**************************************** * CSU Array-Averaged Analysis Products * * Version 3b * **************************************** Release date: 30 September 2014 ------------ Note: this version supercedes V0, V1, and V2 ---- - Version 0 (6-hr) was based on a mixture of partially corrected hi-res sonde data and GTS-resolution uncorrected data. - Version 1a (6-hr) was based on fully corrected hi-res sonde data. - Versions 2a/2b (3-hr) were based on versions 2a/2b of the gridded dataset. - Versions 3a/3b (3-hr) are based on versions 3a/3b of the gridded dataset. *** Some minor errors were detected in versions 2a and 2b of the gridded dataset (bad surface temperature at 4 times and bad surface water vapor mixing ratio at 03Z, 09Z, 15Z, and 21Z at several times in version 2b). These latter errors were seen primarily over the Southern Sounding Array (SSA). All of these errors have been corrected in versions 3a and 3b of the gridded dataset. Note that the change from V2 to V3 did not affect any of the budget results presented in Johnson et al. 2014, so depending on your analyses the corrections in V3 will likely have only a very minor impact on any V2 results that you have. - 21 Nov. 2014: the dse, msep, msec files were updated due to a problem with the meridional advection term - 16 Jan. 2015: in fields file, a few times contained very large RH at upper-levels so RH was reset to 150%. - 29 Sep. 2015: fields files (both nsa and ssa) recomputed using corrected gridded dataset (corrections primarily to vorticity values). Averaging areas: --------------- - Northern Sounding Array (NSA) bounded by core sites (Male, Colombo, Gan, and Revelle) - Southern Sounding Array (SSA) bounded by core sites (Mirai, Gan, Diego, and Revelle) - Figure "dynamo_map.png" shows averaging array and sonde network Time period: 1 October - 31 December 2011 ----------- Resolution: 25-hPa in vertical, 3 hour in time ---------- Array-averaged analyses include: ------------------------------- - basic fields (z, u, v, omega, T, theta, q, rh, div, and vort) - large-scale forcing fields (i.e., advective tendencies of T and q) - Q1 and Q2 (i.e., apparent heat source and moisture sink) - moist static energy terms (based on primitive eqns. with no g*z in tendency or horizontal advection terms) - moist static energy terms (with g*z in tendency and horizontal advection terms) - dry static energy terms - budget-derived quantities (rainfall and which is column integrated net-radiation) along with surface latent and sensible heat WHOI fluxes at daily-resolution and 3-hourly CERES - TRMM 3-hourly rainfall estimates (based on 3B42v7 product) Details for version 3b products: ------------------------------- - The version 3a array-averaged products were computed using the version 3a gridded dataset which was constructed without using supplemental model analysis in data sparse regions. - These version 3b array-averaged products, on the other hand, were computed using the version 3b gridded dataset which was constructed with the supplemental use of ECMWF Operational Analyses (OA) in data sparse regions. - The version 3b gridded dataset is based on the following data sources: - Hi-res (Level 4) sounding data were used at the following core sites (Male, Gan, Diego, Revelle, Mirai, Colombo) and 26 other Priority Sounding Sites (See Ciesielski et al. 2013). - Level 4 sounding data (uniform 5-hPa resolution with QC flags) are based on Level 3 (L3) sounding data (L3 is native resolution, humidity corrections applied as needed); see Ciesielski et al. (2013) for details of sounding dataset. - Hi-res P3 dropsonde data were used. - GTS-resolution (10-25hPa) sounding data were used at 54 other sites. - Soundings at Male' and Colombo were linearly time interpolated to 3-hr resolution to match temporal resolution of sites in SSA. - Because of the large station spacing between sites over the Northern Sounding Array, the strong diurnal cycle and flow-blocking at low-levels at Colombo are aliased onto the large-scale analyses and adversely affect the large-scale budgets. This version of the analyses used adjusted Colombo soundings which mute these effects. To mitigate these local island effects on the large-scale budgets, a procedure was designed which used low-level ECMWF-analyzed fields in the vicinity of Sri Lanka to estimate open-ocean conditions at Colombo’s location as if the island were not present. These “unperturbed” ECMWF fields at