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GFDL Past Events & Seminars - 2020

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Date Speaker Affiliation Title of Presentation
Jan. 8Lunchtime Seminar Series - Johannes QuaasUniversität Leipzig, Institute for Meteorology, Leipzig University, GermanyProgress in quantifying the effective radiative forcing due to aerosol-cloud interactions
The effective radiative forcing due to aerosol-cloud interaction, ERFaci, is composed of the radiative forcing due to aerosol-cloud interactions, RFaci (Twomey effect) that is the immediate response of cloud albedo to an increase in droplet number concentration, Nd. Previous satellite-based quantifications of this effect were hampered by deficiencies in the retrieval of aerosol and also Nd. The talk will firstly discuss progress in this regard, which leads to a stronger estimated RFaci than previous satellite-based approaches. The other component of ERFaci is in the cloud adjustments. These can be split into adjustments of cloud fraction, f, and liquid water path, L. In terms of the latter, statistical relationships between L and Nd show on average negative adjustments of L (a positive forcing component). In turn, the analysis of ship-, volcano- and industry tracks leads to an estimated small overall effect on L; these results are trustworthy since a cause-effect relation is assured. In terms of the f adjustment, the current results point to an increase in cloud fraction at larger Nd. It is unclear which processes lead to this result. The talk will also briefly discuss how cloud-resolving simulations may help to better understand the remaining uncertainties. In the last part, a brief discussion will be presented on initial steps towards an estimate of the response of cirrus to anthropogenic aerosols.
Jan. 9Formal Seminar - Bob KoppRutgers UniversityLinking climate science, economics, and Big Data to estimate climate change impacts and endogenous adaptation
Understanding the likely global economic impacts of climate change is of tremendous practical value to both policymakers and researchers. Yet the economics literature has struggled both to provide empirically founded estimates of the economic damages from climate change and to provide quantitative insight into what climate change will mean at the local level for diverse populations. The Climate Impact Lab (a collaboration among Rutgers, UC-Berkeley, the University of Chicago, and the Rhodium Group) is advancing a method based on combining: (1) probabilistic simple climate model projections of the global mean response to forcing, downscaled and pattern-scaled based on CMIP-class models to translate global mean to local responses, and (2) empirical econometric estimates of the historical response of human systems to weather variability, derived from massive, standardized data sets and incorporating cross-sectional variability to estimate the benefits and costs of climate adaptation. This talk will focus on the example of temperature-related mortality and associated adaptation using sub-national data from 40 countries. Our results demonstrate that the temperature-related mortality impacts fall disproportionately on low-income populations, with high-income counties projected in the median to experience a decline in mortality through 2100, even under RCP 8.5, although the economic benefits of this decline are outweighed by the costs of adaptation. Even moderate emissions reductions result in substantial benefits, with median projected global mortality risk in RCP 4.5 (SSP 3 Socioeconomics) about 85% lower than that under RCP 8.5. Contact: robert.kopp@rutgers.edu
Jan. 15Lunchtime Seminar Series - Yongfei ZhangAssimilation of sea ice observations in MOM6/SIS2 and prospects for improved summer Arctic sea ice predictions
The seasonal prediction of Arctic sea ice, especially in the summertime, is vital to human activities and environment protections. The lack of constraint on sea ice initial conditions is one of the major hurdles for predicting summer Arctic sea ice several months ahead of time. This study exploits data assimilation (DA) to generate a better sea ice reanalysis and study the potential benefits of a more accurate initial condition. The GFDL Sea-Ice Simulator version 2 (SIS2) is coupled with the GFDL Modular Ocean Model version 6 (MOM6) and forced by a single atmosphere from the JRA-55 reanalysis. We link SIS2 and the data assimilation research testbed (DART) to conduct DA experiments. The sea ice concentration (SIC) observations from NSIDC are assimilated every 5 days from 1982 to 2017 through the Ensemble adjustment Kalman filter (EAKF). Before applying DA, we restore the sea surface temperature (SST) to the daily Optimum Interpolation Sea Surface Temperature (OISST), which improves our model background of SIC and also ameliorates an over-shooting problem arisen from SIC DA. We test the influences of different localization cutoffs, observation errors, and DA frequencies on the results. Our best DA experiment increases the September pan-Arctic sea ice extent (SIE) correlation and better reproduces the decreasing trend of pan-Arctic September SIE. Performances of SIC DA at regional scales are also discussed in our study. At the end of the talk, we show that the improved initial conditions of SIC and SIE have prospects for advancing short-lead time predictions of the summer Arctic sea ice.
