scholarly journals MIAWARA-C, a new ground based water vapor radiometer for measurement campaigns

2010 ◽  
Vol 3 (5) ◽  
pp. 1271-1285 ◽  
Author(s):  
C. Straub ◽  
A. Murk ◽  
N. Kämpfer
Keyword(s):  
Water Vapor ◽  
Middle Atmosphere ◽  
Horn Antenna ◽  
Research Centre ◽  
Profile Measurement ◽  
Finnish Meteorological Institute ◽  
Correlation Receiver ◽  
Set Up ◽  
Compact Design ◽  
Measurement Campaigns

Abstract. In this paper a new 22 GHz water vapor spectro-radiometer which has been specifically designed for profile measurement campaigns of the middle atmosphere is presented. The instrument is of a compact design and has a simple set up procedure. It can be operated as a standalone instrument as it maintains its own weather station and a calibration scheme that does not rely on other instruments or the use of liquid nitrogen. The optical system of MIAWARA-C combines a choked gaussian horn antenna with a parabolic mirror which reduces the size of the instrument in comparison with currently existing radiometers. For the data acquisition a correlation receiver is used together with a digital cross correlating spectrometer. The complete backend section, including the computer, is located in the same housing as the instrument. The receiver section is temperature stabilized to minimize gain fluctuations. Calibration of the instrument is achieved through a balancing scheme with the sky used as the cold load and the tropospheric properties are determined by performing regular tipping curves. Since MIAWARA-C is used in measurement campaigns it is important to be able to determine the elevation pointing in a simple manner as this is a crucial parameter in the calibration process. Here we present two different methods; scanning the sky and the Sun. Finally, we report on the first spectra and retrieved water vapor profiles acquired during the Lapbiat campaign at the Finnish Meteorological Institute Arctic Research Centre in Sodankylä, Finland. The performance of MIAWARA-C is validated here by comparison of the presented profiles against the equivalent profiles from the Microwave Limb Sounder on the EOS/Aura satellite.

scholarly journals MIAWARA-C, a new ground based water vapor radiometer for measurement campaigns

2010 ◽  
Vol 3 (3) ◽  
pp. 2389-2432
Author(s):  
C. Straub ◽  
A. Murk ◽  
N. Kaempfer
Keyword(s):  
Water Vapor ◽  
Middle Atmosphere ◽  
Horn Antenna ◽  
Profile Measurement ◽  
Correlation Receiver ◽  
Water Vapor Radiometer ◽  
Set Up ◽  
Compact Design ◽  
Crucial Parameter ◽  
Measurement Campaigns

Abstract. In this paper a new 22 GHz water vapor spectro-radiometer which has been specifically designed for profile measurement campaigns of the middle atmosphere is presented. The instrument is of a compact design and has a simple set up procedure. It can be operated as a standalone instrument as it maintains its own weather station and a calibration scheme that does not rely on other instruments or the use of liquid nitrogen. The optical system of MIAWARA-C combines a choked gaussian horn antenna with a parabolic mirror which reduces the size of the instrument in comparison with currently existing radiometers. For the data acquisition a correlation receiver is used together with a digital cross correlating spectrometer. The complete backend section, including the computer, is located in the same housing as the instrument. The receiver section is temperature stabilized to avoid gain fluctuations. Calibration of the instrument is achieved through a balancing scheme with the sky used as the cold load and the tropospheric properties are determined by performing regular tipping curves. Since MIAWARA-C is used in measurement campaigns it is important to be able to determine the elevation pointing in a simple manner as this is a crucial parameter in the calibration process. Here we present two different methods; scanning the sky and the Sun. Finally, we report on the first spectra and retrieved water vapor profiles acquired during the Lapbiat campaign at Sodankylä Geophysical Observatory. The performance of MIAWARA-C is validated here by comparison of the presented profiles against the equivalent profiles from the Microwave Limb Sounder on the EOS/Aura satellite.

scholarly journals Optical laboratory facilities at the Finnish Meteorological Institute – Arctic Research Centre

2016 ◽  
Vol 5 (2) ◽  
pp. 315-320 ◽  
Author(s):  
Kaisa Lakkala ◽  
Hanne Suokanerva ◽  
Juha Matti Karhu ◽  
Antti Aarva ◽  
Antti Poikonen ◽  
...  
Keyword(s):  
Test System ◽  
Research Centre ◽  
Multidisciplinary Research ◽  
Finnish Meteorological Institute ◽  
Laboratory Facilities ◽  
Biological Studies ◽  
Optical Table ◽  
Set Up ◽  
Dark Room ◽  
Meteorological Institute

