scholarly journals The Low-Level Jet over the Southern Great Plains Determined from Observations and Reanalyses and Its Impact on Moisture Transport

2015 ◽  
Vol 28 (17) ◽  
pp. 6682-6706 ◽  
Author(s):  
Larry K. Berg ◽  
Laura D. Riihimaki ◽  
Yun Qian ◽  
Huiping Yan ◽  
Maoyi Huang
Keyword(s):  
Great Plains ◽  
Moisture Transport ◽  
Department Of Energy ◽  
Radiosonde Data ◽  
Southern Great Plains ◽  
Low Level ◽  
Convective Clouds ◽  
Atmospheric Radiation Measurement ◽  
Low Level Jet ◽  
Regional Reanalysis

Abstract This study utilizes six commonly used reanalysis products, including the NCEP–Department of Energy Reanalysis 2 (NCEP2), NCEP Climate Forecast System Reanalysis (CFSR), ECMWF interim reanalysis (ERA-Interim), Japanese 25-year Reanalysis Project (JRA-25), Modern-Era Retrospective Analysis for Research and Applications (MERRA), and North American Regional Reanalysis (NARR), to evaluate features of the southern Great Plains low-level jet (LLJ) above the U.S. Department of Energy’s Atmospheric Radiation Measurement Program (ARM) Climate Research Facility (ACRF) Southern Great Plains site. Two sets of radiosonde data are utilized: the six-week Midlatitude Continental Convective Clouds Experiment (MC3E) and a 10-yr period spanning 2001 through 2010. All six reanalyses are compared to MC3E data, while only the NARR, MERRA, and CFSR are compared to the 10-yr data. The reanalyses are able to represent most aspects of the composite LLJ profile, although there is a tendency for each reanalysis to overestimate the wind speed between the nose of the LLJ (at approximately 900 mb) and a pressure level of 700 mb. There are large discrepancies in the number of LLJs observed and derived from the reanalysis, particularly for strong LLJs, leading to an underestimate of the moisture transport associated with LLJs. When the 10-yr period is considered, the NARR and CFSR overestimate and MERRA underestimates the total moisture transport, but all three underestimate the transport associated with strong LLJs by factors of 1.4, 2.0, and 2.7 for CFSR, NARR, and MERRA, respectively. During MC3E there were differences in the patterns of moisture convergence and divergence, but the patterns are more consistent during the 10-yr period.

scholarly journals Atmospheric Moisture Transport over the United States and Mexico as Evaluated in the NCEP Regional Reanalysis

2005 ◽  
Vol 6 (5) ◽  
pp. 710-728 ◽  
Author(s):  
Kingtse C. Mo ◽  
Muthuvel Chelliah ◽  
Marco L. Carrera ◽  
R. Wayne Higgins ◽  
Wesley Ebisuzaki
Keyword(s):  
United States ◽  
Gulf Of Mexico ◽  
Great Plains ◽  
Moisture Transport ◽  
Gulf Of California ◽  
Phase Relationship ◽  
The United States ◽  
Low Level ◽  
Low Level Jet ◽  
Regional Reanalysis

Abstract The large-scale atmospheric hydrologic cycle over the United States and Mexico derived from the 23-yr NCEP regional reanalysis (RR) was evaluated by comparing the RR products with satellite estimates, independent sounding data, and the operational Eta Model three-dimensional variational data assimilation (3DVAR) system (EDAS). In general, the winter atmospheric transport and precipitation are realistic. The climatology and interannual variability of the Pacific, subtropical jet streams, and low-tropospheric moisture transport are well captured. During the summer season, the basic features and the evolution of the North American monsoon (NAM) revealed by the RR compare favorably with observations. The RR also captures the out-of-phase relationship of precipitation as well as the moisture flux convergence between the central United States and the Southwest. The RR is able to capture the zonal easterly Caribbean low-level jet (CALLJ) and the meridional southerly Great Plains low-level jet (GPLLJ). Together, they transport copious moisture from the Caribbean to the Gulf of Mexico and from the Gulf of Mexico to the Great Plains, respectively. The RR systematically overestimates the meridional southerly Gulf of California low-level jet (GCLLJ). A comparison with observations suggests that the meridional winds from the RR are too strong, with the largest differences centered over the northern Gulf of California. The strongest winds over the Gulf in the RR extend above 700 hPa, while the operational EDAS and station soundings indicate that the GCLLJ is confined to the boundary layer.

scholarly journals Supplementary material to "On the assessment of the moisture transport by the Great Plains low-level jet"

2018 ◽  
Author(s):  
Iago Algarra ◽  
Jorge Eiras-Barca ◽  
Gonzalo Miguez-Macho ◽  
Raquel Nieto ◽  
Luis Gimeno
Keyword(s):  
Great Plains ◽  
Moisture Transport ◽  
Low Level ◽  
Supplementary Material ◽  
Low Level Jet

scholarly journals A Modified Framework for Quantifying Land–Atmosphere Covariability during Hydrometeorological and Soil Wetness Extremes in Oklahoma

