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Effect of El Niño Southern Oscillation (ENSO) on the number of “leaching
rain” events in Florida and implications on nutrient management
C. Fraisse1, Z. Hu1, E. H. Simonne2
May 21, 2008Apopka, Florida
1Agricultural & Biological Engineering2Horticultural Sciences
OutlineMain hypothesis & Goal Typical rainfall patterns in FloridaENSO phasesMethodsResults & DiscussionSummary & Recommended action items
Hypothesis & GoalHypothesis: Probability of leaching rain occurrence in Florida during fall, winter, and spring cropping seasons is affected by ENSO
Leaching rain is defined as:3 inches in 3 days or 4 inches in 7 days (Simmone & Hochmuth, 2006; FDACS, 2005)
Research on Immokalee fine sand has shown that 1 inch of rainfall may result into nutrient leaching at the beginning of the season (Jaber and Shukla, 2006)
Hypothesis & GoalGoal: To develop a methodology to use ENSO forecast to adapt fertilization recommendations and reduce potential nutrient losses
Assess the effect of ENSO phases on horticultural crop productionIdentify a method to predict ENSO phases (GCM in the future)Develop adjustments to fertilizer recommendations
Typical rainfall patterns in FloridaMost of Florida is in the southern portion of the Northern hemisphere humid subtropical climate zone:
hot and humid summersmild and wet winters
Southern most portion is called tropical savanna also called wet and dry tropics: precipitation is highly concentrated in the warmer months
Climate Normals (1971-2000)
Precipitation Highlights
• Most areas receive at least 50 inches annually• Panhandle and SE are the wettest areas• Two wet seasons in the panhandle• Panhandle: 50% of precipitation during the hot months • SW Peninsula: 70% of precipitation during the hot months• Affected by ENSO 58
52
665460
50
Rainfall Patterns
Bay County Panhandle
Hendry County South Florida
Driving forces behind climate variabilityEl Niño Southern Oscillation (ENSO)
warm
cool
cool
warm
~ ~
Recur every 2-7 yearsNeutral is the term used when neither EN nor LN occurs
Slide courtesy of Greg McCabe, USGS
El Niño Winter Impacts – Air Temperature
Source: NOAA –Earth System Research Laboratory
El Niño Winter Impacts – Rainfall
Source: NOAA –Earth System Research Laboratory
La Niña Winter Impacts – Air Temperature
Source: NOAA –Earth System Research Laboratory
La Niña Winter Impacts – Rainfall
Source: NOAA –Earth System Research Laboratory
ENSO effects on vegetables productionHansen et al. 1999 demonstrated that during El Niño winters:
Yields (tomato, bell pepper, sweet corn, and snap bean) were lower;
Prices (bell pepper, snap bean) were higher.
-20%
-15%
-10%
-5%
0%
5%
10%
Perc
ent y
ield
incr
ease
La Niña neutral El Niño
Tomato
Methods – Cropping SeasonsCropping Seasons:
Fall: Planting on August 15 and lasts for 15 weeks (Nov 30)Winter: Planting on October 15 and lasts for 20 weeks (Mar 5)Spring: Planting on December 15 and lasts for 17 weeks (Apr 15)
Analyze occurrence of leaching rain events during each cropping season and ENSO phase (Index developed by the Japan Meteorological Agency (JMA) was used to classify growing seasons)
Methods – Historical RecordsAnalyze long term records of weather stations located in production areas across south Florida4 weather stations from the NWS Cooperative Observer Network were selected for this pilot study
Station Name
County StartYear
EndYear
La Belle Hendry 1932 2004
Parrish Manatee 1948 2006
Plant City Hillsborough 1895 2006
TamiamiTrail
Dade 1940 2003
We used all years on record and not only 1971-2000 data to include as many ENSO events as possible!
NWS Coop Stations in Florida
Tamiami TrailDade County
La BelleHendry County
ParrishManatee County
Plant CityHillsborough County
Results - Climate Normals (1971-2000): Fall Growing Season
Fall growing seasonPlanting on August 15 Season lasts for 15 weeks (Nov 30)
Results based on krigging of monthly climate normals for COOP stations
1816
14
16
18
20
Results - Climate Normals (1971-2000): Winter Growing Season
Winter growing seasonPlanting on October 15 Season lasts for 20 weeks (Mar 5)
Results based on krigging of monthly climate normals for COOP stations
2321
17
13
11
15
Results - Climate Normals (1971-2000): Spring Growing Season
Spring growing seasonPlanting on December 15 Season lasts for 17 weeks (Apr 15)
Results based on krigging of monthly climate normals for COOP stations
2220
16
12
10
12
Fall – Total Precipitation (in)
Neutral La Nina
Fall – Total Precipitation (in)
Neutral La Nina
Probability of Hurricane Strikes
Source: COAPS-FSU
Winter – Total Precipitation (in)
El Nino
La Nina
Winter – Total Precipitation (in)
El Nino
La Nina
Spring – Total Precipitation (in)
El Nino
La Nina
Spring – Total Precipitation (in)
El Nino
La Nina
El Nino
Number of Events (1 inch in 1 day)
El Niño La NiñaNeutral
Fall SeasonPlant City, FL
Number of Events (1 inch in 1 day)
El Niño La NiñaNeutral
Winter SeasonParrish Station Manatee County
Number of Events (1 inch in 1 day)
El Niño La NiñaNeutral
Spring SeasonParrish StationManatee County
Tables – Probability of ExceedanceNo. of Events
Station Season ENSO0 1 2 3 4 5
Neutral 100 65.4 25.0 5.8 0 0
EL NIŃO 100 73.9 26.1 0 0 0
LA NIŃA 100 65.0 20.0 15.0 0 0
All Years 100 67.3 23.5 6.1 0 0
Neutral 100 32.7 3.8 0 0 0
EL NIŃO 100 37.5 16.7 4.2 4.2 4.2
LA NIŃA 100 18.2 0 0 0 0
All Years 100 30.6 6.1 1.0 1.0 1.0
Neutral 100 30.9 7.3 0 0 0
EL NIŃO 100 59.1 9.1 4.5 0 0
LA NIŃA 100 18.2 0 0 0 0
All Years 100 34.3 6.1 1.0 0 0
Spring
Winter
Fall
PLANT CITY
4 inches in 7 days
Tables – Probability of Exceedance
3 inches in 3 days
El Niño
La Niña
Neutral
All Years
Conclusions & Action ItemsPreliminary results indicate that ENSO phase forecast can be used to anticipate N leaching potential
Source: International Research Institute for Climate & Society (IRI)
Recommended Action ItemsIn-depth study of leaching rainfall frequency Adjustment of N fertilizer recommendations based on ENSO phase (GCM models)ENSO phases should be used as input for assessment of watershed level nutrient loads based on modelsFAWN support and integration with
our climate information systemStandards of on-farm weather data collection for BMP documentation
