Upload
others
View
6
Download
0
Embed Size (px)
Citation preview
Second Lecture Series
in South Africa
October 11−17, 2015
Report on
Lectures in South Africa
October 11−17, 2015, Limpopo Univ.
Moto Ikeda
Yushi Morioka
Jayanthi Venkata Ratnam
Tak Ikeda
Climate variability/change
and Public health
Lecture
Climate Change & Global Warming
Moto Ikeda from Tokyo, Japan
Is global warming real?
What is the mechanism of global warming?
Radiation balance in the atmosphere
Absorption
& heating
Longwave radiation Shortwave radiation
Carbon dioxide
Questions on Global warming
• Is global warming real? YES
• Is it because of CO2? YES
• How much will warming proceed?
• How much should we reduce CO2 emission?
• Is it economically feasible?
• We need more scientific proof rather than “CO2
will be as much as the dinosaur era”.
More rain or less rain? (IPCC Report)
Atmosphere (830 x 10**9 ton=830 x 109)
Ocean
(40000 x 10**9 ton)
Anthropogenic
8 x 10**9
Global Carbon Cycle existing amount and annual flux
revised by AR5
80 x
10**9
120
x 1
0**9
82 x
10**9
122 x
10**9
Terrestrial ecosystem (600 x 10**9 ton)
Soil (3000 x 10**9 ton)
Nature is
important!
River 1 x 10**9 ton
Facts of global warming
• Mechanisms
CO2 increases by human activities.
Outgoing longwave radiation is absorbed by
CO2, and emits it back to the earth surface.
Carbon cycle among atmosphere, land and ocean
• Learn from old time
Higher CO2 in the dinosaur era
Lower CO2 during the glacier period
Impacts on global environmental change
• Tropical disease expands to mid-latitudes due to warming.
• Food production is decreased by precipitation change and soil moisture decrease.
• In subpolar regions, winter becomes shorter, and snow depth decreases.
• Damage in coastal areas by sea level rise
• More damage by unpredictable weather??
• More damage on developing countries
Health: global warming expands malaria
Feedbacks among Urgent Issues
Water resource
Global warming Biodiversity
Energy
& resources
Food
Industrial development
Globalization
Health
Once each issue gets worse, it worsens the others.
Can we solve all issues at once?
Kyoto Protocol
• CO2 emission = 1 tonC/(person・year) as global
average
• 3 tC/(p・y) in Japan, 6 tC/(p・y) in the US
• Reduction of emission by 6% of 1990 amount
before 2010
• No duty on developing countries (China & India)
• US has left from Kyoto Protocol.
• At COP17, Japan expressed withdrawal in the
extended period after 2013.
Kyoto Protocol and its Mechanism
• It makes easier to reduce CO2 emission.
• Joint Efforts
Developed countries (Annex I) can transfer
their reduction and not-yet-achieved
reduction.
• Clean Development Mechanism(CDM)
Annex I countries can buy absorption by
sink from non-Annex I countries.
Some conditions have to be satisfied.
Beyond Kyoto Protocol
• What will come in 2050-2100?
• The global population has increased by a factor of 2.4 in last 50 years, and will increase.
• Some of the developing countries will become developed countries in 50 years, and emit a large amount of carbon dioxide.
• Global warming will change the pattern of rain.
• Biodiversity is reduced and food supply is limited.
• Human health is damaged.
What should we do?
• How can we slow down CO2 increase?
• Technological development: transfer from
developed countries to developing countries
• Renewable energy (wind power, solar power, bio-
energy etc.)
• Changes in our concept and life style: possible ?
• Enhance Kyoto Protocol mechanism: Clean
Development Mechanism for developing
countries to sell carbon emission saving to
developed countries
Lecture
Climate variabilities around South Africa ~The fundamental nature of modeling
and its usefulness~
Yushi Morioka
JAMSTEC/APL
Weather and Climate
Today’s weather Annual mean climate
day-month timescale season-decade timescale
Weather is affected
by atmospheric variability
(e.g. Low/High)
Climate is affected
by oceanic variability
(e.g. El Nino)
News24 CSIR
Oceanic variability
affecting global and local climate
Accurate prediction of oceanic variability is
important for skillful climate prediction.