Abstract. This paper describes the laboratory facilities at the Finnish Meteorological Institute – Arctic Research Centre (FMI-ARC, http://fmiarc.fmi.fi). They comprise an optical laboratory, a facility for biological studies, and an office. A dark room has been built, in which an optical table and a fixed lamp test system are set up, and the electronics allow high-precision adjustment of the current. The Brewer spectroradiometer, NILU-UV multifilter radiometer, and Analytical Spectral Devices (ASD) spectroradiometer of the FMI-ARC are regularly calibrated or checked for stability in the laboratory. The facilities are ideal for responding to the needs of international multidisciplinary research, giving the possibility to calibrate and characterize the research instruments as well as handle and store samples.

scholarly journals Optical laboratory facilities at the Finnish Meteorological Institute – Arctic Research Centre

2016 ◽  
Author(s):  
K. Lakkala ◽  
H. Suokanerva ◽  
J. M. Karhu ◽  
A. Aarva ◽  
A. Poikonen ◽  
...  
Keyword(s):  
Test System ◽  
Research Centre ◽  
Multidisciplinary Research ◽  
Finnish Meteorological Institute ◽  
Laboratory Facilities ◽  
Biological Studies ◽  
Optical Table ◽  
Set Up ◽  
Dark Room ◽  
Meteorological Institute

Abstract. This paper describes the laboratory facilities at the Finnish Meteorological Institute – Arctic Research Centre (FMI-ARC). They comprise an optical laboratory, a facility for biological studies and an office. A dark room has been built, in which an optical table and a fixed lamp test system are set up, and the electronics allow high precision adjustment of the current. The Brewer spectroradiometer, NILU-UV multifilter radiometer and ASD spectroradiometer of the FMI-ARC are regularly calibrated or checked for stability in the laboratory. The facilities are ideal for responding to the needs of international multidisciplinary research, giving the possibility to calibrate and characterize the research instruments as well as handle and store samples.

Proposed reference model for middle atmosphere water vapor

1996 ◽  
Vol 18 (9-10) ◽  
pp. 59-89 ◽  
Author(s):  
E.W. Chiou ◽  
E.E. Remsberg ◽  
C.D. Rodgers ◽  
R. Munro ◽  
R.M. Bevilacqua ◽  
...  
Keyword(s):  
Water Vapor ◽  
Middle Atmosphere ◽  
Reference Model

The Seoul Water Vapor Radiometer for the Middle Atmosphere: Calibration, Retrieval, and Validation

2011 ◽  
Vol 49 (3) ◽  
pp. 1052-1062 ◽  
Author(s):  
Evelyn De Wachter ◽  
Alexander Haefele ◽  
Niklaus Kampfer ◽  
Soohyun Ka ◽  
Jung Eun Lee ◽  
...  
Keyword(s):  
Water Vapor ◽  
Middle Atmosphere ◽  
Water Vapor Radiometer

scholarly journals Sodankylä manual snow survey program

2016 ◽  
Vol 5 (1) ◽  
pp. 163-179 ◽  
Author(s):  
Leena Leppänen ◽  
Anna Kontu ◽  
Henna-Reetta Hannula ◽  
Heidi Sjöblom ◽  
Jouni Pulliainen
Keyword(s):  
Snow Water Equivalent ◽  
Measurement Techniques ◽  
Liquid Water Content ◽  
The Arctic ◽  
Research Centre ◽  
Future Research ◽  
Forest Zone ◽  
Finnish Meteorological Institute ◽  
Snow Properties ◽  
Snow Water

Abstract. The manual snow survey program of the Arctic Research Centre of the Finnish Meteorological Institute (FMI-ARC) consists of numerous observations of natural seasonal taiga snowpack in Sodankylä, northern Finland. The easily accessible measurement areas represent the typical forest and soil types in the boreal forest zone. Systematic snow measurements began in 1909 with snow depth (HS) and snow water equivalent (SWE). In 2006 the manual snow survey program expanded to cover snow macro- and microstructure from regular snow pits at several sites using both traditional and novel measurement techniques. Present-day snow pit measurements include observations of HS, SWE, temperature, density, stratigraphy, grain size, specific surface area (SSA) and liquid water content (LWC). Regular snow pit measurements are performed weekly during the snow season. Extensive time series of manual snow measurements are important for the monitoring of temporal and spatial changes in seasonal snowpack. This snow survey program is an excellent base for the future research of snow properties.

