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Climate (Atms 4600) Professor Anthony R. Lupo Department of Soil, Environmental, and Atmospheric Science University of Missouri Columbia, MO

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ATMS 4600 Climate At the University of Missouri, I teach an introductory climates class (too easy) and a graduate level class (too hard). I wanted to create something in the middle. This class will essentially just go 'upscale' from ATMS 8400 - Theory of the General Circulation.

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ATMS 4600 Climate Some initial questions: What is Climate? How does it differ from weather (synoptic, or even the General Circulation)? How is this different from Climatology? Weather the day to day state of the atmosphere. Includes state variables (T, p) and descriptive material such as cloud cover and precipitation amount and type, etc.

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ATMS 4600 Climate Recall in meteorology, we tend to divide phenomena by scale based on what processes are important to driving them. Table 1 ScaleTimeSpaceForceWeather Planetary7 14 days6000+ kmCo, PGFJet stream Synoptic1 7 days2000 6000 kmCo, PGF, Fric, Bouy Low pressure Meso1 - 24 h10 2000 kmBouy, PGF, Fric Fronts Micro< 1 hr< 10 kmBouy, Fric, PGF Thunderstor m

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ATMS 4600 Climate Time / space Scales / example / forces Micro- 1 hour /

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ATMS 4600 Climate Spatial/Temporal Scales Synoptic- 1 day-1 week / 2000-7000km / cyclones / Coriolis Force, Pressure Gradient force Planetary- >1 week / >7000km / blocking, jet stream / Coriolis force, pressure gradient force

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ATMS 4600 Climate General Circulation statistical features. We think of planetary in scale, but time scales are 2 weeks, 1 month, 1 season, 1 year, a few years. Climate Is the long-term or time mean state of the Earth-Atms. system and the state variables along with higher order statistics. Also, we must describe extremes and recurrence frequencies.

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ATMS 4600 Climate Thus, the general definition of climate is scale independent and a technical definition would depend on your scale, ie we can describe micro, meso, and synoptic climates and climatologies. Climate as we will discuss it many contexts will be "global" or large-scale in nature, or "upscale" in time from the General Circulation.

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ATMS 4600 Climate FIG. 2.1. Annual global surface temperature departures from the 1961 to 1990 average. [Sources: NOAA/ NCDC; CRU/UKMO (HadCRUT3); and NASA GISS.]

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ATM 4600 Climate Observations and the Hockey Stick

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ATMS 4600 TemperaturePrecipitation

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ATMS 4600 Climate Climatology is the study of climate in a mainly descriptive and a statistical sense. Climatologists study these issues. Dynamic Climatology or Climate dynamics are relatively new concepts and involve the study of climate in a theoretical and/or numerical sense. In order to study climate in this sense, we will use models, which will be derived using basic equations. One way to accomplish this is via the scaling of primitive equations, or using basic 'RT' equations (Energy Models, which use concepts like Stefan Boltzman's law). We wont do this in this class, save for ATMS 8600

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ATMS 4600 Climate Key concepts that will be discussed in this course: We'll need to distinguish plainly between weather and climate! (Review the concept of climatic averaging') We'll need to talk about time variations on climate states ('climate' versus climate change) We'll need to examine the components of the climate system

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ATMS 4600 Climate We'll need to examine the state of the climate, in particular this means 'internal variables' (internal vs. external). We'll need to study climatic 'forcing' (this means 'external variables (e.g. Solar, Plate tectonics, humans?), (also how they differ from internal)) We'll need to examine issues surrounding spatial resolution and climatic character.

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ATMS 4600 Climate The earth-atmosphere system, courtesy of Dr. Richard Rood. (http://aoss.engin.umich.edu/class/aoss605/lectures/)

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ATMS 4600 Climate The primary components of the Climate system 1.The Atmosphere (typical response time --> minutes to three weeks) 2.The Ocean (typical response time months and years, for upper ocean) 3.The litho-biosphere (we'll treat as one for now) 4.The cryosphere (both land and sea ice, response times on order of decades to MYs)

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ATMS 4600 Climate Aside: Typical short-hand notations used now in the study of climate: 10,000 Years Before present (10 KY BP) KY = Thousands of years BP = before present MY = Millions of years.

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ATMS 4600 Climate Another view of the climate system

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ATMS 4600 Climate Another view

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ATMS 4600 Climate Each component of the climate system can be described by it's own state variables, which are considered internal variables. External forcing is defined as forcing outside the system or sub-system. Thus, SST anomalies are internal or state variables for the earth atmosphere system, or the ocean. But they are considered 'forcing' or external to the atmospheric component. Also, the dynamics of the internals are fairly well know, but heat and mass exchange processes between sub-sytems not well understood.

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ATMS 4600 Climates Atmospheric Composition Homosphere: