Connect with us


NEMO: a numerical ocean model



A numerical ocean model is a computer programme representing the equations of motion (momentum, conservation of mass and thermodynamics) for the ocean. The model stores each of the physical properties of the ocean (temperatures, salinities and currents) on a three-dimensional grid, writes Ana Aguiar.

Ocean models store physical  properties such as salinity, temperature and currents on a three-dimensional grid. Picture: Adobe Stock

Smaller ocean features can be resolved by using a finer grid with more points, but this requires more computational power. The model evolves these physical properties forward in time using its equations of motion. Models of sea ice and biogeochemistry work using similar principles.

Why do we need a numerical ocean model?

We need these models to predict the state of the ocean within short and long timescales for a variety of purposes, ranging from support to operations at sea (for example, search and rescue) to understanding the role of the ocean in the Earth’s climate system. As the ocean sits beneath the atmosphere, sea-surface temperature patterns have widespread impact on the weather over land. Largely because two-thirds of the Earth is covered by ocean and the heat capacity of water considerably outweighs that of the air, the ocean acts as a regulator of the atmosphere.

In polar regions temperatures become cold enough for seawater to freeze and sea ice forms on the surface of the ocean. Sea ice plays an important role in the climate system because it insulates the ocean from the colder atmosphere in winter and, being whiter than the ocean, reflects sunlight in the summer.

The NEMO modelling framework includes a sea-ice model component, known as SI³ (Sea Ice modelling Integrated Initiative). The sea-ice component is run along with the ocean component in a similar manner but using a different set of equations. To understand and prepare for climate change we need to account for the role of the ocean and sea ice.

How is the NEMO model developed?

Nucleus for European Modelling of the Ocean (NEMO) is a state-of-the-art ocean modelling framework. NEMO is developed by a European consortium with the objective of ensuring long-term reliability and sustainability of the code. In other words, the task of maintaining and developing such a complex computer programme requires a well-coordinated team effort, involves tens of developers and hundreds of users.

In the UK there are two member organisations: the Met Office and the National Oceanography Centre (NOC). Met Office Scientific Manager in Ocean Modelling, Ana Aguiar explains: “We work in partnership through the Joint Marine Modelling Programme, contributing to the development of NEMO. The code is publicly available for use in research and commercial applications. It is imperative to reach as many users as possible, to ensure the code gets tested and pushed to the limits of its usability. User requirements then prompt further advances.”

NEMO benefits from continual work to improve its performance (scientific and computational efficiency), to incorporate new scientific and process understanding, and to exploit the increase in supercomputer resources. When the developments are sufficiently mature and can provide significant scientific or technical improvements, a new NEMO version is released. Along with scientific upgrades (which tend to be increasingly computationally demanding), we must deliver code optimisation to make the best use of the available computing resources.
This video presents how NEMO is used by the Copernicus Marine Environment Monitoring Service.

What’s next?

The next NEMO release (expected to be rolled out this summer) will deliver significant improvements to model performance allowing it to run considerably faster. In the long term, among other things, we are also working towards porting the NEMO code to Graphical Processing Units (GPUs) to ensure continuity of the code in future mainstream High Performance Computing architectures

During April we are exploring the topic of the ocean and climate. Follow the #GetClimateReady hashtag on X (formerly Twitter) to learn more throughout the month.

Source link

Continue Reading
Click to comment

Leave a Reply

Your email address will not be published. Required fields are marked *


Green light for space weather forecasting satellite



The European Space Agency (ESA) today confirmed the contractors for the long-awaited Vigil mission which will transform global space weather forecasting.

The confirmation of the building of the satellite is the next step in the process positioning a satellite with a side-on view of the Sun to provide enhanced space weather forecasting.

The Met Office Space Weather Operations Centre, now celebrating its tenth year in operation, is one of a number of centres that will benefit from the new satellite.

The Vigil mission, as it’s known among space weather scientists, will enhance space weather forecasting capabilities and help provide more notice for potentially impactful space weather events such as coronal mass ejections.

Mark Gibbs, who leads the Met Office Space Weather Operations Centre (MOSWOC), said: “The Vigil mission represents a step-change in space weather forecasting capability. As well as replacing aging satellites, this mission will help to improve our forecasting capability and deepen our scientific understanding of coronal mass ejections (CMEs) that generate geomagnetic storms.”

Confirmation of the contract for the mission, which is being managed by the European Space Agency, represents the next milestone in the process of launching the new satellite by the end of this decade and will revolutionise imagery and data available to space weather forecasts.

Mark continued: “A side-on view of the Sun-Earth line is critical to provide accurate predictions of CME arrival at Earth. We’ll get access to more reliable, more advanced data to initialise models to predict CME arrival and also to monitor their progress as they head towards the Earth. We’ll be continuing to work with ESA to help ensure there’s as much benefit as possible to not just us at MOSWOC, but also to forecasting centres around the world. The Vigil mission will work in tandem with the current and future US missions stationed at L1.”

The news comes after geomagnetic storms two weeks ago brought aurora visibility to much of the UK in what was the strongest event since 2003 to impact Earth. While auroras provide immaculate photos, impactful space weather has the potential to affect everyone and is recognised on the UK’s National Risk Register. The ability to forecast these events can help to mitigate the worst impacts.

Find out more about the contract announcement.

Find out more about the Met Office Space Weather Operations Centre.

Source link

Continue Reading


How do autonomous vehicles react to the weather?



A new discussion paper from the Met Office and the National Physical Laboratory (NPL) highlights the practical challenges of understanding the performance of autonomous vehicles (AVs) in different weather conditions. 

