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Shallow and deep modes of tropical precipitation heating and their relationship to large-scale environments Yukari N. Takayabu, CCSR, Univ. of Tokyo. Topics. Spectral Latent Heating estimate algorithm from TRMM PR Shige, S., Y. N. Takayabu, W.-K. Tao, and D. E. Johnson, 2004, JAM

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  1. Shallow and deep modes of tropical precipitation heating and their relationship to large-scale environments Yukari N. Takayabu, CCSR, Univ. of Tokyo

  2. Topics • Spectral Latent Heating estimate algorithm from TRMM PR • Shige, S., Y. N. Takayabu, W.-K. Tao, and D. E. Johnson, 2004, JAM • Shige, S., Y. N. Takayabu, W.-K. Tao, and C.-L. Shie, 2007, JAMC • Global distribution of shallow and deep Q1-QR heating and its relationship to large-scale environments • Takayabu, Y. N., S. Shige, W.-K. Tao, and N. Hirota, 2009, submitted • An implication on the MJO dynamics

  3. Tropical clouds are under the influence of SST and Large-scale circulation Destabilization of the atmosphere by the warm SST vs stabilization by subsidence and horizontal transport TRMM Jensen and Del Genio (2006) Redelsperger et al (2002) Takemi et al. (2004) Brown and Zhang (1997) Takayabu et al. (2006) Entrainment of mid-troposph. dry air Bony and Dufrence 2005 The largest disagreements in sensitivity of CRF among climate models, and between models and observations are found in regions of large-scale subsidence Cb Convective warm rain Stratocumulus & cumulus high SST low SST w500 (hPa/day)

  4. Shallow /congestus convection has attracted recent attentions Johnson et al. 1999 Zhang and McGauley 2004

  5. Responses to deep and shallow heating Deep Heating Shallow Heating Shallow (congestus) heating is more effective than deep heating for the low-level moisture convergence (Wu 2003)

  6. To discuss the relationships between cloud regimes and environmental conditions (SST, subsidence), utilizing the Q1-QR obtained from TRMM SLH. Objectives Datahttp://www.eorc.jaxa.jp/TRMM/lh/index.html • Three dimensional Q1-QR from the SLH database, generated in TRMM2A25 original resolution and gridded into monthly, 0.5degx0.5deg: L3LH, Dec.1997-Nov.2007 • Japanese Reanalysis (JRA25) and JCDAS • NOAA OI-SST (up to 2005)

  7. Spectral Latent Heating (SLH) algorithm

  8. Spectral Latent Heating (SLH) AlgorithmShige et al. 2004, JAMC ShallowStrat Conv Rain Top Height Deep Strat Melting level precip. TRMMPR2A25 orbital data GCEM TOGA-COARE simulation Rain-LH tables Input Precip. Top H. Melt-Lvl Precip. Sfc Precip. total Estimate LH Data Strat Conv

  9. Q1-QR ALL 98-07 20N-20S Ocean Land Altitudes (km) Total Rain Top Height (km) Organized ~8km Stratiform ~5km Convective ~2km： warm rain RTH~4km K/day K/day

  10. Q1-QR ALL 98-07 20N-20S Ocean Land Shallow-mode contribution ~46.7 % for the average tropical oceans, ~23.7 % over tropical land. Altitudes (km) Total Organized ~8km Stratiform ~5km Convective ~2km： warm rain RTH~4km K/day K/day

  11. Warm convective rain or cumulus congestus

  12. 10-year mean Q1-QR JJA 98-07 Deep Organized Systems 7.5km 2.0km Cumulus Congestus

  13. Relationship to SST

  14. 8-year mean Q1-QR & SST JJA 98-07 7.5km 25℃ 2.0km

  15. UCmean Q1-QR vs. SST 97-0530N-30S 2.0km cumulus congestus JJA JJA 7.5km Deep rain 8 6 4 2 0 8 6 4 2 0 Q1-QR (K/day) Q1-QR (K/day) 16 18 20 22 24 26 28 30 32 16 18 20 22 24 26 28 30 32 DJF DJF 8 6 4 2 0 8 6 4 2 0 Q1-QR (K/day) Q1-QR (K/day) 16 18 20 22 24 26 28 30 32 16 18 20 22 24 26 28 30 32 SST SST

