Snow Wetness Measurement by Fluorescent Dye Dilution

AbstractThe fluorescent dye dilution method for determining the liquid-water content in snow is based on measuring the concentration change of a solution when it is mixed with snow. Samples for analysis can be obtained rapidly and reliably, and, unlike calorimetric or equilibrium-temperature methods, field use requires no on-site data analysis.

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Modeling Surface Temperatures for Snow-Covered Roads: A Case Study for a Heated Pavement in Bærum, Norway

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198118772959 ◽

2018 ◽

Vol 2672 (12) ◽

pp. 220-231

Author(s):

Anne D. W. Nuijten ◽

Inge Hoff ◽

Knut V. Høyland

Keyword(s):

Thermal Conductivity ◽

Water Content ◽

Liquid Water ◽

Surface Condition ◽

Winter Season ◽

High Water ◽

Liquid Water Content ◽

High Water Content ◽

Snow Layer ◽

Snow Samples

Heated pavements are used as an alternative to removing snow and ice mechanically and chemically. Usually a heated pavement system is automatically switched on when snowfall starts or when there is a risk of ice formation. Ideally, these systems run based on accurate predictions of surface conditions a couple of hours ahead of time, for which both weather forecasts and reliable surface temperature predictions are needed. The effective thermal conductivity of the snow layer is often described as a function of its density. However the thermal conductivity of a snow layer can vary considerably, not only for snow samples with a different density, but also for snow samples with the same density, but with a variation in the liquid water content. In this paper a physical temperature and surface condition model is described for snow-covered roads. The model is validated for an entire winter season on a heated pavement in Norway. Two different models to describe the thermal conductivity through the snow layer were compared. Results show that the thermal conductivity of the snow layer can be best described as a function of the density for snow with a low liquid water content. For snow with a high water content, the thermal conductivity can be best described as a function of the volume fractions and thermal conductivity of ice, water, and air, in which air and ice are modeled as a series system and water and air/ice in parallel.

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Determination of the liquid water content of snow by the dye dilution technique

Cold Regions Science and Technology ◽

10.1016/0165-232x(86)90043-1 ◽

1986 ◽

Vol 12 (3) ◽

pp. 295-298 ◽

Cited By ~ 3

Author(s):

Thomas C. Grenfell

Keyword(s):

Water Content ◽

Liquid Water ◽

Liquid Water Content ◽

Dilution Technique ◽

Dye Dilution

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Investigation on Wet-Snow Metamorphism in Respect of Liquid-Water Content

Annals of Glaciology ◽

10.3189/s0260305500007576 ◽

1989 ◽

Vol 13 ◽

pp. 22-26 ◽

Cited By ~ 37

Author(s):

E. Brun

Keyword(s):

Growth Rate ◽

Water Content ◽

Liquid Water ◽

Liquid Water Content ◽

Snow Metamorphism ◽

Wet Snow ◽

The Mean ◽

Water Saturated ◽

Warming Device ◽

Snow Samples

Up to the present time, quantitative investigations on wet-snow metamorphism have mostly been conducted on water-saturated snow, because of the difficulty in getting large enough wet-snow samples at a uniformly low liquid-water content. Using the dielectric properties of snow at a frequency in the range 20–100 kHz, a warming device has been developed which has enabled us to bring samples of 7 × 10−3 m3 snow to any desired liquid-water content. A maximum value of 8% by volume was reached within 2 h.The warming device was used to reproduce natural wetness conditions in the laboratory in order to investigate wet snow metamorphism at low liquid-water content. Snow samples were brought to different liquid-water contents and held in that condition for about 2 weeks, during which grain-size was characterized using a picture-analysis system able to derive the mean radius of curvature of the cluster circumference. At any given liquid-water content value, the growth rate of the mean volume of the crystals building the clusters was constant, a pattern which has also been observed in water-saturated snow by previous investigators. This growth rate is well described by a power function of liquid-water content.

