Transcript Observed Trends in Indices of Daily and Extreme

Overview of
ETCCDI
&
Production of NCMPs
ETCCDI
CCL/CLIVAR/JCOMM-Expert Team (ET) on Climate Change
Detection and Indices (ETCCDI) + its predecessor CCL/CLIVAR WG
on Climate Change Detection
•Coordinate international effort to develop, calculate and analyze
indices which individual countries and regions can calculate in
exactly the same way;
•Study the changes in the temperature and precipitation
extremes.
HOW?
1. develop a comprehensive list of indices meaningful over the
globe
2. coordinate workshops for the preparation of climate change
indices.
Last decade workshops
Central and East Africa, Caribbean, South America, Middle East,
Central, South Asia and South East Asia and South Pacific
October 2009- organised by COI under ETCCDI format @ Regional
Meteorological Training and Research Centre for the Indian Ocean, Mauritius
Meteorological Services (Experts– Lucie Vincent , Enric Aguilar)
2 Participants from the following countries: République des
Comores, République de Madagascar, Republic of Mauritius, La
Réunion (France) and Peoples Republic of Seychelles.
[Citation: Vincent, L. A., et al. (2011), Observed trends in indices of daily and extreme temperature and
precipitation for the countries of the western Indian Ocean, 1961–2008, J. Geophys. Res., 116, D10108,
doi:10.1029/2010JD015303.]
Previous Wkshps
Data
0
Participants
brought digital
long term (19612008) daily
-10
maximum and
minimum
temperature and
precipitation data
Seychelles
Indian Ocean
Comores
Madagascar
The data period
varied but
sufficient (32
stations) to
compute 19612008 trends.
Maurice
-20
Reunion
-30
40
50
60
Methodology
Daily temperature and rainfall data were quality controlled using
RClimDex (Environment Canada).
Monthly mean temperature and monthly total precipitation time
series were examined for homogeneity using the software package
RHTestsV3 (Environment Canada).
Adjustments were applied to 9 and 10 stations (Tx & Tn)
Rainfall data were not adjusted.
For WIO, 13 temperature and 8 precipitation indices (on annual
basis) were appropriate.
Indices definition (WIO)
Element
Index
Descriptive Name
Definition
Unit
Temperature
TXMean
TNMean
DTR
SU25
TR20
TX90P
TX10P
TN90P
TN10P
TXx
TXn
TNx
TNn
PRCPTOT
SDII
CDD
CDD
R10mm
R20mm
RX1day
RX5day
Annual maximum temperature
Annual minimum temperature
Diurnal temperature range
Summer days
Tropical nights
Warm days
Cold days
Warm nights
Cold nights
Highest TX
Lowest TX
Highest TN
Lowest TN
Annual precipitation
Simple daily intensity index
Consecutive dry days
Consecutive wet days
Heavy precipitation day
Very heavy precipitation days
Max 1-day precipitation
Max 5-days precipitation
Annual mean of TX
Annual mean of TN
Annual mean of difference between TX and TN
Annual count when TX > 25°C
Annual count when TN > 20°C
Percentage of days when TX > 90th percentile
Percentage of days when TX < 10th percentile
Percentage of days when TN > 90th percentile
Percentage of days when TN < 10th percentile
Annual highest value of TX
Annual lowest value of TX
Annual highest value of TN
Annual lowest value of TN
Annual total precipitation
Annual precipitation divided by number of wet days
Maximum number of consecutive dry days
Maximum number of consecutive wet days
Annual count of days when RR > 10 mm
Annual count of days when RR > 20 mm
Annual highest daily precipitation
Annual highest 5 consecutive days precipitation
°C
°C
°C
days
days
%
%
%
%
°C
°C
°C
°C
mm
mm
days
days
days
days
mm
mm
Precipitation
Trends
0
0
-10
-10
-20
-20
-2 -1 1
-30
40
50
2 °C / 48 yrs
60
Trends in annual means of
daily maximum
temperature (TXMean)
-2 -1 1
-30
40
50
2 °C / 48 yrs
60
Trends in annual means of
daily minimum
temperature (TNMean)
Trends in extremes
0
0
-10
-10
-20
-20
-15 -10 10 15 % / 48 yrs
-30
40
50
60
Sig. increase of 15 to 20% in the
percentage of warm days (TX90P)
and warm nights (TN90P)
-15 -10 10 15 % / 48 yrs
-30
40
50
60
Sig. decrease of 10 to 15% in
the percentage of cold days
(TX10P) and cold nights (TN10P).
Decadal Pptn trends
Annual
precipitation
has
decreased by
2.76% per
decade
Decadal trends in Pptn extremes
Production of NCMPs
• Host Regional Workshops with climate experts from NHMS
Process standard long term daily data >30yrs (different countries)
Use software packages
 Increase understanding of regional Climate Change and
strengthen regional cooperation on research
 Ensure that NHMS maintain homogeneous climate data
 Encourage the publication of Scientific Papers by participants