Walker Circulation and El Niño / La Niña Sea Surface Temperature, Rainfall, and Zonal Wind

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1 Walker Circulation and El Niño / La Niña Sea Surface Temperature, Rainfall, and Zonal Wind David Halpern NASA / California Institute of Technology Jet Propulsion Laboratory Pasadena, CA 91109, USA Contents Introduction Sea Surface Temperature Re: El Niño and La Niña Rainfall Re: El Niño and La Niña Zonal Wind Re: El Niño and La Niña Ø Surface (10 m) Ø Planetary Boundary Layer (700 m) Ø Upper Troposphere (13-15 km) Conclusion 2015 California Institute of Technology. Government sponsorship acknowledged. 1

2 Introduction Surface and upper troposphere zonal winds and rainfall responded to El Niño / La Niña sea surface temperatures in accord with Walker Circulation (Bjerknes, 1969) Atlantic Indian Pacific Atlantic Indian Pacific 2

3 Sea Surface Temperature Variations MAM SON -1.3 OND Year -1.5 DJF -1.3 JFM FMA AMJ -1.0 MJJ -1.0 JJA -1.1 JAS ASO NDJ Niña # La El Niño # El Niño # La Niña # El Niño # La Niña # La Niña # El Niño # La Niña # on Climate Prediction Prediction Center Center - Monitoring 1/5/15 8:04 Climate & Data: ENSO Impacts the U.S. Previous- Events 12/26/14 4:05 PM La Niña # ttp:// 2 of Page Privacy Policy NOAA/ National Weather Service Act (FOIA) Disclaimer Quality NOAA Center for Weather and Climate Prediction Information Freedom of Information0.2 About Us 120 W) NOAA Oceanic Niño Index for Niño Region Climate Prediction Center Credits 3.4 (5 S 5 N, 170 W 5830 University Research Court Glossary Career Opportunities episodes of DESCRIPTION: Warm (red) and 1.0 cold (blue) based on a- threshold +/oc for the 0.5Niño 0.6Index 0.6(ONI) 0.5[3 month mean 0.2 of 0.5 Oceanic running ERSST.v3b on-5o0.4 o ow)], anomalies in region 0.4 ( SST the Niño S, 120 based on base 0.6 periods 0.2 every 5 years centered 30-year updated For historical purposes cold and warm episodes colored are - defined when the (blue -0.4 and - red numbers) threshold is met a minimum of 5 consecutive for over-lapping seasons ttp:// University Research Court Glossary College Park, Park, Maryland Maryland College Page Author: Author: Climate Climate Prediction Prediction Center Center Internet Internet Team Team Page Page last modified: January 5, 2015 Page last modified: December 4, 2014 Page 1 of 3 Career Opportunities An El Niño (La Niña) event occurs when the SST anomaly in each of five consecutive 3-month average ( -) 0.5 C. Four El Niños and five (six) La Niñas occurred during March 2000 June (February 2014). NOAA Oceanic Niño Index for Niño Region 3.4 (5 S 5 N, 170 W 120 W). An Niño (La Niña) event occurs when the SST anomaly in each of five consecutive 3

Mean Rainfall, 2 x2 Along Equator Specific El Niño

Atlantic y Precipitation Measurement Missions

N, 157 W El Niño: 1 Apr 2002 28 Feb 2003 (11 months)

-landsliden Remote satellite in space Sensing over a

4 Mean Rainfall, 2 x2 Along Equator Specific El Niño Event and Specific La Niña Event Indian Pacific Atlantic y Precipitation Measurement Missions 1/27/15 12:46 PM age Gallery TRMM Christmas Island 2 N, 157 W El Niño: 1 Apr Feb 2003 (11 months) La Niña: 1 Mar Mar 2001 (13 months) -landsliden Remote satellite in space Sensing over a Systems (/image-gallery/trmm-satellite) (/image-gallery/trmm-satelliteimage-tropical-cyclone-yasiprecipitation-radar-image- (/image-gallery/trmm- TMI Rainfall Data from Visualization of the TRMM Daily rainfall uncertainty = 5 mm/hr TRMM Satellite image of magda) violent earth ntain tropical cyclone. (/imagegallery/trmm-satellite) Tropical Cyclone Yasi on February 1st to 3rd, 2011 (left to right) as it made TRMM Precipitation Radar image of tropical cyclone Magda. (/image-gallery/trmm- 4

N Satellite Wind Vector Instruments and Sampling Characteristics PBL Wind Vector Measurement Instruments SeaWinds / QuikSCAT sat_quikscat.

