· Park, Sung-Su, C. B. Leovy, and M. A. Rozendaal, 2004: A new heuristic Lagrangian marine boundary layer cloud model.
J. Atmos. Sci., 61,
3002-3024.
· Min, H.-S., and Yign Noh, 2004: Influence of the surface heating on Langmir circulation.
J. Phys. Oceanogr., 34,
2630-2641.
· Noh, Yign, 2004: Sensitivity to wave breaking and the Prandtl number in the ocean mixed layer model and its dependence on latitude.
Geophys. Res. Lett., 31,
L23305, doi:10.1029/2004GL021289.
· Byun, Young-Hwa, and Song-You Hong, 2004: Impact of boundary-layer processes on simulated tropical rainfall.
J. Climate., 17,
4032-4044.
· Hong, Song-You, 2004: Comparison of heavy rainfall mechanisms in Korea and the central United States.
J. Meteor. Soc. Japan., 82,
1469-1479.
· An, Soon-Il, 2004: Interdecadal changes
in the El Nino-La Nina asymmetry. Geophys. Res. Lett., 31,
L23210, doi:10.1029/2004GL021699.
· McCormack, J. P., S. D. Eckermann, L. Coy, D. R. Allen, Y. -J. Kim, T. Hogan, B. Lawrence, A. Stevens, R. Bevilacqua, E. V. Browell, J.
Burris, T. McGee, and C. R. Trepte: 2004: NOGAPS-ALPHA model simulations of stratospheric
ozone during the SOLVE2 campaign, Atmos. Chem. Phys., 4, 2401-2423.
(available online at http://www.copernicus.org/EGU/acp/acp/4/2401/acp-4-2401.pdf)
· An, Soon-Il, A.
Timmermann, L. Bejarano, F.-F. Jin, F. Justino, Z. Liu, A. and W. Tudhope,
2004: Modeling evidence for enhanced El Nino-Southern Oscillation amplitude
during the last glacial maximum, Paleoceanography, 19, PA4009, doi:10.1029/2004PA0011020
· Kim,
Young-Joon, and Timothy F. Hogan, 2004: Response of a global atmospheric forecast
model to various drag parameterizations. Tellus, 56A, 472-484.
· Chun, Hye-Yeong, In-Sun Song, Jong-Jin Baik, and Young-Joon Kim, 2004: Impact
of a convectively forced gravity-wave drag parameterization in NCAR CCM3. J.
Climate, 17, 3529-3546.
· An, Soon-Il, 2004: A dynamic link between the basin-scale and
zonal modes in the tropical
· Yoo,
S.-H., C.-H. Ho, S. Yang, H.-J. Choi, and J.-G. Jhun, 2004:
Influences of tropical western and extratropical pacific SST on east and
southeast Asian climate in the summers of 1993-94. J. Climate, 17, 2673-2687.
· Kim, H.J., Y. Noh
& S. Raasch, "Interaction between wind and temperature fields under
the heterogeneous heat flux in the planetary boundary layer, Boundary Layer
Meteorol. 111, 225-246, 2004.
· Noh, Y., H.S. Min & S. Raasch, "Large eddy simulation of the ocean
mixed layer: the effects of wave breaking and Langmuir circulation", J.
Phys. Oceanogr. 34, 720-735, 2004.
· Park, S., and S.-Y. Hong, 2004: The role of surface boundary
forcing over south
A regional climate model
sensitivity study. Geophys. Res. Lett., 31, L12112, doi:10.1029/2004GL019729.
· Hong, S.-Y., J. Dudhia, and S.-H.
Chen, 2004: A revised approach to ice-microphysical
processes for the bulk parameterization of clouds
and precipitation. Mon. Wea. Rev., 132, 1,
103-120.
· An,
Soon-Il, and Fei-Fei Jin, 2004: Nonlinearity
and asymmetry of ENSO, J.
Climate, 17, 2399-2412.
· Kang, In-Sik, Jong-Seong Kug, Soon-Il
An, and Fei-Fei Jin, 2004: A near-annual Pacific Ocean basin mode, J. Climate, 17, 2478-2488.
· Jong-Seong Kug, In-Sik Kang, June-Yi
Lee, and Jong-Ghap Jhun, 2004: A statistical approach to Indian
Ocean sea surface temperature prediction using dynamical ENSO prediction. Geo.
Res. Let., Vol. 31, L09212.
· J.H.
Kim, S. Na, M.J. Newchurch, and K.J. Ha, Comparison of Scan-angle
method and convective cloud differential method in retrieving tropospheric
ozone from TOMS, Environmental Monitoring and Assessment, 92, 25-33, 2004.
· Kim,
H. M., M. Morgan, and R. E. Morss, 2004: Evolution of analysis error and
adjoint-based sensitivities: Implications for adaptive observations. Journal of
the Atmospheric Sciences, 61, 795-812.
· Lee, GyuWon, I.
Zawadzki, W. Szymer, D. Sempere-Torres, and R. Uijlenhoet, 2004: A general approach
to double-moment normalization of drop size distributions. J. Appl. Meteo.,
43, 264-281.
