Geophysical Research Letters
Supporting Information for
Role of the strengthened El Niño teleconnection in the May 2015 floods over the
southern Great Plains
S.-Y. Simon Wang1,2*, Wan-Ru Huang3, Huang-Hsiung Hsu4, and Robert Gillies
1Utah
Climate Center, Utah State University, Logan, UT, USA
of Plants, Soils, and Climate, Utah State University, Logan, UT, USA
3
Department of Earth Sciences, National Taiwan Normal University, Taipei, Taiwan
4Research Center for Environmental Changes, Academia Sinica, Taipei, Taiwan
2Department
Contents of this file
Text S1
Figures S1 to S3
Tables S1 to S2
Text S1. (Additional explanatory text)
The Great Plains LLJ is known to interact with upper-level synoptic waves and
generate stronger convection (Uccellini and Johnson 1979; Uccellini 1980). A proper
superposition of the LLJ with the upper-level jet can enhance upward motion throughout
much of the troposphere and assist in the development of deep convection (e.g., Newton
1967). When coupled with an approaching baroclinic wave, moisture is efficiently
converged over the region immediately east of the baroclinic wave in which heavy
rainfall is produced (Chen and Kpaeyeh 1993; Byerle and Paegle 2003). The coupling of
LLJs with the ascending branch ahead of a synoptic wave induces strong updrafts for
convection, while the low-level convergence at the northern terminus of the LLJ supplies
moisture and promotes precipitation (Uccellini and Johnson 1979). These synoptic
characteristics are present in the May 2015 anomaly (Fig. 1c) and the long-term
changes (Fig. 4b), together with the increased southerly component of the water vapor
fluxes that transports moisture into the southern Great Plains.
References:
Byerle, L. A., and J. Paegle, 2003: Modulation of the Great Plains low-level jet and
moisture transports by orography and largescale circulations. J. Geophys. Res.,
108, 8611.
Chen, T.-C., and J. A. Kpaeyeh, 1993: The synoptic-scale environment associated with
the low-level jet of the Great Plains. Mon. Wea. Rev., 121, 416–420.
1
Newton, C. W., 1967: Severe convective storms. Advances in Geophysics, Vol. 12,
Academic Press, 257–303.
Uccellini, L. W., 1980: On the role of upper tropospheric jet streaks and leeside
cyclogenesis in the development of low-level jets in the Great Plains. Mon. Wea.
Rev., 108, 1689–1696.
——, and D. R. Johnson, 1979: The coupling of upper and lower tropospheric jet streaks
and implications for the development of severe convective storms. Mon. Wea.
Rev., 107, 682–703.
Figure S1. Same as Figs. 3a and 3c except for the May 250-hPa geopotential height
and global precipitation anomalies derived from the CMIP5 ensemble of NAT and GHG.
Coutures are +/- 25 m. Notice the anomalous trough in the western U.S. (arrow
indicated) and the stronger precipitation in GHG (outlined)that is stronger in GHG than in
NAT. The Nino-3.4 index was standardized so the variables reflect their native unit.
Figure S2. Power spectral analysis of the zonal wave regimes in the 250-hPa
streamfunction anomaly of May 2015, averaged within the latitude zone of 30º-50ºN.
Note the increased power at wave #5.
2
Figure S3. (Top to bottom) April precipitation anomaly in mm obtained from
http://water.weather.gov/precip/. Soil moisture anomaly provided by the Climate
Prediction Center for April 2015 and May 2015. Notice the increased precipitation in
Texas.