4 GHz and the atmosphere, and the mpacts of different types of atmospheric particles and clouds on climate.

Combined NASA / NASA hniques, this enables construction of 3-D models and estimation of the ht reflected by Earth's diverse environments. ASCAT / MetOp-A metop_silo_1.jpg 568 407 pixels 5.

y calibrated to provide accurate measures of the brightness, contrast, sunlight. 10.2006- Remote Sensing Systems reprocessed QuikSCAT & ASCAT data with 0.25 x 0.

5 N Satellite Wind Vector Instruments and Sampling Characteristics PBL Wind Vector Measurement Instruments SeaWinds / QuikSCAT sat_quikscat.gif pixels 12/14/13 4:45 PM MISR / Terra ypes of information for scientists studying Earth's climate, such as the and carbon between the land surface 13.4 GHz and the atmosphere, and the mpacts of different types of atmospheric particles and clouds on climate. on at different view angles affords the means to distinguish different particles (aerosols), cloud forms, and land surface covers. Combined NASA / NASA hniques, this enables construction of 3-D models and estimation of the ht reflected by Earth's diverse environments. ASCAT / MetOp-A metop_silo_1.jpg pixels 5.3 GHz SR has flown in space before. Viewing the sunlit Earth simultaneously at ngles, MISR provides ongoing global coverage with high spatial detail. y calibrated to provide accurate measures of the brightness, contrast, sunlight Remote Sensing Systems reprocessed QuikSCAT & ASCAT data with 0.25 x 0.25 grid of daily ascending & descending orbits 4/17/14 10:56 AM 672 nm 2 x NASA / NASA QuikSCAT 25 km Resolution 1800 km Swath 10 m Wind Height 06:00 ECT 1 day Global Coverage MISR 17.6 km 380 km many 10: days ESA / EUMETSAT ASCAT Resolution 25 km Swath 1100 km Wind Height 10 m ECT 09:30 Global Coverage 1.5 days 141 W Page 1 of 1 1 N 1 S 139 W Different ECTs for the 10-m height datasets could contribute a diurnal-period error of 5 m s-1. Page 1 of 1 5 m s-1 CONTACT US <rms amplitudes> (m s-1) 140 W, 124 W, 110 W, 95 W u v Diurnal < 1 month Halpern (1988) 5

10-m Zonal Wind: <4 El Niños>, <5 La Niñas>, and Mean in March 2000 June 2011 Atlantic Pacific Indian El Niño Theme Page: images Pacific: Ø 150 E-150 W: westward (easterly) wind in

evidence of El Niño/La Niña Indian: no evidence of El Niño/La Niña El Niño Theme Page: images Home El Nino Normal La Nina TOP TOP TOP Department of Commerce / National Oceanic and

gov 6/17/14 1:33 AM El Niño, La Niña, and Walker Circulation (Pacific) East%Pacific% Reduced%westward%wind% Reduced%upwelling% Increased%thermocline%depth% 6/17/14 1:33 AM

6 10-m Zonal Wind: <4 El Niños>, <5 La Niñas>, and Mean in March 2000 June 2011 Atlantic Pacific Indian El Niño Theme Page: images Pacific: Ø 150 E-150 W: westward (easterly) wind in <5 El Niños> weaker than <5 La Niñas> Ø 150 W-90 W: westward (easterly) wind in <5 El Niños stronger than <5 La Niñas>, contrary to wisdom from El Niño Atlantic: no evidence of El Niño/La Niña Indian: no evidence of El Niño/La Niña El Niño Theme Page: images Home El Nino Normal La Nina TOP TOP TOP Department of Commerce / National Oceanic and Atmospheric Administration Pacific Marine Environmental Laboratory / Tropical Atmosphere Ocean Project Disclaimer Privacy Policy Feedback: oar.pmel.taogroup@noaa.gov 6/17/14 1:33 AM El Niño, La Niña, and Walker Circulation (Pacific) East%Pacific% Reduced%westward%wind% Reduced%upwelling% Increased%thermocline%depth% 6/17/14 1:33 AM Conven;onal%Wisdom% East%Pacific% Stronger%westward%wind% Increased%upwelling% Reduced%thermocline%depth% Page 1 of 2

