We will start by looking at the beginnning.

This is the WMO bulletin from 2009 Addressing climate information needs at the regional level: the CORDEX framework.

The World Climate Research Programme (WCRP) in 2008 created the Task Force on Regional Climate Downscaling (TFRCD), chaired by Filippo Giorgi and Colin Jones. CORDEX was then initiated in 2009 at a meeting in Toulouse.

Before the start of CORDEX there were some skeptical attitudes. William Gutowski, former member of the Science Advisory Team (SAT) and later SAT co-chair, describes what it was like during a meeting:

“I was at a meeting on one WCRP working group, presenting plans for a regional climate modeling assessment program, when one member of the working group stated that regional climate modeling is mathematically ill-posed (and therefore invalid). I could not remember at the time what that meant, but I later dug around to find that a mathematically well-posed problem has a unique solution to the conditions supplied and the solution varies continuously with smooth changes in those conditions. That would then mean that climate simulation with global models is ill-posed, because for many values of the solar constant (the primary boundary condition), Earth has two stable solutions: our contemporary climate and an Ice-covered Earth. Moreover, as the solar constant varies, Earth’s climate can potentially jump discontinuously from one of those climates to the other. This anecdote is an example of the high skepticism we encountered early on, despite all the validation work that had already been occurring with RCMs.”

In response to this earlier skepticism we can today underline the fact that the CORDEX user community is large and continuously growing.

The first International Conference on the Coordinated Regional Climate Downscaling Experiment – CORDEX – was held in Trieste, Italy 21-26 March, 2011. It was devoted to a review of the status and main issues of the CORDEX initiative over the various CORDEX domains. Special sessions were devoted to the Africa domain and to the assessment of the first multi-model CORDEX simulations over this region.

Following the pioneering and successful work of the Task Force on Regional Climate Downscaling (TFRCD) which mandate ended in 2011, the WCRP established a CORDEX Science Advisory Team in 2012. In 2013 CORDEX had 13 domains and was still growing!

There was a call for an International Project Office during 2014 and at the end of the year the office opened at SMHI, in Norrkoping, Sweden. The first Director was Eleanor O’Rourke and these are her memories of CORDEX:

“I became involved in CORDEX in around 2013 helping to support some of the communication activities and events, including the ICRC- CORDEX2013 in Brussels. In 2014 discussions intensified on the need for an International Project Office for CORDEX (IPOC) given the expanding and diverse activities. Given SMHI’s strong contribution and interest in CORDEX, a bid was made to host the new IPOC and was successful. I was delighted to be selected as the founding Director and the IPOC kicked off in January 2015 with the second CORDEX-SAT meeting taking place in Norrkoping in February 2015 (photo below of everyone trying not to look too cold!).

I immensely enjoyed working with everyone in the CORDEX community as it is so diverse, enthusiastic and knowledgeable with a very clear connection to the real world impacts. I was privileged to travel to CORDEX domain meetings in Bogota, Johannesburg, and Manila – experiences, and people, I will never forget.

In terms of achievements, it is all down to the amazing CORDEX community, but seeing some of the results of funding I secured to support CORDEX Africa presented at the WCRP OSC in Kigali during my time as IPOC Director really felt great!

Happy 15th Birthday CORDEX, here’s to many more!”

Africa was the region that was first prioritized within CORDEX. In a flyer from 2012 it is described why and what was initially done:

“The first priority region for CORDEX was Africa because:

• It is highly vulnerable to climate change. Key sectors (such as agriculture, water management and health) have relatively low vulnerability thresholds to deal with climate variability and change;
• Climate change may have significant impacts on Africa, with the potential for interaction with other stressors such as desertification and rapid population growth;
• There is a dearth of high-resolution climate projections for the continent.

Eight groups from the CORDEX community have completed climate projections for Africa with the results now being shared and discussed among international and regional communities. A first multi-authored peer-reviewed article has been published analysing the representation of today’s climate.

Building new relationships for the future

Further, an analysis and training programme was established in early 2011 for an initial assessment of Africa relevant CORDEX model output. Teams were created according to geographical location and scientific expertise, with representation from both the physical sciences and vulnerability, impact and risk assessment communities. Such a multi-disciplinary approach facilitates the building of strong relationships between those producing climate projections and those utilising them for impact and adaptation planning providing maximum benefit.”

Link to the flyer: https://cordex.org/wp-content/uploads/2018/03/cordex_flyer2012.pdf

Since then many more peer reviewed publications have been published. A selection of publications from 2012-2020 can be found here: https://www.csag.uct.ac.za/cordex-africa/cordex-africa-publications/

The programme mentioned above was part of the workshop series CORDEX Africa Analysis Phase 1 2011-2012 which resulted in 13 journal publications and build the foundations of the CORDEX-Africa community that includes climate, hydrology, agriculture and hydrology scientists. Phase 2 took place in 2015-2017 and both are very good examples of capacity building activities within the domain. A highlight of the effort was how CORDEX-Africa participants decided to produce a series of papers targeting the IPCC Special Report on 1.5 degrees (SR15) and this resulted in Box 3.1 in Chapter 3 of the report on the impact of 1.5 degrees of warming on Africa. Furthermore, in the 6th assessment cycle of the IPCC (AR6) CORDEX-Africa had 7 lead authors in various chapters of Working Groups 1 and 2, and the special reports on 1.5 degrees and climate change and land. The full report from Phase 2 can be read here: https://www.csag.uct.ac.za/wp-content/uploads/2015/06/CORDEX-Africa_workshops_2nd_phase.pdf.

