scholarly journals Wet Days in the Dry Quarter of the Alcântara Launch Center Region: Observational Features

2019 ◽  
Author(s):  
Paulo César Silva da Costa ◽  
Marcos Daisuke Oyama ◽  
Rosa de Fátima Cruz Marques
Keyword(s):  
Large Scale ◽  
Daily Precipitation ◽  
Weather Forecasting ◽  
Deep Convection ◽  
Longwave Radiation ◽  
Heavy Precipitation ◽  
Large Area ◽  
Launch Site ◽  
Precipitation Total ◽  
Precipitation Events

Precipitation events are infrequent in the dry quarter (SON) of the Alcântara Launch Center (Centro de Lançamento de Alcântara, CLA), the main launch site of the Brazilian Space Program. However, their occurrence could be a risk for activities during launch missions. In this work, the observational features of wet days (daily precipitation total ≥ 1 mm/day) in the dry quarter of the CLA region were studied. Daily precipitation totals over the course of 37 years (1979-2016, except 2006), outgoing longwave radiation (OLR) data and ERA-Interim reanalysis data were used. On average, in the dry quarter, there were 9 wet days, which accumulated 32 mm. The number and quarterly precipitation total of wet days showed pronounced interannual variability. This variability was negatively and significantly correlated with the interhemispheric sea surface temperature anomalies gradient in the Atlantic Ocean and the wind speed at 925 hPa over the CLA region. Based on a theoretical distribution (log-normal), the probability of occurrence of heavy precipitation days (daily total ≥ 10 mm/day) was only 0.5%. For days with heavy precipitation and deep convection (OLR ≤ 230 W·m-2), over a large area along the northeastern coast of South America including the CLA region, negative OLR differences (from the mean) and the strengthening of favorable conditions for deep convection were found. The large-scale organization of the convective activity and atmospheric features for higher precipitation events obtained in this work could be helpful for nowcasting and short-range weather forecasting during launch missions at the CLA.

Statistical Characteristics of Daily Precipitation: Comparisons of Gridded and Point Datasets

2008 ◽  
Vol 47 (9) ◽  
pp. 2468-2476 ◽  
Author(s):  
Leslie A. Ensor ◽  
Scott M. Robeson
Keyword(s):  
Daily Precipitation ◽  
Heavy Precipitation ◽  
Rain Gauge ◽  
Statistical Characteristics ◽  
Precipitation Data ◽  
Spatial Coverage ◽  
Daily Precipitation Data ◽  
Precipitation Total ◽  
Grid Points ◽  
Precipitation Events

Abstract Gridding of daily precipitation data alleviates many of the limitations of data that are derived from point observations, such as problems associated with missing data and the lack of spatial coverage. As a result, gridded precipitation data can be valuable for applied climatological research and monitoring, but they too have limitations. To understand the limitations of gridded data more fully (especially when they are used as surrogates for station data), annual precipitation total, rain-day frequency, and annual maxima are calculated and compared for five Midwestern grid points from the Climate Prediction Center’s Unified Rain Gauge Dataset (URD) and those of its nearest (rain gauge) station. To further examine differences between the two datasets, return periods of daily precipitation were calculated over a region encompassing Illinois and Indiana. These analyses reveal that the gridding process used to create the URD produced nearly the same annual totals as the rain gauge data; however, the gridding significantly increased the frequency of low-precipitation events while greatly reducing the frequency of heavy-precipitation events. Extreme precipitation values also were greatly reduced in the gridded precipitation data. While smoothing nearly always occurs when data are gridded, the gridding of discrete variables such as daily precipitation can produce datasets with statistical characteristics that are very different from those of the original observations.

scholarly journals The Dynamic and Thermodynamic Structures Associated with a Series of Heavy Precipitation Events over China during January 2008

2010 ◽  
Vol 25 (4) ◽  
pp. 1124-1141 ◽  
Author(s):  
Xiaohui Shi ◽  
Xiangde Xu ◽  
Chungu Lu
Keyword(s):  
Large Scale ◽  
East Coast ◽  
Heavy Precipitation ◽  
Chinese History ◽  
Physical Processes ◽  
Ice Storms ◽  
Upper Level ◽  
Upper Level Jet ◽  
The Western Pacific ◽  
Precipitation Events