2019 ◽  
Vol 58 (7) ◽  
pp. 1465-1483 ◽  
Author(s):  
Ryann A. Wakefield ◽  
Jeffrey B. Basara ◽  
Jason C. Furtado ◽  
Bradley G. Illston ◽  
Craig. R. Ferguson ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Great Plains ◽  
Hot Spot ◽  
Extreme Rainfall ◽  
Southern Great Plains ◽  
Low Level ◽  
Oklahoma Mesonet ◽  
Humidity Index ◽  
Grid Points ◽  
Regional Reanalysis

AbstractGlobal “hot spots” for land–atmosphere coupling have been identified through various modeling studies—both local and global in scope. One hot spot that is common to many of these analyses is the U.S. southern Great Plains (SGP). In this study, we perform a mesoscale analysis, enabled by the Oklahoma Mesonet, that bridges the spatial and temporal gaps between preceding local and global analyses of coupling. We focus primarily on east–west variations in seasonal coupling in the context of interannual variability over the period spanning 2000–15. Using North American Regional Reanalysis (NARR)-derived standardized anomalies of convective triggering potential (CTP) and the low-level humidity index (HI), we investigate changes in the covariance of soil moisture and the atmospheric low-level thermodynamic profile during seasonal hydrometeorological extremes. Daily CTP and HI z scores, dependent upon climatology at individual NARR grid points, were computed and compared to in situ soil moisture observations at the nearest mesonet station to provide nearly collocated annual composites over dry and wet soils. Extreme dry and wet year CTP and HI z-score distributions are shown to deviate significantly from climatology and therefore may constitute atmospheric precursors to extreme events. The most extreme rainfall years differ from climatology but also from one another, indicating variability in the strength of land–atmosphere coupling during these years. Overall, the covariance between soil moisture and CTP/HI is much greater during drought years, and coupling appears more consistent. For example, propagation of drought during 2011 occurred under antecedent CTP and HI conditions that were identified by this study as being conducive to positive dry feedbacks demonstrating potential utility of this framework in forecasting regional drought propagation.

scholarly journals Mesoscale Moisture Transport by the Low-Level Jet during the IHOP Field Experiment

2008 ◽  
Vol 136 (10) ◽  
pp. 3781-3795 ◽  
Author(s):  
Edward I. Tollerud ◽  
Fernando Caracena ◽  
Steven E. Koch ◽  
Brian D. Jamison ◽  
R. Michael Hardesty ◽  
...  
Keyword(s):  
Great Plains ◽  
Cross Sections ◽  
Moisture Transport ◽  
Large Scale ◽  
Wrf Model ◽  
The United States ◽  
Small Scale ◽  
Low Level ◽  
Convective Scale ◽  
Low Level Jet

Previous studies of the low-level jet (LLJ) over the central Great Plains of the United States have been unable to determine the role that mesoscale and smaller circulations play in the transport of moisture. To address this issue, two aircraft missions during the International H2O Project (IHOP_2002) were designed to observe closely a well-developed LLJ over the Great Plains (primarily Oklahoma and Kansas) with multiple observation platforms. In addition to standard operational platforms (most important, radiosondes and profilers) to provide the large-scale setting, dropsondes released from the aircraft at 55-km intervals and a pair of onboard lidar instruments—High Resolution Doppler Lidar (HRDL) for wind and differential absorption lidar (DIAL) for moisture—observed the moisture transport in the LLJ at greater resolution. Using these observations, the authors describe the multiscalar structure of the LLJ and then focus attention on the bulk properties and effects of scales of motion by computing moisture fluxes through cross sections that bracket the LLJ. From these computations, the Reynolds averages within the cross sections can be computed. This allow an estimate to be made of the bulk effect of integrated estimates of the contribution of small-scale (mesoscale to convective scale) circulations to the overall transport. The performance of the Weather Research and Forecasting (WRF) Model in forecasting the intensity and evolution of the LLJ for this case is briefly examined.

scholarly journals Sky cover from MFRSR observations

2011 ◽  
Vol 4 (7) ◽  
pp. 1463-1470 ◽  
Author(s):  
E. Kassianov ◽  
J. C. Barnard ◽  
L. K. Berg ◽  
C. Flynn ◽  
C. N. Long
Keyword(s):  
Great Plains ◽  
Visible Spectral Range ◽  
Department Of Energy ◽  
Research Facility ◽  
Southern Great Plains ◽  
Clear Sky ◽  
The Us ◽  
Atmospheric Radiation Measurement ◽  
Main Components ◽  
Good Agreement

Abstract. The diffuse all-sky surface irradiances measured at two nearby wavelengths in the visible spectral range and their modeled clear-sky counterparts are the main components of a new method for estimating the fractional sky cover of different cloud types, including cumuli. The performance of this method is illustrated using 1-min resolution data from a ground-based Multi-Filter Rotating Shadowband Radiometer (MFRSR). The MFRSR data are collected at the US Department of Energy Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) Southern Great Plains (SGP) site during the summer of 2007 and represent 13 days with cumuli. Good agreement is obtained between estimated values of the fractional sky cover and those provided by a well-established independent method based on broadband observations.

