Introduction to the Climate System and its Dynamics (PDF)

2-Introduction to the Climate system and its dynamics Carme Huguet| BESS| Sci-Tech School IE RECAP FROM VIDEO-Dr Sara Harrys What are the main climate system components? Biosphere, hydrosphere, geosphere and atmosphere What are the three main energy flows in our planet? Incoming sun radiation,...

2-Introduction to the Climate system and its dynamics Carme Huguet| BESS| Sci-Tech School IE RECAP FROM VIDEO-Dr Sara Harrys What are the main climate system components? Biosphere, hydrosphere, geosphere and atmosphere What are the three main energy flows in our planet? Incoming sun radiation, reflectivity of the surface and greenhouse effect. What are the main greenhouse gases? What are the roles of organisms in the climate system? CO2, Methane, water vapour, nitrous oxide and Many roles, they will capture CO2, store it and release ozone it, they can help with cycling of carbon, etc How does water help to reduce heat on earth? Ice will reflect incoming radiation also ocean water will absorb energy and recirculate throught.  Climate system components The climate system is interactive, and the main components are atmosphere, hydrosphere (oceans), to a lesser extent the lithosphere and the biosphere. Climate system components Ocean Circulation Atmospheric Solar Energy Criculation + Earth´s Rotation (Coriolis) General 3.51’: https://www.youtube.com/watch?v=lrPS2HiYVp8 Climate system components ENERGY SOURCE: Solar Radiation The curvature of the planet forms a continually changing angle with respect to the sun's rays (parallel) The differences in this angle (latitude) generate a heterogeneous heat distribution. Maximum sunshine when the sun is directly overhead (solar angle = 90º) At any other point on the planet, the energy is diffused. Climate System components WARMING: Of the 340 watts per square meter of solar energy that falls on the Earth, o 29% is reflected back into space, primarily by clouds, but also by other bright surfaces and the atmosphere itself. o About 23% of incoming energy is absorbed in the atmosphere by atmospheric gases, dust, and other particles. o The remaining 48% is absorbed at the surface. NASA illustration by Robert Simmon. Astronaut photograph ISS013-E- 8948.  Climate system components COOLING: Evaporation (25%): when heat Three processes remove energy from the energy is absorbed by water Earth’s surface. molecules, causing them to move faster and eventually escape into the ( atmosphere as water vapor. https://earthobservatory.nasa.gov/features/EnergyBalance/pag e1.php , NASA illustration by Robert Simmon. Photograph ©2006 Cyron.) Convection (5%): transfer of heat through the movement of a fluid (like air or water). Thermal Infrared Radiation (17%): emission of electromagnetic waves from all matter that has a temperature greater than absolute zero. Climate system components The atmosphere radiates the equivalent of 59% of incoming sunlight back to space as thermal infrared energy, or heat. The atmosphere directly absorbs about 23% of incoming sunlight, and the remaining energy is transferred from the Earth’s surface by evaporation (25%), convection (5%), and thermal infrared radiation (a net of 5-6%). The remaining thermal infrared energy from the surface (12%) passes through the atmosphere and escapes to space. (https://earthobservatory.nasa.gov/features/EnergyBalance/page1.php, NASA illustration by Robert Simmon. Astronaut photograph ISS017-E- 13859.)  Climate system components EEI 381±61 ZJ The Earth climate system is out of energy balance, and heat has accumulated x10 continuously over the past decades, warming the ocean, the land, the cryosphere, and the atmosphere. According to the 6º Sixth Assessment Report by IPCC, this planetary warming over multiple decades is human-driven and results in unprecedented and committed changes to the Earth system, with adverse impacts for ecosystems and human systems. Total Earth system heat gain in ZJ (1 ZJ =1021 J) relative to 1960 and from 1960 to 2020. Climate system components The Earth heat inventory provides a measure of the Earth energy imbalance (EEI) and allows for quantifying how much heat has accumulated in the Earth system, as well as where the heat is stored. This is equivalent to a heating rate (i.e., the EEI) of 0.48±0.1 W m−2.  