scholarly journals A network of water vapor Raman lidars for improving heavy precipitation forecasting in southern France: introducing the WaLiNeAs initiative

2021 ◽  
Vol 2 (1-4) ◽  
Author(s):  
Cyrille Flamant ◽  
Patrick Chazette ◽  
Olivier Caumont ◽  
Paolo Di Girolamo ◽  
Andreas Behrendt ◽  
...  
Keyword(s):  
Water Vapor ◽  
Heavy Precipitation ◽  
Southern France ◽  
Precipitation Forecasting

scholarly journals Tracking an Atmospheric River in a Warmer Climate: from Water Vapor to Economic Impacts

2017 ◽  
Author(s):  
Francina Dominguez ◽  
Sandy Dall'erba ◽  
Shuyi Huang ◽  
Andre Avelino ◽  
Ali Mehran ◽  
...  
Keyword(s):  
Water Vapor ◽  
Economic Impacts ◽  
Heavy Precipitation ◽  
Integrated Modeling ◽  
Vapor Transport ◽  
Water Vapor Transport ◽  
Economic Losses ◽  
Radiative Forcings ◽  
Hypothetical Scenario ◽  
Western Washington

Abstract. Atmospheric rivers (ARs) account for more than 75 % of heavy precipitation events and nearly all of the extreme flooding events along the Olympic Mountains and western Cascade mountains of western Washington state. In a warmer climate, ARs in this region are projected to become more frequent and intense, primarily due to increases in atmospheric water vapor. However, it is unclear how the changes in water vapor transport will affect regional flooding and associated economic impacts. In this work, we present an integrated modeling system to quantify the atmospheric-hydrologic-hydraulic and economic impacts of the December 2007 AR event that impacted the Chehalis river basin in western Washington. We use the modeling system to project impacts under a hypothetical scenario where the same December 2007 event occurs in a warmer climate. This method allows us to incorporate different types of uncertainty including: a) alternative future radiative forcings, b) different responses of the climate system to future radiative forcings and c) different responses of the surface hydrologic system. In the warming scenario, AR integrated vapor transport increases, however, these changes do not translate into generalized increases in precipitation throughout the basin. The changes in precipitation translate into spatially heterogeneous changes in sub-basin runoff and increased streamflow along the entire Chehalis main stem. Economic losses due to stock damages increased moderately, but losses in terms of business interruption were significant. Our integrated modeling tool provides communities in the Chehalis region with a range of possible future physical and economic impacts associated with AR flooding.

scholarly journals The South Carolina Flood of October 2015: Moisture Transport Analysis and the Role of Hurricane Joaquin

2017 ◽  
Vol 18 (11) ◽  
pp. 2973-2990 ◽  
Author(s):  
Christopher G. Marciano ◽  
Gary M. Lackmann
Keyword(s):  
South Carolina ◽  
Water Vapor ◽  
Moisture Transport ◽  
Heavy Precipitation ◽  
Water Vapor Content ◽  
Precipitation Event ◽  
The South ◽  
Flooding Event ◽  
Additional Water ◽  
Upper Level

Abstract Record-setting rainfall occurred over the state of South Carolina in early October 2015, with maximum accumulations exceeding 500 mm. During the heavy rainfall, Hurricane Joaquin was located offshore to the southeast of the flooding event. Prior research, storm summaries, satellite imagery, and media accounts suggest that Joaquin played a major role in the flooding, mostly through the provision of additional water vapor. Here, numerical simulations are utilized to elucidate Joaquin’s role in the flooding and to diagnose moisture transport mechanisms. The South Carolina precipitation event and the track of Hurricane Joaquin are reasonably represented by two control simulations, a 36-km simulation without nesting and another with 12- and 4-km nests added; the latter improves upon a negative intensity bias for Joaquin. A band of intense moisture transport into the flooding region is associated with a narrow, diabatically produced cyclonic lower-tropospheric potential vorticity (PV) maximum. Simulations in which Joaquin is removed exhibit a similar moisture transport mechanism and also produce a band of heavy precipitation, though the axis of heaviest precipitation shifts northward into North Carolina, and there is a modest reduction (~7%) in area-averaged rainfall. Removing Joaquin produces negligible changes in regional total water vapor content but diminished upper-tropospheric diabatic outflow. The diminished outflow allows greater eastward progression of an upper-level trough, consistent with the northward precipitation shift and with weaker forcing for ascent. Changes in the upper jet associated with Joaquin appear to exert a greater influence on the flooding event than Joaquin’s contribution to water vapor content.

