LONGTERM CHANGES IN CLIMATIC EXTREMES OVER SPAIN

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LONG-TERM CHANGES IN CLIMATIC EXTREMES OVER SPAIN

• By M. Brunet,
• With the help of J. Sigró, O. Saladié, E.
  Aguilar and P.D. Jones?
  
• Climate Change Research Group, URV, Tarragona,
  Spain
  
• ? Climatic Research Unit, UEA, Norwich, UK
• Meeting of the CCl Expert Team on Climate
  Monitoring
  
• 20-22 September 2006, Tarragona, Spain

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AIM To document changes in climatic extremes
occurrence over Spain across the 20th century
with a special emphasis in the recent period of
strong Spanish warming (1973-2005)

• OUTLINE
• Data and Analysis
• Changes in temperature extremes
• Changes in precipitation extremes

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THE DATA

• 22 Daily maximum and minimum temperature time
  series recovered under the framework of the
  EU-funded project EMULATE (http//www.cru.uea.ac.u
  k/cru/projects/emulate.html)
• Localization Map
• Available versus potential data

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THE ANALYSIS

• The raw temperature data were
• Minimised accounting for the screen bias
• Quality Controlled (QCed)
• Homogenised on a daily basis, according to the
  procedures described in
  
• Brunet, M., O. Saladié, P. Jones, J. Sigró, A.
  Moberg, E. Aguilar, A. Walther, D. Lister, and D.
  López (2006), The development of a new daily
  adjusted temperature dataset for Spain
  (1850-2003), Int. J. Climatol., in press (now
  online on the IJC website)
• And the raw daily rainfall data were QCed and
  adjusted on a daily basis by using SNHT
  (Alexandersson and Moberg (1997) and Vincent et
  al. (2002) approaches
• The adjusted daily data were converted in the
  following climate extreme indices and analysed
  both on an annual and seasonal basis
  
• Exc. of Tmax/Tmin 2nd, 5th, 10th, 90th, 95th and
  98th percentiles, CSDI, WSDI
  
• Fraction of precipitation above of the 90th,
  95th and 98th percentiles, Greatest 1- and 5-days
  total rainfall, SDII90, 95 and 98, CDD
  
• The development of regional climate extreme
  series has been achieved by averaging daily
  series of indices and then adding back the
  base-period mean, according to the Jones and
  Hulme (1996) method.
• Linear trends Mann-Kendall test and the Sens
  nonparametric method (Gilbert, 1987)
  
• PCA in S mode with the correlation matrix on a
  monthly scale and retaining those PCs exceeding
  the 1 threshold of Kaisers rule and the
  inspection of the scree plots. The resulting PCs
  have been subjected to Varimax rotation

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EXPLORING TRENDS AND CHANGES IN SOME SELECTED
TEMPERATURE EXTREMES INDICES DURING THE 20TH
CENTURY AND THE RECENT PERIOD OF FORCED WARMING
OVER SPAIN (1973-2005)
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Changes in percentile based temperature indices
(TX/TN2p, 5p, 10p, 90p, 95p and 98p) on annual
basis and in no. of days
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Comparing trends among indices and periods (in
ºC/decade)

• Long-term Spanish warming was driven by highest
  reductions (increases) of extremely cold (warm)
  days than for increases (reductions) of extremely
  warm (cold) nights
• Slight shift in this pattern during 1973-2005
  Larger increases of warm nights and days than
  reductions in cold nights and days

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Seasonal changes in daily temperature extremes
Tmax lower percentiles indices
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Seasonal changes in daily temperature extremes
Tmax upper percentiles indices
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Seasonal changes in daily temperature extremes
Tmin upper percentiles indices
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Seasonal changes in daily temperature extremes
Tmin lower percentiles indices
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-0.24/-0.65

• Spatial patterns for some temperature extreme
  indices Number of very extremely colds days
  Tmax1973-2005. Bold (italic) indicates significance
  at 1 (5) confidence level.

-0.21/-0.61
-0.13/-0.85
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Number of warm days (daily TX 90p)
0.82/2.98
0.81/2.97
0.74/2.85
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Number of very warm nights TN 95p
0.41/3.50
0.44/2.73
0.20/1.70
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Annual changes in the duration of warm and cold
spells (WSDI and CSDI in n. days/decade)
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EXPLORING TRENDS AND CHANGES IN PRECIPITATION
EXTREMES OCCURRENCE
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Annual changes of very (R95p) and very extremely
wets (R98p) days (in mm/decade)
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Seasonal changes in the fraction of precipitation
above of the 90th, 95th and 98th percentiles (in
/decade)
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Changes in the greatest 1- and 5-days total
rainfall (trends in mm/decade)
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Seasonal changes in daily rainfall intensity
above the 90th, 95th and 98th percentiles (SDII)
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Annual and seasonal changes in the no. of
consecutive dry days (CDD)
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THANKS!!ANY QUESTIONS?