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Investigation on Wet-Snow Metamorphism in Respect of Liquid-Water Content

Annals of Glaciology ◽

10.1017/s0260305500007576 ◽

1989 ◽

Vol 13 ◽

pp. 22-26 ◽

Cited By ~ 55

Author(s):

E. Brun

Keyword(s):

Growth Rate ◽

Water Content ◽

Liquid Water ◽

Liquid Water Content ◽

Snow Metamorphism ◽

Wet Snow ◽

The Mean ◽

Water Saturated ◽

Warming Device ◽

Snow Samples

Up to the present time, quantitative investigations on wet-snow metamorphism have mostly been conducted on water-saturated snow, because of the difficulty in getting large enough wet-snow samples at a uniformly low liquid-water content. Using the dielectric properties of snow at a frequency in the range 20–100 kHz, a warming device has been developed which has enabled us to bring samples of 7 × 10−3 m3 snow to any desired liquid-water content. A maximum value of 8% by volume was reached within 2 h. The warming device was used to reproduce natural wetness conditions in the laboratory in order to investigate wet snow metamorphism at low liquid-water content. Snow samples were brought to different liquid-water contents and held in that condition for about 2 weeks, during which grain-size was characterized using a picture-analysis system able to derive the mean radius of curvature of the cluster circumference. At any given liquid-water content value, the growth rate of the mean volume of the crystals building the clusters was constant, a pattern which has also been observed in water-saturated snow by previous investigators. This growth rate is well described by a power function of liquid-water content.

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ANALISIS PROFIL CAPE (CONVECTIVE AVAILABLE POTENTIAL ENERGY) SELAMA KEGIATAN INTENSIVE OBSERVATION PERIOD DI DRAMAGA BOGOR

Jurnal Sains & Teknologi Modifikasi Cuaca ◽

10.29122/jstmc.v17i2.1053 ◽

2016 ◽

Vol 17 (2) ◽

pp. 83

Author(s):

Alfan Muttaqin ◽

Fikri Nur Muhammad ◽

Purnomo Arif Abdillah

Keyword(s):

Data Analysis ◽

Potential Energy ◽

Water Content ◽

Liquid Water ◽

Convective Available Potential Energy ◽

Liquid Water Content ◽

Moderate Intensity ◽

Available Potential Energy ◽

Intensive Observation ◽

Altitude Level

IntisariProfil nilai CAPE(Convective Available Potential Energy) telah didapatkan dari analisis data Radiometer untuk wilayah Dramaga Kabupaten Bogor dan sekitarnya. Kegiatan pengamatan dilakukan dari tanggal 18 Januari – 16 Februari 2016. Radiometer mampu mengamati profil atmosfer sampai level ketinggian 10 km. Dengan kemampuan tersebut maka kandungan air (Liquid Water Content), kelembaban relatif (RH) dan suhu bisa teramati sampai level atas. Hasil pengolahan dan analisis menunjukkan bahwa nilai CAPE, sesaat akan terjadi hujan, cenderung terlihat turun dan bernilai mendekati 0 (nol). Ketika terjadi hujan dengan instensitas sedang maka nilai CAPE turun perlahan dan mendekati 0 (nol), ketika terjadi hujan dengan instensitas ringan maka nilai CAPE turun namun tidak mendekati 0 (nol) dan nilai CAPE ketika hari tidak hujan cenderung tidak ada yang mendekati 0 (nol). Besarnya nilai CAPE tidak berpengaruh terhadap intensitas curah hujan. Pada saat hari terjadi hujan maka akan disertai terjadinya penurunan nilai CAPE karena tidak ada konveksi. AbstractCAPE value profile has been obtained from the Radiometer data analysis for Dramaga region and its surrounding. Observation activities conducted from January 18th to February 16th, 2016. Radiometer can observe atmospheric profiles up to 10 km altitude level. With this capability, the water content (Liquid Water Content), Relative Humidity (RH) and temperature can be measured up to 10 km. The results of processing and data analysis shows that the value of CAPE, just before the rain occur, tends to decline and approaching 0 (zero). When it rains with moderate intensity the value of CAPE decrease slowly and close to 0 (zero), when it rains with light intensity CAPE values is decrease but not close to 0 (zero) and CAPE value when it is not rain, tends to not approaching 0 (zero). The CAPE value does not affect the rain intensity. When the rain occurred, the CAPE value has been decrease because there is no convection..

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