Jan. 21Informal Seminar - Daniel McCoyUniversity of Leeds, UKEmpirical constraints on midlatitude cloud feedbacks and aerosol-cloud interactions
Constraining how much the Earth's climate will warm in response to greenhouse gas emissions is one of the primary goals of climate science. Our understanding of clouds and their interactions with their environment represent a central uncertainty in constraining climate sensitivity. I will present research seeking empirical constraints on two features of clouds that substantially impact our ability to constrain climate sensitivity: shortwave cloud feedback and aerosol-cloud interactions (aci). I will focus on the midlatitude regime because it has been shown in recent research to contribute strongly to uncertainty in both effective radiative forcing due to aci (ERFaci), and global-mean cloud feedback in global climate models (GCMs).
Jan. 22David Lindo-AtichatiCollege of Staten Island, CUNYWhat are Eddy fluxes? Biological and Chemical Feedbacks from (and to) the Ocean
Submesoscale and mesoscale eddies are ubiquitous and highly energetic rotating features of ocean circulation. Their influence on biological and biogeochemical processes stem not only from advective transport but also from the generation of variations in the environment, from the microscale to the mesoscale. A multidisciplinary approach involving sampling, remote sensing, and high-resolution modeling is woven through this presentation in an attempt to: 1) bridge long-standing scientific controversies on the signature of eddies on larval-fish distribution, 2) shed light on the transport and fate of underwater hydrocarbon plumes and surface UV filters, and 3) build a paradigm-shift in marine biophysics; quantifying the relationship of eddy activity at the length scale of biological community aggregations, where the collective behavior and motion of marine animal might also be relevant to the large scale driven motion of eddies.
Jan. 22Chris Bretherton and Oli FuherVulcan Inc., and University of WashingtonThe Vulcan Climate Modeling/GFDL collaboration: First and next steps toward using convection-resolving global SHiELD simulations to train machine learning parameterizations for moist physics in coarser-resolution versions of FV3-GFS
10-10:30 Chris: Vulcan/GFDL project Machine Learning (ML) overview 10:30-11 Oli: Vulcan/GFDL project Domain Specific Language (DSL) overview 11-11:30: DSL discussion 11:30-noon: ML discussion
Jan. 23Formal Seminar - Kyle ArmourUniversity of Washington An update on the pattern effect and its confounding role in estimates of equilibrium climate sensitivity
I'll give an overview of recent work on how radiative feedbacks depend on the spatial pattern of sea-surface temperature (SST) - the so-called 'pattern effect' - and how this dependence confounds our estimates of equilibrium climate sensitivity (ECS) from both instrumental and proxy records. New modeling and observational analyses, such as the use of localized warming patch simulations and the use of satellite observations, provide clarity on the key regions and mechanisms linking radiative feedbacks to SST patterns. New analyses using CMIP5 and CMIP6 models quantify how radiative feedbacks will change as warming patterns evolve in the future, but large uncertainty remains, implying that the historical record currently provides limited information about the upper bound of ECS. It has been suggested that the paleoclimate proxy record may thus provide our strongest constraints on ECS, but the role of SST patterns in the radiative feedbacks estimated from past climate states has not yet been accounted for. I will describe preliminary work to estimate the importance of the pattern effect in the context of the Last Glacial Maximum and the Pliocene. Speakers Email: karmour@uw.edu
Jan. 28Seung Hun BaekColumbia UniversityCharacterizing the Oceanic and Atmospheric Drivers of Spatially Widespread Droughts over the Contiguous United States
Droughts that achieve extreme spatial extent over the contiguous United States (herein pan-CONUS droughts) pose unique challenges because of their potential to strain multiple water resources simultaneously. Understanding the causes of these extreme droughts is critical given the significant financial damages of these droughts: pan-CONUS droughts in 1988 and 2012, for instance, cost an estimated $40 and $30 billion, respectively. The canonical understanding of oceanic influences on North American hydroclimate would suggest that pan-CONUS droughts are forced by a contemporaneous cold tropical Pacific Ocean and warm tropical Atlantic Ocean. However, analyses using mechanism-denial climate model simulations, observations, and paleoclimate reconstructions demonstrate this not to be the case. The contributions of oceanic and atmospheric variability to pan-CONUS droughts are first investigated using three 16-member ensembles atmospheric models forced with observed sea surface temperatures (SST) from 1856 to 2012. The employed SST forcing fields are either (i) global or restricted to the (ii) tropical Pacific or (iii) tropical Atlantic to isolate the impacts of these two ocean regions on pan-CONUS droughts. Model results show that SST forcing of pan-CONUS droughts originates almost entirely from the tropical Pacific