Abstract In the winter of 2008, China experienced once-in-50-yr (or once in 100 yr for some regions) snow and ice storms. These storms brought huge socio economical impacts upon the Chinese people and government. Although the storms had been predicted, their severity and persistence were largely underestimated. In this study, these cases were revisited and comprehensive analyses of the storms’ dynamic and thermodynamic structures were conducted. These snowstorms were also compared with U.S. east coast snowstorms. The results from this study will provide insights on how to improve forecasts for these kinds of snowstorms. The analyses demonstrated that the storms exhibited classic patterns of large-scale circulation common to these types of snowstorms. However, several physical processes were found to be unique and thought to have played crucial roles in intensifying and prolonging China’s great snowstorms of 2008. These include a subtropical high over the western Pacific, an upper-level jet stream, and temperature and moisture inversions. The combined effects of these dynamic and thermodynamic structures are responsible for the development of the storms into one of the most disastrous events in Chinese history.

Changes in Observed Daily Precipitation over the United States between 1950–79 and 1980–2009

2013 ◽  
Vol 14 (1) ◽  
pp. 105-121 ◽  
Author(s):  
R. W. Higgins ◽  
V. E. Kousky
Keyword(s):  
United States ◽  
Great Plains ◽  
El Niño ◽  
Daily Precipitation ◽  
El Nino ◽  
Southern Oscillation ◽  
Heavy Precipitation ◽  
The United States ◽  
Enso Cycle ◽  
Precipitation Events

Abstract Changes in observed daily precipitation over the conterminous United States between two 30-yr periods (1950–79 and 1980–2009) are examined using a 60-yr daily precipitation analysis obtained from the Climate Prediction Center (CPC) Unified Raingauge Database. Several simple measures are used to characterize the changes, including mean, frequency, intensity, and return period. Seasonality is accounted for by examining each measure for four nonoverlapping seasons. The possible role of the El Niño–Southern Oscillation (ENSO) cycle as an explanation for differences between the two periods is also examined. There have been more light (1 mm ≤ P < 10 mm), moderate (10 mm ≤ P < 25 mm), and heavy (P ≥ 25 mm) daily precipitation events (P) in many regions of the country during the more recent 30-yr period with some of the largest and most spatially coherent increases over the Great Plains and lower Mississippi Valley during autumn and winter. Some regions, such as portions of the Southeast and the Pacific Northwest, have seen decreases, especially during the winter. Increases in multiday heavy precipitation events have been observed in the more recent period, especially over portions of the Great Plains, Great Lakes, and Northeast. These changes are associated with changes in the mean and frequency of daily precipitation during the more recent 30-yr period. Difference patterns are strongly related to the ENSO cycle and are consistent with the stronger El Niño events during the more recent 30-yr period. Return periods for both heavy and light daily precipitation events during 1950–79 are shorter during 1980–2009 at most locations, with some notable regional exceptions.

A Diagnosis of the 1979–2005 Extreme Rainfall Events in the Southeastern United States with Isentropic Moisture Tracing

2010 ◽  
Vol 138 (4) ◽  
pp. 1172-1185 ◽  
Author(s):  
Steven C. Chan ◽  
Vasubandhu Misra
Keyword(s):  
United States ◽  
Land Surface ◽  
Southeastern United States ◽  
Extreme Rainfall ◽  
Heavy Precipitation ◽  
Extreme Rainfall Events ◽  
Moisture Sources ◽  
Precipitation Total ◽  
Precipitation Anomalies ◽  
Precipitation Events

