Causes of Natural Variability

Slides:



Advertisements
Similar presentations
The Ice Age Cometh. Where did they come from? - ERRATICS.
Advertisements

GEOS 112 Lecture Topics 4/28/03 Read Chapter 12 (Glaciers) Final Exam – Monday, May 5 1:00pm 1.Types of Glaciers; 2.Glacier Formation, Mass Balance, and.
Global Air temperature from 1850 The time series shows the combined global land and marine surface temperature record from 1850 to The year 2007.
14.3 Climatic Changes.
Climatology Climatology is the study of Earth’s climate and the factors that affect past, present, and future climatic changes. Climate describes the long-term.
Sea-Tac. Glacial evidence In what way is a glacier like a water reservoir (other than they are both water)?
Myr ago Puzzle: Ice Ages! Occur with a period of ~ 250 million yr Cycles of glaciation within the ice age occur with a period of 40,000 yr Most recent.
Fossils, Paleoclimate and Global Climate Change. Global Warming CO 2 levels in the atmosphere rising Average global temperature is rising Polar ice caps.
MET 112 Global Climate Change -
Last Time - Short Term Climate Change  Methods to Document Climate Change 1. Sedimentation 2. Ice cores 3. Dendrochronolgy 4. Coral Reefs 5. Pollen 6.
Gyroscope.
Earth Sun Geometry.
Climate and Climate Changes
Essential Principles Challenge
Climate and Climate Change
EARTH’S CLIMATE PAST and FUTURE SECOND EDITION CHAPTER 16 Climate Changes During the Last 1000 Years WILLIAM F. RUDDIMAN © 2008 W. H. Freeman and Company.
Climate & Climate Change Objectives: 1. What factors affect climate? 2. What is El Nino & how does it work? 3. What causes ice ages? 4. How can scientists.
What is an Ice Age ? Ice ages are times when large areas of the earths surface are covered with ice sheets The term is used to describe time periods when.
Ch : Climate & Climate Change Objectives: 1
Samayaluca Dune Field, south of Juarez, Chihuahua Global Climate Change.
OC 450: Orbital Controls on Climate (Chaps 8 and 10) Main Points: Small cyclic variations in the earth’s orbital characteristics affect the distribution.
Insolation and the Seasons Unit 6. Solar Radiation and Insolation  Sun emits all kinds of E E.  Most of the E E is visible light.  Sun emits all kinds.
History of Climate Change  During earth’s history, climate has generally been warmer than it is today, but is periodically interrupted by short cooler.
Natural Climate Changes Processes Resulting in Changes in Climate Trends Over Time.
Climate change – “science catfight” or not?. The Record Of Climate Change Proxy Data.
21.3 Climate Change. Natural Processes That Change Climate Volcanic eruptions The presence of volcanic ash, dust, & aerosols in the air increases the.
Module 4 Changes in Climate. Global Warming? Climate change –The pattern(s) of variation in climate (temperature, precipitation) over various periods.
Climate Change. Determining past climate The methods used to study the past climate typically involve physical, chemical, biological processes sensitive.
14.3 – CLIMATIC CHANGES. Ice Age  Periods of extensive glacial coverage  Lots of ice sheets  Average global temperature decreased by about 5°C  Most.
1 Geologic Perspective on Climate  El Nino  The last 1,000 Years: Natural Variability?  The Ice Ages and their cause  The world the Dinosaurs inhabited.
Honors 1360 Planet Earth Last time: Measuring Earth’s Hydrosphere Obs : Gravity changes (allow us to see “hidden” groundwater; can also separate steric.
CHAPTER 15 THE EARTH’S CHANGING CLIMATE CHAPTER 15 THE EARTH’S CHANGING CLIMATE.
Lecture 15 Defining climate, climate controls Climate classification
How does the Earth on which we live function as a whole?
Global Climate Change A long term perspective. Global Warming CO 2 levels in the atmosphere rising Average global temperature is rising Polar ice caps.
Honors 1360 Planet Earth Last time: Measuring Earth’s Hydrosphere Obs : Altimetric height changes on rivers & lakes (with strong seasonal cycle & dependence.
Climate and Climate Change Chapter 21
Abrupt Climate Change. Review of last lecture Large spread in projected temperature change comes from uncertainties in climate feedbacks Main climate.
Natural Climate Changes Processes Resulting in Changes in Climate Trends Over Time.
Climate Change Monday, November 5th. Anthropogenic Climate Change Thomas Jefferson, 1781 Notes on the State of Virginia –Springs are warmer –Less winter.
Discuss the relationship between climate and biomes.
History of Climate Change  During earth’s history, climate has generally been warmer than it is today, but is periodically interrupted by short cooler.
Causes of Climate Change Think: What is climate change? (key words you have heard on the news, important impacts, etc) Global Climate Change
CHAPTER 15 THE EARTH’S CHANGING CLIMATE CHAPTER 15 THE EARTH’S CHANGING CLIMATE.
Chapter: Climate Section 3: Climatic Changes.
An Orbital Theory For Glacial Periods
Climate Change: Ice Ages Naturally Occuring, Long Term
 On a climograph, what data are represented with bars? ◦ What data are represented with a line graph?  How can you determine the climate classification.
Long-Term Changes in Climate
Causes of Global Warming. “Over the last few decades there’s been much more evidence for the human influence on climate…. We’ve reached the point where.
Ice Age Ice Age, a time when ice sheets and alpine glaciers were EXTENSIVE, and advanced and receded repeatedly over LONG PERIODS of time.
LONG AND SHORT TERM CHANGES IN CLIMATE. LONG TERM CHANGES Continental Drift When continents move, ocean currents and wind patterns change which affects.
To recap Give 2 examples of research methods that show long term historical climate change? How reliable are these? Give 2 ways of measuring medium term.
The Earth's Changing Climate Chapter 16. Climate of the earth has always changed over time. Currently evidence shows that the earth is warming, this can.
The Earth’s Orbit and Climate
Lecture 20: Orbital Variations in Ice Sheets (Milankovitch Cycles)
Long and Short Term Changes in Climate
Long-term climate change & Short-term climate variability
14.3 Climatic Changes.
Natural & anthropogenic causes
DO NOW Pick up notes and Review #25..
The Earth’s Orbit and Climate
Long-Term Changes in Climate
Past Climates - the mechanisms
Long-Term Changes in Climate
Climate Changes due to Natural Processes
The Earth’s Orbit and Climate
Chapter: Climate Section 3: Climatic Changes.
Historical Climate Change
Climate Change.
Presentation transcript:

