Storm Atlas Product

The MAXSS storm (wind extremes) atlas  will provide multi-variate observations  for 

  • Tropical Cyclones (EA for TC),
  • Extra-Tropical Cyclones (EA for ETC), and
  • Polar lows  (EA for PL)

The MAXSS Storm Atlas generation will be based on the methodology developed for SMOS Storm project, which provided an Atlas for tropical cyclones covering 5 years over the 2010-2015 period. MAXSS will augment this atlas and extend it to the period 2010-2020.  Technically, it will be fully regenerated using new input tracks (including ETCs and PLs, in addition the TCs) and a new set of observation data.

The development of the storm atlas shall include a phase for exploration, analysis and tests of the potential methodologies. In particular, we shall have to determine the wake domain of analysis and collect and merge the above listed data into a suite of wake files for each individual storm. This involves efforts regarding the

●      the definition of the spatial wake domain of analyses (e.g., how to define it for ETC and PL),

●      dealing with data having different spatial and temporal resolution (re-gridding, (tropics vs polar sea), spatial resolution choice, co-localization methods, etc..)

●       the definition of merging methods to gather data acquired or produced at different vertical locations around the air-sea interface (satellite, ARGO, atmosphere & ocean model outputs),

●       the compilation of the data into standardized file formats and database organisation (per basin, per year, etc..) to ease data manipulation for users that are not used to work with this wealth of data

●      The production system has also to be designed to allow several iterations when building the database to test several options and possibly include additional parameters not only during the course of the atlas development phase, but also after.

For each given storm, and for all points within the spatial domain radially extending by at least +750 km around the storm center track, we will collect an ensemble of following variables within a period of time t ranging from about -30 days to +90 days from the storm center date of closest passage to . At each considered location (lat,lon) within the storm wake domain, if available from any potential source (satellite, model, in situ), these variables shall include:

 

Ocean/Atmosphere Wake parameters (satellite and models)

●      SWS(lat,lon,t-to) :                project MM surface wind speed time series (m/s)

●      SSS(lat,lon,t-to) :                  haline wake time series (psu)

●      SST(lat,lon,t-to) :                  thermal wake time series (°C)

●      SSH(lat,lon,t-to):                  Sea surface height wake time series (m)

●      SLA(lat,lon,t-to):                  Sea level anomaly (m)

●      Chl-a(lat,lon,t-to):                Chlorophyll-A wake time series (g/m3)

●      Cdom(lat,lon,t-to):               Cdom wake time series (1/m)

●      Rain(lat,lon,t-to):                 Rain rate time series (mm/h)

●      Evaporation(lat,lon,t-to):    Evaporation time series (mm/h)

●      r(lat,lon):                               across-track distance (nm)

●      SWH(lat,lon,t-to):               significant wave height (m)

●      PP(lat,lon,t-to):                    peak period of the wave spectrum (s)

 

Satellite data will be quality controlled and filtered to keep best quality values in the EA. Time series for each variable within the wake will be stored in separate files, depending on the variable (e.g., SSS) and source (e.g. SMOS or SMAP).

 

Storm parameters at the date to of the storm center closest passage from location (lat,lon). These information shall be derived (when available) from the storm track datasets:

 

  • Vmax(lat,lon) :      Storm intensity from the tracks (knots or m/s)
  • Rmax(lat,lon) :      Radius of Max Wind (nm)
  • R34(lat,lon) :        Wind radii at 34 kt (nm)
  • R50(lat,lon) :        Wind radii at 50 kt (nm)
  • R64(lat,lon) :        Wind radii at 34 kt (nm)
  • Vstorm(lat,lon) :    Storm center translation speed (m/s)
  • ϕstorm(lat,lon) :    Storm center direction (deg N)
  • Vshr(lat,lon) :       850-200-mb environmental vertical wind shear amplitude (m/s)
  • ϕshr(lat,lon) :       Vertical wind shear vector direction (deg N)
  • T(lat,lon) :           Storm intensity tendency, defined as the mean of the temporal

derivative of the intensity T(t)=<dVmax/dt> over a 36h period centered on the date of closest storm center passage (Llyod and Vecchi, 2011). Intensifying (decaying) tropical cyclones being defined by T >0 (<0).

  • RI(lat,lon) :         Rapid Intensification (RI) defined as the 95th percentile of 24-hr over-water intensity changes, or an increase in intensity of at least 30 kt in a 24-hr period (Kaplan and DeMaria, 2003).

 

 

Hydrologic conditions in the wake domain obtain from in situ data, in situ data analyses & model reanalyses:

 

❏    T(lat,lon,t,z): Vertical Temperature Profile time series within the wake

❏    S(lat,lon,t,z): Vertical Salinity Profile time series within the wake

❏    S-(lat,lon,t,z=MLD): salinity at the base of the Mixed Layer

❏    T-(lat,lon,t,z=MLD): temperature at the base of Mixed Layer

❏    MLD(lat,lon,t): mixed layer depth

❏    ILTD(lat,lon,t): Isothermal-layer depth

❏    D26(lat,lon,t): Depth of the 26°C isotherm

❏    BLT(lat,lon,t) : Barrier Layer thickness

❏    N2(lat,lon,t,z): Brunt-Väisälä frequency

❏    Max(N2): maximum of the Brunt-Väisälä frequency in the upper 200 m

 

Storm collocated ocean in situ data will be quality controlled and filtered to keep only best quality values in the EA.

For each type of storms (TC,ETC,PL), the data will be stored and organised per year per basin and then per storm name or identifier.

IBTrACS: International Best Track Archive for Climate Stewardship

IBTrACS: International Best Track Archive for Climate Stewardship 

MAXSS products

MAXSS products