased to 31 or about 55%, and in cycle III the more increased to 45 or about 125%. Level of increase between cycle I with cycle II about 29%, between cycle II with cycle III about 45%, between cycle III with cycle I about 87%. With the increase of students' learning motivation, their learning achievement also increased, whereas the average value of pre test of 6.60 increased to 6.84 or about 4% in cycle I, in cycle II more increased again to 7.75 or about 17 %, and in cycle III it increases to 8.80 or about 35%. The level of improvement between cycle I with cycle II is about 13%, between cycle II with cycle III about 15%, between cycle III with cycle I about 30%.


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