Sources of uncertainty in climate projections and their relative importance for different variables and regions.
Large Ensemble model simulations help to better quantify sources of uncertainty in climate projections

A new collection of single model initial-condition large ensembles (SMILEs) can test statistical assumptions with a cleaner separation between sources of uncertainty in climate projections. In particular, the potential bias at regional scales or for variables with a lot of internal variability can be greatly reduced.

Time of emergence of the anthropogenic signal in storm-related extreme sea level at New York in the GFDL CM4 simulations.
Elevated storm surge differs in origin along the US East and Gulf Coasts

Yin and coauthors use the new GFDL CM4 and CM4HR models to consider a series of climate change experiments under the CMIP6 protocol to study characteristics of extreme sea level events and their future evolution in a fully coupled weather, climate, sea level, and storm surge modeling system. They found that even in the absence of global warming, the Gulf Coast is most vulnerable to hurricane-induced storm surge.

A schematic of the transport structure across the Labrador Sea
Density compensation minimizes the impact of the Labrador Sea convection to the AMOC

Zou and coauthors analyzed the transport and property fields across the Labrador Sea using OSNAP observations and an ocean reanalysis dataset GloSea5 to study why recent observations revealed minimal contribution of the Labrador Sea convection to the subpolar AMOC strength. They found that the density compensation has important consequences on the strength of the overturning circulation.

Efficacy of tropical width perturbations versus normalized extratropical static stability
Tropical belt width proportionately more sensitive to aerosols than greenhouse gases

Internal variability and anthropogenic forcing have contributed to the widening of the tropical belt during the last several decades. To better understand the effect of individual anthropogenic drivers (including aerosols) on the tropical belt, Zhao, Allen, and coauthors utilize idealized simulations with very large single forcing perturbations in comprehensive coupled ocean-atmosphere models from the PDRMIP.

Zonally averaged multi-model average shortwave low cloud feedbacks
Latest Earth System Models predict more global warming than their predecessors

Zelinka and coauthors compared ECS values derived from CO2 quadrupling experiments conducted with CMIP6 and CMIP5 models and found that the latest models warm more than their predecessors by about 0.5˚C. The primary culprit for the enhanced warming was shown to be clouds.

Mean 2014-2016 sea surface temperature anomaly (SSTa) in the Northeast Pacific
Diverse processes driving a heatwave’s evolution result in conditional forecast skill for the US West Coast

A recent study explored sea surface temperature anomaly forecasts from an ensemble of eight global climate prediction systems contributing to NMME and found that predictability of warm temperature anomalies off the US West Coast was conditional on which process was driving the temperature anomalies in different phases of the heatwave.

Welcome to the US Climate Variability and Predictability Program

Current and Emerging Developments in Subseasonal to Decadal Prediction

Current and Emerging Developments in Subseasonal to Decadal Prediction
Recently published in BAMS, "Current and Emerging Developments in Subseasonal to Decadal Prediction" outlines commonalities in the prediction of weather and climate across time scales and Earth system components, and through the value cycle from basic research to operational delivery.

CLIVAR-relevant sessions at 2020 AGU Fall Meeting

AGU Fall Meeting

The 2020 AGU Fall Meeting will be held from December 7-11 virtually (mostly), in San Francisco (possibly), and in other regional hubs (if it is safe). In preparation for the meeting, we have compiled a list of sessions and town halls that are relevant to the community and organized by our Panels, Working Groups, and community members. The list of sessions is not intended to be exhaustive but to help digest the collection of the hundreds of sessions and events. Abstract submissions are due July 29, 2020.

NEW DATES - Multi-Year Workshop

Multi-Year Workshop

The Workshop on Societally-Relevant Multi-Year Climate Predictions is now rescheduled for June 2-4, 2021. The plan is to hold this as an in-person meeting with opportunity for remote participation for those unable to travel. Registration and poster abstract submission will open again this fall for additional participants.

AMOC Webinar Series

AMOC Webinar Series

US AMOC and UK RAPID have organized a webinar series to share summaries of the papers published in the AGU special collection with the broad international ocean and climate science community. The webinars are held on the third Thursday of every month @ 11am EDT/4pm BST.

NEW DATES - US AMOC Science Team Meeting

US AMOC Science Team Meeting

Save the new dates for the US AMOC Science Team Meeting, scheduled for April 12-15, 2021 in Woods Hole, MA. Now in its final year, the Science Team invites colleagues from the US and international community to review progress over the past decade in observing, modeling, understanding, and predicting AMOC and to identify remaining priorities to guide future international collaborations in the decade ahead. Registration and abstract submission will open this fall.

NEW DATES - Arctic Circulation Workshop

Arctic Circulation Workshop

Mark your calendars with the new dates for the Workshop on Observing, Modeling, and Understanding the Circulation of the Arctic Ocean and Sub-Arctic Seas to be held July 12-15, 2021 in Seattle, Washington. The organizing committee will initiate an online topical community discussion this summer to share perspectives in advance of the workshop. Registration and abstract submission will open this winter.

CLIVAR-relevant meetings and workshop status

Coronavirus news

We have compiled a list of relevant meetings and workshops and their status as we all grapple with the fast-changing evolution of the Coronavirus (COVID-19) outbreak and the governmental, organizational, and personal decisions that are affecting our work lives. The list is not intended to be exhaustive and status of these events may change at any time.