Rainfall Profiling Using Atmospheric Radiation Measurement Program Vertically Pointing 8-mm Wavelength Radars

Matrosov, Sergey Y.; May, Peter T.; Shupe, Matthew D.

doi:10.1175/jtech1957.1

Cited by 34 publications

(19 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Matrosov (2005) demonstrated that at 35 GHz there is a nearly linear relation between specific attenuation (A) and R. The linearity of this relation and its low sensitivity to the DSD details is explained by the fact that at Ka band both A and R are approximately proportional to the 3.65th DSD moment (Matrosov et al, 2006). These authors used this relation to retrieve layer-average rain rates from a vertically pointing Ka-band radar and showed that relative retrieval errors generally increase for lighter rainfall when reflectivity changes due to attenuation become smaller compared to vertical changes of non-attenuated reflectivity.…”

Section: A-r Based Rain Rate Estimationmentioning

confidence: 99%

Automated rain rate estimates using the Ka-band ARM zenith radar (KAZR)

et al. 2015

View full text Add to dashboard Cite

Abstract. The use of millimeter wavelength radars for probing precipitation has recently gained interest. However, estimation of precipitation variables is not straightforward due to strong signal attenuation, radar receiver saturation, antenna wet radome effects and natural microphysical variability. Here, an automated algorithm is developed for routinely retrieving rain rates from the profiling Ka-band (35-GHz) ARM (Atmospheric Radiation Measurement) zenith radars (KAZR). A 1-dimensional, simple, steady state microphysical model is used to estimate impacts of microphysical processes and attenuation on the profiles of radar observables at 35-GHz and thus provide criteria for identifying situations when attenuation or microphysical processes dominate KAZR observations. KAZR observations are also screened for signal saturation and wet radome effects. The algorithm is implemented in two steps: high rain rates are retrieved by using the amount of attenuation in rain layers, while low rain rates are retrieved from the reflectivity-rain rate (Z e -R) relation. Observations collected by the KAZR, rain gauge, disdrometer and scanning precipitating radars during the DY-NAMO/AMIE field campaign at the Gan Island of the tropical Indian Ocean are used to validate the proposed approach. The differences in the rain accumulation from the proposed algorithm are quantified. The results indicate that the proposed algorithm has a potential for deriving continuous rain rate statistics in the tropics.

show abstract

Section: A-r Based Rain Rate Estimationmentioning

confidence: 99%

Automated rain rate estimates using the Ka-band ARM zenith radar (KAZR)

et al. 2015

View full text Add to dashboard Cite

show abstract

“…The attenuation Z K linearly depends on CLWP because cloud droplets, which are generally smaller than 50 µm, are within the Rayleigh scattering regime for radar wavelengths, so there is a linear relation between cloud liquid water content and the attenuation coefficient. The linearity of the K a -band attenuation coefficient in rain as a function of rain rate is due to the proportionality of both these quantities to the similar moments of rain DSDs (e.g., Matrosov et al, 2006). The expressions for the coefficients C K and B K are given by Matrosov (2009a).…”

Section: An Approach To Retrieve Cloud and Rain Parameters From Mmcr mentioning

confidence: 99%

Synergetic use of millimeter- and centimeter-wavelength radars for retrievals of cloud and rainfall parameters

Matrosov

2010

Atmos. Chem. Phys.

View full text Add to dashboard Cite

Abstract.A remote sensing approach for simultaneous retrievals of cloud and rainfall parameters in the vertical column above the US Department of Energy's (DOE) Climate Research Facility at the Tropical Western Pacific (TWP) Darwin site in Australia is described. This approach uses vertically pointing measurements from a DOE K a -band radar and scanning measurements from a nearby C-band radar pointing toward the TWP Darwin site. Rainfall retrieval constraints are provided by data from a surface impact disdrometer. The approach is applicable to stratiform precipitating cloud systems when a separation between the liquid hydrometeor layer, which contains rainfall and liquid water clouds, and the ice hydrometeor layer is provided by the radar bright band. Absolute C-band reflectivities and K a -band vertical reflectivity gradients in the liquid layer are used for retrievals of the mean layer rain rate and cloud liquid water path (CLWP). C-band radar reflectivities are also used to estimate ice water path (IWP) in regions above the melting layer. The retrieval uncertainties of CLWP and IWP for typical stratiform precipitation systems are about 500-800 g m −2 (for CLWP) and a factor of 2 (for IWP). The CLWP retrieval uncertainties increase with rain rate, so retrievals for higher rain rates may be impractical. The expected uncertainties of layer mean rain rate retrievals are around 20%, which, in part, is due to constraints available from the disdrometer data. The applicability of the suggested approach is illustrated for two characteristic events observed at the TWP Darwin site during the wet season of 2007. A future deployment of W-band radars at the DOE tropical Climate Research Facilities can improve CLWP estimation accuracies and provide retrievals for a wider range of stratiform precipitating cloud events.

show abstract

“…Note that K a band rain attenuation and K a and W band liquid water cloud attenuations do not exhibit significant variability due to DSD details [e.g., Matrosov, 2005;Matrosov et al, 2006]. The JWD DSD estimates are corrected for dead-time effects [Sheppard and Joe, 1994], which brings the disdrometer estimates of total rainfall accumulation to a close agreement with measurements from the standard rain gauge deployed near the JWD.…”

mentioning

confidence: 95%

Simultaneous estimates of cloud and rainfall parameters in the atmospheric vertical column above the Atmospheric Radiation Measurement Program southern Great Plains site

Matrosov

2009

J. Geophys. Res.

Self Cite

View full text Add to dashboard Cite

[1] A novel remote sensing approach to simultaneously retrieve cloud liquid water paths (LWP) and ice water paths (IWP) and mean rainfall rate in a vertical atmospheric column was applied for stratiform-like precipitation events observed during the warm period of 2007 at the southern Great Plains site of the Atmospheric Radiation Measurement (ARM) Program. The retrieval method is based on multifrequency radar measurements at W, K a , and S bands and raindrop size distribution estimates from a ground-based impact disdrometer. The radar measurements also provide a robust separation of the liquid, mixed, and ice hydrometeor layers. Characteristic values of LWP are about 300-400 g m À2 , although values up to 1000 g m À2 and higher are not uncommon. There is on average insignificant correlation between cloud LWP and rainfall rates. IWP, which represents the precipitating cloud part of the atmospheric column that is observed above the freezing level, usually significantly exceeds cloud LWP in the liquid hydrometeor layer and can reach values of approximately 10 4 g m À2 and even higher. On average, mean rainfall in the liquid layer, R m , increases with an increase in ice mass observed above the melting layer, although a corresponding mean correlation coefficient between R m and IWP is only 0.32. There is noticeable variability in IWP-R m relations between individual events. Storm dynamics is likely to influence the correlation between cloud and rainfall parameters as inferred from simultaneous columnar retrievals. Initial estimates indicate that IWP and rainfall are stronger related for events which exhibit lower vertical variability of wind.

show abstract

Rainfall Profiling Using Atmospheric Radiation Measurement Program Vertically Pointing 8-mm Wavelength Radars

Cited by 34 publications

References 22 publications

Automated rain rate estimates using the Ka-band ARM zenith radar (KAZR)

Automated rain rate estimates using the Ka-band ARM zenith radar (KAZR)

Synergetic use of millimeter- and centimeter-wavelength radars for retrievals of cloud and rainfall parameters

Simultaneous estimates of cloud and rainfall parameters in the atmospheric vertical column above the Atmospheric Radiation Measurement Program southern Great Plains site

Contact Info

Product

Resources

About