objectives diurnal cycle of convection forecasting ... science … · cjschrec@ncsu.edu pdfof this...

Objectives

cjschrec@ncsu.edu pdf ofthisposter

MultiscaleinteractionsbetweentheMJO,equatorialwaves,andthediurnalcycleovertheMaritimeContinent

CarlJ.Schreck III1,Anantha Aiyyer1,Ademe Mekonnen21NorthCarolinaStateUniversity,2NorthCarolinaA&TUniversity

NASAPMMScienceTeamMeeting24–28October2016,HoustonTX

NASAPMMGrantNNX16AE33G

DiurnalCycleofConvection ForecastingConvectiveEnvelopes

MJO’spropagationacrosstheMaritimeContinentisamajorsubseasonal predictabilityproblem.

• HowdoequatorialwavesmodulatediurnalcycleofconvectionovertheMaritimeContinent?

• WhatroledoequatorialwavesplayintheMJO’stransitionacrosstheMaritimeContinent?

• HowwelldonumericalmodelsliketheCFSpredictequatorialwavesovertheMaritimeContinent?

ISCCP IR weather states (IR-WS) identify eight cloud regimes based on theircloud-top pressure (CTP) and their corresponding IR-regime in the ISCCP D1data. IR-WS1 (left) corresponds to well organized convection (i.e., MCS) andIR-WS3 (right) represents isolated cumulonimbus or cumulus congestusclouds. The diurnal cycles of these IR-WS data will be compared with TRMMPrecipitation Feature (PF) data over the Maritime Continent.

Hypothesis1:• LiketheMJO,equatorialwaves

favorupscalegrowthofconvection• However,theirshorterperiods

reducetheinteractionwiththediurnalcycle

Task1:• Identifythediurnalcycleof

convectionineachphaseofKelvinandEquatorialRossby waves

• CompareresultswithISCCP,TRMMPF,andTRMM/IMERGrainfall

Hypothesis2:• Thepopulationofequatorialwaves

dictateswhichMJOeventstraversetheMaritimeContinent

• Beinglesssensitivetothediurnalcycle,equatorialwavesprovideabridgefortheMJO

Task2:• Comparewavevariancebetween

MJOsthatdoordonotpropagateacrossMaritimeContinent

Hypothesis3:• TheCFSismoreskillfulat

forecastingtheconvectiveenvelopesoftheMJOandequatorialwavesthanactualrainfall

Task3:• FilterCFSReforecastto

createretrospectiveforecastsofOLRandrainfall

• Examineanomalycorrelationswithobserveddata

Hypothesis4:• TheCFSskillatforecasting

theMJO,equatorialwaves,andthediurnalcycleareallcorrelatedwitheachother

Task4:• Identifygoodandbad

forecastsoftheMJOovertheMaritimeContinent

• Comparethewaveactivity,waveforecasts,anddiurnalcyclesbetweeneach

Hovmöller oftotalrainfall(shading).MJO(blue),equatorialRossbywaves(magenta),andKelin waves(red)arecontoured.Vertical

dashedlinesoutlinetheMaritimeContinent

Homoller countsofISCCPWeatherStates(WS)ofMCSs(left)anddisorganizedconvection(right).

ExampleforecastHovmöllers ofOLRanomalies(shading)andfilteredwavemodes.(left)Observationsareappendedwithclimatologicalvaluesforfiltered(WheelerandWieckmann 2000).(right)ObservationsareappendedwithCFS

forecasts.

ncics.org/mjo