precipitation climatology of costa rica and its variability
DESCRIPTION
Precipitation Climatology of Costa Rica and its Variability. Atmospheric, Oceanic and Topographic Interactions. Characters in The Play. Topography Oceans Northeast Trade Winds ( aka Los Alisios ) Caribbean Low Level Jet ( aka Veranillos de San Juan) Inter-tropical Convergence Zone - PowerPoint PPT PresentationTRANSCRIPT
Precipitation Climatology ofCosta Rica and its Variability
Atmospheric, Oceanic and Topographic Interactions
Characters in The Play
• Topography
• Oceans
• Northeast Trade Winds (aka Los Alisios)
• Caribbean Low Level Jet (aka Veranillos de
San Juan)
• Inter-tropical Convergence Zone
• Cold Fronts (aka Los Nortes)
• ENSO (El Niño y La Niña)
Act 1: November - April “Los Alisios”
LOW LOW LOW
LOW LOW
LOW LOW
HIGH HIGH HIGH
HIGH HIGH HIGH
HIGH
HIGH
~0°
~30°S
~30°N
~45-60°S
~45-60°N
~90°S
~90°N
NortheastTrades
Hadley Cell
Costa Rica~ 8-11.5°N
NortheastTrades
Andes
STANDARD CLIMATOLOGICALPICTURE
Source: NASA
Source: Instituto Merteorologico Nacional and Instituto Costarricense de Electricidad
Act 2: May - October “ITCZ”
ITCZ Feb3°N
NortheastTrades
Andes
STANDARD CLIMATOLOGICALPICTURE
Peru-HumboldtCurrent
ITCZ Feb3°N
NortheastTrades
Andes
STANDARD CLIMATOLOGICALPICTURE
Cross-EquatorialWesterlies
10°N
NortheastTrades
Andes
STANDARD CLIMATOLOGICALPICTURE
ITCZ Sep
Cross-equatorialWesterlies
Act 3: July - August “Veranillo de San Juan”
Lat
itu
de
(° N
ort
h)
2
4
6
8
10
12
2
4
6
8
10
12
Mean Position
J F M A M J J A S O N D
Costa RicaCosta Rica
Mean Monthly Position of ITCZ inEastern Equatorial Pacific
VERANILLOS DE SAN JUAN OR CANICULAMid-Summer Drought
Month
Ave
rage
Lat
itud
e (°
N)
of I
TC
Z
in E
aste
rn E
quat
oria
l Pac
ific
Hastenrath, 1991
San Andrés orCaribbean Low
Level JetCoolUpwelling
GAP IN CENTRAL AMERICAN CORDILLERA
DJF1000hPa
m/s
NCEP-NCARRE-ANALYSIS
Source: Kalnay et al., 1996
80°W
Caribbean Low Level Jet (CLLJ)
SEASONAL STRENGTHS OF CLLJWesterly Component of Wind Velocity at 80°WMAM
JJA
SON DJF
Source: NCEP-NCAR Reanalysis, Kalnay et al., 1996
CLLJ
Latitude Latitude
Pre
ssur
e (m
m)
~Alt
itud
e
GAP IN CENTRAL AMERICAN CORDILLERA
JUNE JULY
AUGUST SEPTEMBER
EVIDENCE OF VERANILLOS ?
Source: Mejiaand Poveda2003
Meso-ScaleConvectiveSystems1998 as detected by TRMM
Act 4: November - April “Los Nortes”
H
HRockies etc.
Appalachians
North America as Funnel of Cold Air in Boreal Winter
Surges of Cold Air over Gulf of Mexico and Caribbean
ITCZ Feb3°N
NortheastTrades
ColdFronts
Andes
STANDARD CLIMATOLOGICALPICTURE
Act 4: ENSO “El Niño y La Niña”
ITCZ Feb3°N
NortheastTrades
Andes
STANDARD CLIMATOLOGICAL PICTURE EL NIŇO
Peru-HumboldtCurrent
1. Warmer surface waters appear in Eastern Equatorial Pacific November onwards
ITCZ Feb3°N
NortheastTrades
Andes
STANDARD CLIMATOLOGICAL PICTURE EL NIŇO
Peru-HumboldtCurrent
1. Warmer surface waters appear in Eastern Equatorial Pacific November onwards
2. ITCZ shifts south and west of normal position
ITCZ Feb3°N
NortheastTrades
Andes
STANDARD CLIMATOLOGICAL PICTURE EL NIŇO
Peru-HumboldtCurrent
1. Warmer surface waters appear in Eastern Equatorial Pacific November onwards
2. ITCZ shifts south and west of normal position
3 Northeast Trades intensify
Positive = More Westerly (Less Easterly)Negative = More Easterly (Less Westerly)
Difference in Velocities (Warm – Cold Phase of ENSO)
MAM
Poveda et al., 2001
“In El Niño, trades weaker (less easterly) than in La Niña.”
Spring:
JJA
Poveda et al., 2001
“In El Niño, trades stronger (less westerly) than in La Niña.”
Summer:
Positive = More Westerly (Less Easterly)Negative = More Easterly (Less Westerly)
Difference in Velocities (Warm – Cold Phase of ENSO)
SON
Poveda et al., 2001
“In El Niño, trades stronger (less westerly) than in La Niña, but not as marked as in summer.”
Fall:
Positive = More Westerly (Less Easterly)Negative = More Easterly (Less Westerly)
Difference in Velocities (Warm – Cold Phase of ENSO)
DJF
Poveda et al., 2001
“In El Niño, trades much weaker (less easterly) than in La Niña.”
Winter:
Positive = More Westerly (Less Easterly)Negative = More Easterly (Less Westerly)
Difference in Velocities (Warm – Cold Phase of ENSO)
SeasonalPrecipitation as a Normalized deviate
Standard Deviations above/below mean
La Niña El Niño
SeasonalPrecipitation as a Normalized deviate
Standard Deviations above/below mean
La Niña El Niño
SeasonalPrecipitation as a Normalized deviate
Standard Deviations above/below mean
La Niña El Niño
SeasonalPrecipitation as a Normalized deviate
Standard Deviations above/below mean
La Niña El Niño
?
SeasonalPrecipitation as a Normalized deviate
Standard Deviations above/below mean
La Niña El Niño
?
Act 5: Epilogue “The Atlantic”
SeasonalPrecipitation as a Normalized deviate
Standard Deviations above/below mean
La Niña El Niño
SeasonalPrecipitation as a Normalized deviate
Standard Deviations above/below mean
La Niña El Niño
SeasonalPrecipitation as a Normalized deviate
Standard Deviations above/below mean
La Niña El Niño
SeasonalPrecipitation as a Normalized deviate
Standard Deviations above/below mean
La Niña El Niño
SeasonalPrecipitation as a Normalized deviate
Standard Deviations above/below mean
La Niña El Niño