Real-timeWhole Atmosphere Model

(WAM)

prospects for following impact of lower atmosphere on temporal changes of neutral

density (specification and forecast)

Tim Fuller-Rowell, Rashid Akmaev, Fei Wu, Houjun Wang

Sept 25-26th, 2012 NADIR MURI

Application Areas

• Midnight temperature and density maxima

• Tidal temporal variability

• Density variability in the sub-orbital and re-entry region

• Global mean demsity response to the lower atmosphere forcing

Sept 25-26th, 2012 NADIR MURI

MTM/MDM:MTM/MDM: Large scale temperature and density structureLarge scale temperature and density structure

Akmaev et al. 2009, 2010 Sept 25-26th, 2012 NADIR MURI

• CTIPe simulations with WAM winds (lower panel) appear to reproduce the main features in the observed vertical plasma drift (upper panel) during a SSW, including the stronger upward drift early in the morning and reversal to downward in the afternoon

Electrodynamic comparison JRO vs WAM-CTIPeElectrodynamic comparison JRO vs WAM-CTIPe

Sept 25-26th, 2012 NADIR MURI

Chau et al.

Fuller-Rowell et al. 2011

Sept 25-26th, 2012 NADIR MURI

2010

Electrodynamic Response – contribution from changes in amplitude and phase of migrating semi-diurnal (SW2)

SW2 phase change appears to be responsible for a large part of the change

in local time of electrodynamics

Source of variability in re-entry region:neutral density and zonal wind profile every hour

Sept 25-26th, 2012 NADIR MURI

zonal wind

neutraldensity

CHAMP neutral density response 2009 SSW

Sept 25-26th, 2012 NADIR MURI

Dayside ~16.5 LT

CHAMP satellite neutral density: SSW or geomagnetic activity?

SSW SSW

Ap Ap

WAM neutral density response to changing tides during SSW in upper thermosphere (300 to 400

km altitude) 1)global mean increase by ~ 5%

from 15th to 23rd

2) change in phase of “diurnal” variation

15th

Sept 25-26th, 2012 NADIR MURI

23rd

Prospects for a real-time WAM to follow temporal changes in the re-entry region at NOAA Space Weather Prediction Center

• Whole Atmosphere Model (WAM) is based on the Global Forecast System (GFS) US NWS operational weather forecasting model

• WAM can be run with the operational Grid-point Statistic Interpolation (GSI) NCEP data assimilation system so is able to follow the response of the upper atmosphere to real lower atmosphere dynamics (e.g., sudden stratospheric warmings, severe weather events, etc.)

• WDAS (WAM/GSI) has a forecast capability of several days

• Possible to extend GSI into the lower thermosphere using additional data sets to improve penetration of tides into the lower thermosphere

• WAM is being coupled to an Ionosphere Plasmasphere Electrodynamics (IPE) module (WAM + IPE = IDEA) to provide ion-neutral heating rates

• IDEA is scheduled to be transitioned into NOAA operations in FY16

• System will be fully supported by NOAA operations Sept 25-26th, 2012 NADIR MURI