The work within the domain has continued and workshops have been held both online and in-person. More recently a workshop was held online in December 2021 that gathered thirty participants from thirteen countries. https://cordex.org/2022/03/28/cordex-workshop-for-thirteen-african-countries/ and was then followed up by a joint in-person workshop organized by CORDEX Africa and the CORDEX Flagship South-East Africa Pilot Study held in Johannesburg in April 2022 after being postponed due to Covid-19. The purpose of these workshops was extended collaboration and to discuss the most pressing issues and gaps in climate information in order to enable well informed decisions for Africa.

There are also currently two Flagship Pilot Studies focusing on Africa:

ELVIC – Climate Extremes in the Lake Viktoria Basin
https://cordex.org/experiment-guidelines/flagship-pilot-studies/endorsed-cordex-flagship-pilote-studies/africa-elvic-climate-extremes-in-the-lake-viktoria-basin/

Modelling the southeast African regional climate
https://cordex.org/experiment-guidelines/flagship-pilot-studies/endorsed-cordex-flagship-pilote-studies/africa-modelling-the-southeast-african-regional-climate/

The MENA (Middle East and North Africa) CORDEX domain was established in 2012, user-driven by a need of high-resolution regional climate information from the Regional Initiative for the Assessment of the Impact of Climate Change on Water Resources and Socio-Economic Vulnerability in the Arab Region (RICCAR, https://riccar.org/).

Since 2012 regional downscaling activities in the MENA region have been growing together with the number of participants involved. The first results from the MENA domain were presented at the International Conference on Regional Climate - CORDEX 2013 in Brussels where a scoping meeting for the MENA domain was held. An active working group of several regional climate modelling teams from the region and Europe was successfully launched in November 2014 at the CORDEX MENA meeting in Nicosia (Cyprus). The first MENA CORDEX simulations were made publicly available on the Earth System Grid Federation (ESGF) in 2013.

The first common publication effort from the MENA CORDEX:
Zittis G., Hadjinicolaou P., Almazroui M., Bucchignani E., Driouech F., El Rhaz K., Kurnaz L., Nikulin G., Ntoumos A., Ozturk T., Proestos Y., Zaaboul R., Lelieveld J. (2020) Business-as-usual will lead to ultra-extreme heatwaves in the Middle East and North Africa. npj Climate and Atmospheric Science https://www.nature.com/articles/s41612-021-00178-7

Although the number of active participants is rather small in the domain at the moment there are a few modelling groups that are considering in proceeding with CMIP6 downscaling and a few presentations were also made during a workshop in Saudi Arabia in 2023. Information about the workshop can be found in the domain report for 2023: https://cordex.org/domains/domain-activities-2/domain-activities-2023/

Since the CORDEX Africa and MENA CORDEX domain share the North African region collaboration is important and it will be developed further as the CORDEX Africa domain is about to form a North African team.

The current Points of Contact in these domains are:

Africa: Chris Lennard, Nana Ama Browne Klutse, Amira Nasser Mostafa and Rondrotiana Barimalala

MENA: Panos Hadjinicolaou, Fatima Driouech and Mansour Almazroui.

Africa domain

MENA domain

Group photo from one of the CORDEX Africa Workshops

Med-CORDEX is an open club of Mediterranean climate model developers and users, driven by scientific curiosity. It is self-organized, and based on voluntary efforts and is endorsed by CORDEX, Med-CLIVAR, and HyMeX.
Its scientific focus is on the regionally closed energy and water cycles, which implies developing and applying coupled ocean-atmosphere-land high-resolution climate models.

Over the past 15 years, our overarching scientific goals have been to:

• understand the past variability of the Mediterranean regional climate system and characterize its potential future evolution;
• investigate, understand, and improve the description of regional climate phenomena and
• contribute to the characterization of the impacts of Mediterranean climate change

Med-CORDEX began in 2009 as an official CORDEX domain, following the European CIRCE project and funded by the HyMeX program. It develops reference modeling frameworks to provide coordinated regional climate simulations, focusing on the various components of the Mediterranean climate system, including the atmosphere, land, ocean, and aerosols.
Multi-channel coordination is achieved through a mailing list (medcordex@meteo.fr), a website (www.medcordex.eu), a Slack-based discussion forum (medcordex.slack.com), a Zenodo community (https://zenodo.org/communities/medcordex/), and an active steering committee (medcordex-sc@meteo.fr).
Med-CORDEX has published numerous scientific works, including two reference publications (Ruti et al. 2016, Somot et al. 2018b) and 145 scientific articles between 2011 and 2024, including a special issue in Climate Dynamics in 2018 and various multi-model studies.
The Med-CORDEX centralized database hosted by ENEA includes 125 datasets (12 TB uploaded, 42 TB downloaded), contributed by 15 institutes and used by 305 registered users. This database supports extensive research and collaboration within the Mediterranean climate community. Three of the first endorsed CORDEX Flagship Pilot Studies (FPSs) were proposed by Med-CORDEX, focusing on key regional climate processes and their interactions:

