Estimation of liquid water path below the melting layer in stratiform precipitation systems using radar measurements during MC3E

In this study, the liquid water path (LWP) below the melting layer in stratiform precipitation systems is retrieved, which is a combination of rain liquid water path (RLWP) and cloud liquid water path (CLWP). The retrieval algorithm uses measurements from the vertically pointing radars (VPRs) at 35 and 3 GHz operated by the US Department of Energy Atmospheric Radiation Measurement (ARM) and National Oceanic and Atmospheric Administration (NOAA) during the field campaign Midlatitude Continental Convective Clouds Experiment (MC3E). The measured radar reflectivity and mean Doppler velocity from both VPRs and spectrum width from the 35 GHz radar are utilized. With the aid of the cloud base detected by a ceilometer, the LWP in the liquid layer is retrieved under two different situations: (I) no cloud exists below the melting base, and (II) cloud exists below the melting base. In (I), LWP is primarily contributed from raindrops only, i.e., RLWP, which is estimated by analyzing the Doppler velocity differences between two VPRs. In (II), cloud particles and raindrops coexist below the melting base. The CLWP is estimated using a modified attenuation-based algorithm. Two stratiform precipitation cases (20 and 11 May 2011) during MC3E are illustrated for two situations, respectively. With a total of 13 h of samples during MC3E, statistical results show that the occurrence of cloud particles below the melting base is low (9 %); however, the mean CLWP value can be up to 0.56 kgm(2), which is much larger than the RLWP (0.10 kgm(2)). When only raindrops exist below the melting base, the average RLWP value is larger (0.32 kgm(2)) than the with-cloud situation. The overall mean LWP below the melting base is 0.34 kgm(2) for stratiform systems during MC3E.DOE CMDV project [DE-SC0017015]; NASA CERES project [NNX17AC52G]; DOE ASR project [DE-SC0014294]Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Characteristics of Ice Cloud–Precipitation of Warm Season Mesoscale Convective Systems over the Great Plains

In this study, the mesoscale convective systems (MCSs) are tracked using high-resolution radar and satellite observations over the U.S. Great Plains during April-August from 2010 to 2012. The spatiotemporal variability of MCS precipitation is then characterized using the Stage IV product. We found that the spatial variability and nocturnal peaks of MCS precipitation are primarily driven by the MCS occurrence rather than the precipitation intensity. The tracked MCSs are further classified into convective core (CC), stratiform rain (SR), and anvil clouds regions. The spatial variability and diurnal cycle of precipitation in the SR regions of MCSs are not as significant as those of MCS precipitation. In the SR regions, the high-resolution, long-term ice cloud microphysical properties [ice water content (IWC) and ice water paths (IWPs)] are provided. The IWCs generally decrease with height. Spatially, the IWC, IWP, and precipitation are all higher over the southern Great Plains than over the northern Great Plains. Seasonally, those ice and precipitation properties are all higher in summer than in spring. Comparing the peak timings of MCS precipitation and IWPs from the diurnal cycles and their composite evolutions, it is found that when using the peak timing of IWPSR as a reference, the heaviest precipitation in the MCS convective core occurs earlier, while the strongest SR precipitation occurs later. The shift of peak timings could be explained by the stratiform precipitation formation process. The IWP and precipitation relationships are different at MCS genesis, mature, and decay stages. The relationships and the transition processes from ice particles to precipitation also depend on the low-level humidity.6 month embargo; published online: 21 February 2020This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Retroperitoneal Laparoscopic Nephroureterectomy for Tuberculous Nonfunctioning Kidneys: a single-center experience

Purpose To present our surgical techniques and experiences of retroperitoneal laparoscopic nephroureterectomy for the treatment of tuberculous nonfunctioning kidneys. Materials and Methods From March 2005 to March 2013, a total of 51 patients with tuberculous nonfunctioning kidney underwent retroperitoneal laparoscopic nephroureterectomy at our medical center. The techniques included early control of renal vessels and dissection of the diseased kidney along the underlying layer outside the Gerato’s fascia. The distal ureter was dissected through a Gibson incision and the entire specimen was removed en bloc from the incision. Patient demographics, perioperative characteristics and laboratory parameters as well as postoperative outcome were retrospectively reviewed. Results Retroperitoneal laparoscopic nephroureterectomy was successfully performed in 50 patients, whereas one case required conversion to open surgery due to non-progression of dissection. The mean operating time was 123.0 minutes (107-160 minutes) and the mean estimated blood loss was 134 mL (80-650 mL).The mean postoperative hospital stay was 3.6 days (3-5days) and the mean return to normal activity was 11.6 days (10-14days). Most intra-operative and post-operative complications were minor complications and can be managed conservatively. After 68 months (12-96 months) follow-up, the outcome was satisfactory, and ureteral stump syndrome did not occur. Conclusions Retroperitoneal laparoscopic nephroureterectomy as a minimally invasive treatment option is feasible for treatment of tuberculous nonfunctioning kidneys

Profiles of MBL Cloud and Drizzle Microphysical Properties Retrieved From Ground‐Based Observations and Validated by Aircraft In Situ Measurements Over the Azores

