Currently, I am developing
a cloud scale model that can be used to study aerosol - cloud interactions which have a major role in the climate change.
Not exact matches
Oracle has said it runs its data centers on Oracle Exadata servers, which are turbocharged machines that differ fundamentally from the bare - bones servers that other public
cloud providers deploy by the hundreds of thousands in what is called a
scale - out
model.
Included in the new data are finer -
scale cloud processes than have been available in previous climate
models.
In fact,
cloud and mesoscale, or medium -
scale, processes in the atmosphere are among the biggest uncertainties in today's climate
models, Rasmussen said.
Unfortunately, many of these
cloud properties must be estimated through parameterization, a technique used to represent complex small -
scale systems, because climate
model resolution is too coarse to resolve small -
scale cloud features.
Because small -
scale climate features, such as
clouds and atmospheric aerosol particles, have a large impact on global climate, it's important to improve the methods used to represent those climate features in the
models.
What's Next: PNNL scientists are using a regional
model at a much finer
scale than conventional climate
models to understand the processes that determine the time -
scales of MJO and the roles of various types of
clouds in its energy cycle.
These programs focus on climate, aerosol and
cloud physics; global and regional
scale modeling; integrated assessment of global change; and complex regional meteorology and chemistry.
He has had a central role in PNNL's global aerosol, chemistry, and climate
modeling, and in
modeling studies of aerosols and
cloud - aerosol interactions at local and regional
scales.
Tompkins, A., 2002: A prognostic parameterization for the subgrid -
scale variability of water vapor and
clouds in large -
scale models and its use to diagnose
cloud cover.
Within the integrated Earth system science paradigm, our major research thrusts include the physics and chemistry of aerosols,
clouds and precipitation; integrating our understanding of climate, energy, and other human and natural systems through the development and application of
models that span a wide range of spatial
scales; and determining the impacts of and informing responses to climate and other global and regional environmental changes.
The workshop, building on the knowledge and practical skills acquired during the school, aims to bring together expertise on large -
scale atmospheric and oceanic dynamics, small
scale cloud and precipitation processes, hierarchical climate
modeling and observation.
This session invites both
modeling and observational presentations, from
cloud -
scale understandings to large -
scale circulation and moisture feedback.
Earth system
models integrate atmospheric, oceanic, chemical, and biological processes, many of which are too complex or occur at
scales too small to simulate directly (e.g., formation of individual
clouds).
Aerosols and
cloud processes vary on much smaller time and space
scales than climate
models can simulate.
-- These storms should penetrate higher as climate warms according to the
models, a positive feedback, and satellite data looking at
cloud height changes over El Nino time
scales show something similar and show the
models getting that about right also, for physical reasons we think we understand
The response of low
clouds to warming is uncertain because the dynamics governing low
clouds occur on
scales of tens of meters, whereas climate
models have horizontal grid spacings of 50 — 100 km (see the sketch at the top).
Studies with climate
models have noted that the ITCZ width depends on interactions between radiation and
clouds (Voigt & Shaw 2015) and how the
model represents sub-grid
scale convection (Kang et al. 2009), but a physical understanding of why the ITCZ width is affected by these processes is lacking.
Pressel, K. G., S. Mishra, T. Schneider, C. M. Kaul, Z. Tan, 2017: Numerics and subgrid -
scale modeling in large eddy simulations of stratocumulus
clouds.
Instead,
clouds are represented through parameterizations that link their unresolvable small -
scale dynamics to properties (temperature, humidity etc.) on the
models» grid
scale.
This uncertainty is attributable to the inadequate resolution of climate
models for resolving the small -
scale turbulent dynamics of MBL
clouds.
To answer such questions, we analyze observational data and perform systematic studies with numerical
models, with which we simulate flows ranging from the meter -
scale motions in
clouds to global circulations.
Climate
models can not simulate
clouds explicitly because their dynamic
scales (10 - 100 m) are much smaller than typical length
scales of climate
model grid boxes (25 - 100 km).
(Phys.org)-- The first study that combines different
scales —
cloud - sized and earth - sized — in one
model to simulate the effects of Asian pollution on the Pacific storm track shows that Asian pollution can influence weather...
Restricting 32 — 128 km horizontal
scales hardly affects the MJO in the Superparameterized Community Atmosphere
Model v. 3.0 but the number of
cloud - resolving grid columns constrains vertical mixing, Journal of Advances in
Modeling Earth Systems, 06, doi: 10.1002 / 2014MS000340.
The effect of large -
scale model time step and multiscale coupling frequency on
cloud climatology, vertical structure, and rainfall extremes in a superparameterized global climate
model.
In this paper we explore the effect of reducing the large -
scale model time step, which has the byproduct of increasing the frequency with which the planetary vs.
cloud resolving
scales are allowed to interact.
«Climate
model errors are dominated by errors in fast physical processes on the sub-grid
scale such as the ones related to
clouds.»