Role of the natural and anthropogenic aerosols in the Mediterranean region: past climate variability and future climate sensibility

Role of the air-sea coupling and small-scale ocean processes on regional climate

Convective phenomena at high resolution over Europe and the Mediterranean

Over the years, Med-CORDEX's contributions to Mediterranean climate and ocean science have been recognized by international initiatives such as Med-CLIVAR, C3S, IPCC-AR6, and MedECC-MAR1. Notably, it was the only coordinated initiative providing ocean variables from regional climate models to the IPCC-AR6 interactive atlas.

In 2023 Med-CORDEX published an updated version of the Med-CORDEX-CMIP6 baseline run protocol: Med-CORDEX phase 3: Common protocol for the Baseline runs for the CORDEX-CMIP6 framework.

The current Points of Contact:

MED-CORDEX: Erika Coppola, Bodo Ahrens, Gabriel Jordà, Gianmaria Sannino, Samuel Somot and Fabien Solmon

MED-CORDEX domain

Group photo from the 6th Med-CORDEX workshop in Toulouse in 2019. The same place where it all started.

EURO-CORDEX is the European branch of CORDEX. EURO-CORDEX has been active since the beginning of CORDEX and during the General assembly this year they celebrated the 15th anniversary of the EURO-CORDEX initiative. It was also the 14th time the General assembly was held. The first dedicated EURO-CORDEX Modeling Meeting took place in November 2011 in Hamburg, Germany.

EURO-CORDEX is a voluntary effort of many of the leading and most active institutions in the field of regional climate research in Europe. The core of EURO-CORDEX consists of the simulations provided by the participating groups.

In 2021 German TV interviewed CORDEX co-chair Daniela Jacob, also highly involved in the EURO-CORDEX initiative, about the release of information sheets based on EURO-CORDEX simulations. https://cordex.org/2021/07/09/german-tv-interviews-cordex-co-chair-about-the-release-of-information-sheets-based-on-euro-cordex-simulations/

In 2023 the White paper on CMIP6 GCM selection and Matrix design for EURO-CORDEX was published: EURO-CORDEX CMIP6 GCM Selection & Ensemble Design: Best Practices and Recommendations

Three Flagship Pilot Studies for the European region have been endorsed so far, dedicated to different topics (one covering both Europe and the Mediterranean):
Convective phenomena at high resolution over Europe and the Mediterranean

Impact of land use changes on climate in Europe across spatial and temporal scales

URBan environments and Regional Climate Change (URB-RCC)

In 2024, an article was published in the Bulletin of the American Meteorological Society
"Delivering an Improved Framework for the New Generation of CMIP6-Driven EURO-CORDEX Regional Climate Simulations" https://doi.org/10.1175/BAMS-D-23-0131.1
The paper presents the protocol for the CMIP6/EURO-CORDEX simulations and highlights the improvements we expect in the new generation regional climate ensemble.

The current Points of Contact in this domain are:

EURO-CORDEX: Daniela Jacob, Stefan Sobolowski, Eleni Katragkou, José Manuel Gutierrez and Claas Teichmann

EURO-CORDEX domain

CORDEX South America (SAM) and Central America (CAM: Mexico, Central America, and the Caribbean) domains, conforming the Latin America CORDEX region, have collaborated in many CORDEX initiatives throughout the years to improve the regional climate modeling capacities, the understanding of physical processes and their impacts, and to support scientific capacity.

The initial activities were developed in the framework of a collaboration between VAMOS (CLIVAR) and CORDEX, and co-financed by WCRP, ICSU, and the IAI. In 2013 and 2014, two major capacity building activities were organized in Lima, Peru, and Santo Domingo, Dominican Republic with the aim of bringing together the international community of regional climate scientists to pursue an initial assessment of the various CORDEX downscaling initiatives over the South American and Central American CORDEX domains, to develop regionally focused vulnerability, impact and adaptation (VIA) user-knowledge, and to identify stakeholders’ needs to support science-based information required for climate adaptation, mitigation and risk management in the region. These two events gathered more than 130 scientists from Latin America and the Caribbean together and were the initial seed to coordinate regional climate science in the region.

Dynamical and statistical downscaling simulations

In these 15 years, the regional climate model (RCM) simulations for the two domains increased from ~50 km resolution (CAM-44 and SAM-44) during the CORDEX-Phase 1 and CORDEX-CORE stages, to ~25 km (CAM-22 and SAM-22). The International Centre for Theoretical Physics (ICTP) and the Rossby Centre of the Swedish Meteorological and Hydrological Institute (SMHI) produced present and future 50 Km resolution simulations for CORDEX-CAM using RegCM and RCA regional models, respectively. Additionally, the ICTP produced the CAM-22 simulations with RegCM RCM. For the CORDEX-SAM domain, an unprecedented modeling effort developed under the auspices of an EU project allowed producing RCM simulations at 44 km resolution including more than 7 RCMs for present and future climate conditions driven by CMIP3 GCMs. Additionally, the CPTEC (INPE, Brazil) provided a 20km resolution simulation with the ETA RCM nested into three CMIP3 GCMs. On top of all these simulations, the CORDEX-CORE initiative provided the simulations produced by the REMO2019 and RegCM4 RCMs nested into three different global models from the CMIP5 ensemble.