  16. What suppresses the deep convection?

  17. 10-year mean Q1-QR & ω500 JJA 98-07 7.5km 2.0km

  18. Q1-QR stratified against large-scale subsidence

  19. Uncnd-Mean Q1-QR vs dp/dt500hPa 15N-15S 98-04 OCEAN LAND Total x10 -100 -80 -60 -40 -20 0 20 40 60 80 -100 -80 -60 -40 -20 0 20 40 60 80  w500 (hPa/day) Conv. x10. Strat. x10 Warm convective rain heating is dominant in subsidence region over ocean, but not over land.

  20. Cond-Mean Q1-QR vs w500hPa 15N-15S 98-04 OCEAN LAND Total x10 w500 w500 Conv. x2.5 Strat. x10 The subsidence is strongly suppressing deep convection over oceans, while it does not work in the same manner over land.

  21. Effect of large-scale vertical motion on the environmental condition

  22. Cond-Mean Q1-QR& RH vs w500hPa 30N30S 9804

  23. Cond-Mean Q1-QR& RH vs w500hPa 30N30S 9804 22-23℃ 24-25℃ 26-27℃ 28-29℃ In order to separate the effects of large-scale circulation from those of SST, plots are separated in terms of SST. It was shown that similar significant dryness in the mid-to-lower troposphere is found in the subsidence region irrespective of the SST.

  24. Longitude-height cross section

  25. Q1-QR, qes JRA25 SON98-05 10S

  26. An implication on the MJO dynamics

  27. UCmean Q1-QR vs. SST 97-0530N-30S 2.0km cumulus congestus JJA JJA 7.5km Deep rain 8 6 4 2 0 8 6 4 2 0 Q1-QR (K/day) Q1-QR (K/day) 16 18 20 22 24 26 28 30 32 16 18 20 22 24 26 28 30 32 DJF DJF 8 6 4 2 0 8 6 4 2 0 Q1-QR (K/day) Q1-QR (K/day) 16 18 20 22 24 26 28 30 32 16 18 20 22 24 26 28 30 32 SST SST

  28. Shallow CISK (Wu 2003)

  29. SST-Convection Interaction “High SST precedes the MJO’s deep convection” Flatau et al. (1997) Woolnough et al. (2000) Stephens et al. (2004) (Stephens et al. 2004)

  30. MJO composites of Cloud Top Height Cloud Top Temperature TOGA-COARE TBB Three-steps-wise development of convections is observed in association with MJO. In the shallow-convection stage, mid-troposphere is very dry. Relative Humidity Pressure Kikuchi and Takayabu (2004, GRL) Time

  31. SST-Convection Interaction (Stephens et al. 2004)

  32. SummaryTakayabu et al. 2009, submitted Distinct two regimes of convective heating are confirmed with TRMM-PR based Q1-QR; a cumulus congestus rain regime with a peak at ~2km, and a deep organized convection regime with ~8km Q1-QR peak. Under large-scale subsidence, cumulus congestus rain regime dominates over ocean, but not over land. A rough estimate of shallow mode contribution against the total heating is about 46.7 % for the average tropical oceans, which is substantially larger than 23.7 % over tropical land. Cumulus congestus rain heating correlates linearly with SST, while deep organized convection is effectively suppressed by large-scale subsidence, probably through the entrainment of dry air. An implication to the MJO dynamics is that the linear correlation of shallow heating with SST may play another role for shallow circulation to take part in the MJO dynamics.