Abstract A detailed analysis is performed to better understand the interannual and subseasonal variability of moisture sources of major recent dry (1980, 1990, and 2000) and wet (1994, 2003, and 2005) June–August (JJA) seasons in the southeastern United States. Wet (dry) JJAs show an increased (decreased) standard deviation of daily precipitation. Whereas most days during dry JJAs have little or no precipitation, wet JJAs contain more days with significant precipitation and a large increase of heavy (+10 mm) precipitation days. At least two tropical cyclone/depression landfalls occur in the southeastern United States during wet JJAs, whereas none occur during dry JJAs. The trajectory analysis suggests significant local recycling of moisture, implying that land surface feedback has the potential to enhance (suppress) precipitation anomalies during a wet (dry) JJA. Remote moisture sources during heavy precipitation events are very similar between wet and dry JJAs. The distinction between wet and dry JJAs lies in the frequency of heavy precipitation events. During the wet JJAs, heavy precipitation events contribute to more than half of the JJA precipitation total.

scholarly journals Winter Orographic Precipitation Ratios in the Sierra Nevada—Large-Scale Atmospheric Circulations and Hydrologic Consequences

2004 ◽  
Vol 5 (6) ◽  
pp. 1102-1116 ◽  
Author(s):  
Michael Dettinger ◽  
Kelly Redmond ◽  
Daniel Cayan
Keyword(s):  
Sierra Nevada ◽  
Large Scale ◽  
Precipitation Amount ◽  
Heavy Precipitation ◽  
Winter Precipitation ◽  
Orographic Precipitation ◽  
Simple Experiment ◽  
Westerly Direction ◽  
Winter Flood ◽  
Precipitation Events

Abstract The extent to which winter precipitation is orographically enhanced within the Sierra Nevada of California varies from storm to storm, and season to season, from occasions when precipitation rates at low and high altitudes are almost the same to instances when precipitation rates at middle elevations (considered here) can be as much as 30 times more than at the base of the range. Analyses of large-scale conditions associated with orographic precipitation variations during storms and seasons from 1954 to 1999 show that strongly orographic storms most commonly have winds that transport water vapor across the range from a more nearly westerly direction than during less orographic storms and than during the largest overall storms, and generally the strongly orographic storms are less convectively stable. Strongly orographic conditions often follow heavy precipitation events because both of these wind conditions are present in midlatitude cyclones that form the cores of many Sierra Nevada storms. Storms during La Niña winters tend to yield larger orographic ratios (ORs) than do those during El Niños. A simple experiment with a model of streamflows from a river basin draining the central Sierra Nevada indicates that, for a fixed overall basin-precipitation amount, a decrease in OR contributes to larger winter flood peaks and smaller springtime flows, and thus to an overall hastening of the runoff season.

scholarly journals Climatology of Daily Precipitation and Extreme Precipitation Events in the Northeast United States

2015 ◽  
Vol 16 (6) ◽  
pp. 2537-2557 ◽  
Author(s):  
Laurie Agel ◽  
Mathew Barlow ◽  
Jian-Hua Qian ◽  
Frank Colby ◽  
Ellen Douglas ◽  
...  
Keyword(s):  
Extreme Precipitation ◽  
Seasonal Cycle ◽  
Large Scale ◽  
Daily Precipitation ◽  
Warm Season ◽  
Extreme Precipitation Events ◽  
Tail Distribution ◽  
Hourly Data ◽  
Early Fall ◽  
Precipitation Events

Abstract This study examines U.S. Northeast daily precipitation and extreme precipitation characteristics for the 1979–2008 period, focusing on daily station data. Seasonal and spatial distribution, time scale, and relation to large-scale factors are examined. Both parametric and nonparametric extreme definitions are considered, and the top 1% of wet days is chosen as a balance between sample size and emphasis on tail distribution. The seasonal cycle of daily precipitation exhibits two distinct subregions: inland stations characterized by frequent precipitation that peaks in summer and coastal stations characterized by less frequent but more intense precipitation that peaks in late spring as well as early fall. For both subregions, the frequency of extreme precipitation is greatest in the warm season, while the intensity of extreme precipitation shows no distinct seasonal cycle. The majority of Northeast precipitation occurs as isolated 1-day events, while most extreme precipitation occurs on a single day embedded in 2–5-day precipitation events. On these extreme days, examination of hourly data shows that 3 h or less account for approximately 50% of daily accumulation. Northeast station precipitation extremes are not particularly spatially cohesive: over 50% of extreme events occur at single stations only, and 90% occur at only 1–3 stations concurrently. The majority of extreme days (75%–100%) are related to extratropical storms, except during September, when more than 50% of extremes are related to tropical storms. Storm tracks on extreme days are farther southwest and more clustered than for all storm-related precipitation days.