Trends in noctilucent clouds

2021 ◽  
Author(s):  
Franz-Josef Lübken ◽  
Gerd Baumgarten
Keyword(s):  
Carbon Dioxide ◽  
Water Vapor ◽  
Middle Atmosphere ◽  
Transport Model ◽  
Particle Model ◽  
Noctilucent Clouds ◽  
Middle Latitudes ◽  
Ice Particles ◽  
Highly Correlated ◽  
Ice Water

<p>Noctilucent clouds are often cited as potential indicators of climate change in the middle<br>atmosphere. They owe their existence to the very cold summer mesopause region (~130K) at mid<br>and high latitudes. We analyze trends derived from the Leibniz-Institute Middle Atmosphere<br>Model (LIMA) and the MIMAS ice particle model (Mesospheric Ice Microphysics And tranSport model)<br>for the years 1871-2008 and for middle, high and arctic latitudes, respectively.<br>Model runs with and without an increase of carbon dioxide and water vapor (from methane oxidation)<br>concentration are performed. Trends are most prominent after ~1960 when the increase of both<br>carbon dioxide and water vapor accelerates. Negative trends of (geometric) NLC altitudes are primarily<br>due to cooling below NLC altitudes caused by carbon dioxide increase. Increases of ice particle<br>radii and NLC brightness with time are mainly caused by an enhancement of water vapor.<br>Several ice layer and background parameter trends are similar at high and arctic latitudes but are<br>substantially different at middle latitudes. This concerns, for example, occurrence rates, ice water<br>content (IWC), and number of ice particles in a column. Considering the time period after 1960,<br>geometric altitudes of NLC decrease by approximately 260m per decade, and brightness increases by<br>roughly 50% (1960-2008), independent of latitude. NLC altitudes decrease by approximately 15-20m<br>per increase of carbon dioxide by 1ppmv. The number of ice particles in a column and also at the<br>altitude of maximum backscatter is nearly constant with time. At all latitudes, yearly mean NLC<br>appear at altitudes where temperatures are close to 145+/-1K. Ice particles are present nearly<br>all the time at high and arctic latitudes, but are much less common at middle latitudes. Ice water<br>content and maximum backscatter are highly correlated, where the slope depends on latitude. This<br>allows to combine data sets from satellites and lidars. Furthermore, IWC and the concentration of<br>water vapor at the altitude of maximum backscatter are also strongly correlated. Results from<br>LIMA/MIMAS agree nicely with observations.</p>

scholarly journals Railway Ballast Monitoring by Gpr: A Test Site Investigation

2019 ◽  
Vol 11 (20) ◽  
pp. 2381 ◽  
Author(s):  
Bianchini Ciampoli ◽  
Calvi ◽  
D’Amico
Keyword(s):  
Asset Management ◽  
Construction Materials ◽  
Site Investigation ◽  
Horn Antenna ◽  
Test Site ◽  
Electromagnetic Response ◽  
Actual Condition ◽  
Railway Ballast ◽  
Set Up ◽  
Ground Penetrating

Effective maintenance of railways requires a comprehensive assessment of the actual condition of the construction materials involved. In this regard, Ground-Penetrating Radar (GPR) stands as a viable alternative to the invasive and time-consuming traditional techniques for the inspection of these infrastructures. This work reports the experimental activities carried out on a test-site area within a railway depot in Rome, Italy. To this purpose, a 30 m-long railway section was divided into 10 sub-sections reproducing different various physical and structural conditions of the track-bed. In more detail, combinations of varying scenarios of fragmentation and fouling of the ballast were reproduced. The set-up was then investigated using different multi-frequency GPR horn antenna systems. The effects of the different physical conditions of ballast on the electromagnetic response of the material were analysed for each scenario using time- and frequency-domain signal processing techniques. Parallel to this, modelling was provided to estimate fouling content. Interpretation of results has proven the viability of the GPR method in detecting signs of decay at the network level, thereby proving this technique to be worthy of implementation in asset management systems.

The First Women’s Studies Research Centre: A History of Women’s Studies and Its Progenitors

2018 ◽  
Vol 25 (2) ◽  
pp. 212-233
Author(s):  
Maithreyi Krishnaraj
Keyword(s):  
Women's Studies ◽  
Academic Disciplines ◽  
Research Centre ◽  
Women's Issues ◽  
Women’S Studies ◽  
Master's Thesis ◽  
History Of ◽  
The Government ◽  
Set Up ◽  
The University

The beginning of Women’s Studies has a special history in India. It owes its origin not only to some stalwarts but also to the historical times in which its birth took place. Its location in the SNDT Women’s University in Mumbai was at the initiative of Dr Neera Desai, a Professor of Sociology at that university. Her own work on women’s issues in her Master’s thesis and her involvement in the women’s movement gave her the background for envisaging that a women’s university should engage with analysis of women’s condition and not just teach women other academic disciplines. It was with this motive, that the Research Centre for Women’s Studies was set up in 1974, a year before the publication of the report Towards Equality of the Government of India. The university - originally begun at the initiative of the educationist Shri Dhondo Kheshav Karve received a handsome grant from the industrialist Shri Damodar Thackersey and got named after his mother Shrimathi Nathibai Damodar Thackersey hereafter SNDT Women’s University. The Centre with the involvement of able and farsighted administrators at this university spearheaded the development of this Centre, which became the torch bearer for raising women’s issues.

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