Warm
Cold
El Nino is developing in the tropical Pacific !
Current status of global ocean
Numerical simulation for climate
3. Earth Simulator
2. Governing equations
4. Predicted climate
1. Ocean and Atmosphere
El Nino
Peak in autumn, then
decay in next spring
Indian Ocean Dipole
Prediction results
Peak in autumn, then
decay in winter
Predicted climate (Dec-Feb)
Global: warmer climate
SA: warmer, drier
JP: drier
Introduction to Statistical downscaling and Dynamical downscaling
J. V. Ratnam
Application Laboratory, Japan Agency for Marine-Earth Science and Tech
(JAMSTEC) Japan
Global Models
The global General Circulation Models (GCMs) are run at coarser horizontal resolutions
http://serc.carleton.edu/eet/envisioningclimatechange/part_2.html
Downscaling
• The global General Circulation Models (GCMs) are run at coarser horizontal resolutions.
• To get the weather/climate forecast at regional scales, the coarser GCM forecasts are downscaled.
• Downscaling can be either statistical or Dynamical. • Statistical downscaling assumes that the relationship between the larger
scale variables such as pressure and the actual rainfall measured at one particular station will always be the same.
• Embed a regional climate model in a GCM
Global forecasts at coarser Resolution
Statistical Downscaling Dynamical Downscaling
Regional/Local Forecasts
or
Observed Large scale variable for eg. Pressure
Observed local rainfall
Statistical model
Forecast Large scale variable
Forecast local rainfall
Statistical downscaling
• Regional or local climate information is derived by first determining the statistical model which relates large-scale climate variable to regional and local variables.
• Then the large scale output of GCM simulation is fed into this statistical model to estimate the corresponding local and regional climate characteristics.
Statistical Model: a) Weather Typing b) Weather generators c) Regression models
Courtesy: Google earth
Global Model (100km)
Regional Model 1st Domain (27km)
Regional Model 2nd Domain (9km)
Dynamical downscaling • Regional climate model at high resolution embedded into the GCM output • Multiple two-way interacting domains can be used for downscaling.
Advantages and disadvantages Statistical downscaling Advantages: a) The statistical models are computationally inexpensive. b) The models provide site specific information required for impact study. Disadvantages: a) The relationship developed for the present climate may not be true for the future climate. b) Results are dependent on the statistical method used for downscaling. Dynamical downscaling Advantages: a) Consistent with GCM b) Resolve local processes responsible for the rainfall. Disadvantages: a) The results depend on how good the GCM is in representing the large scale processes. b) Results depend on the choice of domain. c) Computationally expensive
Application of Regional downscaling
The downscaled results are used to drive hydrological models.
Limpopo River Basin www.limpoporak.org
Application of Regional downscaling The global seasonal forecasts are downscaled for local climate change.
Current and possible future impacts and vulnerabilities associated with climate variability and climate change for Africa. Source: Adapted from IPCC Fourth Assessment Report (2007), Working Group 2: Impacts, Adaptation and Vulnerability, Chapter 9, Figure 9.5
What we plan to do under the joint AMED/JICA - DST SA project
Picture Courtesy: Google earth
SINTEX-F
WRF 27km
WRF 9km
Malaria Model
http://users.ictp.it/~tompkins/vectri/
• Seasonal Forecasts from SINTEX-F CGCM will be downscaled using both Statistical and Dynamical downscaling methods.
• The downscaled results will be used for driving Disease models such as Malaria model with focus on Limpopo province.
http://www.jamstec.go.jp/frcgc/research/d1/iod/sintex_f1_forecast.html.en
Summary
• To get a local forecast from a global model, the technique of downscaling is used.