Climate system components Near the equator energy is almost constant all year round http://earthobservatory.nasa.gov /Features/EnergyBalance/page 1.php Climate system components Why does the planet have seasons? Tilt of earth axis Variation Seasonality Orbit in sunlight Day length https://spaceplace.nasa.gov/seasons/en/ https://sitn.hms.harvard.edu/flash/2019/going-back-moon-uncover-origins/  Climate system components What caused the earths TILT? In Earth's early history, a large celestial body named Theia collided with it, causing a tilt in its axis and ejecting debris into orbit. This debris eventually coalesced to form the Moon. As Earth orbits the Sun, its tilted axis remains fixed, leading to varying solar exposure throughout the year. https://spaceplace.nasa.gov/seasons/en/ https://sitn.hms.harvard.edu/flash/2019/going- back-moon-uncover-origins/ Climate system components There is an excess of incoming energy at low latitudes and a deficit at high latitudes. This imbalance explains the formation of climatic belts. The heat needs to be redistributed, and this is achieved through atmospheric and ocean circulation. https://www.researchgate.net/publication/332326791_High- rate_lithium_ion_energy_storage_to_facilitate_increased_penetration_of_photovoltaic_systems_in_electricity_grids/figures?lo=1 Climate system components ATMOSPHERIC CIRCULATUON 3.35’: https://www.youtube.com/watch?v=xqM83_og1Fc o It is clearly associated with the different climatic zones. o It is essential to redistribute heat. o Three cell system due to temperature gradient and Coriolis force. Further information 6’: https://www.youtube.com/wat h?v=PDEcAxfSYaI  Climate system components OCEAN CURRENTS: Video on currents 4.33’: https://www.youtube.c om/watch?v=p4pWafuvdrY Surface currents: Top 10 % of ocean water, moved by wind. Deep currents: The heat stored in the ocean gets redistributed thanks to the global ocean conveyor belt that is a constantly moving system of deep- ocean circulation driven by temperature and salinity. Climate system components o The oceans transport a large amount of energy from the equator to the poles. o Ocean functions as a regulator of the Earth's climate. o Global circulation is maintained by cooling water in the North Atlantic. What will happen with global warming? https://uw.pressbooks.pub/fundamentalsofclimatechange/chapter/moving-energy/ How will global Slowing of the thermohaline Circulation: warming affect Global warming will alter the density of sea water by increasing its temperature and changing its salinity through the melting of ice. ocean circulation? Disruption of currents: Melting of the ice and increases the amount of fresh water in the ocean, which can disrupt ocean currents. Weakening of Currents: This could cause heat and cold extremes in certain regions and rapid sea-level rise along specific coastlines. Key examples that will affect heat redistribution  Climate system components Albedo: Percentage of incident solar energy that is reflected. The average albedo of the planet is 31% The albedo changes with the seasons (changes in vegetation, clouds, snow, etc.)  Climate system components The GESOPHERE, impacts the climate system in a variety of ways, typically reacting on geologic timescales and affecting climate slowly and over millions of year. o Plate tectonic movements, are responsible for the positions of continents. This can have a large effect on regional and global climates. o The growth of mountain ranges affects atmospheric circulation patterns and the number of alpine glaciers. o Volcanic eruptions lead to more sulfuric acid/ash blocking solar radiation. This can have a cooling effect. o Carbon Sequestration: Over millions of years, CO2 becomes sequestered in rocks like limestone and fossilized plants that may become coal and other fossil fuels. Climate system components The BIOSPHERE, plays a crucial role in modulating the climate system. o All organisms affect the composition of the atmosphere because they take in and release gases, such as CO2 and CH4 o The biosphere plays a significant role in the carbon cycle. Plants, for instance, absorb CO2 for photosynthesis and store C in their tissues, effectively removing it from the atmosphere. o The variety of life forms in an area can influence local climates. For example, forests have a cooling effect. o The biosphere can also provide feedbacks to the climate system. We will see more in a minute.  Climate system forcings EXTERNAL FORCING: Changes external to the climate system o Changes in plate tectonics, o Changes in earths orbit, o Sun’s strength.  