Table 1. Dynamical RCMs (and resolution) participating in CORDEX phases for CAM and SAM domains.

 

Domains	CORDEX-PHASE 1	CORDEX-CORE
CAM	RegCM4, RCA	RegCM4
SAM	RCA, RegCM3, REMO, ETA, MM5, PROMES, LMDZ	RegCM4, REMO

Multiple analyses were performed based on the simulations available. Additionally, several training activities focused on specific regional climate phenomena were developed based on the availability of the simulations indicated above. A comprehensive list of publication can be found on the CORDEX web page.

The two domains have also advanced in statistical downscaling analyses. Recently, the University of Costa Rica produced statistically downscaled monthly estimates of precipitation and temperature at 1 km horizontal resolution for the Central American countries and the Dominican Republic from 1979-2099. Several subregions (e.g. Panama Canal and selected municipalities of Costa Rica) also contain daily data, which are available for six CMIP6 GCMs and three scenarios: SSP1-2.6, SSP2-4.5 and SSP5-8.5. CORDEX-SAM has also published several studies based on statistical downscaling. These analyses mainly focused on daily maximum and minimum temperatures over Southern South America and explored different standard ESD techniques (analogs, generalized linear models, artificial neural networks and generalized linear models conditioned by weather types) from the prefect prognosis approach. The evaluations were based on perfect conditions (ERA Interim driven simulations) and projections driven by GCMs from CMIP5 and CMIP6 simulations and scenarios. In addition, deep learning-based ESD models have been tested and compared with benchmarking ESD models over Southern South America.

Advances in the understanding of physical processes and regional impacts

The major scientific advances for a better understanding of physical processes include studies on the North American and South American monsoons, tropical cyclones, synoptic scale cyclones in SAM, subtropical jet streams, low-level jets, extreme events, droughts, heat waves, compound extreme events (heatwaves and droughts), seasonal circulations, present and future changes of regional climates and extremes, land use impacts, impacts of local convection (convection permitting), and role of physical parameterizations, grid size and domain size in regional processes.

Some modeling studies have focused on impacts of current and future climate change applications in different sectors, for example on viticulture and climate change in Mexico, changes in grain yields in several regions of the two domains, impact of climate change in pine distributions in Mexico, surface water budgets, global and regional droughts, and wind energy potential among others.

Training and capacity building

CORDEX-CAM and CORDEX-SAM have organized training activities and special sessions in international meetings with financial support from CORDEX, ICTP, and universities of the region. Some of the activities were online and others on-site, particularly during and after the COVID pandemic. These activities have contributed to capacity building for the advancement of climate science through the participation of many scientists, particularly graduate and postgraduate students, and early career scientists of the region. CORDEX members from the two domains have also co-directed several regional climate modelling events at the ICTP, and organized sessions in the ICRC-CORDEX conferences:

• 2013: LAC-CORDEX - 11-13th September - Lima, Peru
• 2014: LACII-CORDEX - 7-9th April - Santo Domingo, Dominican Republic
• 2014: RegCM4 Workshop, CICESE, Baja California México - November.
• 2016: Third ICRC-CORDEX 2016 Stockholm, Sweden (participation of domains members).
• 2016: RegCM4 - 15-19th February 2016 - Sao Paulo - Brazil - (Joint ICTP-Trieste/ICTP-SAIFR Advanced School on Regional Climate Modeling over South America). (45 participants and 9 invited speakers)
• 2016: RegCM4 Workshop - November, University of Costa Rica.
• 2018: CORDEX Workshop - 25-27 June, La Paz, Bolivia (30 participants from 11 countries within SAM/CAM and 10 invited speakers) -
• 2018: RegCM4 - 05-09 Nov 2018 - Sao Paulo - Brazil - meeting of FPS_SESA - defining simulation strategies for extreme events analysis (53 participants and 16 invited speakers)
• 2018, 2020 and 2021: Organization of Special Sessions (SE) in the Annual Meeting of the Mexican Geophysical Union in Mexico (RAUGM): Regional climate modeling and CORDEX (SE04-2017, SE05-2018, 2020, 2021), Puerto Vallarta, México - October-November.
• 2019: Fourth ICRC-CORDEX 2019 Conference in Beijing, China, October (participation of domain members and focal points).
• 2020-2021: During the pandemia CORDEX CAM-SAM organized two Online Writing Workshops: Nov 2020 and Apr 2021 - 4 published/2 submitted papers from this activity (42 participants and 8 invited speakers).
• 2022: CORDEX CAM-SAM, 04-06 September - Buenos Aires - (38 in person attendees + 12 remote attendees, plus invited speakers).
• 2023: Fifth ICRC-CORDEX 2023 Conference in the ICTP, Trieste. The two domains contributed with works, and organized the Flagship Pilot Studies from Southeast South America (FPS-SESA) meeting, and several sessions.

