LIMITLESS POTENTIAL | LIMITLESS OPPORTUNITIES | LIMITLESS IMPACT Copyright University of Reading CURRENT CHANGES IN EARTH’S ENERGY IMBALANCE Richard Thanks to Chunlei Liu, Norman Loeb and all co-authors 1 Department of Meteorology

AT WHAT RATE IS EARTH HEATING? Harries & Belotti (2010) J. ClimHarries & Belotti (2010) J. Clim | Loeb et al. (2012) Nat. Geosci | Trenberth et al. (2014) J ClimLoeb et al. (2012) Nat. Geosci| Trenberth et al. (2014) J Clim Upper ocean heating rate (Wm -2 ) What are implications for climate sensitivity and the global water cycle?

ERBS/CERES variability CERES monthly climatology ERA Interim spatial anomalies Combine CERES/ARGO accuracy, ERBS WFOV stability and reanalysis circulation patterns to reconstruct radiative fluxes ERBS WFOV CERES ERA Interim RECONSTRUCTING GLOBAL RADIATIVE FLUXES SINCE 1985

0.62±0.43 Wm -2 Imbalance: (Wm -2 ) Allan et al. (2014) GRL Volcano La Niña El Niño 0.34±0.67 Wm -2 EARTH CONTINUES TO HEAT UP

LIMITLESS POTENTIAL | LIMITLESS OPPORTUNITIES | LIMITLESS IMPACT DISCREPANCY BETWEEN RADIATION BUDGET & OCEAN HEATING Large ocean heating anomaly in 2002 Inconsistent with radiation budget observations and simulations Changing observing system influence? Slight drop in net flux ? Smith et al. (2015) GRL 5

LIMITLESS POTENTIAL | LIMITLESS OPPORTUNITIES | LIMITLESS IMPACT WHERE IS THE HEAT GOING? NEW ESTIMATES OF SURFACE ENERGY FLUX 6 CERES/Argo Net Flux Surface Flux Net surface downward energy flux (Wm -2 ) Liu et al. (2015) JGR

LIMITLESS POTENTIAL | LIMITLESS OPPORTUNITIES | LIMITLESS IMPACT Changes in energy fluxes to Surface energy flux dominated by atmospheric transports Contrasting model pattern of change Are reanalysis transports reliable? 7 WHERE IS THE HEAT GOING? CHANGES IN SURFACE ENERGY FLUX Liu et al. (2015) JGR

LIMITLESS POTENTIAL | LIMITLESS OPPORTUNITIES | LIMITLESS IMPACT OBSERVED ASYMMETRY IN EARTH’S ENERGY BUDGET Observed inter- hemispheric imbalance in Earth’s energy budget Not explained by albedo: brighter NH surface but more clouds in SH (Stephens et al. 2015)Stephens et al Imbalance explains position of ITCZ (Frierson et al. 2013)Frierson et al Loeb et al. (2015) Clim. DynLoeb et al. (2015) Clim. Dyn PW PW PW 0.60 PW 0.23 PW PW PW-0.01 PW PW

LIMITLESS POTENTIAL | LIMITLESS OPPORTUNITIES | LIMITLESS IMPACT EQUATORIAL HEAT TRANSPORT AND MODEL PRECIPITATION BIAS Clear link between bias in cross-equatorial heat transport by atmosphere and inter-hemispheric precipitation asymmetry Loeb et al. (2015) Clim. DynLoeb et al. (2015) Clim. Dyn. 9

LIMITLESS POTENTIAL | LIMITLESS OPPORTUNITIES | LIMITLESS IMPACT CONCLUSIONS Heating of Earth continues at rate of ~0.6 Wm -2 Manifest as positive imbalance in Southern Hemisphere Energy transport by ocean to Northern Hemisphere offset by atmospheric energy transport to Southern Hemisphere Variability from radiative forcings & ocean internal changes Where is the excess energy going in the oceans? Toward reconciled ocean heating & radiation budget changes Do feedbacks amplify/extend hiatus/surge events? Inter-hemispheric heating links to model precipitation biases See posters on: Changing water cycle and interhemispheric energy transports (Allan & Liu) Recent changes in precipitation over Africa (Maidment et al. ) Clouds, radiation and precipitation in west Africa (DACCIWA; Hill et al.) 10

LIMITLESS POTENTIAL | LIMITLESS OPPORTUNITIES | LIMITLESS IMPACT OBSERVED ASYMMETRY IN EARTH’S ENERGY BUDGET Observed inter- hemispheric imbalance in Earth’s energy budget Not explained by albedo: brighter NH surface but more clouds in SH (Stephens et al. 2015)Stephens et al Imbalance explains position of ITCZ (Frierson et al. 2013)Frierson et al Loeb et al. (2015) Clim. DynLoeb et al. (2015) Clim. Dyn PW-0.05 PW PW 0.60 PW 0.23 PW PW PW PW PW

LIMITLESS POTENTIAL | LIMITLESS OPPORTUNITIES | LIMITLESS IMPACT +ve RF trend AR5 RF 0 RF trend -ve RF trend N N=ΔF–YΔT s D ΔTsΔTs ΔTDΔTD Analysis using simple energy balance model Allan et al. (2014) GRL supplementarysupplementary UNDERSTANDING CHANGES IN NET IMBALANCE

LIMITLESS POTENTIAL | LIMITLESS OPPORTUNITIES | LIMITLESS IMPACT TAMSAT PROJECTS: RECENT TRENDS IN AFRICA RAINFALL 14 Evaluating and understanding recent changes in Africa rainfall (Ross Maidment, Emily Black) PhD project extending this work: changes in impact-relevant metrics for Africa (Caroline Dunning, Emily Black) Maidment et al. (2015) submitted

LIMITLESS POTENTIAL | LIMITLESS OPPORTUNITIES | LIMITLESS IMPACT EARTH’S ENERGY BUDGET & REGIONAL CHANGES IN THE WATER CYCLE cooling Enhanced energy transport Sulphate aerosol effects on Asian monsoon e.g. Bollasina et al Science (left)Bollasina et al Science Links to drought in Horn of Africa? Park et al. (2011) Clim DynPark et al. (2011) Clim Dyn GHGs & Sahel rainfall recovery? Dong & Sutton (2015) Nature ClimDong & Sutton (2015) Nature Clim. Regional precipitation changes sensitive to asymmetries in Earth’s energy budget N. Hemisphere cooling: stronger heat transport into hemisphere Reduced Sahel rainfall from: -Anthropogenic aerosol cooling s: Hwang et al. (2013) GRL Hwang et al. (2013) GRL -Asymmetric volcanic forcing e.g. Haywood et al. (2013) Nature Climate Haywood et al. (2013) Nature Climate

LIMITLESS POTENTIAL | LIMITLESS OPPORTUNITIES | LIMITLESS IMPACT Replotted so that CERES and ERA Interim sample 6-months later than ARGO Is there a lag in the system? Where in ocean is energy accumulating? Mechanism? COMBINING EARTH RADIATION BUDGET AND OCEAN HEAT CONTENT DATA (2)

LIMITLESS POTENTIAL | LIMITLESS OPPORTUNITIES | LIMITLESS IMPACT Outgoing Longwave Radiation

LIMITLESS POTENTIAL | LIMITLESS OPPORTUNITIES | LIMITLESS IMPACT Absorbed Shortwave Radiation

LIMITLESS POTENTIAL | LIMITLESS OPPORTUNITIES | LIMITLESS IMPACT NET Radiation

LIMITLESS POTENTIAL | LIMITLESS OPPORTUNITIES | LIMITLESS IMPACT LW & SW FLUXES 20