Recurrent Supersynoptic Evolution of the Great Plains Low-Level Jet

2011 ◽  
Vol 24 (2) ◽  
pp. 575-582 ◽  
Author(s):  
Scott J. Weaver ◽  
Sumant Nigam
Keyword(s):  
Great Plains ◽  
Large Scale ◽  
Large Scale Circulation ◽  
Low Level ◽  
The North ◽  
Analysis Strategy ◽  
Precipitation Anomalies ◽  
North American Regional Reanalysis ◽  
Low Level Jet ◽  
Regional Reanalysis

Abstract The evolution of supersynoptic (i.e., pentad) Great Plains low-level jet (GPLLJ) variability, its precipitation impacts, and large-scale circulation context are analyzed in the North American Regional Reanalysis (NARR)—a high-resolution precipitation-assimilating dataset—and the NCEP–NCAR reanalysis. The analysis strategy leans on the extended EOF technique, which targets both spatial and temporal recurrence of a variability episode. Pentad GPLLJ variability structures are found to be spatially similar to those in the monthly analysis. The temporal evolution of the supersynoptic GPLLJ-induced precipitation anomalies reveal interesting lead and lag relationships highlighted by GPLLJ variability-leading precipitation anomalies. Interestingly, similar temporal phasing of the GPLLJ and precipitation anomalies were operative during the 1993 (1988) floods (drought) over the Great Plains, indicating the importance of these submonthly GPLLJ variability modes in the instigation of extreme hydroclimatic episodes. The northward-shifted (dry) GPLLJ variability mode is linked to large-scale circulation variations emanating from remote regions that are modified by interaction with the Rocky Mountains, suggesting that the supersynoptic GPLLJ fluctuations may have their origin in orographic modulation of baroclinic development.

scholarly journals Sky cover from MFRSR observations: cumulus clouds

2011 ◽  
Vol 4 (1) ◽  
pp. 715-735 ◽  
Author(s):  
E. Kassianov ◽  
J. Barnard ◽  
L. K. Berg ◽  
C. Flynn ◽  
C. N. Long
Keyword(s):  
Great Plains ◽  
Visible Spectral Range ◽  
Department Of Energy ◽  
Cumulus Clouds ◽  
Southern Great Plains ◽  
Clear Sky ◽  
The Us ◽  
Atmospheric Radiation Measurement ◽  
Main Components ◽  
Good Agreement

Abstract. The diffuse all-sky surface irradiances measured at two nearby wavelengths in the visible spectral range and their model clear-sky counterparts are two main components of a new method for estimating the fractional sky cover of different cloud types, including cumulus clouds. The performance of this method is illustrated using 1-min resolution data from ground-based Multi-Filter Rotating Shadowband Radiometer (MFRSR). The MFRSR data are collected at the US Department of Energy Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) Southern Great Plains (SGP) site during the summer of 2007 and represent 13 days with cumulus clouds. Good agreement is obtained between estimated values of the fractional sky cover and those provided by a well-established independent method based on broadband observations.

scholarly journals Long-term aerosol-mediated changes in cloud radiative forcing of deep clouds at the top and bottom of the atmosphere over the Southern Great Plains

2014 ◽  
Vol 14 (4) ◽  
pp. 4599-4625
Author(s):  
Hongru Yan ◽  
Zhanqing Li ◽  
Jianping Huang ◽  
Maureen Cribb ◽  
Jianjun Liu
Keyword(s):  
Great Plains ◽  
Radiative Forcing ◽  
Reanalysis Data ◽  
Southern Great Plains ◽  
Convective Clouds ◽  
The Us ◽  
Atmospheric Radiation Measurement ◽  
Core Thickness ◽  
Weak Wind

Abstract. Aerosols can alter the macro- and micro-physical properties of deep convective clouds (DCC) and their radiative forcing (CRF). This study presents what is arguably the first long-term estimate of the aerosol-mediated changes in CRF (AMCRF) for deep cloud systems derived from decade-long continuous ground-based and satellite observations, model simulations and reanalysis data. Measurements were made at the US Department of Energy's Atmospheric Radiation Measurement Program's Southern Great Plains (SGP) site. Satellite retrievals are from the Geostationary Operational Environmental Satellite (GOES). Increases in aerosol loading were accompanied by the thickening of DCC cores and the expansion and thinning of anvils, due presumably to the aerosol invigoration effect (AIV) and the aerosol microphysical effect (AME). Meteorological variables dictating these cloud processes were investigated. Consistent with previous findings, the AIV is most significant when the atmosphere is moist and unstable with weak wind shear. Such aerosol-mediated systematic changes in DCC core thickness and anvil size alter CRF at the top of atmosphere (TOA) and at the surface. Using extensive observations, ~300 DCC systems were identified over a 10 yr period at the SGP site (2000–2011) and analyzed. Daily mean AMCRF at the TOA and at the surface are 29.3 W m−2 and 22.2 W m−2, respectively. This net warming effect due to changes in DCC microphysics offsets the cooling resulting from the first aerosol indirect effect.

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