because of atmospheric highs from the northern Pacific to eastern North America established by La Niña conditions, with little contribution from the tropical Atlantic. Notably, in all three model configurations, internal atmospheric variability influences pan-CONUS drought occurrence by as much or more than the ocean forcing and can alone cause pan-CONUS droughts by establishing a dominant high centered over the US Montane West. Model results are compared to and reconciled with the observational record. A millennium-length (850 - 1850 C.E.) perspective on the causes of pan-CONUS droughts is also provided using a new paleo reconstruction product that merges climate model information with multiple climate proxies (including tree rings, ice cores, and corals). Composite analyses show robust association between pan-CONUS drought events and cold tropical Pacific conditions, but not with warm Atlantic conditions. Similarly, self-organizing map analyses shows that pan-CONUS drought years are most commonly associated with a global SST patterns displaying strong La Niña and cold Atlantic conditions. These results show that La Niña events in the tropical Pacific are the principal oceanic influence on pan-CONUS droughts, while variability in the Atlantic has not played a significant role; the oceanic drivers over the paleo record are thus consistent with the model-based findings over the observational record.
Jan. 29Lunchtime Seminar Series - John Krasting, Wenhao Dong and Tom JacksonGFDL, UCAR and SAIC respectivelyAn Introduction to the NOAA Model Diagnostics Task Force (MDTF) Analysis Package and Application to GFDL Model Output
Despite decades of research and significant advancements in resolution and complexity, global climate models (GCMs) still suffer from persistent and often common biases that contribute to uncertainty in their projections of weather and climate. The climate and weather forecasting communities have great interest in improving these biases and have sought to better understand the causes and consequences of these long-standing biases. Among these efforts are the development of process-oriented diagnostics (PODs). A POD characterizes a specific physical process or emergent behavior that is found to be closely related to the ability to simulate an observed phenomenon. Applying these designed PODs routinely on model output -- especially in the context of model development -- could lead to improvements aimed at alleviating these model biases. This talk will first describe outcomes of activities by the NOAA Modeling, Analysis, Prediction, and Projections Program (MAPP) Model Diagnostic Task Force (MDTF). The MDTF Diagnostics effort, currently led by the GFDL, builds on prior existing community efforts aimed at developing process-oriented diagnostics. It provides an open-source analysis package that is portable, extensible, and usable to aid the application of PODs to the model development process. Application of this package to three latest GFDL models (i.e. AM4, CM4, and ESM4) will be presented as examples on initial steps towards an evaluation of our model performance and a verification of the capacity and efficiency of the diagnostic package. In the second part, a hands-on training on the use and application of the package will be provided.
Jan. 30Formal Seminar - Gerard RoeUniversity of WashingtonEnergetic and heat-engine constraints on the spatial patterns of climate and climate change
The climate system operates as a thermodynamic heat engine. A surplus of energy in the tropics and a deficit of energy in the high latitudes must be balanced with a poleward transport of energy by atmospheric and oceanic motions that ultimately do work against frictional dissipation. Sadi Carnot understood as much when formulating the laws of thermodynamics in the early nineteenth century. Atmospheric motions carry approximately eighty percent of the maximum poleward energy transport, and latent heat in the form of water vapor is a crucial component of this transport. Thus, the climatic patterns of temperature, evaporation, precipitation, the isotopic composition of water vapor, and even natural aerosols, are all linked through this transport. Recent research has demonstrated that atmospheric energy transport can be usefully approximated as a linear down-gradient transport of moist enthalpy. This single simple rule for transport explains many features of the mean climate, the predicted climate changes under global warming, and the spread of uncertainty among numerical climate models. Among these features are: polar amplification; the poleward migration of the subtropics, storm tracks, and jet stream under warming; uncertainty in model predictions maximizing in polar regions; hydrologic change as a function of climate state; and the sensitivity of the isotopic composition of precipitation to climate change. Speaker email: gerard@ess.washington.edu
Jan. 31Gerard RoeUniversity of WashingtonCentennial glacier retreat as categorical evidence of regional climate change
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Feb. 5Lunchtime Seminar Series - William KuoUniversity Corporation for Atmospheric Research, Boulder, U.S.A. (UCAR)Impact of Radio Occultation Data on the prediction of Tropical Cyclogenesis