scholarly journals Forecasting Atmospheric Rivers during CalWater 2015

2017 ◽  
Vol 98 (3) ◽  
pp. 449-459 ◽  
Author(s):  
Jason M. Cordeira ◽  
F. Martin Ralph ◽  
Andrew Martin ◽  
Natalie Gaggini ◽  
J. Ryan Spackman ◽  
...  
Keyword(s):  
Water Vapor ◽  
West Coast ◽  
Heavy Precipitation ◽  
Field Studies ◽  
Field Phase ◽  
Forecast System ◽  
Field Campaign ◽  
Atmospheric Rivers ◽  
Vapor Flux ◽  
The U.S

Abstract Atmospheric rivers (ARs) are long and narrow corridors of enhanced vertically integrated water vapor (IWV) and IWV transport (IVT) within the warm sector of extra tropical cyclones that can produce heavy precipitation and flooding in regions of complex terrain, especially along the U.S. West Coast. Several field campaigns have investigated ARs under the CalWater program of field studies. The first field phase of CalWater during 2009–11 increased the number of observations of precipitation and aerosols, among other parameters, across California and sampled ARs in the coastal and near-coastal environment, whereas the second field phase of CalWater during 2014–15 observed the structure and intensity of ARs and aerosols in the coastal and offshore environment over the northeast Pacific. This manuscript highlights the forecasts that were prepared for the CalWater field campaign in 2015, and the development and use of an “AR portal” that was used to inform these forecasts. The AR portal contains archived and real-time deterministic and probabilistic gridded forecast tools related to ARs that emphasize water vapor concentrations and water vapor flux distributions over the eastern North Pacific, among other parameters, in a variety of formats derived from the National Centers for Environmental Prediction (NCEP) Global Forecast System and Global Ensemble Forecast System. The tools created for the CalWater 2015 field campaign provided valuable guidance for flight planning and field activity purposes, and they may prove useful in forecasting ARs and better anticipating hydrometeorological extremes along the U.S. West Coast.

scholarly journals Benefits of a Closely-Spaced Satellite Constellation of Atmospheric Polarimetric Radio Occultation Measurements

2019 ◽  
Vol 11 (20) ◽  
pp. 2399 ◽  
Author(s):  
F. Joseph Turk ◽  
Ramon Padullés ◽  
Chi O. Ao ◽  
Manuel de la Torre Juárez ◽  
Kuo-Nung Wang ◽  
...  
Keyword(s):  
Water Vapor ◽  
Radio Occultation ◽  
Sampling Strategy ◽  
Weather Forecast ◽  
Heavy Precipitation ◽  
Predictive Capability ◽  
Convective Clouds ◽  
Convective Processes ◽  
Convective Process ◽  
Ray Paths

The climate and weather forecast predictive capability for precipitation intensity is limited by gaps in the understanding of basic cloud-convective processes. Currently, a better understanding of the cloud-convective process lacks observational constraints, due to the difficulty in obtaining accurate, vertically resolved pressure, temperature, and water vapor structure inside and near convective clouds. This manuscript describes the potential advantages of collecting sequential radio occultation (RO) observations from a constellation of closely spaced low Earth-orbiting satellites. In this configuration, the RO tangent points tend to cluster together, such that successive RO ray paths are sampling independent air mass quantities as the ray paths lie “parallel” to one another. When the RO train orbits near a region of precipitation, there is a probability that one or more of the RO ray paths will intersect the region of heavy precipitation, and one or more would lie outside. The presence of heavy precipitation can be discerned by the use of the polarimetric RO (PRO) technique recently demonstrated by the Radio Occultations through Heavy Precipitation (ROHP) receiver onboard the Spanish PAZ spacecraft. This sampling strategy provides unique, near-simultaneous observations of the water vapor profile inside and in the environment surrounding heavy precipitation, which are not possible from current RO data.

