effect of el niño southern oscillation (enso) on the...

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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

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