Back
 GEP  Vol.7 No.2 , February 2019
Analysis of Vertical Profiles of Precipitable Liquid Water Content in a Tropical Climate Using Micro Rain Radar
Abstract: In this paper, some distinctive features of the vertical profile of precipitable liquid water content (LWC) with considerable respect to rain rates (R) and radar reflectivity (Z) obtained in a tropical location are presented. Assessment of LWC allows applications in the specific area of flight icing severity, aviation safety as well as signals traversing through the atmosphere. The parameters were typically measured using vertically-pointing Micro Rain Radar (MRR) over a period of 2 years (2011-2012) at Akure, a tropical location of Nigeria. The radar scanned at every 10 seconds and integrated over one minute samples to reduce event logging error associated with the instrument. The vertical profile of the LWC typically reveals a prominent seasonal variation. However, majority of the LWC profiles has low LWC, less than 0.1 gm−3 while the maximum observed LWC is about 3.18 gm−3. A strong like hood relation was observed between the melting layer height and the LWC, with the LWC reaches peak at the considerable height of about 4160 m which coincides precisely with the freezing height level (rain height of ~4520 m) of the study location. Good correlation was also observed between the LWC and R in most of the heights considered. The results obtained will assist system engineers to assess the level of absorption, reflection and attenuation of electromagnetic signals as a result of precipitable LWC along the transmitting paths. The novelty of the present work is in the area of linking LWC and Z as against usual relation between Z and R.
Cite this paper: Ojo, J. , Daodu, O. and Ojo, O. (2019) Analysis of Vertical Profiles of Precipitable Liquid Water Content in a Tropical Climate Using Micro Rain Radar. Journal of Geoscience and Environment Protection, 7, 140-155. doi: 10.4236/gep.2019.72010.
References

[1]   Atlas, D. (1954). The Estimation of Cloud Content by Radar. J. Meteor, 11, 309-317.
https://doi.org/10.1175/1520-0469(1954)011<0309:TEOCPB>2.0.CO;2

[2]   Barker, H. W., & Räisänen, P. (2005). Radiative Sensitivities for Cloud Structural Properties That Are Unresolved by Conventional GCMs. Quarterly Journal of the Royal Meteorological Society, 131, 3103-3122.
https://doi.org/10.1256/qj.04.174

[3]   Brandau, C. L., Russchenberg, H. W. J., & Knap, W. H. (2010). Evaluation of Ground-Based Remotely Sensed Liquid Water Cloud Properties Using Shortwave Radiation Measurements .Atmospheric Research, 96, 366-377.
https://doi.org/10.1016/j.atmosres.2010.01.009

[4]   Browning, K. A. (1994). Survey of Perceived Priority Issues in the Parameterization of Cloud-Related Processes in GCMs. Quarterly Journal of the Royal Meteorological Society, 120, 483-487.

[5]   Calheiros, A. J. P., & Machado, L. A. T. (2014). Cloud and Rain Liquid Water Statistics in the CHUVA Campaign. Atmospheric Research, 144, 126-140.
https://doi.org/10.1016/j.atmosres.2014.03.006

[6]   Chakraborty, S., & Maitra, A. (2012). A Comparative Study of Cloud Liquid Water Content from Radiosonde Data at a Tropical Location. International Journal of Geosciences, 3, 44-49.
https://doi.org/10.4236/ijg.2012.31006

[7]   Clothiaux, E., Miller, M., Perez, R., Turner, D., Moran, K., Martner, B., Ackerman, T., Mace, G., Marchand, R., Widener, K., Rodriguez, D., Uttal, T., Mather, J., Flynn, C., Gaustad, K., & Ermold, B. (2001). The ARM Millimeter Wave Cloud Radars (MMCRs) and the Active Remote Sensing of Clouds (ARSCL) Value Added Product (VAP). Technical Report DOE Tech. Memo. ARM VAP-002.1, US Department of Energy, Office of Science, Office of Biological and Environmental Research.

[8]   Crewell, S., & Löhnert, U. (2003). Accuracy of Cloud Liquid Water Path from Ground-Based Microwave Radiometry. Part II. Sensor Accuracy and Synergy. Radio Science, 38.
https://doi.org/10.1029/2002RS002634

[9]   Donaldson, R. J. (1955). Measurement of Cloud Liquid Water Content by Radar. Journal of Meteorology, 12, 238-244.
https://doi.org/10.1175/1520-0469(1955)012<0238:TMOCLW>2.0.CO;2

[10]   Foote, G. B., & Dutoit, P. S. (1969). Terminal Velocity of Raindrops Aloft. Journal of Applied Meteorology, 8, 249-253.
https://doi.org/10.1175/1520-0450(1969)008<0249:TVORA>2.0.CO;2

[11]   Green, D. R., & Clark, R. A. (1972). Vertically Integrated Liquid Water—A New Analysis Tool. Monthly Weather Review, 100, 548-552.
https://doi.org/10.1175/1520-0493(1972)100<0548:VILWNA>2.3.CO;2