• The downscaling can be applied by using statistical techniques or by using regional climate models
• Statistical techniques are easy to use, but the regional models are physically consistent.
• The downscaled products are used at many forecasting centers for daily weather forecast/ hydrology forecast/ climate forecasts.
The 5W1H of Statistics By Tak Ikeda
STATISTICS
WHAT
WHERE
WHEN
WHO
WHY
HOW
Outline: I will introduce the basics of statistics and how it is used in different scenarios, starting from the everyday things around us to more specific areas of research. If you are working or studying in the field of statistics, or already using statistics as a tool in your research or study, then GREAT (and keep learning)! If statistics is new to you, then I hope you learn something here. I am 95% confident that you will have to use statistics at some point of your life.
To learn more about statistics, you should take a course on it, or do some reading. I often make use of the sites below. Links: Online stats textbooks http://onlinestatbook.com/ http://www.statsoft.com/Textbook Forums http://stats.stackexchange.com http://stackoverflow.com/questions/tagged/r Social network www.researchgate.net Useful R related links https://cran.r-project.org/web/views/ http://www.r-bloggers.com http://www.ats.ucla.edu/stat/r/
5W1H Topics
• WHAT is statistics? • WHERE is statistics used around us? • WHO uses statistics? • WHEN can you use statistics? • WHY use statistics? • HOW to do statistics and interpret results
WHAT is statistics? “Statistics is the study of the collection, analysis, interpretation, presentation and organization of data.” - The Oxford Dictionary of Statistical Terms
• A “multi-tool” that can be used in any discipline. We could: • calculate probabilities • measure performance
• quantify uncertainty
• learn data
• predict the future
• make better decisions…
WHERE is statistics used around us?
• Statistics South Africa • Sports • Scientific research
WHEN can you use statistics?
You will need: • Some math skills • Calculator or computer software
(e.g. R, Stata, SPSS, MS Excel) • Data • Research question
WHO uses statistics?
•A “multi-tool” to: • calculate probability (or risk) of getting a disease – epidemiologist
• measure performance of 2 insect repellents – lab technician
• quantify uncertainty of future earthquake – seismologist
• learn data to decide what product to sell to who – data scientist
• predict the future of stock exchange – economist
• make better decisions, like which pair of shoes to buy – you
WHY use statistics?
• Give more meaning to data
• Describe the data -> trend, variability, correlation, patterns, etc
• Make inferences
-> generalizations of a population from a sample
• Make predictions -> future events in terms of probability, confidence
levels, uncertainty
Example – Risk of getting malaria Data: • Monthly malaria cases in Vhembe • For years 1998 to 2014
=> What is the relationship between
the number of malaria cases and temperature/precipitation?
Logarithm of malaria count
Precipitation
Temperature
Data are shown here by graphs and numbers. Intercepts and slopes are calculated from regression of Logarithm of malaria count on three variables: (1) Precipitation, (2) Temperature and (3) Multiplication of Precipitation by Temperature.
log.count = 5.296 + 0.135 x tempc + 0.011 x prcpc – 0.004 x tempc x prcpc • At mean temp and mean prcp: log.count = 5.296 (count = 200) • temp increase of 1 deg, no change in prcp: 5.296 + 0.135*1 + 0.011*0 – 0.004*1*0 = 5.431 (count = 228) • prcp increase by 30mm, no change in temp: 5.296 + 0.135*0 + 0.011*30 – 0.004*0*30 = 5.626 (count =278)
Results from regression model * temp.c = temperature - mean temperature
Let’s look at the effect of the interaction term (multiplication of precipitation and temperature): • At temp increase of 3 deg and prcp change of X, : 5.296 + 0.135*3 + 0.011*X – 0.004*3*X =5.296 + 0.405 + 0.011*X – 0.012*X =5.701 - 0.001*X Increase (decrease) in precipitation yields decrease (increase) in count. This suggests that warmer and drier conditions (like El Nino) => increase in malaria.