scholarly journals Detecting Water Vapor Variability during Heavy Precipitation Events in Hong Kong Using the GPS Tomographic Technique

2017 ◽  
Vol 34 (5) ◽  
pp. 1001-1019 ◽  
Author(s):  
Biyan Chen ◽  
Zhizhao Liu ◽  
Wai-Kin Wong ◽  
Wang-Chun Woo
Keyword(s):  
Hong Kong ◽  
Water Vapor ◽  
Heavy Rain ◽  
Heavy Precipitation ◽  
Radiosonde Data ◽  
Weather Forecasts ◽  
Moisture Variation ◽  
Tomographic Technique ◽  
Rain Events ◽  
Precipitation Events

AbstractWater vapor has a strong influence on the evolution of heavy precipitation events due to the huge latent heat associated with the phase change process of water. Accurate monitoring of atmospheric water vapor distribution is thus essential in predicting the severity and life cycle of heavy rain. This paper presents a systematic study on the application of tomographic solutions to investigate water vapor variations during heavy precipitation events. Using global positioning system (GPS) observations, the wet refractivity field was constructed at a temporal resolution of 30 min for three heavy precipitation events occurring in Hong Kong, China, in 2010–14. The zenith wet delay (ZWD) is shown to be a good indicator in observing the water vapor evolution in heavy rain events. The variabilities of water vapor at five altitude layers (<1000, 1000–2000, 2000–3000, 3000–5000, and >5000 m) were examined. It revealed that water vapor above 3000 m has larger fluctuation than that under 3000 m, though it accounts for only 10%–25% of the total amount of water vapor. The relative humidity fields derived from tomographic results revealed moisture variation, accumulation, saturation, and condensation during the heavy rain events. The water vapor variabilities observed by tomography have been validated using European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis and radiosonde data. The results positively demonstrated the potential of using water vapor tomographic technique for detecting and monitoring the evolution of heavy rain events.

scholarly journals A New Method for Determining an Optimal Diurnal Threshold of GNSS Precipitable Water Vapor for Precipitation Forecasting

2021 ◽  
Vol 13 (7) ◽  
pp. 1390
Author(s):  
Haobo Li ◽  
Xiaoming Wang ◽  
Suqin Wu ◽  
Kefei Zhang ◽  
Erjiang Fu ◽  
...  
Keyword(s):  
Water Vapor ◽  
Weather Prediction ◽  
Precipitable Water ◽  
Heavy Precipitation ◽  
Precipitable Water Vapor ◽  
Global Navigation Satellite Systems ◽  
New Method ◽  
New Model ◽  
Precipitation Records ◽  
Optimal Set

Nowadays, precipitable water vapor (PWV) retrieved from ground-based Global Navigation Satellite Systems (GNSS) tracking stations has heralded a new era of GNSS meteorological applications, especially for severe weather prediction. Among the existing models that use PWV timeseries to predict heavy precipitation, the “threshold-based” models, which are based on a set of predefined thresholds for the predictors used in the model for predictions, are effective in heavy precipitation nowcasting. In previous studies, monthly thresholds have been widely accepted due to the monthly patterns of different predictors being fully considered. However, the primary weakness of this type of thresholds lies in their poor prediction results in the transitional periods between two consecutive months. Therefore, in this study, a new method for the determination of an optimal set of diurnal thresholds by adopting a 31-day sliding window was first proposed. Both the monthly and diurnal variation characteristics of the predictors were taken into consideration in the new method. Then, on the strength of the new method, an improved PWV-based model for heavy precipitation prediction was developed using the optimal set of diurnal thresholds determined based on the hourly PWV and precipitation records for the summer over the period 2010–2017 at the co-located HKSC–KP (King’s Park) stations in Hong Kong. The new model was evaluated by comparing its prediction results against the hourly precipitation records for the summer in 2018 and 2019. It is shown that 96.9% of heavy precipitation events were correctly predicted with a lead time of 4.86 h, and the false alarms resulting from the new model were reduced to 25.3%. These results suggest that the inclusion of the diurnal thresholds can significantly improve the prediction performance of the model.