ABSTRACT
Normalization of drop size
distributions (DSDs) is reexamined here. First, an extension of the scaling
normalization that uses one moment of the DSD as a scaling parameter to a more
general scaling normalization that uses two moments as scaling parameters of
the normalization is presented. In addition, the proposed formulation includes
all two-parameter normalizations recently introduced in the literature. Thus, a
unified vision of the question of DSD normalization and a good model
representation of DSDs are given. Data analysis of some convective and
stratiform DSDs shows that, from the point of view of the compact
representation of DSDs, the double-moment normalization is preferred. However,
in terms of physical interpretation, the scaling exponent of the single-moment
normalization clearly indicates two different rain regimes, whereas in the
double-moment normalization the two populations are not readily separated. It
is also shown that DSD analytical models (exponential, gamma, and generalized
gamma DSD) have the same scaling properties, indicating that the scaling
formalism of DSDs is a very general way of describing DSDs.
· Miriovsky,
B. J., A. A. Bradley, W. N. Eichinger, W. F. Krajewski, A. Kruger, B. R.
Nelson, J.-D. Creutin, J.-M. Lapetite, GyuWon Lee, I. Zawadzki, and F.
L. Ogden, 2004: An experimental study of small-scale variability of radar
reflectivity using disdrometer observations. J. Appl. Meteo., 43,
106-118.
ABSTRACT
Analysis of data collected by
four disdrometers deployed in a 1-km2 area is presented with the
intent of quantifying the spatial variability of radar reflectivity at small
spatial scales. Spatial variability of radar reflectivity within the radar beam
is a key source of error in radar-rainfall estimation because of the assumption
that drops are uniformly distributed within the radar-sensing volume. Common
experience tells one that, in fact, drops are not uniformly distributed, and,
although some work has been done to examine the small-scale spatial variability
of rain rates, little experimental work has been done to explore the
variability of radar reflectivity. The four disdrometers used for this study
include a two-dimensional video disdrometer, an X-band radar-based disdrometer,
an impact-type disdrometer, and an optical spectropluviometer. Although
instrumental differences were expected, the magnitude of these differences
clouds the natural variability of interest. An algorithm is applied to mitigate
these instrumental effects, and the variability remains high, even as the
observations are integrated in time. Although one cannot explicitly quantify
the spatial variability from this experiment, the results clearly show that the
spatial variability of reflectivity is very large.
· Benedict J. J., Lee S,
Feldstein S. B., 2004: Synoptic view of the North Atlantic Oscillation, J.
Atmos. Sci. 61(2), 121-144.
· Franzke C, Lee S, Feldstein S. B., 2004: Is the North
Atlantic Oscillation breaking wave? J. Atmos. Sci. 61(2), 145-160.
· Kang, In-Sik, June-Yi Lee, and Chung-Kyu
Park, 2004: Potential predictability of summer mean precipitation in a
dynamical seasonal prediction system with systematic error correction. J.
Climate, 17, 834-844
· Lau,
K.-M., J.-Y. Lee, K.-M. Kim, and I.-S. Kang, 2004: The
North Pacific as a regulator of summertime climate over Eurasia and North
America. J. Climate 17, 819-833.
· Wang,
Bin, In-Sik Kang, and June-Yi Lee, 2004: Ensemble simulations of
Asian-Australian monsoon variabiliy by 11 AGCMs. J. Climate 17, 803-818.
· Leung, L. Ruby, Yun Qian, Jongil Han, and
John O. Roads, 2003: Intercomparison of global reanalyses and regional
simulations of cold season water budgets in the western United States. JOURNAL
OF HYDROMETEOROLOGY, 4(6), 1067-1087.
ABSTRACT
Estimating
water budgets of river basins in the western United States is a challenge
because of the effects of complex terrain and lack of comprehensive observational
datasets. This study aims at comparing different estimates of cold season water
budgets of the Columbia River (CRB) and Sacramento-San Joaquin River (SSJ)
basins. An intercomparison was performed based on the NCEP-NCAR reanalysis I
(NRA1), NCEP-Department of Energy (DOE) reanalysis II (NRA2), ECMWF reanalyses
(ERA), regional climate simulations produced by the fifth-generation
Pennsylvania State University-NCAR Mesoscale Model (MM5) and NCEP Regional
Spectral Model (RSM) driven by the reanalyses, and two precipitation datasets
gridded at 2.5degrees and 1/8degrees for 7 yr between 1986 and 1993. The
purpose of the intercomparison was to understand the effects of spatial
resolution, model configuration and associated parameterizations, and
large-scale conditions on basin-scale water budgets.
Overall,
the regional simulations were superior to the global reanalyses in terms of the
spatial distribution of mean precipitation and precipitation anomalies.
However, cold season precipitation was generally amplified in the regional
models. Basin mean precipitation was typically higher than observed in the
regional models and less than observed in the reanalyses. The amplification was
the largest in the RSM simulation driven by NRA2, which had the biggest
difference between the reanalyzed and regional simulation of basin mean
precipitation. ERA and the MM5 simulations driven by ERA provided the best
basin mean precipitation estimates when compared to the 1/8degrees
observational dataset.