[12]   Gultepe, I., & Rao, G. V. (1993). Moisture and Heat Budget of a Cirrus Cloud from Aircraft Measurements during Fire. Quarterly Journal of the Royal Meteorological Society, 119, 957-974.
https://doi.org/10.1002/qj.49711951306

[13]   Gunn, R., & Kinzer, G. D. (1949). The Terminal Velocity of Fall for Water Droplets in Stagnant Air. J. Meteorol, 6, 243-248.
https://doi.org/10.1175/1520-0469(1949)006<0243:TTVOFF>2.0.CO;2

[14]   Hagen, M., & Yuter, S. E. (2003). Relations between Radar Reflectivity, Liquid Water Content, and Rainfall Rate during the MAP SOP. Quarterly Journal of the Royal Meteorological Society, 129, 477-493.
https://doi.org/10.1256/qj.02.23

[15]   IPCC (2013). Fifth Assessment Report of the Intergovernmental Panel on Climate Change-IPCC. Chapter 7, 573.

[16]   Joss, J., & Dyer, R. (1972). Large Errors Involved in Deducing Drop-Size Distributions from Doppler Radar Data Due to Vertical Air Motion. In 15th Radar Meteorology Conference (pp. 179-180). Boston, MA: American Meteorological Society.

[17]   Korolev, A. V., Isaac, G. A., Strapp, J. W., Cober, S. G., & Barker, H. W. (2007). In Situ Measurements of Liquid Water Content Profiles in Midlatitude Stratiform Clouds. Quarterly Journal of the Royal Meteorological Society, 133, 1693-1699.
https://doi.org/10.1002/qj.147

[18]   Li, J., & Barker, H. W. (2002). Accounting for Unresolved Clouds in a 1D Infrared Radiative Transfer Model. Part II. Horizontal Variability of Cloud Water Path. Journal of the Atmospheric Sciences, 59, 3321-3339.
https://doi.org/10.1175/1520-0469(2002)059<3321:AFUCIA>2.0.CO;2

[19]   Maitra, A., & Chakraborty, S. (2009). Cloud Liquid Content and Cloud Attenuation Studies with Radiosonde Data at a Tropical Location. Journal of Infrared, Milli-Meter and Terahertz Waves, 30, 367-373.
https://doi.org/10.1007/s10762-008-9452-8

[20]   McFarlane, S., Mather, J., Ackerman, T., & Liuand, Z. (2008). Effect of Clouds on the Calculated Vertical Distribution of Shortwave Absorption in the Tropics. Journal of Geophysical Research, 113, D18203.
https://doi.org/10.1029/2008JD009791

[21]   Michaelides, S., Tymvios, F., & Michaelidou, T. (2009). Spatial and Temporal Characteristics of the Annual Rainfall Frequency Distribution in Cyprus. Atmospheric Research, 94, 606-615.
https://doi.org/10.1016/j.atmosres.2009.04.008

[22]   Ojo, J. S., Falodun, S. E., & Odiba, O. (2014). 0 ºC Isotherm Height Distribution for Earth-Space Communication Satellite Links in Nigeria. Indian Journal of Radio and Space Physics, 43, 225-234.

[23]   Paul, T., & Paul, T. W. (1985). Model Vertical Profile of Extreme Rainfall Rate, Liquid Water Content, and Drop Size Distribution. Environmental Research Paper No. 926.

[24]   Peter, G., Fischer, B., & Anderson, T. (2002). Rain Observation with Vertically Looking Micro Rain Radar (MRR). Boreal Environment Research, 7, 353-362.

[25]   Peters, G., Fischer, B., Münster, H., Clemens, M., & Wagner, A. (2005). Profiles of Raindrop Size Distributions as Retrieved by Micro Rain Radars. Journal of Applied Meteorology, 44, 1930-1949.
https://doi.org/10.1175/JAM2316.1

[26]   Richter, C. (1994). Niederschlagsmessungen mit dem vertikal ausgerichteten FM-CW Doppler radar-RASS-System, Validierung und Anwendung. Dissertation Universität Hamburg. Berichte aus dem Zentrum für Meeres-und Klimaforschung Nr. 12, 143.

[27]   Sauvegeot, H., & Omar, J. (1987). Radar Reflectivity of Cumulus Clouds. Journal of Atmospheric and Oceanic Technology, 4, 264-272.
https://doi.org/10.1175/1520-0426(1987)004<0264:RROCC>2.0.CO;2

[28]   Slingo, A., & Schrecker, H. M. (1982). On the Shortwave Radiative Properties of Stratiform Water Clouds. Quarterly Journal of the Royal Meteorological Society, 108, 407-426.
https://doi.org/10.1002/qj.49710845607

[29]   Strauch, R. G. (1976). Theory and Application of the FM-CW Doppler Radar (p. 97). PhD Electrical Engineering. Denver, CO: University of Colorado.

[30]   Tattelmann, P., & Willis, P. (1989). Drop-Size Distribution Associated with Intense Rainfall. Journal of Applied Meteorology, 28, 3-15.
https://doi.org/10.1175/1520-0450(1989)028<0003:DSDAWI>2.0.CO;2

 
 
Top