scholarly journals Climatology of Vb-cyclones, physical mechanisms and their impact on extreme precipitation over Central Europe

2015 ◽  
Vol 6 (1) ◽  
pp. 907-941
Author(s):  
M. Messmer ◽  
J. J. Gómez-Navarro ◽  
C. C. Raible
Keyword(s):  
Central Europe ◽  
Extreme Precipitation ◽  
Large Scale ◽  
Heavy Precipitation ◽  
Western Mediterranean ◽  
Physical Mechanisms ◽  
Detection And Tracking ◽  
The Alps ◽  
Precipitation Events ◽  
Thermodynamic Processes

Abstract. Cyclones, which develop over the western Mediterranean and move northeastward are a major source of extreme weather and known to be responsible for heavy precipitation over Central Europe and the Alps. As the relevant processes triggering these so-called Vb-events and their impact on extreme precipitation are not yet fully understood, this study focusses on gaining insight into the dynamics of past events. For this, a cyclone detection and tracking tool is applied to the ERA-Interim reanalysis (1979–2013) to identify prominent Vb-situations. Precipitation in the ERA-Interim and the E-OBS datasets is used to evaluate case-to-case precipitation amounts and to assess consistency between the two datasets. Both datasets exhibit high variability in precipitation amounts among different Vb-events. While only 23 % of all Vb-events are associated with extreme precipitation, around 15 % of all extreme precipitation days (99 percentile) over the Alpine region are induced by Vb-events, although Vb-cyclones are rare events (2.3 per year). To obtain a better understanding of the variability within Vb-events, the analysis of the 10 heaviest and lowest precipitation Vb-events reveals noticeable differences in the state of the atmosphere. These differences are most pronounced in the geopotential height and potential vorticity field, indicating a much stronger cyclone for heavy precipitation events. The related differences in wind direction are responsible for the moisture transport around the Alps and the orographical lifting along the Alps. These effects are the main reasons for a disastrous outcome of Vb-events, and consequently are absent in the Vb-events associated with low precipitation. Hence, our results point out that heavy precipitation related to Vb-events is mainly related to large-scale dynamics rather than to thermodynamic processes.

A Comparison of CMIP3 Simulations of Precipitation over North America with Observations: Daily Statistics and Circulation Features Accompanying Extreme Events

2013 ◽  
Vol 26 (10) ◽  
pp. 3209-3230 ◽  
Author(s):  
Anthony M. DeAngelis ◽  
Anthony J. Broccoli ◽  
Steven G. Decker
Keyword(s):  
North America ◽  
Extreme Events ◽  
Extreme Precipitation ◽  
Large Scale ◽  
Climate Model ◽  
Heavy Precipitation ◽  
Convective Precipitation ◽  
Southern Mexico ◽  
Extreme Precipitation Events ◽  
Precipitation Events

Abstract Climate model simulations of daily precipitation statistics from the third phase of the Coupled Model Intercomparison Project (CMIP3) were evaluated against precipitation observations from North America over the period 1979–99. The evaluation revealed that the models underestimate the intensity of heavy and extreme precipitation along the Pacific coast, southeastern United States, and southern Mexico, and these biases are robust among the models. The models also overestimate the intensity of light precipitation events over much of North America, resulting in fairly realistic mean precipitation in many places. In contrast, heavy precipitation is simulated realistically over northern and eastern Canada, as is the seasonal cycle of heavy precipitation over a majority of North America. An evaluation of the simulated atmospheric dynamics and thermodynamics associated with extreme precipitation events was also conducted using the North American Regional Reanalysis (NARR). The models were found to capture the large-scale physical mechanisms that generate extreme precipitation realistically, although they tend to overestimate the strength of the associated atmospheric circulation features. This suggests that climate model deficiencies such as insufficient spatial resolution, inadequate representation of convective precipitation, and overly smoothed topography may be more important for biases in simulated heavy precipitation than errors in the large-scale circulation during extreme events.

