Results 61 to 70 of about 1,744 (240)

The benefits of a hybrid‐3DEnVar data assimilation scheme for the convection‐permitting NWP model AROME–Austria

Quarterly Journal of the Royal Meteorological Society, EarlyView.
The climatological‐error covariance matrix used in three‐dimensional variational data assimilation (3DVar) provides smooth and isotropic increments spread to long distances. In contrast, three‐dimensional ensemble variational data assimilation (3DEnVar) with a purely ensemble‐error covariance matrix provides inhomogeneous increments and contains the ...
Kaushambi Jyoti, Philipp Griewank, Florian Meier, Martin Weissmann   +3 more
wiley   +1 more source

Epistemic and aleatoric uncertainty quantification in weather and climate models

Quarterly Journal of the Royal Meteorological Society, EarlyView.
Aleatoric and epistemic uncertainties over time on weather and climate time‐scales, estimated through ensembles that sample aleatoric and epistemic uncertainty using Bayesian neural networks for parameterisations in the Lorenz 1996 model. The spread shows the 16th and 84th percentiles.
Laura A. Mansfield, Hannah M. Christensen   +1 more
wiley   +1 more source

Ensemble reliability and the signal‐to‐noise paradox in ECMWF subseasonal forecasts

Quarterly Journal of the Royal Meteorological Society, EarlyView.
We derive a general expression for the ratio of predictable components (RPC) in terms of correlation, spread–error ratio, and total variance ratio. Physical constraints on the admissible solutions (i.e., real‐valued and non‐negative variances) provide a mechanism to identify statistically paradoxical sample combinations of reliability and correlation ...
Christopher D. Roberts, Frederic Vitart
wiley   +1 more source

Sensitivity of Self‐Aggregation and the Key Role of the Free Convection Distance

Journal of Advances in Modeling Earth Systems
Recently, Biagioli and Tompkins (2023, https://doi.org/10.1029/2022ms003231) used a simple stochastic model to derive a dimensionless parameter to predict convective self aggregation (SA) development, which was based on the derivation of the maximum free
A. Casallas, A. M. Tompkins, C. Muller, G. Thompson   +3 more
doaj   +1 more source

Parameterization of convective clouds, mesoscale convective systems, and convective-generated cirrus [PDF]

, 1992
A level 2.5w deep convection updraft/downdraft parameterization scheme has been refined and tested against 3D simulations of sea-breeze generated convection over S. Florida. Cases for explicit simulation of MCSs in mid-latitudes and tropics have been encouraging.
openaire   +2 more sources

Numerical simulation and physical understanding of a locally initiated sea fog event over the eastern Yellow Sea with a transition of air–sea temperature difference

Quarterly Journal of the Royal Meteorological Society, EarlyView.
Unexpected sea fog in the west coast of South Korea had a huge impact on the transportations in the Seoul–Incheon metropolitan area. We reproduced successfully the formation and evolution of a sea event with a transition of air–sea temperature difference using the Weather Research and Forecasting model.
Jeonghoe Kim, Jung‐Hoon Kim, Clive E. Dorman, Harindra J. S. Fernando   +3 more
wiley   +1 more source

Reduction of Pacific Double‐ITCZ Bias by Convection Parameterization in NCAR CESM2.2

Journal of Advances in Modeling Earth Systems
The impact of convective closure on the double‐ITCZ bias in the NCAR CESM2.2 is investigated in this study. The standard CESM2.2 simulates a remarkable double‐ITCZ bias in the central and eastern Pacific, especially in boreal winter and spring ...
Xiaoliang Song, Guang J. Zhang
doaj   +1 more source

Assessing the Grell‐Freitas Convection Parameterization in the NASA GEOS Modeling System

Journal of Advances in Modeling Earth Systems, 2018
We implemented and began to evaluate an alternative convection parameterization for the NASA Goddard Earth Observing System (GEOS) general circulation model (GCM).
Saulo R. Freitas, Georg A. Grell, Andrea Molod, Matthew A. Thompson, William M. Putman, Claudio M. Santos e Silva, Enio P. Souza   +6 more
doaj   +1 more source

EnKF and expectation‐maximization based parameter estimation of a convective gravity‐wave parameterization using Strateole 2 constant‐level balloon data

Quarterly Journal of the Royal Meteorological Society, EarlyView.
An offline methodology is applied to estimate parameters of a convective gravity‐wave scheme using momentum flux (MF) observations from constant‐level balloons (left panels: pdfs of east and west MFs in green from observations and black from EnKF). The approach integrates an ensemble Kalman filter with an expectation‐maximization algorithm and permits ...
F. Lott, P. Tandeo, M. Pulido, D. Bardet
wiley   +1 more source

Modeling rainfall drop size distribution moments using an S‐band polarimetric radar in complex terrain

Quarterly Journal of the Royal Meteorological Society, EarlyView.
Using S‐band dual‐polarization radar and disdrometers during PRECIP 2022 in Taiwan, we analyze a Mei‐Yu frontal event with widespread stratiform rain and embedded convection. Multiple disdrometers are used to create a novel drop size distribution model for S‐band radars resolving both the drizzle and precipitation modes. The model reveals both inferred
Ian C. Cornejo, Angela K. Rowe, Michael M. Bell, Wei‐Yu Chang   +3 more
wiley   +1 more source