Causes of Natural Variability Volcanoes and Ice Ages Causes of Natural Variability To download: Shift LeftClick PowerPoint 97 Please respect copyright on this material

Key Points Past Variations in Global Temperature Volcanoes 100 yrs Warming + Volcanoes 1000 yrs Medieval Optimum + Little Ice age 10,000 yrs Post glacial 1,0000,000 yrs Milankovitch Cycles Volcanoes Climate records from ice and sediment cores Ice ages Worldwide, most small glaciers are receding

El Nino Events and Global Temperature

The last 1,000 years Note +/- 0.5 oC

South Western U.S. 1300 AD Why did these communities collapse? Mesa Verde Cliff House

Since the end of the last ice age Note range of +/- 1 oC since 10,000 BP

Last Glacial Maximum xxx

Signs of Past Glaciation xxx

A million years of ice ages and interglacials Estimated global surface temperature from ocean sediments Present temperature 15 oC

Key Points Past Variations in Global Temperature Volcanoes Large volcanoes inject sulfate aerosols into stratosphere Sulfate aerosols reflect sunlight back to space Cool the earth, but only for a year Climate records from ice and sediment cores Ice ages Worldwide, most small glaciers are receding

Mount Saint Helens May 18, 1980 United States Geological Survey

Atmospheric Transmission Interrupted by large volcanoes Mount Pinetubo El Chichon

Global temperature and volcanoes Each event followed by a drop for 2-3 years

Key Points Past Variations in Global Temperature Volcanoes Climate records from ice and sediment cores O18 (temperature), CO2, sulfate, ... Ice ages Worldwide, most small glaciers are receding

Drilling Ice Cores in Peru Annual layers in the Quelccaya Ice Cap Distant view of ice cap Lonnie Thompson

Inca Country Peru

Equator Peru Lonnie Thompson &Ellen Mosely Thompson

Annual Signature in O18 Quelccaya - 1976 Core Also measured are dust, and sulfate CO2 , methane can also be measured from ice cores, though not from this one

Drilling Ice Cores in Greenland xxx

Key Points Past Variations in Global Temperature Volcanoes Climate records from ice and sediment cores Ice ages Last ice age ended 12,000 years ago Changes over tens of thousands of years Driven by Milankovitch cycles in Earth orbit Recent evidence of abrupt transitions within 100 years Worldwide, most small glaciers are receding

A million years of ice ages and interglacials Estimated global surface temperature from ocean sediments Present temperature 15 oC

Land Ice in the Northern Hemisphere (now vs 18,000 BP)

Alaskan Glacier Photo Inge Bretherton

Greenland Ice Sheet More great pictures (University of Cincinnati)

Key Points Past Variations in Global Temperature Volcanoes Climate records from ice and sediment cores Ice ages Last ice age ended 12,000 years ago Changes over tens of thousands of years Driven by Milankovitch cycles in Earth orbit Recent evidence of abrupt transitions within 100 years Worldwide, most small glaciers are receding

Milankovitch Cycles Small, predictable, changes in orbit of Earth around the sun Departures from idealized elliptic orbit of Newton, Kepler Precession: period 23,000 years Tilt: period 41,000 years Ellipticity: period 100,000 years Calculated in 1920’s but then no evidence Do not change total radiation reaching earth, only distribution among seasons

Elliptic Orbit (Newton) Ellipticity exaggerated For small sun, earth, orbit is fixed in space

Tilt Present tilt 23.5o Varies 22o - 24.5o every 41,000 years No tilt, no seasons

Precession - 1 Earth’s axis of rotation moves in space Because earth not quite spherical like a spinning top Earth now closest to sun in Northern winter was/ will be in Northern summer Period 23,000 years About 12,000 years ago Hudson Bay ice cap melted

Precession - 2

Incoming solar radiation Tilt + precession + ellipticity Varies with latitude Direct effects largest for continents

Key Points Past Variations in Global Temperature Volcanoes Climate records from ice and sediment cores Ice ages Worldwide, most small glaciers are receding

Evidence for Ice Cap Melting 1976 - Right Clear annual trace 1991 - Left Warmed and melted

Melting Glaciers xxx

Key Points Past Variations in Global Temperature Volcanoes Climate records from ice and sediment cores Ice ages Worldwide, most small glaciers are receding

Sources of Information Horel & Geisler Chapter 4,5 Lonnie Thompson and Ellen Mosely-Thompson, Ohio State University http://polarmet.mps.ohio-state.edu/Icecore/Quelccaya.html Thomas Lowell, University of Cincinnati http://tvl1.geo.uc.edu/ice/glacier.html