Response of Humidity and Clouds to Tropical Deep Convection

2009 ◽  
Vol 22 (9) ◽  
pp. 2389-2404 ◽  
Author(s):  
Mark D. Zelinka ◽  
Dennis L. Hartmann
Keyword(s):  
Large Scale ◽  
Deep Convection ◽  
Lower Troposphere ◽  
Upward Motion ◽  
Temporal Separation ◽  
Convective Event ◽  
Clear Sky ◽  
Intense Precipitation ◽  
Upper Level ◽  
Precipitation Events

Abstract Currently available satellite data can be used to track the response of clouds and humidity to intense precipitation events. A compositing technique centered in space and time on locations experiencing high rain rates is used to detail the characteristic evolution of several quantities measured from a suite of satellite instruments. Intense precipitation events in the convective tropics are preceded by an increase in low-level humidity. Optically thick cold clouds accompany the precipitation burst, which is followed by the development of spreading upper-level anvil clouds and an increase in upper-tropospheric humidity over a broader region than that occupied by the precipitation anomalies. The temporal separation between the convective event and the development of anvil clouds is about 3 h. The humidity increase at upper levels and the associated decrease in clear-sky longwave emission persist for many hours after the convective event. Large-scale vertical motions from reanalysis show a coherent evolution associated with precipitation events identified in an independent dataset: precipitation events begin with stronger upward motion anomalies in the lower troposphere, which then evolve toward stronger upward motion anomalies in the upper troposphere, in conjunction with the development of anvil clouds. Greater upper-tropospheric moistening and cloudiness are associated with larger-scale and better-organized convective systems, but even weaker, more isolated systems produce sustained upper-level humidity and clear-sky outgoing longwave radiation anomalies.

scholarly journals An Analogue Approach to Identify Heavy Precipitation Events: Evaluation and Application to CMIP5 Climate Models in the United States

2014 ◽  
Vol 27 (15) ◽  
pp. 5941-5963 ◽  
Author(s):  
Xiang Gao ◽  
C. Adam Schlosser ◽  
Pingping Xie ◽  
Erwan Monier ◽  
Dara Entekhabi
Keyword(s):  
United States ◽  
Large Scale ◽  
Heavy Precipitation ◽  
The United States ◽  
Cmip5 Models ◽  
Atmospheric Conditions ◽  
South Central ◽  
Simulated Precipitation ◽  
Analogue Method ◽  
Precipitation Events

Abstract An analogue method is presented to detect the occurrence of heavy precipitation events without relying on modeled precipitation. The approach is based on using composites to identify distinct large-scale atmospheric conditions associated with widespread heavy precipitation events across local scales. These composites, exemplified in the south-central, midwestern, and western United States, are derived through the analysis of 27-yr (1979–2005) Climate Prediction Center (CPC) gridded station data and the NASA Modern-Era Retrospective Analysis for Research and Applications (MERRA). Circulation features and moisture plumes associated with heavy precipitation events are examined. The analogues are evaluated against the relevant daily meteorological fields from the MERRA reanalysis and achieve a success rate of around 80% in detecting observed heavy events within one or two days. The method also captures the observed interannual variations of seasonal heavy events with higher correlation and smaller RMSE than MERRA precipitation. When applied to the same 27-yr twentieth-century climate model simulations from Phase 5 of the Coupled Model Intercomparison Project (CMIP5), the analogue method produces a more consistent and less uncertain number of seasonal heavy precipitation events with observation as opposed to using model-simulated precipitation. The analogue method also performs better than model-based precipitation in characterizing the statistics (minimum, lower and upper quartile, median, and maximum) of year-to-year seasonal heavy precipitation days. These results indicate the capability of CMIP5 models to realistically simulate large-scale atmospheric conditions associated with widespread local-scale heavy precipitation events with a credible frequency. Overall, the presented analyses highlight the improved diagnoses of the analogue method against an evaluation that considers modeled precipitation alone to assess heavy precipitation frequency.

Sign in / Sign up

Export Citation Format

Share Document