Tropical cyclones are one of the most devastating severe weather systems that are responsible for huge loss of lives and properties every year. Accurate prediction of tropical cyclogenesis by numerical models has been a significant challenge, largely because of the lack of observations over the tropical oceans. The atmospheric limb sounding technique, which makes use of radio signals transmitted by global navigation satellite systems (GNSS), has evolved as a robust global observing system. This technique, known as radio occultation (RO) can provide valuable water vapor and temperature observations for the analysis and prediction of tropical cyclogenesis. Using the WRF modeling and data assimilation system, we show that the assimilation of RO data can substantially improve the skills of the model in predicting the tropical cyclogenesis for ten typhoon cases that took place over the Western Pacific from 2008 to 2010. To gain insight on the impact of GPS RO data assimilation, we perform a detailed analysis of the formation process of Typhoon Nuri (2008), and examine how the assimilation of the GPS RO data enables the model to capture the cyclogenesis. The joint Taiwan-U.S. COSMIC-II mission was launched in June 2019. It is currently going through check-out phase, and will provide 5,000 GPS RO data per day over the tropics when it is fully operational. This will provide a great opportunity for research and operational prediction of tropical cyclogenesis. Host: Leo Donner
Feb. 6Formal Seminar - Kevin ReedStony Brook UniversityDetecting climate change impacts on extreme weather
The next century will see unprecedented changes to the climate system with direct consequences for society. As stated in the National Climate Assessment, "changes in extreme weather events are the primary way that most people experience climate change." In this sense, the characteristics of extreme weather are key indicators of climate change impacts, at both local and regional scales. Understanding potential changes in the location, intensity and structure of such extremes (e.g., tropical cyclones and flooding) is crucial in planning for future adaptation as these events have large economic and social costs. The goal of this work is to better understand climate impacts on extreme weather events in various high-resolution configurations of the Community Atmosphere Model (CAM) run at horizontal grid spacings of approximately 28 km and forced with prescribed sea-surface temperatures and greenhouse gas concentrations for past, present, and future climates. This analysis will include the evaluation of conventional (AMIP-style) decadal simulations typical of climate models, short 7-day ensemble hindcasts of recent devastating events (e.g., Hurricane Florence in 2018), and reduced complexity simulations of idealized states of the climate system. Through this hierarchical modeling approach the impact of climate change on the characteristics (frequency, intensity, rainfall, etc.) of extreme weather, including tropical cyclones, can be quantified. Speaker Email: kevin.a.reed@stonybrook.edu
Feb. 7Informal Seminar - Pavel BerloffImperial College of LondonSome novel approaches for parameterizing mesoscale eddies
This talk focuses on some new approaches for parameterizing oceanic mesoscale eddy effects for use in non-eddy-resolving and eddy-permitting general circulation models. The context is provided in terms of discussing the existing ideas and problems with their realizations. Specific example of eddy-rich eastward jet extensions of western boundary currents and their adjacent recirculation zones is considered in the classical multi-layer quasigeostrophic model of the wind-driven midlatitude circulation. First, the key dynamical mechanism operating in the eddy-resolving model and maintaining the eastward jet is identified as the ''eddy backscatter'', which is based on persistent and positive time-lag correlations between the transient part of the nonlinear eddy forcing and the large-scale flow response. Second, this mechanism has to be ultimately parameterized, and discussing how this can be done is the main part of the talk. We will systematically (but not too technically) discuss 4 different, novel parameterization approaches, which are complimentary to the existing ones: (1) direct stochastic forcing (DSF); (2) implicit stochastic footprints (ISF); (3) data-driven eddy emulations (DEE); and (4) local eddy amplification (LEA). DSF approach explicitly adds statistically constrained stochastic forcing to the coarse model. ISF approach imposes statistically constrained stochastic forcing on an intermediate-complexity eddy-resolving model, obtains its nonlinear response in terms of the coarse-grained footprint, and then imposes local footprints on the coarse model. DEE approach emulates eddies via multi-layer nonlinear regression, then feeds them to the deterministic eddy forcing operator coupled to the large-scale flow fields, and adds the resulting forcing to the coarse model. LEA approach interactively identifies eddies and amplifies them locally and in a simple way --- this is the simplest and also most practical approach for the present state of modelling. Relative strengths and weaknesses of these approaches, as well as some future developments will be also discussed.