  33. Air-Sea Interaction Zhang & McPhaden, 2000 Some studies emphasize the role of air-sea interactions. It is not clear if air-sea interaction is crucial or not. ZM00 compared their observation with previous studies. There are still controversies in phase relationship among variables even in observations. Lin and Johnson, 1996 Flatau et al. , 1997 Jones and Weare, 1997 Zhang, 1996 Cronin and McPhaden, 1998 Hendon and Salby, 1994 Shinoda et al., 1998 WHSHIE Emanuel, 1987 Neelin et al., 1987

  34. Potential temperatureJRA JJA 98-0620N-20S Pressure (hPa) qe* q Potential temperature (K) Potential temperature (K) Ocean Land Lower-tropospheric stable layer

  35. 10-year mean Q1-QR & SST JJA 98-07 7.5km 25℃ 2.0km 2.0km 7.5km

  36. UCmean Q1-QR vs. OMG500 97-05 2.0km 7.5km 150-240E 30N-30S Ocean MAM MAM Q1-QR (K/day) SON SON Q1-QR (K/day) Omega 500hPa Omega 500hPa

  37. SLHWeb Page for Distribution Orbital and gridded data available for Dec. 1997- Dec. 2008

  38. Question 1: Should there be three or more heating products? Answer: Five products (two PR, one TMI, and two PR-TMI combined) Question 2: Orbital and/or gridded products and at what temporal and spatial scales? Answer: Three types of heating products are needed: (1) monthly gridded at 0.5 x 0.5 degrees, (2) orbital (e.g., 2a25) and (3) orbital gridded at 0.5 x 0.5 degrees with time stamps at each grid (blue are the priority). The products will have 19 vertical layers, plus the inputs for each algorithm (i.e., surface rain rate, stratiform percentage, etc.). In addition, CSH will produce model QR and model eddy terms.

  39. Question 3: Should the products be in separate files or not? Answer: Yes, they should be in separate files. Question 4: What format should the products be in? Answer: The products should be in HDF. TSDIS should provide a routine (toolkit) to accommodate each of the products in HDF. In addition, the input parameters for each algorithm (e.g., surface rain rate, stratiform %, etc.) will be included in with each of the heating products. The products will consist of Q1-QR, LH and model simulated QR and eddy flux convergence. In addition, the SLH algorithm will be used to generate Q2. Action Items: (1) Bill Olson: Contact Tristan L’Ecuyer about producing QR using the same resolution and format as the heating products and linking to the TRMM Standard Product web site. (2) Scott Braun: Check with Erich on acceptable data volume in TSDIS and a routine for HDF, and deadline for the format.

  40. FY2009 plan • Comparison of 3D and 2D tables • Inclusion of QR (by Dr. Tristan L’Ecuyer) for the understanding of the tropical global energy circulation and its role to large scale circulation. • Examination of Latent Heating over land • Standardization of the SLH product

  41. Thank you.

  42. Episodic trade wind regime over the western Pacific warm pool Johnson and Lin (1997)

  43. SummaryTakayabu et al. 2009 in prep. Distinct two regimes of convective heating are found with TRMM-PR based Q1-QR; a cumulus congestus rain regime with a peak at ~2km, and a deep organized convection regime with ~8km Q1-QR peak. Note: Stratocumulus regime over cold water is not detected by TRMM PR. Under large-scale subsidence, cumulus congestus rain regime dominates over ocean, but not over land. It is probably because lower tropospheric drying does not accompany the large-scale subsidence over land. Cumulus congestus rain heating correlates linearly with SST, while deep organized convection does not. Deep organized convection is effectively suppressed by large-scale subsidence, probably through the entrainment of dry air. An implication : warm convective rain may increase with SST, independently from deep organized rain in a warmer climate.

  44. Spectral Latent Heating (SLH) Algorithm (Shige et al. 2004) Conv Shallow Strat Rain Top Height Deep Strat Melting level precip.

  45. Hawaii Sounding 7.5km Over Hawaii, we also observe only shallow heating without deep heating. 2.0km

  46. JRA25 vs SLH の比較

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