1 / 16

Context – Better Early Warning Science

Exploring Western and Eastern Pacific contributions to the 21st century Walker circulation intensification and teleconnected precipitation declines.

art
Download Presentation

Context – Better Early Warning Science

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Exploring Western and Eastern Pacific contributions to the 21st century Walker circulation intensification and teleconnected precipitation declines Chris C. Funk (USGS), Martin P. Hoerling (NOAA CAB), Andrew Hoell (UCSB CHG), James P. Verdin (USGS), Franklin R. Robertson (NASA MSC), David Alured (NOAA CAB), Brant Liebmann (NOAA CAB)

  2. Context – Better Early Warning Science Ethiopia Somalia Kenya March15th 2011 1979-2012 ECHAM5 March-May ensemble means USAID and NASA are supporting new science that seeks to understand and, if possible, anticipate future droughts in food insecure East Africa.

  3. Overview • Background: Trend and PDV • PDV Climate Impacts • PDV = ENSO + PDO • Trend Climate Impacts • Exploring decadal predictions for East Africa • All data based on March-May averages

  4. Background-Centennial Trends Compo & Sardeshmukh (2010) Correlation between EA ECHAM5 ensemble averages and March-May SST. From Liebmann et al. (2013) Solomon & Newman (2012)

  5. Background-Pacific Decadal Variability Aiguo Dai’s IPO (2012) Correlation between EA ECHAM5 ensemble averages and March-May SST. From Liebmann et al. (2013) Lyon et al. PDV (2013)

  6. 1983-2012 Estimates of Trend & PDV SST changes Western Pacific Eastern Pacific Correlation between EA ECHAM5 ensemble averages and March-May SST. From Liebmann et al. (2013) Change in SST [K]

  7. 1983-2012 Estimates of PDV and Trend forced changes in precipitation and low level circulation Regression estimates from ensemble mean NOAA CAB GFS AGCM simulations, 1950-2010 Regression estimates from ensemble mean LDEO CAM4 AGCM simulations, 1900-2008 CAM5 driven with SST change field, precipitation and Moisture transports Western Pacific Eastern Pacific -1 +1 -100 +100 Dprecip [mm] DSPI

  8. Global Precipitation Responses EP WP +100 -100 Duqmin=-208 kgms-1Duqmin=-299 kgms-1 DP [mm per season]

  9. CAM5 Experiment Results – 500 hPa Trend Circulation Changes descending velocity contours ascending velocity contours 30N L STWJ 0N Gill response to off-equatorial Heating anomaly? +14 -4 Dumax=1.4 ms-1 DZ[m]

  10. CAM5 Experiment Results – 900 hPa Trend Circulation Changes 30N L 0N Gill off-equatorial Heating anomaly? +5 -5 Dumax=1.8 ms-1 DZ[m]

  11. Matched Filter Regression (MFR) Predictions MFR Field Fancy Coupled Model Seasonal Forecasts BetterForecasts MFR Field CMIP5 SST predictions Decadal Predictions?

  12. Matched Filter Regression (MFR) Predictions CFSv2 Precipitation 1998-02 2003-12 2000 2011 1933-2012 ER five-year SST avgs

  13. Estimating Trend and PDV signals CMIP5 SST Predictions Detrended ER five-year SST obs

  14. Decadal Predictions and Standard Error Estimates Decadal predictions based solely on CMIP5 SSTs  PDV component assumed unpredictable Estimate of Uncertainty (s2CMIP5 estimates+ s2Non-CMIP5 residuals)0.5 Accounting for uncertainty in both the CMIP5 and PDV suggests a predictable range for 2003-2012 of [0,-0.7] SPI

  15. Conclusions • New research with AGCMs is helping us understand recent EA droughts • Centennial Trend SST warming pattern linked to Walker Circulation Intensification • At least some recent EA droughts are predictable • It might be possible to link Trend SST patterns to decadal predictions

  16. Thanks! • Liebmann, B., Hoerling, M. P., Funk, C., Bladé, I., Dole, R. M., Allured, D., Pegion, P., and Eischeid, J. K.: Understanding Eastern Horn of Africa Rainfall Variability and Change, J. Climate, In Review, 2013. • Hoell, A., and Funk, C.: Indo-Pacific Sea Surface Temperature Influences on Failed Consecutive Rainy Seasons over Eastern Africa, ClimDyn, in press, 2013a. • Hoell, A., C. Funk and M. Barlow, 2013: The Regional Forcing of Northern Hemisphere Drought During Recent Warm Tropical West Pacific Ocean La Nina Events, Climate Dynamics, in press,doi:10.1007/s00382-013-1799-4 • Hoell, A., C. Funk and M. Barlow: La Nina Diversity and the Forcing of Drought over East Africa and Central-Southwest Asia, Climate Dynamics. • Hoell, A., and Funk, C.: The ENSO-related west pacific sea surface temperature gradient, Journal of Climate, 2013c. journals.ametsoc.org/doi/abs/10.1175/JCLI-D-12-00344.1 • Funk, C., Husak, G., Michaelsen, J., Shukla, S., Hoell, A., Lyon, B., Hoerling, M. P., Liebmann, B., Zhang, T., Verdin, J., Galu, G., Eilerts, G., and Rowland, J.: Attribution of 2012 and 2003-12 rainfall deficits in eastern Kenya and southern Somalia, Bull. Amer. Meteor. Soc., , 95, 2013a. http://www1.ncdc.noaa.gov/pub/data/cmb/bams-sotc/extreme-events/2012/BAMS-Extremes-of-2012-Section-15.pdf • Williams, P., and Funk, C.: A westward extension of the warm pool leads to a westward extension of the Walker circulation, drying eastern Africa, Climate Dynamics, DOI 10.1007/s00382-010-0984-y, 2011. link.springer.com/article/10.1007/s00382-010-0984-y

More Related