Feb. 10Informal Seminar - Rebecca BeadlingU of ArizonaSimulation of large-scale circulation and properties in the North Atlantic and Southern Ocean in coupled climate models
The global oceans act as a mediator of Earth's climate due to their role in the storage of heat and carbon. Presently, the oceans account for the storage of approximately 93% of the anthropogenic heat on our planet and ~27% of the anthropogenic CO2. Two regions in particular, the Southern and North Atlantic Ocean (SO,NA), act as gateways for the exchange of CO2 and heat between the atmosphere and the interior ocean, due to the unique deep and intermediate water formation processes that occur here. Large uncertainty exists with respect to understanding how the ocean circulation patterns and properties are projected to change in these regions throughout the 21st century. One avenue of reducing projection uncertainty is through improved representation of ocean circulation and properties in these regions in historical simulations relative to the observational record and through the interpretation of projected trends with knowledge of mean state biases. In the subtropical NA, a key region through which properties from the tropics are advected to the subpolar latitudes, the volume transports of the major flow regimes are reasonably represented in many CMIP5 models relative that observed by the RAPID array at 26oN. As the climate warms, the NA subtropical gyre is weakened in response to a reduced wind stress curl, which acts as a source of significant additional weakening to the northward western boundary current flow. In the SO, despite its dominant role in the oceanic uptake of anthropogenic carbon and heat relative to other basins, the large-scale circulation and properties have been poorly represented in climate models, resulting in low confidence ascribed to 21st century projections of the state of the SO. A comprehensive assessment performed across ensembles of models contributed to the past three CMIP generations (CMIP3 - CMIP6) show improved representation of key observable-metrics in this region including surface wind stress and wind stress curl, strength of the ACC, and density gradients in the region of the ACC. However, some persistent biases have carried over into CMIP6 including an upper ocean that remains too fresh and too warm, significant warm biases at depth in several simulations, and a poor representation of Antarctic sea ice extent. These biases in observable metrics need to be considered when interpreting projected trends or biogeochemical properties in this region.
Feb. 12Lunchtime Seminar Series -Prof Jan ZikaUniversity of New South Wales, Sydney, AustraliaChanges in ocean water masses reveal the distribution of excess heat in the climate system
Over 90% of the excess heat trapped in the earth system is contained in the ocean and the consequent thermal expansion was the largest contributor to sea level rise in recent decades. Since 2006 ocean warming and hence sea level rise has been spatially heterogenous, with some regions such as the Southern Ocean showing intense warming and others such as the sub-polar North Atlantic showing intense cooling. This heterogeneity may be due to spatial variability in the rate at which heat added to the ocean at the sea surface propagates into the ocean interior or to changes in circulation which redistribute the existing heat reservoirs within the ocean. However, the importance of these two mechanisms at a regional scale is unclear. Here we show that the spatial variability in warming and sea level rise is dominated by changes in ocean circulation. In some regions the redistribution term is 10 times larger than the excess heat component which is distributed much more homogenously across the oceans. In the North Atlantic, substantial excess heat uptake is balanced by cooling due to redistribution associated with a slowdown in the Atlantic Meridional Overturning Circulation. Both circulation change and heat uptake drive intense warming in the Southern Ocean with an anomalous poleward heat transport of 118 ±50 PW the largest effect. Our results suggest near term projections of sea level change will hinge on understanding and predicting changes in ocean circulation. Host: Steve Griffies
Feb. 13Formal Seminar - Ron KwokNASA JPLChanges in Arctic Ocean sea-ice thickness, volume, and multiyear ice coverage: A record from multiple sources
In parallel to the widely reported decline in Arctic ice extent, there have also been dramatic losses in sea ice thickness and volume, and in multiyear sea ice coverage. Instead of a relatively a consistent satellite record from passive microwave radiometers, assessments of large-scale decadal changes in thickness, volume, and multiyear sea ice coverage are dependent on observations from multiple sources: submarine and airborne surveys, and satellite altimetry and scatterometry. The submarine ice draft record spans the period between 1958 and 2000, the satellite altimeter records of thickness estimates between 2003 and 2018, and the scatterometer records of multiyear sea ice coverage between 1999 and present. Even though there is sometimes sparse sampling (in space and time), lack of consistency in measurement approaches and continuity in individual records, these datasets broadly depict an ice cover that has thinned everywhere and a multiyear sea ice cover that is rapidly thinning. The recently launched ICESat-2, equipped with a photon counting altimeter, adds to the record of thickness and volume estimates. I will discuss the multi-decadal record trends and highlight the potential contribution ¬ ¬of this unique ICESat-2 instrument - with examples from recent results - to various aspects of cryospheric science and oceanography of the ice-covered oceans. Speakers email: ronald.kwok@jpl.nasa.gov