Km-scale modelling

Starting in 2016, the CORDEX FPS initiative allowed the development of strategies towards km-scale regional climate modeling and ESD techniques over Southeastern South America. A collaborative team including groups from both South America and Europe created an unprecedented ensemble of km-scale 3 year-long simulations over the region that allowed improving our understanding of various climatic features occurring on the region, including the diurnal cycle of heavy rainfall events, the impact of heavy rainfall events on the hydrology of the Uruguay river basin, the impact of rainfall on crop production over southern Brazil, the representation of the urban effect on heat waves and wind intensity over several cities in Southeastern South America, among others. The main outcomes from this initiative can be also found on the CORDEX web site.

Challenges

SAM and CAM CORDEX domains still have many challenges; the large size of the domains and the complex terrain that dominates Latin America make some evaluation studies complicated due to the lack of sufficient observational data at fine-scale spatial resolution. From the scientific point of view, the region has not advanced in regional climate attribution studies with the exception of a couple of detection and attribution studies; the lack of fine-scale simulations in most of the two domains has hindered the advancement in convection permitting (CP) studies and the analysis of extreme events at local scale; only CORDEX-SAM have some studies on CP thanks to the collaboration in the framework of a CORDEX FPS and the collaboration with scientists from NCAR. Computational capabilities and storage also continue to be a challenge due to the lack of scientific support from the government in most of the countries.

The current Points of Contact in these domains are:

Central America: Tereza Cavazos, Tannecia Stephenson and Hugo Hidalgo
South America: Silvina Solman, Rosmeri Porfirio da Rocha and Maria Laura Bettolli

Central America domain

South America domain

Polar CORDEX includes both Arctic and Antarctic domains and is coordinated jointly with WCRP Climate and Cryosphere (CliC). Its primary goal is to organize an international coordinated framework to produce an improved generation of regional climate change projections for input into impact and adaptation studies.

The Polar CORDEX community organized itself in 2013. The first meeting was held as a side event during the International Conference on Regional Climate (CORDEX 2013) in Brussels in November 2013.

Since then CORDEX Polar has met almost every year to discuss the progress and the planned activities. This year the meeting will be held in Potsdam, Germany 23-25 October 2024 with the possibility to attend online.

Reports from the annual meetings can be found here.

Recently, new coordinated multi-model research activities were started. Those use the unique observations from the year-long MOSAiC expedition to evaluate a multi-model ensemble. The initiated studies include an evaluation of:
(i) Arctic atmospheric boundary layer stability regimes, their frequency and radiative and mechanical forcing, and
(ii) aerosol-cloud-radiation processes during a warm airmass intrusion. Other research activities cover improved polar process understanding and parameterizations, high-resolution future projections for the Arctic and Antarctic, and more.

The CORDEX Polar community is a well-organized group and to help facilitate communication between people interested in regional downscaling of climate models in the polar regions, CORDEX Polar has an email list for anyone to join. It is meant to be a discussion platform to share ideas, progress updates, ask questions, and more. You can find information on how to join on the CORDEX Polar website.

The current Points of Contact in these domains are:

Polar CORDEX: John Cassano, Annette Rinke, Andrew Orr, Chris Kittel

CORDEX Antarctica domain

CORDEX Arctic domain

Activity in the CORDEX Australasia domain has grown rapidly over the last 15 years, and the increased level of coordination/collaboration has been transformative for regional climate modelling efforts in the region. Already at least 6 modelling groups have contributed simulations to CORDEX-CMIP6 for the Australasia domain. We also see potential for further growth in the Western Pacific. CORDEX Australasia has access to a variety of models and approaches, which has greatly strengthened the robustness of its regional climate projections. Various advancements in the modelling efforts are being pursued on the path to regional earth system modelling. A particularly exciting development is the emergence of machine learning methods, with generative adversarial methods being developed.

The Australasian community relies on CORDEX as a demonstration of international best practice when undertaking climate downscaling for regional projections. For example, archiving standards defined by CORDEX have been adopted by all major modelling activities in the region (which was not the case in the past). This has facilitated a much greater exchange of information between researchers and has directly encouraged a multi-model ‘sparse matrix’ approach to regional climate projections in the region. In the case of Australia, the National Partnership for Climate Projections (NPCP) was established by the Federal Department of Climate Change, Energy, the Environment and Water to further grow the opportunities by such collaboration including for scientific advancement, computing infrastructure and for climate services. This work is also beginning to bridge international borders and should further enhance regional climate modelling for CORDEX in the region. The Australian Meteorological and Oceanographic Society (AMOS) has also supported annual workshops for CORDEX Australasia, encouraging new researchers to take advantage of the regional climate projections provided.