7 Reliability of 10-m Zonal Wind Indian 700 m PBL 10 m Pacific Atlantic ( m) winds had same results as at 10 m Independent analysis confirms 10-m wind results <4 El Niños> <5 La Niñas> 7

8 10-m Zonal Wind and Thermocline Depth Pacific <4 El Niños> <5 La Niñas> Mean 20 C Depth, m <4 El Niños> <5 La Niñas> TAO / TRITON (Dai McClurg, PMEL) 20 C Depth, m D20 Depth(m) E 160E 180E 160W 140W 120W 100W 80W <4 El Niños> <5 La Niñas> ECCO-Pro v4 (Xiaochun Wang, UCLA) El Niño events La Niña events 8

9 10 m Zonal Wind 10-m (Surface) and 14-km (Upper Troposphere) km Indian <4 El Niños> <6 La Niñas> Mean <4 El Niños> <5 La Niñas> Mean Atlantic Pacific Pacific, 150 E-150W 14 km eastward wind El Niño was weaker than La Niña by 5 m s m to 14-km layer reduced (increased) vertical shears through the troposphere in El Niño (La Niña) promote (suppress) generation of typhoons Pacific, 150 W-90 W 14 km slight evidence of influence by El Niño/La Niña Atlantic 14 km eastward wind speed was larger in El Niño than in La Niña 10-m to 14,000-km layer increased vertical shear through the troposphere in El Niño suppresses generation 9 of hurricane

10 80 (A)$140 W$ Transport (Sv, 10 m s ) Potential Conclusion 50 Kelvin Wave Propagation (2) Surface zonal winds in east Pacific in El Niño / La Niña were not consistent 20 ECCO2 (Δx = 20 km, Δy = 20 km, archive Δt = 3 days) with thermocline displacements, indicating increased emphasis on far-field 10 Average Eastward Propagation Speedfor From 170 W todepth 140 W = 3.0 m s-1 response, e.g., oceanic Kelvin waves, thermocline variations 0 ECCO2 EUC Transport (0 443m), 2004 Average Eastward Propagation Speed 140 W = 2.8Dec m s-1 Jan Jan Feb Mar Apr May Jun JulFrom Aug Sep to 110 W Oct Nov EUC Transport Transport (Sv, 10 m s(sv) ) EUC NECC (B)$EUC$170 W annual notch in other years? w 140w 110w 140 W Figure 1: EUC total transport and NECC total transport from ECCO2. EU 110 W 50 ransport is based on seven 0.5 boxes from 1.5S to 1.5N and NECC transport based on twelve 0.5 boxes from 4.25N to 9.75N. The depth integration is from 0 t 30 43m Halpern et al. (2013) 0 Jan ONI ECCO2 NECC Transport (0 443m), 2004 Feb 1 Mar Apr May 2 Jun Jul 2004 KW Pulse (C)$NECC$ Aug Sep 3 Oct 4 170w 140w 110w Nov Dec 5 Jan Transport (Sv, 10 m s ) JPL ECCO2 Propagation Figure 1: EUC total transport from ECCO2 for Speeds 2004 along 170W, 140W and 110W W-140 W 3.0the m s-1integration of transport of seve EUC transport at each longitude is based on W-110 W s-1. The depth integration is from boxes centered at 1.5S to 1.5N with a width2.8 ofm to 443m. 10

11 Thank you QuestionsPic.jpg 11

Satellite Observations of Equatorial Planetary Boundary Layer Wind Shear

Satellite Observations of Equatorial Planetary Boundary Layer Wind Shear David Halpern and Michael Garay NASA / California Institute of Technology Jet Propulsion Laboratory Pasadena, California, USA Thanks