Modern City Climate monitoring for smart cities
"Cities should be built in the countryside; the air is better." - Henry Monnier (1799 - 1877)
People recognized differences in air quality between the city and its surroundings already in the 19th century. A city has a different climate, the so-called urban climate, which is different to the surrounding area with respect to temperature, wind, humidity, and other meteorological variables. Today, these climatic differences are increasing due to climate change.
The new meteoblue city climate monitoring system enables cities to develop an affordable infrastructure to precisely measure, forecast, and model their city climate within less than a year. This creates a reliable information basis for the city planners, decision makers, and the citizens.
The system has been tested in Switzerland for a full season and is expected to evolve rapidly in 2020 in co-development with universities and further partner cities.
The Swiss cities of Basel and Zurich have already implemented their meteoblue city climate monitoring system:
Why is it important to monitor city climate? What are the benefits for the city?
More than half of the world's population is living in urban areas, and this number is continuing to rise. The increasing number of people in cities require more living space and more infrastructure. With increasing infrastructure density, further local temperature increases are likely and may require mitigation also in cities where up to now this has not been necessary. Systematic monitoring of the city climate in meaningful detail is the basis for maintaining or improving the quality of life through suitable measures and urban planning. With access to city climate information, municipal agencies can provide more effective services for traffic control, road and construction management, water management, etc. City planners, event organizers, and insurance companies can benefit from better risk assessment for heat, precipitation, wind, and other factors.
Climate change is real, now is time to act. The meteoblue city climate monitoring system enables cities to address:
Heat wave management
Urban heat islands
Flood and hail warnings
Climate change scenarios
City planning scenarios
Diligent verification of our city climate model shows a model error below 1°C for temperatures calculated between weather stations. Our 24h air temperature forecast has an accuracy of 1.2 K, effectively providing the most precise forecast possible.
Our city climate models have a horizontal resolution of 10m and resolve the entire micro-scale variability of air temperature and wind velocity fields, bringing weather information to each doorstep.
The meteoblue city climate monitoring system uses proprietary artificial intelligence to combine in-situ meteorological measurements with satellite data and numerical forecast models in order to produce precise data with a minimum of sensors in the most economical way.
Multiple meteorological variables
We offer measurements of various meteorological variables (air temperature, relative humidity, precipitation) and provide modeled wind speed and direction at high spatial resolution for a wide range of applications.
Seamlessly from history to forecast
We offer historical data, real-time updates and a 7-day forecast for any location within a city. Additionally, we use climate projections to estimate the air temperature and precipitation for different future time horizons (e.g. out to 2050) under different emission scenarios.
Our products are available via API, FTP server, web and mobile app, giving you easy plug-and-play access for a wide range of applications.
Plug&play approach for modern cities
Modern high-resolution measurement network
The first step of developing a city climate system is the installation of a meteorological sensor network (air temperature, relative humidity, precipitation, etc.) within the city. meteoblue has developed several tools to assess the best sensor locations within a city and in the surrounding areas. Once the sensors are installed, meteorological data can be received real-time via API, web, FTP or mobile app. Meteorological data are quality controlled and corrected for e.g. radiation measurement errors. The sensor network is key to provide reliable information for managing a city’s climate change mitigation measures.
Mapping local climate zones for any city in the world
meteoblue provides local climate zone maps for any city in the world. A climate zone map is generated from satellite images with a horizontal resolution of 10m. Local climate zone information is the basis for sensor placement, for statistical analysis, and for model validation and improvement.
Small-scale modelling of meteorological variables
meteoblue calculates small-scale meteorological variable fields for cities with a horizontal resolution of 10m for each measurement time step of 15 minutes. The meteoblue city climate models interpolate locations in between sensor locations with special techniques accounting for data from satellites as well as digital surface and elevation models. Air temperature, precipitation, wind speed and wind direction are assessed for any location in the city, bringing weather information to each doorstep. Based on the small-scale air temperature field, urban heat islands are detected as well as cold inflows. In addition, flood and hail warnings for the city can be created on the base of high resolution precipitation data. Air pollution is assessed automatically by combining local air pollution sources with a three-dimensional wind field calculation.
High computational power from the meteoblue high performance computing cluster
meteoblue runs city climate models on a very fine horizontal resolution down to 0.5 m (see sky view factor on the right). The sky view factor expresses the proportion of sky visible from a point on a surface. Street canyons or areas covered by trees have a low sky view factor in contrast to the high sky view factor of open places and building rooftops. The model calculations require substantial computational power. Historical data, a nowcast, a seven-day forecast as well as climate projections are all calculated for any point in the city and stored on the meteoblue cluster.
High accuracy of city climate models
The meteoblue city climate models perform better than 1°C for the spatial interpolation technique, with a decreasing error when using more stations. We can calculate the number of stations needed to achieve the desired accuracy of modelled data. Based on our existing verifications, for our 24h forecast an accuracy of 1.2 °C for air temperature can be expected.
What is city climate?
City climate is defined as "local climate which differs from that in neighbouring rural areas, as a result of urban development". This means air temperature, precipitation, concentration of air pollutants, and wind speed often differ from the surrounding areas. Differences in air temperature between a city and its surrounding areas can reach up to 10 °C at night. City effects on precipitation intensity and wind fields are also documented.
Why do cities heat up but do not cool off as much?
Cities are characterized by densely built-up areas and surface sealing. This leads to higher air temperatures and reduced wind speeds. Buildings and streets store the energy of solar radiation during the day and release this energy in form of heat at night. Wind speed, and thus ventilation of the city, is often reduced by buildings. Vegetation such as urban trees or green spaces that could provide shade and cooling by evaporation can be rare or missing altogether.
What are the consequences?
Heat waves particularly affect the elderly and the sick, since cardiovascular diseases increase the risk of death during the heat. Increasing temperatures also increase the number of heavy precipitation events in cities, thereby causing floods whose impact is much more severe in cities than in the open countryside: the sealed surfaces of the city increase water runoff and prevent seeping of rainwater into the ground. The sewer system provides only limited buffer for rainwater and can overflow if precipitation is high. The increased likelihood of heavy precipitation and hail events can require additional insurance services due to the enormous damage they can cause in a city.
How to better predict the city climate and its effects?
The first step to better understand a city’s climate and its possible future change is to install a modern sensor network at suitable locations within the city to measure and store hourly data for air temperature, precipitation, and other variables. Based on these data, special city climate models fill the gaps between the measurements and generate a comprehensive climate information system for the city. This system can then produce risk maps and assessments, as well as forecasts, warnings, and planning scenarios. The system can be used to inform the citizens, support decision makers, and help develop plans to improve the city climate.