It is worth noting that the number of submissions to CORDEX has doubled between CORDEX-CMIP5 and CORDEX-CMIP6, signifying the rapid growth in regional climate modelling in the region. Initiatives for better collaboration between atmospheric and coastal modelling is underway, as well as advancing bias correction methods to further improve the utility of projections for climate services. Extreme weather projections are a strong focus of current and future modelling activities, with new convective scale simulations in the region. Combined with machine learning approaches, we hope to see a further step change in projection capabilities within the next generation of regional climate models.

The current Points of Contact in this domain are:

CORDEX Australasia: Jason Evans and Marcus Thatcher

CORDEX Australasia domain

South Asia is extremely vulnerable to climate disasters. Climate services play an important role in managing present and future climate risks. In the last 15 years a number of activities have been conducted by the CORDEX South Asia domain.

In 2012, the Centre for Climate Research (CCCR) at the Indian Institute of Tropical Meteorology (IITM) hosted the first CORDEX South Asia Training Workshop in Pune. This training workshop was organized by the WCRP in partnership with START, and in collaboration with ICTP, CSAG, SMHI and ICSU-ROAP.

In 2013, the CORDEX South-Asia 2nd Science and Training Workshop was hosted by the International Centre for Integrated Mountain Development (ICIMOD) in Kathmandu.

From 2019 to 2024 Institutional capacity building in CORDEX data access and use was held as part of the Asia Regional Resilience to a Changing Climate (ARRCC) programme funded by the UK’s Foreign, Commonwealth & Development Office (FCDO). A series of training workshops, focussed on the analysis, use and communication of future climate projections, have been led by ICIMOD, in partnership with the Met Office and organisations involved in the CORDEX South Asia initiative, including the World Climate Research Programme (WCRP), the Swedish Meteorological and Hydrological Institute (SMHI) and Indian Institute of Tropical Meteorology (IITM)-Pune. The capacity building has targeted NMHSs and other organisations working to deliver climate services to government, communities, and industrial sectors.

Regional trainings: Climate change analysis using CORDEX regional climate models over South Asia (October 2020) and Spatial and temporal analysis of climate change indices (June 2022)

National trainings: Spatial and temporal climate change analysis using CORDEX regional climate projections for Nepal (June 2021), Bangladesh (December 2021, March 2022), Bhutan (December 2022). Trainings workshops were held virtually and in person over 5 days and attended by participants from the Nepal Department of Hydrology and Meteorology (DHM) and climate research organisations in Nepal (June 2021), Bangladesh University of Engineering and Technology (BUET) (December 2021), and Bangladesh Meteorological Department (BMD), Institute of Water Modelling in Bangladesh (March 2022) and National Centre for Hydrology and Meteorology (NCHM) and Royal University of Bhutan. They built on the content from part 1, refreshing participant skills in how to access and download CORDEX data, but focused on how to apply bias calculations in CORDEX data against reference historical data sets, and more specific analysis of model simulations for user-specified locations. The training provided experience of using R-based tools to generate annual and monthly data plots using CORDEX and APHRODITE data, visualisation of climate change projections over different space and timescales, and the interpretation of uncertainty in model results.

Impact

Overall, the training workshops reached approximately 80 participants 33% of which are women from across the region, with many of those attending multiple training workshops and some who were able to attend the whole series. These workshops have helped to increase the capacity of people from a range of climate services organisations to access, use and generate new information from climate model data, which can be used to support their work on climate resilience in vulnerable sectors. These events have supported the CORDEX initiative ambitions to increase the usage of CORDEX data in climate change applications and strengthened collaboration between the partner organisations involved in training development and delivery.

Scoping Workshop on developing a Strategy for Future Climate Projections in South Asia was held in Dhulikhel, Nepal with key stakeholders in Nepal in December 2023. The workshop discussed the development on access and use of CORDEX South Asia datasets and other relevant future climate projections. It also aimed at identifying gaps and opportunities and contribute to the development of a strategy.

ICIMOD was engaged to co-organize the WCRP’s First Climate Research Forum: Southern Asia Climate research priorities for the next decade held online in November 2021. Climate Research Forums are a series of regionally-based online Forums whose purpose is to exchange ideas, discuss new activities and opportunities of WCRP, as well as support other WCRP activities to strengthen our engagement in the regions around the world. And a presentation was made on CORDEX South Asia and Interaction with Society at the WCRP Open Science Conference in Kigali, Rwanda in October 2023.

The International Conference on Regional Climate (ICRC CORDEX 2023) was held in September at the IITM in Pune. As the India Hub, the conference served as a nexus for the global regional climate research community, focusing on high-resolution climate information and its practical applications in vulnerability assessment, impact analysis, and adaptation strategies. One of the key discussions revolved around the increasing demand for reliable regional climate information that is not only scientifically rigorous but also effectively communicated to diverse end users.