scholarly journals Impact of Assimilating Advanced Himawari Imager Channel 16 Data on Precipitation Prediction over the Haihe River Basin

Atmosphere ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1253
Author(s):  
Hongxiang Ouyang ◽  
Zhengkun Qin ◽  
Juan Li
Keyword(s):  
Water Vapor ◽  
Brightness Temperature ◽  
River Basin ◽  
Geostationary Satellite ◽  
Haihe River Basin ◽  
Tropospheric Temperature ◽  
Haihe River ◽  
Precipitation Forecasting ◽  
Precipitation Prediction ◽  
The Haihe River Basin

Assimilation of high-resolution geostationary satellite data is of great value for precise precipitation prediction in regional basins. The operational geostationary satellite imager carried by the Himawari-8 satellite, Advanced Himawari Imager (AHI), has two additional water vapor channels and four other channels compared with its predecessor, MTSAT-2. However, due to the uncertainty in surface parameters, AHI surface-sensitive channels are usually not assimilated over land, except for the three water vapor channels. Previous research showed that the brightness temperature of AHI channel 16 is much more sensitive to the lower-tropospheric temperature than to surface emissivity, which is similar to the three water vapor channels 8–10. As a follow-up work, this paper evaluates the effectiveness of assimilating brightness temperature observations over land from both the three AHI water vapor channels and channel 16 to improve watershed precipitation forecasting through both case analysis (in the Haihe River basin, China) and batch tests. It is found that assimilating AHI channel 16 can improve the upstream near-surface atmospheric temperature forecast, which in turn affects the development of downstream weather systems. The precipitation forecasting test results indicate that adding the terrestrial observations of channel 16 to the assimilation of AHI data can improve short-term precipitation forecasting in the basin.

scholarly journals Intensified Moisture Sources of Heavy Precipitation Events Contributed to Interannual Trend in Precipitation Over the Three-Rivers-Headwater Region in China

2021 ◽  
Vol 9 ◽  
Author(s):  
Ruiyu Zhao ◽  
Bin Chen ◽  
Xiangde Xu
Keyword(s):  
Water Vapor ◽  
Heavy Precipitation ◽  
Water Vapor Transport ◽  
Boreal Summer ◽  
Precipitation Trend ◽  
Moisture Source ◽  
Moisture Sources ◽  
Increasing Trend ◽  
Three Rivers ◽  
Precipitation Events

Evidence has indicated an overall wetting trend over the Three-Rivers Headwater Region (TRHR) in the recent decades, whereas the possible mechanisms for this change remain unclear. Detecting the main moisture source regions of the water vapor and its increasing trend over this region could help understand the long-term precipitation change. Based on the gauge-based precipitation observation analysis, we find that the heavy precipitation events act as the main contributor to the interannual increasing trend of summer precipitation over the TRHR. A Lagrangian moisture tracking methodology is then utilized to identify the main moisture source of water vapor over the target region for the boreal summer period of 1980–2017, with focus particularly on exploring its change associated with the interannual trend of precipitation. On an average, the moisture sources for the target regions cover vast regions, including the west and northwest of the Tibetan Plateau by the westerlies, the southwest by the Indian summer monsoon, and the adjacent regions associated with the local recycling. However, the increased interannual precipitation trend over the TRHR could be largely attributed to the enhanced moisture sources from the neighboring northeastern areas of the targeted region, particularly associated with the heavy precipitation events. The increased water vapor transport from the neighboring areas of the TRHR potentially related to the enhanced local hydrological recycling over these regions plays a first leading role in the recent precipitation increase over the TRHR.

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