Feb. 18Informal Seminar - Rei ChemkeColumbia UniversityRecent atmospheric circulation trends: two major flaws in reanalyses and in climate models
The weakening of the Hadley cell and of the midlatitude eddy heat fluxes are two of the most robust responses of the atmospheric circulation to increasing concentrations of greenhouse gases. These changes have important global climatic impacts, as the large-scale circulation acts to transfer heat and moisture from the tropics to polar regions. Here, we examine Hadley cell and eddy heat flux trends in recent decades: contrasting model simulations with reanalyses, we uncover two important flaws -- one in the reanalyses and other in the model simulations -- that have, to date, gone largely unnoticed. First, we find that while climate models simulate a weakening of the Hadley cell over the past four decades, most atmospheric reanalyses indicate a considerable strengthening. Interestingly, that discrepancy does not stem from biases in climate models, but appears to be related to artifacts in the representation of latent heating in the reanalyses. This suggests that when dealing with the divergent part of the large-scale circulation, reanalyses may be fundamentally unreliable for the calculation of trends, even for trends spanning several decades. Second, we examine recent trends in eddy heat fluxes at midlatitudes, which are directly linked to the equator-to-pole temperature gradient. In the Northern Hemisphere models and reanalyses are in good agreement, and show a robust weakening that has emerged from the internal variability around the year 2000, and we attribute it to increasing greenhouse gases. In the Southern Hemisphere, however, models disagree on the trends while reanalyses indicate a robust strengthening. In this case, the flaw is found to be with the climate models, which are unable to simulate the observed multidecadal cooling of the Southern Ocean at high-latitudes, and the accompanying increase in sea ice. While the biases in modeled Antarctic sea ice trends have been widely reported, our results demonstrates that such biases have important implications well beyond the high Southern latitudes, as they impact the equator-to-pole temperature and, as a consequence, the midlatitude atmospheric circulation.
Feb. 25Informal Seminar - Youngji Joh (postdoc candidate)Georgia Institute of TechnologyCouplings in the Pacific in a changing climate: Theories, Observations, and Models
Pacific climate and weather extremes including heatwaves, drought, and hydrological hazard, which drive significant impact on the U.S. community and thus have been paid great attention, are dynamically linked to not only local air-sea interactions, but also large-scale climate variability (e.g., Pacific decadal variability and El Niño Southern Oscillation). This study aims at improving the theories of climate coupling within the North Pacific and across to the central tropical Pacific with investigating their response to anthropogenic forcing. Using multiple observational reanalyses and global climate model ensembles, we first show that winter ocean temperature extremes over the Northeast Pacific significantly resemble the representations of the North Pacific decadal variability (e.g., North Pacific Gyre Oscillation, NPGO and Pacific Decadal Oscillation, PDO). We find that the multi-year warm anomalies in the Northeast Pacific are associated with the consecutive occurrences of NPGO-like and PDO-like ocean signatures via ENSO atmospheric teleconnections. The results suggest that the increasing coupling between NPGO and PDO leads to the prolonged North Pacific marine heatwaves, and those warm events are becoming stronger in amplitude with a larger area under anthropogenic forcing. Combining satellite data with several observation reanalysis products, we next offer observational evidence revealing that a preferred decadal timescale (~10yrs) in the North Pacific western boundary current system, the Kuroshio Extension (KE) region, may arise from an interaction with the central tropical Pacific (CP) (e.g., CP-ENSO). The results show that the KE decadal dynamic state can drive a persistent downstream wind stress curl that projects on atmospheric forcing of the CP-ENSO, which in turn excites westward oceanic Rossby waves in the central North Pacific that reach the western boundary back. Consistent with this hypothesis, the cross-correlation function between the KE and CP-ENSO indices exhibits a significant sinusoidal shape corresponding to a preferred spectral power at 10yrs. Using high-resolution coupled climate models, we finally show that the decadal KE dynamics are not independent of the central tropics and their coupling is becoming stronger under anthropogenic forcing. The results suggest that a higher amplitude quasi-decadal KE/CP-ENSO sequence under warmer climate may allow a stronger basis for decadal predictions of Pacific climate variability, further for societally relevant biogeochemical quantities (e.g., salinity, oxygen, and chlorophyll-A) and fisheries.