The current Points of Contact in this domain are:

CORDEX South Asia: Sanjay Jayanarayanan, Mandira Shrestha, Lalu Das and Koji Dairaku

CORDEX South Asia domain

Group photo from the ICRC CORDEX 2023
India hub

Group photo of participants and resource persons
at the part 3 regional
(Photo: ICIMOD)

- A decade of progress and growth

CORDEX Southeast Asia began from the initiative of a group of climate scientists in the region. During a workshop hosted by VNU Hanoi University of Science on 2-3 August 2012, the Southeast Asia Regional Climate Initiative (SEARCI) was informally established, and they agreed to work on a proposal to the Asia-Pacific Network for Global Change Research (APN) to produce high resolution multi-model climate projections for Southeast Asia. This project was called the Southeast Asia Climate Downscaling (SEACLID) project and was led by Prof Fredolin Tangang of Malaysia. Since CORDEX had already been established at that time and recognizing the shared goals, SEACLID was streamlined and integrated into CORDEX as the 14th domain. Henceforth, the project was known as SEACLID/CORDEX Southeast Asia.

The overarching goals of CORDEX Southeast Asia are to (1) advance the science and understanding of climate change over the region, (2) provide downscaled data products for users to promote application and understanding of climate change impacts, (3) strengthen regional and international networking and collaboration, and (4) build capacity of students and climate researchers.

To achieve these goals, CORDEX Southeast Asia has conducted four collaborative downscaling activities since 2013, where three have been funded by APN. The first was the SEACLID project, led by Prof Tangang from Malaysia, followed by the SEACLID/CORDEX Southeast Asia Phase 2: High-resolution analysis of climate extreme over key areas in Southeast Asia, also funded by APN and led by Dr Jerasorn Santisirisomboon of Thailand. At present, the group is finishing the downscaling of CMIP6 GCMs over Southeast Asia which is coordinated by Dr Thanh Ngo-Duc of Vietnam. The third APN-funded project, Climatic hazard assessment to enhance resilience against climate extremes for Southeast Asian megacities (CARE for SEA megacities), led by Dr Faye Cruz of the Philippines is currently being implemented. The focus of these activities has evolved in response to the needs of the region. Key to these activities were the support of collaborators from both within and outside Southeast Asia as well as the fundings provided by the APN and other organizations. Also worth highlighting is the changing leadership, which reflects the importance of providing equal opportunity and task sharing within the group.

These downscaling efforts played a major role in providing multi-model multi-scenario regional climate projections that have been analyzed, along with observational data, in over 40 peer-reviewed scientific literature, contributing to a more robust assessment of Southeast Asia regional climate changes in the IPCC Sixth Assessment Report (AR6). Researchers and scientists who are actively involved in CORDEX Southeast Asia have also significantly contributed to the AR6 as authors and expert reviewers.

CORDEX Southeast Asia also established the Southeast Asia Regional Climate Change Information System (SARCCIS), an Earth System Grid Federation (ESGF) node, as an online platform for the downscaled climate data, and is hosted by the Center of Regional Climate Change and Renewable Energy (RU-CORE), Ramkhamhaeng University, Thailand.

In over a decade since its inception, CORDEX Southeast Asia have organized a total of 13 workshops (2 of which are virtual), and 7 training (including manuscript writing) workshops. These were crucial avenues for capacity building of climate researchers and students in the region.

The community continues to grow with more institutions and individual scientists in and outside Southeast Asia contributing not only through their regional climate models and computational resources, but also with their expertise. Since its inception in 2013, CORDEX Southeast Asia has been coordinated by Prof Tangang. With this growth, CORDEX Southeast Asia formally approved an internal Council on 23 November 2023 with Dr Faye Cruz and Dr Jerasorn Santisirisomboon as co-chairs. Moving forward, CORDEX Southeast Asia aims to develop capacities in statistical downscaling, and coupled regional ocean-atmosphere for regional downscaling, and continue other capacity building activities. SARCCIS will also be further developed to provide tools for data users and stakeholders and strengthen collaboration with stakeholders and policymakers.

The current Points of Contact in this domain are:

CORDEX SEA: Fredolin Tangang, Faye Cruz, Thanh Ngo Duc, Koji Dairaku and Liew Juneng

CORDEX SEA domain

 

CORDEX Southeast Asia Council in Bangkok, Thailand 23 November 2023

CARE for SEA megacities and CORDEX-SEA:
A Special Session in the 4th International Vietnam Conference on Earth and Environmental Sciences (iVCEES-2024)
International Centre for Interdisciplinary Science and Education (ICISE), Quy Nhon, Vietnam,
26-28 November 2024

CORDEX-East Asia (EA) has been established since 2009, building on the Regional Climate Model Intercomparison Project (RMIP), which began in the late 1990s. China, Korea, and Japan collaboratively held seven RMIP workshops to focus on reproducing the East Asian climate and advancing Regional Climate Models (RCMs). During the RMIP period, downscaling research was conducted using ECHAM5, a model contributing to CMIP3, with the RCMs from each country. CORDEX-EA subsequently succeeded RMIP, expanding efforts to downscale Global Climate Models (GCMs) from CMIP5 and CMIP6 using multiple RCMs and Empirical Statistical Downscaling (ESD) methods.

China, Korea, and Japan have jointly led the CORDEX Phase 1 and Phase 2 experiments for the EA domain, producing results from both historical experiments and future scenario simulations under the CORE program. RCMs commonly used in CORDEX-EA include RegCM, WRF, CCLM, MM5, GRIMS, HadGEM3RA, and NHRCM.