Earth system
models integrate atmospheric, oceanic, chemical, and biological processes, many of which are too complex or occur at
scales too small to simulate directly (e.g., formation of individual
clouds).
The meeting will mainly cover the following themes, but can include other topics related to understanding and
modelling the atmosphere: ● Surface drag and momentum transport: orographic drag, convective momentum transport ● Processes relevant for polar prediction: stable boundary layers, mixed - phase
clouds ● Shallow and deep convection: stochasticity,
scale - awareness, organization, grey zone issues ●
Clouds and circulation feedbacks: boundary - layer
clouds, CFMIP, cirrus ● Microphysics and aerosol -
cloud interactions: microphysical observations, parameterization, process studies on aerosol -
cloud interactions ● Radiation: circulation coupling; interaction between radiation and
clouds ● Land - atmosphere interactions: Role of land processes (snow, soil moisture, soil temperature, and vegetation) in sub-seasonal to seasonal (S2S) prediction ● Physics - dynamics coupling: numerical methods,
scale - separation and grey - zone, thermodynamic consistency ● Next generation
model development: the challenge of exascale, dynamical core developments, regional refinement, super-parametrization ● High Impact and Extreme Weather: role of convective
scale models; ensembles; relevant challenges for
model development
We use the large - eddy simulation code PyCLES to simulate the dynamics of
clouds and boundary layers, to elucidate their response to climate changes, and to develop closure schemes for representing their smaller -
scale dynamics in larger -
scale climate and weather forecasting
models.
(Note: the biggest issue is climate sensitivity, with a secondary issue being the magnitude of modes of natural internal variability on multi-decadal time
scales, and tertiary issues associated
model inadequacies in dealing with aerosol -
cloud processes and solar indirect effects.)
This
model could be used as a starting point in the development of a GCM parameterization of a the ice mixing - ratio probability distribution function and
cloud amount, if a means of diagnosing the depth of the saturated layer and the standard deviation of
cloud depth from basic large -
scale meterological parameters could be determined.
The missing variability in the
models highlights the critical need to improve
cloud modeling in the tropics so that prediction of tropical climate on interannual and decadal time
scales can be improved.»
In fact,
cloud and mesoscale, or medium -
scale, processes in the atmosphere are among the biggest uncertainties in today's climate
models, Rasmussen said.
Included in the new data are finer -
scale cloud processes than have been available in previous climate
models.
We also have to simplify our
models of many processes which occur at very small
scales, such as
cloud formation.
The parameterization is intended for application in large -
scale atmospheric and
cloud models that can predict 1) the supersaturation of water vapor, which requires a representation of vertical velocity on the
cloud scale, and 2) concentrations of a variety of insoluble aerosol species.
Erl Happ (19:22:39): I am fumbling like everyone else This might help: http://www.leif.org/research/2008GL035673.pdf
Cloud radiative effect on tropical troposphere to stratosphere transport represented in a large -
scale model
Nonetheless our understanding of aerosol -
cloud interactions is incomplete, and what is well - understood, is incompletely represented in large -
scale models.
Recent efforts to consistently address both types of
cloud representations represent a significant advance in large
scale -
modelling (Jacobson, 2003; Lohmann, 2008; Suzuki et al., 2008).
Although today's state - of - the - art
models accurately depict many physical processes, they are deficient in several respects, owing to difficulties in representing small -
scale processes, such as those associated with
clouds.
To improve the representation of sub-grid convective transport and wet deposition in large -
scale models, general characteristics, such as species mass flux, from the high resolution
cloud chemistry
models can be used.
But we know that the mechanisms responsible for the variation of Ts are different in internal variability on these time
scales and in forced climate change, then my questions is that: is it possible that the spread in ECS might not be so directly caused by low -
cloud feedback, although the low
cloud feedback is a very good indictor for the
model uncertainty?
This approach, described in a recent article in the journal Geoscientific
Model Development, improves the way
models represent atmospheric particles,
clouds, and particle -
cloud interactions and how they vary at regional and local
scales.
They will focus on simulations that explore how the
scale of the
model affects
clouds and atmospheric particles in different climate regimes.
Today she is an inspired investigator of severe storms, as well as an ascendant expert in
modeling cloud - aerosol interactions at the process
scale.
My own objection to acting on current climate
models is that the obvious major contributors,
clouds and aerosols, are not being addressed on a
scale commensurate with their dominance of the overall problem.
Additionally, climatological
models, which incorporate CCN generation mechanisms and
cloud microphysics, fail to produce significant change in global -
scale CCN populations,
cloud optical properties, or radiative forcing (Snow - Kropla et al. 2011; Dunne et al. 2012; Kazil et al. 2012).
This
scale factor was based on simulations with an early climate
model [3,92]; comparable forcings are found in other
models (e.g. see discussion in [93]-RRB-, but results depend on
cloud representations, assumed ice albedo and other factors; so the uncertainty is difficult to quantify.