3
Acronym
Model full name
Center/Institute, country
Resolution Ensemble
(lon.xlat.) size (max)
BCC-CSM1
Beijing Climate Center, Climate System Beijing Climate Center, Meteorological 2.8° x 2.8° 1
Model, version 1.1
Administration, China
BNU-ESM
Beijing Normal University—Earth
College of Global Change and Earth
2.8° x 2.8° 1
System Model
System Science (GCESS), China
CanESM2
Canadian Earth System Model, version 2 Canadian Center for Climate Modeling 2.8° x 2.8° 5
and Analysis, Canada
CCSM4
Community Climate System Model,
National Center for Atmospheric
1.25°x1.0° 5
version 4
Research, USA
CNRM-CM5 Centre National de Recherches
National Centre for Meteorological
1.4° x 1.4° 10
Météorologiques Coupled Global Climate Research, France
Model, version 5
CSIRO-Mk3 Commonwealth Scientific and Industrial Commonwealth Scientific and
1.8° x 1.8° 10
Research Organisation Mark, version
Industrial Research Organization/
3.6.0
Queensland Climate Change Centre of
Excellence, AUS
FGOALS-g2 Flexible Global Ocean-Atmosphere-Land LASG, Institute of Atmospheric
2.8° x 1.6° 4
System Model, grid point version 2
Physics, Chinese Academy of
Sciences, China
GFDL-CM3 Geophysical Fluid Dynamics Laboratory NOAA Geophysical Fluid Dynamics
2.5° x 2.0° 5
Climate Model version 3
Laboratory, USA
GFDL-ESM2 Geophysical Fluid Dynamics Laboratory NOAA Geophysical Fluid Dynamics
2.5° x 2.0° 3
Earth Science Model 2 with Modular
Laboratory, USA
Ocean Model (MOM), version 4.1
GISS-E2-H
Goddard Institute for Space Studies
NASA Goddard Institute for Space
2.5° x 2.0° 5
Atmospheric Model E, version 2, coupled Studies, USA
with the Hybrid Coordinate Ocean Model
(HyCOM)
GISS-E2-R
Goddard Institute for Space Studies
NASA Goddard Institute for Space
2.5° x 2.0° 5
Model E, version 2, coupled with Russell Studies, USA
ocean model
HadGEM2-ES Hadley Centre Global Environmental
Met Office Hadley Centre, UK
1.8° x 1.25° 4
Model 2, Earth System
IPSL-CM5A- L'Institut Pierre-Simon Laplace Coupled Institute Pierre Simon Laplace, France 2.5° x 1.25° 1
MR
Model, version 5A, medium resolution
MIROCESM-CHEM
Model for Interdisciplinary Research on
Climate Earth System Model, chemistry
coupled version
Japan Agency for Marine-Earth
Science and Technology, Atmosphere
and Ocean Research Institute (The
University of Tokyo), and National
Institute for Environmental Studies,
Japan
Japan Agency for Marine-Earth
Science and Technology, Atmosphere
and Ocean Research Institute, and
National Institute for Environmental
Studies, Japan
Meteorological Research Institute,
Japan
2.8° x 2.8°
3
2.8° x 2.8°
3
1.1° x 1.1°
3
Norwegian Climate Center, Norway
2.5° x 1.9°
3
MIROC-ESM Model for Interdisciplinary Research on
Climate Earth System Model
MRI-CGCM3 Meteorological Research Institute
Coupled General Circulation Model,
version 3
NorESM1-M Norwegian Earth System Model, version
1, intermediate resolution
Table S1. Full name, institute, ensemble size, and spatial resolution of the CMIP5
models.
4
Name
Full Name & Agency
Spatial Resolution
MERRA
Modern-Era Retrospective Analysis for Research
and Applications, by the National Aeronautics
and Space Administration (NASA)
1.0° long. x lat. extrapolated
to 2.5°
ERA-Interim
ECMWF Interim Reanalysis Project, by the
European Centre for Medium-Range Weather
Forecasts (ECMWF)
1.5° long. x lat. 
extrapolated to 2.5°
CFSR
Climate Forecast System Reanalysis, by the
National Oceanic and Atmospheric
Administration (NOAA)
2.5° long. x lat.
JRA-25
Japanese 25-year ReAnalysis, by the Japan
Meteorological Agency (JMA)
2.5° long. x lat.
Table S2. Full name, institute, and spatial resolution of the 4 global reanalyses used for
the computation of post-1979 trends in the circulation features.
5