The paper draws from an ongoing project conducted by the Met Office and NPL and is funded by the UK’s Centre for Connected and Autonomous Vehicles (CCAV)

This Sensor Assurance Framework (SAF) project aims to create a reliable and usable framework for understanding how well AV perception sensors (the eyes and ears of the vehicle) perform in different weather-related conditions. When fully developed, this framework will support validation, safety assurance and simulation testing of AVs across the UK.   

Central to SAF project has been the Cardington weather-sensor testbed, which has accumulated over two years of detailed weather measurements and corresponding AV sensor measurements as they observe targets set up at varied distances in a wide range of weather conditions including fog, intense rainfall, clear and cloudy skies and direct sunlight. 

Weather observations are made at the Cardington test site to compare with sensor performance

Met Office Observations Principal Consultant Dave Jones, who is part of the team leading the weather measurement side of the Cardington testing, said: “The effect of weather on sensor performance is very complex and it is challenging to reflect this when trying to capture the weather envelope for the AV as simply as possible. 

“This discussion paper gives examples of how this complexity reveals itself on our testbed and how we might begin to handle this by careful consideration of uncertainty.  We are very interested in hearing views from everyone in the wider AV community involved in safety assurance.” 

National Physical Laboratory’s Andre Burgess, who looks after strategic partnerships, said: “As well as the scientific and technical aspects of our joint SAF project, we are placing a huge emphasis on engagement with regulators, industry, standards bodies and academia to ensure that these testbed results make a positive difference to the AV industry and public safety.” 

The discussion paper comes as the Automated Vehicles Act became law this week and paved the way for self-driving vehicles to be possibly on the UK’s roads as soon as 2026.

Lidar imagery of the team working at Cardington

Ongoing research 

The Met Office and NPL’s Sensor Assurance Framework research at Cardington has been undertaken for around two years, with the aim to test sensor performance against as many different weather types as possible, including rain, hail, sunshine and fog.  

The research so far demonstrates an observable relationship between weather conditions and sensor performance, though further study is needed to fully understand this area, including the impact of different locations, road surfaces, vehicle movements and a broader range of weather types. It’s hoped this research will help the autonomous vehicle industry to develop further in the coming years.  

The Met Office and NPL will continue collecting weather data and assessing sensor performance in the coming months, with a new testbed at NPL’s headquarters in Teddington and plans to develop a relocatable testbed which can be deployed in a wider range of weather conditions.  

The SAF principles also extend to marine autonomous vehicles. Plans are already well underway to build a demonstration testbed around Plymouth Sound UK, as part of the Maritime Autonomy Assurance Testbed (MAAT) project, which is lead by NPL and Lloyds Register with partners including the Met Office, Plymouth Marine Lab (PML), University of Plymouth, and Warwick Manufacturing Group (WMG). 

Read the AV and weather discussion paper on the NPL website.  

Find out more about the Met Office’s services with Connected and Autonomous Vehicles.

Source link

Continue Reading


Building resilience: climate solutions for a changing world



In an era defined by environmental uncertainty, the need to fortify our communities against the impacts of climate change has never been more pressing. Climate resilience – a term often heard in discussions surrounding climate action – refers to humanity’s capacity to adapt and withstand the adverse effects of climate change while maintaining essential functions and minimizing disruption to livelihoods and ecosystems.

But what exactly are climate resilience and climate solutions?

Understanding Climate Resilience: Climate resilience encompasses a spectrum of strategies aimed at softening the risks posed by climate change. It involves building robust infrastructure, implementing sustainable land-use practices, fostering community preparedness, and enhancing ecosystem resilience. Essentially, it’s about future-proofing societies and environments against the challenges of a changing climate.

Defining Climate Solutions: Climate solutions refer to the various interventions, technologies, and policies designed to address climate change and enhance resilience. These solutions span a wide range of sectors, from renewable energy and sustainable agriculture to disaster risk reduction and climate-smart infrastructure. By adopting and scaling up these solutions, society can partially adapt to climate impacts, and build a more sustainable future.

Case Studies: Met Office’s Climate Resilience Initiatives:

  1. Climate Services for Developing Nations: The Met Office, in collaboration with international partners, provides climate services to developing nations to enhance their resilience to climate change. These services include tailored climate information, early warning systems for extreme weather events, and capacity-building initiatives to empower local communities to manage climate risks effectively. By equipping vulnerable regions with the tools and knowledge needed to anticipate and respond to climate impacts, the Met Office is helping build resilience on a global scale.
  2. Climate Change Adaptation in Urban Environments: With rapid urbanisation and population growth, cities face unique challenges in the face of climate change. The Met Office is involved in research and development projects aimed at enhancing climate resilience in urban environments. This includes modelling future climate scenarios, assessing climate risks to infrastructure and communities, and developing adaptation strategies to bolster resilience. By integrating climate considerations into urban planning and infrastructure development, cities can better withstand the impacts of extreme weather events and changing climate patterns.
  3. Enhancing Agricultural Resilience: Agriculture is particularly vulnerable to the impacts of climate change, with shifting weather patterns, extreme temperatures, and fluctuations in rainfall posing significant challenges to food security and livelihoods. The Met Office collaborates with agricultural stakeholders to consider climate-smart farming practices, improve crop forecasting capabilities, and provide climate information to farmers. By promoting sustainable agriculture and supporting adaptive measures, the Met Office is helping farmers build resilience to climate variability and ensure food security for future generations.

In conclusion, ‘resilience’ is not just a buzzword; it’s critical for safeguarding our planet and securing a sustainable future for all. By embracing climate solutions and investing in resilience-building initiatives, we can navigate the challenges of a changing climate and create a more resilient, equitable, and prosperous world for generations to come.

Source link

Continue Reading


Copyright © 2024 World Daily Info. Powered by Columba Ventures Co. Ltd.