Qiu YangPacific Northwest National Laboratory | PNNL · Atmospheric Sciences and Global Change Division
Qiu Yang
Doctor of Philosophy in Mathematics and Atmospheric Science
About
17
Publications
1,156
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
102
Citations
Citations since 2017
Introduction
My current research focuses on two topics, including 1) studying the multi-scale interactions between mesoscale convective systems and large-scale circulation, and 2) developing the superparameterization version of the Energy Exascale Earth System Model (E3SM).
Publications
Publications (17)
This paper studies the mechanisms behind the multiscale organization of tropical moist convection using a trio of cloud-resolving atmospheric simulations performed in a periodic two-dimensional 32,000-km domain. A simulation with interactive surface fluxes and long-wave radiation over a constant sea surface temperature of 300.15 K produces a planet...
Tropical convection associated with convectively coupled Kelvin waves (CCKWs) is typically organized by an eastward-moving synoptic-scale convective envelope with numerous embedded westward-moving mesoscale disturbances. Such a multiscale structure of tropical convection is a challenge for present-day cloud-resolving simulations and its representat...
Superclusters on the synoptic scale containing mesoscale systems are frequently organized by convectively coupled equatorial waves (CCEWs). Present-day global models struggle to simulate multiscale tropical convection, and the upscale effects of mesoscale systems are not well understood. A simple two-dimensional multiscale model with prescribed two...
The eastern Pacific (EP) intertropical convergence zone (ITCZ) is sometimes observed to break down into several vortices on the synoptic time scale. It is still a challenge for present-day numerical models to simulate the ITCZ breakdown in the baroclinic modes. Also, the upscale impact of the associated mesoscale fluctuations on the planetary-scale...
The eastward-propagating Madden-Julian oscillation (MJO) typically exhibits complex behavior during its passage over the Maritime Continent, sometimes slowly propagating eastward and other times stalling and even terminating there with large amounts of rainfall. This is a huge challenge for present-day numerical models to simulate. One possible rea...
Mesoscale convective systems (MCSs) are the dominant rainfall producer over the U.S. during the warm season, causing natural disasters and severe weather every year. Global climate models have large uncertainty in projecting precipitation changes in the future climate. Here a simple Lagrangian parcel model is used to investigate the impact of globa...
Convective momentum transport (CMT) is the process of vertical redistribution of horizontal momentum by small‐scale turbulent flows from moist convection. Traditional general circulation models (GCMs) and their multiscale modeling framework (MMF) versions poorly represent CMT due to insufficient information of subgrid‐scale flows at each GCM grid....
Plain Language Summary
Convective storm systems that extend over several hundred kilometers are frequently observed and contribute to a majority of the warm season rainfall over the US Great Plains. It is a major challenge for climate models to simulate these storms because the processes governing their initiation and evolution are not well resolve...
Precipitation over tropical oceans rapidly increases when the environmental column saturation fraction (CSF) increases past a critical value of ∼0.7. Past studies suggested that increased stratiform rainfall greatly contributes to the rapid rainfall enhancement. In this study, the sequential roles of non-deep convection, deep convection, and mesosc...
The rapid onset of the South Asian summer monsoon (SASM) is featured as an abrupt increase of rainfall and atmospheric column-integrated moist static energy (MSE). Using convection-permitting simulations, a novel cloud tracking technique, and an MSE budget, the relative roles of mesoscale convective systems (MCSs) and non-MCS deep convection in the...
Mesoscale convective systems (MCSs) account for more than 50% of summer-time precipitation over the central United States (US) and have a significant impact on local weather and hydrologic cycle. It is hypothesized that the inadequate treatment of MCSs is responsible for the longstanding warm and dry bias over the central US in coarse-resolution ge...
The El Niño-Southern Oscillation (ENSO) diversity has a significant impact on global climate and seasonal prediction. However, it is still a challenging problem for present-day global climate models to simulate different types of ENSO events with realistic features simultaneously. In this paper, a tropical stochastic skeleton model for the interact...
Atmospheric convection exhibits distinct spatiotemporal variability at different latitudes. A good understanding of the effects of rotation on the multiscale organization of convection from the mesoscale to synoptic scale to planetary scale is still lacking. Here cloud-resolving simulations with fixed surface fluxes and radiative cooling are implem...
The Madden-Julian oscillation (MJO) typically contains several superclusters and numerous embedded mesoscale convective systems (MCSs). It is hypothesized here that the poorly simulated MJOs in current coarse-resolution global climate models (GCMs) is related to the inadequate treatment of unresolved MCSs. So its parameterization should provide the...
A simple multilayer zonally symmetric model, using a multicloud convective parameterization and coupled to a dynamical bulk atmospheric boundary layer, is used here to simulate boreal summer intraseasonal oscillations (BSISO) in the summer monsoon trough and elucidate the underlying main physical mechanisms responsible for their initiation, propaga...
Westward-propagating 2-day waves with embedded mesoscale disturbances contribute a large portion of synoptic variability of tropical convection over the western Pacific. It is of crucial importance to assess the upscale impact on 2-day waves of these mesoscale disturbances that propagate at various tilt angles. Also, it will be informative to consi...
One of the crucial features of tropical convection is the observed variability on multiple spatiotemporal scales, ranging from cumulus clouds on the daily time scale over a few kilometers to intraseasonal oscillations over planetary scales. The diurnal cycle of tropical convection is a significant process, but its large-scale impact is not well und...
Projects
Project (1)
(1) theoretically predicting the upscale impact of mesoscale convective systems on the large-scale tropical circulation based on multi-scale asymptotic models; (2) diagnostically assessing the eddy flux divergence of momentum and temperature through reanalysis data and numerical models in a hierarchy of complexity; (3) providing practical strategy for parameterization of eddy transport of momentum and temperature in global climate models.