Separation of Antarctica contributed Climate system forcings to its unique climate cold and dry causes by several circumpolar currents. https://www.whoi.edu/oceanus/feature/how-the- isthmus-of-panama-put-ice-in-the-arctic/ EXTERNAL FORCING: o Changes in plate tectonics, The rise of the Isthmus of Panama restricted water exchange between the Atlantic and Pacific, and their salinities diverged. The isthmus diverted waters that once flowed through the Seaway. The Gulf Stream began to intensify. The Isthmus closing has been suggested to be key to the formation of Ice sheets in the arctic. https://www.whoi.edu/oceanus/feature/how-the- isthmus-of-panama-put-ice-in-the-arctic/ Climate system forcings EXTERNAL FORCING: o Changes in earths orbit, Serbian mathematician Milutin Milankovitch demonstrated that variations in the Earth's orbit were fundamental causes of glaciations More in depth 5.44’: https://www.youtube.com/watch?v=xQ and other climatic variations. SHxY5ZR6w  Climate system forcings EXTERNAL FORCING: o Sun’s strength. The Sun’s overall brightness varies on an 11-year cycle, and these changes are detectable in the global temperature record. During strong solar cycles (more sun spots), the Sun's total average brightness varies by up to 1 Watt per square meter; this variation affects global average temperature by 0.1ºC or less. https://www.climate.gov/news-features/understanding-climate/ climate-change-incoming-sunlight Climate system forcings INTERNAL FORCINGS: Changes that occur within the Earth’s climate system: o Feedback, o Global and hemispheric variability, o Regional variability.  Climate system forcings Climate Feedbacks play a crucial. role in the climate system POSITIVE Climate Feedbacks: An initial change in the climate causes a secondary change that increases the effects of the initial change. For example, the melting of ice decreases. NEGATIVE Climate Feedbacks: An initial change in the climate causes a secondary change that reduces the effect of the initial change. For example, increased evaporation results in more clouds forming in the lower atmosphere, increasing solar radiation reflection. Climate system forcings Climate Feedbacks exercise: In your groups draw a positive and negative feedback loop with o Increased/decreased temperature o Increased/decreased precipitation Climate system forcings Some examples Climate scales The climate system presents multidimensional scales, not only temporal but also geographical. It is a continuum Biogeochemical Cycles A biogeochemical cycle is a pathway by which a chemical element or molecule moves through the biotic and abiotic compartments of the Earth. Biogeochemical cycles important to living organisms include the water, carbon, nitrogen, phosphorus, and sulphur cycles. Biogeochemical Cycles o RESIDENCE TIME: how quickly a material is moving through a system, and more important, it tells us how quickly some part of the system, or the system as a whole can respond to changes. o If something has a short residence time, it can respond quickly to changes, whereas if it has a long residence time, it responds very slowly. Carbon Cycle Now we will draw a carbon cycle with the person next to you 1st make a list of: o Reservoirs (Sources and Sinks) o Flows: natural and anthropic Carbon cycle RESERVOIRS: FLOWS: RESERVOIRS Atmosphere Natural FLOWS Oceans: surface, deep, Weathering Geosphere: Rocks, sediments, mantle Photosynthesis-Respiration Soil Outgassing Biosphere: Land-Ocean Volcanism Anthropic: Fossil fuel burning Vegetation burning Farming Carbon Cycle Now we will draw a carbon cycle incorporating all the reservoirs and flows with the person next to you Then compare with other groups Simplifed carbon cycle  Carbon cycle RESERVOIRS: o Atmosphere o Oceans: surface, deep, o Geosphere: Rocks, sediments, mantle o Soil o Biosphere: Land-Ocean Calculate the residence time: Carbon cycle Soil=26.33 years Sedimentary Rocks= 1.67e6 years Land Biota= 5.54 years Ocean Biota=0.3 years Atmosphere=3.75 years Carbon Cycle The Slow Carbon Cycle Through a series of chemical reactions and tectonic activity, carbon takes between 100- 200 million years to move between rocks, soil, ocean, and atmosphere. The Fast Carbon Cycle The time it takes carbon to move through the fast carbon cycle is measured in a lifespan. The fast carbon cycle is largely the movement of carbon through life forms on Earth, or the biosphere. We are shifting carbon from the slow to the fast cycle! Carbon cycle >10 GtC/year) >5 GtC/year) Friedlingstein et al., 2022 Key compartments, processes and pathways that govern historical and future CO2 concentrations and carbon–climate feedbacks through the coupled Earth system. 6th IPCC