The profiles of marine boundary layer (MBL) cloud and drizzle microphysical properties are important for studying the cloud-to-rain conversion and growth processes in MBL clouds. However, it is challenging to simultaneously retrieve both cloud and drizzle microphysical properties within an MBL cloud layer using ground-based observations. In this study, methods were developed to first decompose drizzle and cloud reflectivity in MBL clouds from Atmospheric Radiation Measurement cloud radar reflectivity measurements and then simultaneously retrieve cloud and drizzle microphysical properties during the Aerosol and Cloud Experiments in the Eastern North Atlantic (ACE-ENA) campaign. These retrieved microphysical properties, such as cloud and drizzle particle size (r(c) and r(m,d)), their number concentration (N-c and N-d) and liquid water content (LWCc and LWCd), have been validated by aircraft in situ measurements during ACE-ENA (158 hr of aircraft data). The mean surface retrieved (in situ measured) r(c), N-c, and LWCc are 10.9 mu m (11.8 mu m), 70 cm(-3) (60 cm(-3)), and 0.21 g m(-3) (0.22 g m(-3)), respectively. For drizzle microphysical properties, the retrieved (in situ measured) r(d), N-d, and LWCd are 44.9 mu m (45.1 mu m), 0.07 cm(-3) (0.08 cm(-3)), and 0.052 g m(-3) (0.066 g m(-3)), respectively. Treating the aircraft in situ measurements as truth, the estimated median retrieval errors are 15% for r(c), 35% for N-c, 30% for LWCc and r(d), and 50% for N-d and LWCd. The findings from this study will provide insightful information for improving our understanding of warm rain processes, as well as for improving model simulations. More studies are required over other climatic regions.National Science Foundation6 month embargo; first published online 23 April 2020This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Understanding Ice Cloud‐Precipitation Properties of Three Modes of Mesoscale Convective Systems During PECAN

This study analyzes the precipitation and ice cloud microphysical features of three common modes of linear mesoscale convective systems during the Plains Elevated Convection at Night (PECAN) campaign. Three cases, one for each linear mesoscale convective system archetype (trailing stratiform, leading stratiform, and parallel stratiform precipitation), are selected. We focus primarily on analyzing ice cloud microphysical properties and precipitation rates (PRs) over the classified convective core (CC) and stratiform rain (SR) regions, as well as the two stratiform regions that developed behind (SR1) and ahead (SR2) of the convective line relative to the storm motion. In the three selected cases, the ice water path (IWP) and PR have strong correlations in the CC, but not in the SR. In terms of the temporal evolution of the mean IWPs and PRs, both CC and SR IWPs, as well as CC PRs, reach peaks quickly but take a longer time to dissipate than the increase period. For all the three cases, both SR1 and SR2 IWPs are 20-70% of their corresponding CC values in both the leading stratiform and parallel stratiform cases and up to 95% for the trailing stratiform case, while all of their PRs are only 7-25% of their CC values. These values suggest not only that the SR PRs may depend on IWPs but also that the microphysical properties of ice particles such as habit and size distribution may play an important role. Utilizing cloud-resolving simulations of these systems may provide better understanding of the physical meanings behind the results in the future.Climate Model Development and Validation (CMDV) program - Office of Biological and Environmental Research in the US Department of Energy Office of Science [DE-SC0017015]; NASA CERES project [NNX17AC52G]6 month embargo; first published: 29 March 2019This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Understanding Ice Cloud‐Precipitation Properties of Three Modes of Mesoscale Convective Systems During PECAN

This study analyzes the precipitation and ice cloud microphysical features of three common modes of linear mesoscale convective systems during the Plains Elevated Convection at Night (PECAN) campaign. Three cases, one for each linear mesoscale convective system archetype (trailing stratiform, leading stratiform, and parallel stratiform precipitation), are selected. We focus primarily on analyzing ice cloud microphysical properties and precipitation rates (PRs) over the classified convective core (CC) and stratiform rain (SR) regions, as well as the two stratiform regions that developed behind (SR1) and ahead (SR2) of the convective line relative to the storm motion. In the three selected cases, the ice water path (IWP) and PR have strong correlations in the CC, but not in the SR. In terms of the temporal evolution of the mean IWPs and PRs, both CC and SR IWPs, as well as CC PRs, reach peaks quickly but take a longer time to dissipate than the increase period. For all the three cases, both SR1 and SR2 IWPs are 20-70% of their corresponding CC values in both the leading stratiform and parallel stratiform cases and up to 95% for the trailing stratiform case, while all of their PRs are only 7-25% of their CC values. These values suggest not only that the SR PRs may depend on IWPs but also that the microphysical properties of ice particles such as habit and size distribution may play an important role. Utilizing cloud-resolving simulations of these systems may provide better understanding of the physical meanings behind the results in the future.Climate Model Development and Validation (CMDV) program - Office of Biological and Environmental Research in the US Department of Energy Office of Science [DE-SC0017015]; NASA CERES project [NNX17AC52G]6 month embargo; first published: 29 March 2019This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]