Brandon Kaplan, Corporate Communications
Michael Sullivan, Mechanical Engineer, Test Solutions
Increases in the frequency and severity of extreme weather events as well as mounting public debate about the causes and effects of climate change have underscored the need for technology to measure and understand trends in the global climate. RF systems play a critical part in the global network of observation stations and instruments that scientists and policy stakeholders rely on to make informed decisions and steer the world toward a sustainable future.
The UN Framework Convention on Climate Change (UNFCCC) was established in 1992 with the goal of supporting the global response to climate change. The convention has 197 signatory parties, nearly all the world’s nations, and creates a venue for intergovernmental negotiation as well as a hub of technical expertise for the analysis of information on climate change. Agreements under the treaty include the 1997 Kyoto Protocol and the 2015 Paris Agreement, both aimed at curbing greenhouse gas emissions to prevent human-driven environmental dangers while enabling sustainable development. The convention stresses that climate policies should be based on science and therefore necessitates extensive global infrastructure for robust and reliable measurement of the indicators that provide a clear and complete picture of the long-term behavior of Earth’s systems.
Surface- and space-based climate observing systems. Image credit: https://public.wmo.int
The planet is covered by networks of sensors and measurement instruments on land, in the oceans, in the atmosphere and in space to measure 54 essential climate variables (ECVs) needed to understand and predict the evolution of the climate. These systems are owned and operated by numerous national and international organizations including the World Meteorological Organization Integrated Global Observing System (WIGOS), World Weather Watch (WWW) and many others. Data collected from some of these systems dates back over a century, so scientists already understand a lot about patterns and trends in climate history. But over time, the various organizations involved have moved to implement new technologies for more advanced measurement capabilities and to integrate and standardize data from all participating organizations to create a comprehensive, free and open resource to support sophisticated modelling and prediction.
Whether Earth observations are taken from sensors mounted on ocean buoys and ships, land-based weather stations, weather balloons or satellites, RF signals are almost always used either directly in the measurement process or in the transmission of measurement data back to research hubs. Wind Profiling Radar (WPR), for example, is a radar device that allows researchers to remotely measure wind speed at various elevations above the Earth’s surface without sending a physical device into the atmosphere. WPRs send electromagnetic pulses in the VHF/UHF range upward in two or more different directions and measure the “backscatter,” or signal reflections from atmospheric features such as clouds and precipitation to resolve the wind speed. These radars are capable of distinguishing between reflections from atmospheric elements and non-atmospheric elements (such as insects or aircrafts), and some include Radio Acoustic Sounding Systems (RASS) which use differences in the speed of sound due to air temperature to measure vertical air temperature profiles together with wind speed. WPRs are one example of a surface-based, in situ measurement of an essential climate variable.
Wind Profiling Radar. Image credit: https://www.esrl.noaa.gov
Space-based sensing via satellite has become increasingly important as one of the most accurate, real-time sources of Earth observation data for weather forecasts, climate modelling and early warning systems for severe weather events. NASA’s SNoOPI satellite (Signals of Opportunity P-band Investigation), launched in January of 2021 uses P-band signals (240 to 270 MHz) to provide more accurate measurements of soil moisture at deeper soil depths than previous generation technologies allowed. Soil moisture measurements are not only ECVs for long-term climate observation, but also critical information for farmers and agricultural decision makers to predict crop yield and food production to minimize food shortages in different regions of the world. A Mini-Circuits blog post from September 2020 goes into detail on the SNoOPI satellite and Mini-Circuits role in supporting its development.
ASIMET sensing system mounted on a buoy. Image credit: https://whoi.edu
In addition to the many ways RF enables surface- and space-based measurement of climate variables, it’s also a vital factor in researchers’ ability to access information from thousands of remote sensors in near-real-time. The Woods Hole Oceanographic Institution’s ASIMET (Air-Sea Interaction METeorology) system is a set of seven precise sensors that measure how energy and water move between the ocean and the atmosphere. The systems are mounted on buoys or on the bows of ships, each of which has different advantages. ASIMET’s sensors record data once per minute into a central data logger and transmit averages back to researchers once per hour. Since these measurements are collected in the middle of the ocean out of range of terrestrial communications networks, ASIMET systems transmit data back to land via satellite. Buoy mounted sensors transmit via the ARGOS constellation, while shipboard sensors use INMARSAT.
These are only a few of the many ways RF technology enables faster, more accurate, and more integrated observations of Earth’s climate. Mini-Circuits is proud to support the global scientific community in their work to gain an ever deeper and more complete understanding of climate change. In addition to producing technology that goes into weather radars, satellites and other critical systems used by meteorologists and climatologists, the company is committed to operating practices that minimize waste and environmental impact through its ISO 14001 certified Environmental Management System. This Earth Day, the Mini-Circuits team salutes researchers everywhere contributing to the growing body of knowledge that governments and private organizations need to work together in building a safer, healthier and more sustainable world.