1. Monitoring Earth’s Climate System
Current Weather
Indicators of Climate Change
Climatic Anomalies and Feedback Loops
Observing the Climate System
Remote Sensing by Satellite
International Cooperation
Modeling Earth’s Climate System
For Next Class: Read Chapter 3

2. Numerical Weather Prediction
We will keep a close eye on the numerical forecast models, including the Global Forecast System (GFS) model run by the National Centers for Environmental Prediction (NCEP):
Specifically, we will look at the 850 mb temperature (equivalent to ~4750 ft asl or the top of Rich Mountain), mean sea level pressure, and quantitative precipitation forecast (850temp_mslp_precip).

3. Indicators of Climate Change
IPCC 2013

5. IPCC 2013

6. What is the difference between Weather and Climate?

7. What is the difference between Weather and Climate?
Weather: State of the atmosphere over the short term (minutes to ~15 days).
Climate: Synthesis of weather conditions in a given area, characterized by long-term statistics (mean values, variances, probabilities of extreme values, etc.) of the meteorological elements in that area.
Climate is what you expect, weather is what you get!

8. Defining Climate The Climatic Norm
Encompasses the total variation in the climate record, that is, both averages plus extremes
© AMS

9. Defining Climate Historical Perspectives At present,
840 automated weather stations operated by NWS and FAA
11,700 cooperative weather stations
© AMS

10. What is the difference between Climate Variability and Climate Change?
Climate Variability: deviations of climate statistics over a given period of time (e.g., specific month, season or year) from the long-term climate statistics relating to the corresponding calendar period.
Climate Change: a significant change (e.g., having important economic, environmental and social effects) in the mean values of a meteorological element (e.g., temperature or precipitation) in the course of a certain period of time, where the means are taken over periods of the order of a decade or longer.
Source: National Snow and Ice Data Center (NSIDC)

11. The Climate System
System: entity whose components interact in an orderly manner according to the laws of physics, chemistry, and biology
Earth’s Climate System: defined as the totality of the atmosphere, hydrosphere, biosphere and geosphere and their interactions
© AMS

12. The Climate System Atmosphere
Relatively thin envelope of gases and tiny suspended particles surrounding the planet
Divided into four layers:
Troposphere
Stratosphere
Mesosphere
Thermosphere
© AMS

13. Driving Question
How do climate scientists investigate the spatial and temporal characteristics of climate, climate variability and climate change?
© AMS

14. Climatic Anomalies Departures from the long-term average
Do not occur with the same sign or magnitude everywhere
Positive anomalies: above long-term averages
Negative anomalies: below long-term averages
Westerly wave pattern exhibits changes in wavelength, amplitude, and wave number
Patterns in the westerlies determine location of weather extremes
© AMS

15. Climatic Anomalies Feedback Loops
Many variables in the climate system are linked together in complex forcing/response chains
Interactions between variables involve feedback loops that either amplify (positive feedback) or weaken (negative feedback) fluctuations in climate
© AMS

16. Group Exercise
Please discuss the difference between a positive and negative feedback and provide examples of each.

17. Climatic Anomalies Positive feedback example Negative feedback example
© AMS

18. Observing the Climate System
In Situ Measurement
Radiosonde: small instrument package equipped with a radio transmitter that is carried aloft by a balloon
Create soundings, or altitude readings of temperature, air pressure and dewpoint
Launched at 12 hour intervals
at ground stations world wide
© AMS

19. © AMS

20. Radiosonde Release in Peru

21. Observing the Climate System
In Situ Measurement
Ships, buoys, floats, gliders, piloted submersibles, autonomous instrumented platforms and vehicles, and undersea observatories provide in situ ocean data
© AMS

22. Argo floats obtain profiles of temperature and salinity in the ocean
Sample plots of float-derived temperature and salinity profiles
© AMS

23. Observing the Climate System
Remote Sensing by Satellite
Sensors observing Earth from orbiting spacecraft measure selected wavelengths of the electromagnetic radiation reflected or emitted by the Earth’s climate system
© AMS

24. Observing the Climate System
Remote Sensing by Satellite
Electromagnetic radiation: both a form of energy and a means of energy transfer, travel as waves
Electromagnetic spectrum: composed of different forms of radiation
© AMS

25. Observing the Climate System
Remote Sensing by Satellite
Wavelength: distance between successive wave crests
Wave Frequency: number of crests that passes a given point in a specified period of time
© AMS

26. Observing the Climate System
Remote Sensing by Satellite
Satellites fly in either geostationary or polar orbits
Geostationary orbit
Polar orbit
© AMS

27. Observing the Climate System
Visible Satellite Image
© AMS

28. Observing the Climate System
Infrared Satellite Image
© AMS

29. Observing the Climate System
Water Vapor Satellite Image
© AMS

30. International Cooperation in Understanding Earth’s Climate System
Intergovernmental Panel on Climate Change (IPCC)
Formed in 1988 by the World Meteorological Organization (WMO) and the United Nations Environmental Programme (UNEP)
Evaluates the state of climate science
Composed of three working groups and a task force
© AMS

31. Modeling Earth’s Climate System
Model: an approximate representation or simulation of a real system, incorporating only the essential features of a system while omitting details considered non-essential or non-predictable
© AMS

32. Modeling Earth’s Climate System
Physical Model: small-scale portrayal of a system
Numerical Model: consists of many mathematical equations that simulate the processes under study
Numerical weather and climate forecasting done at National Centers for Environmental Prediction (NCEP)
© AMS

33. © AMS

34. Modeling Earth’s Climate System
© AMS

35. Modeling Earth’s Climate System
Short-Term Climate Forecasting
NCEP’s Climate Prediction Center
30-day (monthly), 90-day (seasonal), and multi-seasonal climate outlooks prepared
Outlooks issued two weeks to 12.5 months in advance for the coterminous U.S., Hawaii, and other Pacific islands
© AMS

36. Climate Prediction Center

37. Modeling Earth’s Climate System
Long-Term Climate Forecasting
Global Climate Model (GCM): simulates Earth’s climate system
Numerical models
Boundary conditions can be changed to determine how Earth adjusts to new conditions
© AMS