scholarly journals The Green Ocean: precipitation insights from the GoAmazon2014/5 experiment

2018 ◽  
Vol 18 (12) ◽  
pp. 9121-9145 ◽  
Author(s):  
Die Wang ◽  
Scott E. Giangrande ◽  
Mary Jane Bartholomew ◽  
Joseph Hardin ◽  
Zhe Feng ◽  
...  
Keyword(s):  
Drop Size ◽  
Department Of Energy ◽  
Size Distributions ◽  
Wet Season ◽  
Radar Rainfall ◽  
Precipitation Characteristics ◽  
Central Amazonia ◽  
Atmospheric Radiation Measurement ◽  
Drop Size Distributions ◽  
Self Consistency

Abstract. This study summarizes the precipitation properties collected during the GoAmazon2014/5 campaign near Manaus in central Amazonia, Brazil. Precipitation breakdowns, summary radar rainfall relationships and self-consistency concepts from a coupled disdrometer and radar wind profiler measurements are presented. The properties of Amazon cumulus and associated stratiform precipitation are discussed, including segregations according to seasonal (wet or dry regime) variability, cloud echo-top height and possible aerosol influences on the apparent oceanic characteristics of the precipitation drop size distributions. Overall, we observe that the Amazon precipitation straddles behaviors found during previous U.S. Department of Energy Atmospheric Radiation Measurement (ARM) program tropical deployments, with distributions favoring higher concentrations of smaller drops than ARM continental examples. Oceanic-type precipitation characteristics are predominantly observed during the Amazon wet seasons. An exploration of the controls on wet season precipitation properties reveals that wind direction, compared with other standard radiosonde thermodynamic parameters or aerosol count/regime classifications performed at the ARM site, provides a good indicator for those wet season Amazon events having an oceanic character for their precipitation drop size distributions.

scholarly journals The Green Ocean: Precipitation Insights from the GoAmazon2014/5 Experiment

2018 ◽  
Author(s):  
Die Wang ◽  
Scott E. Giangrande ◽  
Mary Jane Bartholomew ◽  
Joseph Hardin ◽  
Zhe Feng ◽  
...  
Keyword(s):  
Drop Size ◽  
Department Of Energy ◽  
Size Distributions ◽  
Wet Season ◽  
Radar Rainfall ◽  
Precipitation Characteristics ◽  
Central Amazonia ◽  
Drop Size Distributions ◽  
Self Consistency ◽  
Radiation Measurements

Abstract. This study summarizes the precipitation properties collected during the GoAmazon2014/5 campaign near Manaus in central Amazonia, Brazil. Precipitation breakdowns, summary radar rainfall relationships and self-consistency concepts from a coupled disdrometer and radar wind profiler measurements are presented. The properties of Amazon cumulus and associated stratiform precipitation are discussed, including segregations according to seasonal (Wet/Dry regime) variability, cloud echo-top height and possible aerosol influences on the apparent oceanic characteristics of the precipitation drop size distributions. Overall, we observe that the Amazon precipitation straddles behaviors found during previous U.S. Department of Energy Atmospheric Radiation Measurements program (ARM) tropical deployments, with distributions favoring higher concentrations of smaller drops than ARM continental examples. Oceanic type precipitation characteristics are predominantly observed during the Amazon Wet seasons. An exploration of the controls on Wet season precipitation properties reveals that wind direction, as compared with other standard radiosonde thermodynamic parameters or aerosol count/regime classifications performed at the ARM site, provides a good indicator for those Wet season Amazon events having an oceanic character for their precipitation drop size distributions.

scholarly journals A Study of the Error Covariance Matrix of Radar Rainfall Estimates in Stratiform Rain

2008 ◽  
Vol 23 (6) ◽  
pp. 1085-1101 ◽  
Author(s):  
Marc Berenguer ◽  
Isztar Zawadzki
Keyword(s):  
Covariance Matrix ◽  
Drop Size ◽  
Size Distributions ◽  
Radar Rainfall ◽  
Error Covariance Matrix ◽  
Error Covariance ◽  
Drop Size Distributions ◽  
The Impact ◽  
Dependent Error ◽  
Rainfall Estimates

Abstract The contribution of various physical sources of uncertainty affecting radar rainfall estimates at the ground is quantified toward deriving and understanding the error covariance matrix of these estimates. The focus here is on stratiform precipitation at a resolution of 15 km, which is most relevant for data assimilation onto mesoscale numerical models. In the characterization of the error structure, the following contributions are considered: (i) the individual effect of the range-dependent error (associated with beam broadening and increasing height of radar measurements with range), (ii) the error associated with the transformation from reflectivity to rain rate due to the variability of drop size distributions, and (iii) the interaction of the first two, that is, the term resulting from the cross correlation between the effects of the range-dependent error and the uncertainty related to the variability of drop size distributions (DSDs). For this purpose a large database of S-band radar observations at short range (where reflectivity near the ground is measured and the beam is narrow) is used to characterize the range-dependent error within a simulation framework, and disdrometric measurements collocated with the radar data are used to assess the impact of the variability of DSDs. It is noted that these two sources of error are well correlated in the vicinity of the melting layer as result of the physical processes that determine the density of snow (e.g., riming), which affect both the DSD variability and the vertical profile of reflectivity.

scholarly journals A Summary of Precipitation Characteristics from the 2006–11 Northern Australian Wet Seasons as Revealed by ARM Disdrometer Research Facilities (Darwin, Australia)

2014 ◽  
Vol 53 (5) ◽  
pp. 1213-1231 ◽  
Author(s):  
Scott E. Giangrande ◽  
Mary Jane Bartholomew ◽  
Mick Pope ◽  
Scott Collis ◽  
Michael P. Jensen
Keyword(s):  
Large Scale ◽  
Atmospheric Conditions ◽  
Wet Season ◽  
Rainfall Characteristics ◽  
Precipitation Characteristics ◽  
Continuous Record ◽  
Atmospheric Radiation Measurement ◽  
Drop Size Distributions ◽  
Storm Characteristics ◽  
Research Facilities

AbstractThe variability of rainfall and drop size distributions (DSDs) as a function of large-scale atmospheric conditions and storm characteristics is investigated using measurements from the Atmospheric Radiation Measurement Program (ARM) facility at Darwin, Australia. Observations are obtained from an impact disdrometer with a near continuous record of operation over five consecutive wet seasons (2006–11). Bulk rainfall characteristics are partitioned according to diurnal accumulation, convective and stratiform precipitation classifications, objective monsoonal regime, and MJO phase. Findings support previous Darwin studies suggesting a significant diurnal and DSD parameter signal associated with both convective–stratiform and wet season monsoonal regime classification. Negligible MJO phase influence is determined for cumulative disdrometric statistics over the Darwin location.

Drop-size distributions from pneumatic atomizers

AIChE Journal ◽  
1971 ◽  
Vol 17 (3) ◽  
pp. 575-584 ◽  
Author(s):  
K. Y. Kim ◽  
W. R. Marshall
Keyword(s):  
Drop Size ◽  
Size Distributions ◽  
Drop Size Distributions

scholarly journals Raindrop Size Distribution and Rain Characteristics during the 2013 Great Colorado Flood

2015 ◽  
Vol 17 (1) ◽  
pp. 53-72 ◽  
Author(s):  
Katja Friedrich ◽  
Evan A. Kalina ◽  
Joshua Aikins ◽  
Matthias Steiner ◽  
David Gochis ◽  
...  
Keyword(s):  
Drop Size ◽  
Doppler Radar ◽  
Liquid Water Content ◽  
Size Distributions ◽  
Intense Rainfall ◽  
Wind Fields ◽  
Raindrop Size Distribution ◽  
Median Volume ◽  
Drop Size Distributions ◽  
Analysis System

Abstract Drop size distributions observed by four Particle Size Velocity (PARSIVEL) disdrometers during the 2013 Great Colorado Flood are used to diagnose rain characteristics during intensive rainfall episodes. The analysis focuses on 30 h of intense rainfall in the vicinity of Boulder, Colorado, from 2200 UTC 11 September to 0400 UTC 13 September 2013. Rainfall rates R, median volume diameters D0, reflectivity Z, drop size distributions (DSDs), and gamma DSD parameters were derived and compared between the foothills and adjacent plains locations. Rainfall throughout the entire event was characterized by a large number of small- to medium-sized raindrops (diameters smaller than 1.5 mm) resulting in small values of Z (<40 dBZ), differential reflectivity Zdr (<1.3 dB), specific differential phase Kdp (<1° km−1), and D0 (<1 mm). In addition, high liquid water content was present throughout the entire event. Raindrops observed in the plains were generally larger than those in the foothills. DSDs observed in the foothills were characterized by a large concentration of small-sized drops (d < 1 mm). Heavy rainfall rates with slightly larger drops were observed during the first intense rainfall episode (0000–0800 UTC 12 September) and were associated with areas of enhanced low-level convergence and vertical velocity according to the wind fields derived from the Variational Doppler Radar Analysis System. The disdrometer-derived Z–R relationships reflect how unusual the DSDs were during the 2013 Great Colorado Flood. As a result, Z–R relations commonly used by the operational NEXRAD strongly underestimated rainfall rates by up to 43%.

scholarly journals On the Shape–Slope Relation of Drop Size Distributions in Convective Rain

2005 ◽  
Vol 44 (7) ◽  
pp. 1146-1151 ◽  
Author(s):  
Axel Seifert
Keyword(s):  
Size Distribution ◽  
Gamma Distribution ◽  
Drop Size ◽  
Empirical Relation ◽  
Size Distributions ◽  
Shape Parameters ◽  
Raindrop Size Distribution ◽  
Raindrop Size ◽  
Drop Size Distributions ◽  
Good Agreement

Abstract The relation between the slope and shape parameters of the raindrop size distribution parameterized by a gamma distribution is examined. The comparison of results of a simple rain shaft model with an empirical relation based on disdrometer measurements at the surface shows very good agreement, but a more detailed discussion reveals some difficulties—for example, deviations from the gamma shape and the overestimation of collisional breakup.

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