CORE and FPS programs

• Phase 1: RCMs with a horizontal resolution of 50 km were employed, covering a broad domain that included East Asia, South Asia, parts of Oceania, and India. Based on Assessment Report 5 (AR5)’s Representative Concentration Pathways (RCP) scenarios, detailed regional climate change projections were conducted.
• Phase 2: Higher-resolution RCMs with a 25 km horizontal resolution were used to refine regional climate change scenarios based on AR5’s RCP scenarios. This phase also incorporated a larger number of GCM-driven large-scale forcings into RCMs, significantly increasing the ensemble size compared to Phase 1. Recently, CORE experiments based on AR6’s Shared Socioeconomic Pathways (SSP) emission scenarios have been completed.

Figure 1. Domains of CORDEX-EA Phase I (left) and Phase II (right)

Additionally, participating countries have conducted research using ESD methods to statistically downscale GCM outputs. In Korea, for example, scenarios with a resolution as fine as 1 km have been produced by combining dynamic downscaling with RCMs and further refining them statistically.

In addition to the CORE program, each country is actively conducting studies under FPS to improve the simulation of high-impact weather and climate phenomena, such as heavy rainfall, typhoons, and heat waves. These efforts involve using convection-permitting models with resolutions of 4 km or finer. Research is also ongoing to develop coupled regional climate models integrating atmosphere-ocean interactions.

Workshops and publications

Starting with the Jeju Workshop in 2012, several regional scientific workshops have been held in Korea and China to compare simulation results and share scientific achievements. Over the past 15 years, CORDEX-EA teams have published approximately 200 papers in international SCI(E) journals. Since 2015, they have also hosted a regular CORDEX session at the annual Asia Oceania Geoscience Society (AOGS) meeting. This session, held in collaboration with teams from the Australia and South Asia domains, features diverse oral and poster presentations on topics related to regional climate downscaling and CORDEX.

 

Jeju meeting 2019

Data distribution

The CORDEX-EA CORE output is distributed through the ESGF node jointly operated by the National Institute of Meteorological Sciences (NIMS) and the APEC Climate Center (APCC). The data can be accessed here.

The current Points of Contact in this domain are:

CORDEX East Asia: Young-Hwa Dyun, Hiroaki Kawase, Dong-Hyun Cha and Koji Dairaku

CORDEX East Asia domain

2021-2022: Laying the foundation

During several years there were not many activities in the CORDEX Central Asia domain. At the end of 2021 when Dr. Shaukat Ali, took on the role of Point of Contact (PoC) for the CORDEX Central Asia it was clear that the domain faced significant challenges in building a cohesive research group and advancing CORDEX activities. The lack of regional climate research initiatives and limited collaborations posed major obstacles to progress in climate modeling and capacity building. The first year was dedicated to overcoming barriers and laying the groundwork for CORDEX activities in the region. Despite resource constraints, we saw promising progress as regional researchers and institutions showed growing interest.

Key initiatives during this period were identification of researchers, compilation of publications, preparation of a list of climate modeling publications relevant to the Central Asia domain to support researchers and encourage knowledge sharing, proposal of development for funding and tutorial on Accessing CORDEX Data.

These foundational efforts established a solid base for future collaborations and activities, setting the stage for meaningful progress in the years ahead.

2023: A year of progress and achievements

The biggest event in 2023 was the CORDEX Central Asia Workshop in Samarkand, Uzbekistan. Michelle Simões Reboita was the main trainer and it included technical sessions, hands-on training, and discussions on future collaborations. Other events were a seminar at National Research University in Tashkent, Uzbekistan and represented the CORDEX Central Asia Domain at COP28, presenting its activities at the Uzbekistan Pavilion and also a two-day workshop in Bahawalpur, Pakistan.

2024: The year of presentation and collaboration

Stefan Rahimi and Callie Merissa Berman from the University of Wyoming collaborated with Shaukat Ali and Michelle to promote the dissemination of CORDEX activities in the Central Asia domain and support efforts to conduct climate projections for the region. This team has been holding regular online meetings to plan a workshop in Central Asia for 2025 and provide capacity-building opportunities for undergraduate, master's, and PhD students interested in climate modeling. During these meetings, professors from Central Asia were invited to discuss the challenges and opportunities related to regional climate downscaling initiatives.

Shaukat Ali and Michelle Simões Reboita also presented at two events in China during 2024: Scientific Forum for Numerical Simulation of Asian Regional Climate Change and Earth System Process and CORDEX - MAIRS-FE Joint Workshop: Multi-scale climate-air-water nexus for sustainable health, food and energy.

The plans for the near future are to hold another workshop in Central Asia, hopefully including all countries of Central Asia and to have joint projects and research papers with Universities in Central Asia domain.

The current Point of Contact in this domain is:

Central Asia: Shaukat Ali

CORDEX Central Asia domain

Shaukat Ali in Tashkent, Uzbekistan in 2023

Michelle Simões Reboita at the Workshop
in Samarkand, Uzbekistan in 2023.