Large
differences remain in estimating the water budgets of western river basins,
such as CRB and SSJ. In terms of atmospheric moisture flux, there was a 15%-20%
difference between the global reanalyses. In terms of basin mean precipitation,
differences among the reanalyses,
regional simulations, and observations were as large as 100% of the
overall mean. There were large differences in spatial distribution of
precipitation between the RSM and MM5 simulations because of terrain
representations and other factors. Runoff and snowpack showed the most
sensitivity to model differences in spatial resolution, physics
parameterizations, and model representations. Better simulations of basin mean
precipitation did not necessarily imply superior simulations of runoff or
snowpack.
· Han, Jongil and John O. Roads, 2004: U.S.
Climate Sensitivity Simulated with the NCEP Regional Spectral Model. Climate
Change, 62(1-3), 115-154.
ABSTRACT
10-year
continuous U.S. climate simulations were conducted with the Regional Spectral Model
(RSM) using boundary conditions from the National Centers for Environmental
Prediction/Dept. of Energy reanalyses and the global PCM (Parallel Climate
Model) simulations for present day (1986–1996) and future (2040–2050) CO2
concentrations (about a 36% increased CO2). In order to examine the influence
of physical parameterization differences as well as grid-resolution, fine
resolution RSM simulations (50 km) were compared to coarse resolution (180 and
250 km) RSM simulations, which had resolutions comparable to the T62 reanalysis
and PCM simulations. During the winter, the fine resolution RSM simulations
provided more realistic detail over the western mountains. During the summer,
large differences between the RSM and driving PCM simulations were found. Our
results with present CO2 suggest that most of the differences between the
regional climate model
simulations and the climate simulations driven by the global model used to
drive the regional climate model were not due to the finer resolution of the regional
climate model but to the different treatment of the physical processes in the
two models, especially when the subgrid scale physics was important, like
during summer. Compared to the coarse resolution RSM simulation results, on the
other hand, the fine resolution RSM simulations did show improved simulation
skills especially when a good boundary condition such as the reanalysis was
used to drive the RSM. Under increased CO2, the driving PCM and downscaled RSM
simulations exhibited warming over all vertical layers and all regions. Both
the RSM and PCM had increased precipitation during the winter, but during the
summer, the PCM simulation had an overall
precipitation increase mainly due to increased subgrid scale convective
activity, whereas the RSM simulations exhibited precipitation decreases and the
resulting RSM soil moisture became dryer, especially in the U.S. Southwest.
Most of differences in the simulated climate change signals were produced by
the distinct model physics rather than by differences in grid resolution.
· Leung, L. Ruby, Yun Qian, Xindi
Bian, Warren M. Washington, Jongil Han, and John O. Roads, 2004:
Mid-Century Ensemble Regional Climate Change Scenarios for the Western United
States. Climate Change, 62(1-3), 75-113.
ABSTRACT
To study
the impacts of climate change on water resources in the western U.S., global
climate simulations were produced using the National Center for Atmospheric
Research/Department of Energy (NCAR/DOE) Parallel Climate Model (PCM). The Penn
State/NCAR Mesoscale Model (MM5) was used to downscale the PCM control (20
years) and three future (2040–2060) climate simulations to yield ensemble
regional climate simulations at 40 km spatial resolution for the western U.S.
This paper describes the regional simulations and focuses on the hydroclimate
conditions in the Columbia River Basin (CRB) and Sacramento-San Joaquin River
(SSJ) Basin. Results based on global and regional simulations show that by
mid-century, the average regional warming of 1 to 2.5 °C strongly affects
snowpack in the western U.S. Along coastal mountains, reduction in annual
snowpack was about 70% as indicated by the regional simulations. Besides
changes in mean temperature, precipitation, and
snowpack, cold season extreme daily precipitation increased by 5 to 15 mm/day
(15–20%) along the Cascades and the Sierra. The warming resulted in increased
rainfall at the expense of reduced snowfall, and reduced snow accumulation (or
earlier snowmelt) during the cold season. In the CRB, these changes were accompanied
by more frequent rain-on-snow events. Overall, they induced higher likelihood
of wintertime flooding and reduced runoff and soil moisture in the summer.
Changes in surface water and energy budgets in the CRB and SSJ basin were
affected mainly by changes in surface temperature, which were statistically
significant at the 0.95 confidence level. Changes in precipitation, while
spatially incoherent, were not statistically significant except for the drying
trend during summer. Because snow and runoff are highly sensitive to spatial
distributions of temperature and precipitation, this study shows that (1)
downscaling provides more realistic estimates of hydrologic impacts in
mountainous regions such as the western U.S., and (2) despite relatively small
changes in temperature and precipitation, changes in snowpack and runoff can be
much larger on monthly to seasonal time scales because the effects of
temperature and precipitation are integrated over time and space through
various surface hydrological and land-atmosphere feedback processes. Although
the results reported in this study were derived from an ensemble of regional
climate simulations driven by a global climate model that displays low climate
sensitivity compared with most other models, climate change was found to
significantly affect water resources in the western U.S. by the mid
twenty-first century.