The Effect of the MJO on the North American Monsoon*

Lorenz, David J.; Hartmann, Dennis L.

doi:10.1175/jcli3684.1

Cited by 111 publications

(81 citation statements)

References 15 publications

(22 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…modulations of monsoonal rainfall from Asia (Krishnamurthy and Kinter, 2003) to West Africa (Niang et al, 2016) and North America, where MJO influence is most limited geographically (Higgins and Shi, 2001;Lorenz and Hartmann, 2006). PC1 relationships to RMM2 and the similar magnitude of PC1 correlations with Niño3.4 and the best MJO RMMs combination for the AM might reflect the complexity of scale interactions between ENSO and MJO activity (Figure 12).…”

Section: Modulation Of Skill By Enso and The Mjomentioning

confidence: 95%

“…NAM precipitation is influenced by the MJO particularly over southern Mexico (Higgins and Shi, 2001), but Lorenz and Hartmann (2006) also found that associated westerly wind anomalies in the eastern tropical Pacific lead, from several days to over a week later, to above-normal rainfall in the monsoon regions of Arizona, New Mexico and northwest Mexico. These changes occur through modulations in the strength of lowlevel easterly waves off the coast of Mexico, which in turn trigger the development of moisture surges from the Gulf of California and could indicate potentials for predictability.…”

Section: Introductionmentioning

confidence: 97%

See 1 more Smart Citation

Subseasonal Predictability of Boreal Summer Monsoon Rainfall from Ensemble Forecasts

Vigaud

Robertson

Tippett

et al. 2017

Front. Environ. Sci.

View full text Add to dashboard Cite

Subseasonal forecast skill over the broadly defined North American (NAM), West African (WAM) and Asian (AM) summer monsoon regions is investigated using three Ensemble Prediction Systems (EPS) at sub-monthly lead times. Extended Logistic Regression (ELR) is used to produce probabilistic forecasts of weekly and week 3-4 averages of precipitation with starts in May-Aug, over the 1999-2010 period. The ELR tercile category probabilities for each model gridpoint are then averaged together with equal weight. The resulting Multi-Model Ensemble (MME) forecasts exhibit good reliability, but have generally low sharpness for forecasts beyond 1 week; Multi-model ensembling largely removes negative values of the Ranked Probability Skill Score (RPSS) seen in individual forecasts, and broadly improves the skill obtained in any of the three individual models except for the AM. The MME week 3-4 forecasts have generally higher RPSS and comparable reliability over all monsoon regions, compared to week 3 or week 4 forecast separately. Skill is higher during La Niña compared to El Niño and ENSO-neutral conditions over the 1999-2010 period, especially for the NAM. Regionally averaged RPSS is significantly correlated with the Maden-Julian Oscillation (MJO) for the AM and WAM. Our results indicate potential for skillful predictions at subseasonal time-scales over the three summer monsoon regions of the Northern Hemisphere.

show abstract

Section: Modulation Of Skill By Enso and The Mjomentioning

confidence: 95%

Section: Introductionmentioning

confidence: 97%

Subseasonal Predictability of Boreal Summer Monsoon Rainfall from Ensemble Forecasts

Vigaud

Robertson

Tippett

et al. 2017

Front. Environ. Sci.

View full text Add to dashboard Cite

show abstract

“…ISV over the EP exerts broad impacts on regional weather and climate phenomena, including tropical cyclone activity over the EP and the Gulf of Mexico, the summertime gap wind near the Gulfs of Tehuantepec and Papagayo, the Caribbean low-level jet and precipitation, the midsummer drought over Central America and Mexico, and the North American monsoon (e.g., Magaña et al 1999;Maloney and Hartmann 2000b,a;Maloney and Esbensen 2003;Lorenz and Hartmann 2006;Serra et al 2010;Martin and Schumacher 2011).…”

Section: Tropical Intraseasonal Variabilitymentioning

confidence: 99%

North American Climate in CMIP5 Experiments. Part II: Evaluation of Historical Simulations of Intraseasonal to Decadal Variability

et al. 2013

View full text Add to dashboard Cite

This is the second part of a three-part paper on North American climate in phase 5 of the Coupled Model Intercomparison Project (CMIP5) that evaluates the twentieth-century simulations of intraseasonal to multidecadal variability and teleconnections with North American climate. Overall, the multimodel ensemble does reasonably well at reproducing observed variability in several aspects, but it does less well at capturing observed teleconnections, with implications for future projections examined in part three of this paper. In terms of intraseasonal variability, almost half of the models examined can reproduce observed variability in the eastern Pacific and most models capture the midsummer drought over Central America. The multimodel mean replicates the density of traveling tropical synoptic-scale disturbances but with large spread among the models. On the other hand, the coarse resolution of the models means that tropical cyclone frequencies are underpredicted in the Atlantic and eastern North Pacific. The frequency and mean amplitude of ENSO are generally well reproduced, although teleconnections with North American climate are widely varying among models and only a few models can reproduce the east and central Pacific types of ENSO and connections with U.S. winter temperatures. The models capture the spatial pattern of Pacific decadal oscillation (PDO) variability and its influence on continental temperature and West Coast precipitation but less well for the wintertime precipitation. The spatial representation of the Atlantic multidecadal oscillation (AMO) is reasonable, but the magnitude of SST anomalies and teleconnections are poorly reproduced. Multidecadal trends such as the warming hole over the central-southeastern United States and precipitation increases are not replicated by the models, suggesting that observed changes are linked to natural variability.

show abstract

“…Most CMIP5 models underestimate MJO amplitude, especially when outgoing longwave radiation (OLR) is used in the evaluation, and exhibit too fast phase speed while lacking extent and low frequency (zonal wavenumbers 1-3 and 30-90 days period). The MJO interacts with a wide range of tropical weather and climate phenomena that include the onset and break of monsoons (Yasunari 1979(Yasunari , 1980Lau and Chan 1986;Hendon and Liebmann 1990;Sperber et al 2000;Sultan et al 2003;Annamalai and Sperber 2005;Wheeler and McBride 2005;Lorenz and Hartmann 2006;Wheeler et al 2009), tropical cyclone activity (Nakazawa 1988;Liebmann et al 1994;Maloney and Hartmann 2000;Bessafi and Wheeler 2006;Klotzbach 2010;Jiang et al 2012), and the El Niño Southern Oscillation (Kessler et al 1995;McPhaden 1999;Takayabu et al 1999;Kessler and Kleeman 2000;Bergman et al 2001;Kessler 2001;Zhang and Gottschalck 2002;Hendon et al 2007). The MJO also influences mid-and high-latitudes through atmospheric teleconnections (Weickmann et al 1985;Ferranti et al 1990;Berbery and Nogués-Paegle 1993;Higgins and Mo 1997;Matthews et al 2004;Vecchi and Bond 2004;Cassou 2008;L'Heureux and Higgins 2008;Lin et al 2009;Johnson and Feldstein 2010;Seo and Son 2011;…”

Section: Introductionmentioning

confidence: 99%

MJO simulation in CMIP5 climate models: MJO skill metrics and process-oriented diagnosis

et al. 2017

View full text Add to dashboard Cite

coherence between eastward propagation of precipitation/ convection and the wind field. The RHCP-metric, indicative of the sensitivity of simulated convection to low-level environmental moisture, and the NGMS-metric, indicative of the efficiency of a convective atmosphere for exporting moist static energy out of the column, show robust correlations with a large number of MJO skill metrics. The GEFmetric, indicative of the strength of the column-integrated longwave radiative heating due to cloud-radiation interaction, is also correlated with the MJO skill metrics, but shows relatively lower correlations compared to the RHCPand NGMS-metrics. Our results suggest that modifications to processes associated with moisture-convection coupling and the gross moist stability might be the most fruitful for improving simulations of the MJO. Though the GEF-metric exhibits lower correlations with the MJO skill metrics, the longwave radiation feedback is highly relevant for simulating the weak precipitation anomaly regime that may be important for the establishment of shallow convection and the transition to deep convection.

show abstract

The Effect of the MJO on the North American Monsoon*

Cited by 111 publications

References 15 publications

Subseasonal Predictability of Boreal Summer Monsoon Rainfall from Ensemble Forecasts

Subseasonal Predictability of Boreal Summer Monsoon Rainfall from Ensemble Forecasts

North American Climate in CMIP5 Experiments. Part II: Evaluation of Historical Simulations of Intraseasonal to Decadal Variability

MJO simulation in CMIP5 climate models: MJO skill metrics and process-oriented diagnosis

Contact Info

Product

Resources

About