low-levels were then merged with the observed Colombo soundings. Details can be found in Ciesielski et al. (2014). - Sounding data were supplemented with CIMSS cloud drift winds, ASCAT surface winds, and COSMIC thermodynamic profiles (COSMIC moisture data were not used below 850 hPa due to issues with these data at lower-levels). - ECMWF OA is used at 5 degree grid intersections if no observations were present within 4.5 degrees of such a grid intersection. No OA is used within core sounding arrays, however, OA is used (as described above) at 5 degree grid intersections near the arrays when one or both ships were offsite. - Johnson and Ciesielski (2013) describes the V1 gridded dataset (6hr, soundings only) and some preliminary findings. - Johnson et al. (2014, submitted to JAS) describes the V2 gridded dataset and atmospheric budgets. - If one wants to use the analyses with no model influence, then the V3a analyses should be used realizing that those analyses are most reliable when the ships are on-site. - Revelle was onsite (nominal position 80.5E,Eq.) from 4 Oct. - 29 Oct., 10 Nov. - 04 Dec., and 18 Dec. - 31 Dec. - Mirai was on site (nominal position 80.5E,8S) from 1 Oct. - 24 Oct. and 1 Nov. - 27 Nov. - Analyses over NSA are less reliable after 5 Dec. when Colombo went from 4/day to 1/day sonde observations. - Male' ended sonde operation on 15 Dec. 2011 at 00Z so in effect there was no NSA after this date even though the Revelle returned on 18 Dec. - See figure "invent_vis.png" which shows a visual inventory of soundings for 6 core Indian Ocean sites (Fig. 2 of Ciesielski et al. 2013). Additional comments: ------------------- - These data products were created by objectively analyzing upper-air soundings and other data sources onto a regular 1-degree, 25-hPa grid using multiquadric interpolation. The gridded data fields were then averaged over the Northern Sounding Array (NSA) and the Southern Sounding Arrays (SSA). - As discussed in Johnson and Ciesielski (2013), the NSA analyses were strongly modulated by the MJO signal, while the SSA analyses were modulated more by ITCZ convection. References: ---------- Ciesielski, P. E. and coauthors, 2014: Quality-controlled upper-air sounding dataset for DYNAMO/CINDY/AMIE: Development and corrections. J. Atmos. Oceanic Technol., 31, 741-764. Ciesielski, P. E., R. H. Johnson, K. Yoneyama, and R. K. Taft, 2014: Mitigation of Sri Lanka island effects in Colombo sounding data and its impact on DYNAMO analyses. To appear in J. Meteor. Soc. Japan. Johnson, R. H., and P. E. Ciesielski, 2013: Structure and properties of Madden-Julian Oscillations deduced from DYNAMO sounding arrays. J. Atmos. Sci., 70, 3157-3179. Johnson, R. H. and coauthors, 2014: Sounding-Based Thermodynamic Budgets for DYNAMO. Submitted to J. Atmos. Sci. Register to obtain future updates: --------------------------------- - To register to receive any future updates of these analyses, send an email to Paul Ciesielski (paulc@atmos.colostate.edu). Problems or questions: --------------------- - Should be referred to Paul Ciesielski at: paulc@atmos.colostate.edu ******************************************************************************** File format for BASIC fields: fields.nsa_{ver} ============================ fields.ssa_{ver} - For each 3 hour period there is one line with date/time information followed by 40 lines with data as a function of pressure: - Line 1: year(yy) month(mm) day(dd) hour(hh) Fortran format: (4(1x,i2)) - Lines 2 - 41: p(hPa) z(m) u(m/s) v(m/s) omega(mb/hr) T(C) theta(K) \ wmr(g/kg) rh(%) div(10^[-6] 1/s) vort(10^[-5] 1/s) \ num_pts_used Fortran format: (11(1x,f8.2),i5) - To convert omega (mb/hr) to w (mm/s) use the following approximate eqn: omega/(-g*rho)/3600 = w - With: g = 9.8 m/s^2 rho = p/RT can be computed from fields provided (for example near 1000 mb, rho ~ 1.15 kg/m^3, near 100 mb, rho ~ 0.18 kg/m^3) - So that: 1 mb/hr near 1000 mb is ~2.5 mm/s, while 1 mb/hr near 100 mb is ~16 mm/s File format for LARGE-SCALE FORCING fields: lsf.nsa_{ver} ========================================== lsa.ssa_{ver} - Contain 736 periods of 3-hourly forcing data (01 Oct. - 31 Dec. 2011). - For each 3 hour period there is one line with date/time information followed by 40 lines with data as a function of pressure: - Line 1: year(yy) month(mm) day(dd) hour(hh) Fortran format: (4(1x,i2)) - Lines 2 - 41: p(hPa) hT(C/s) vT(C/s) hq(gr/(kg*s)) vq(gr/(kg*s)) Fortran format: (f8.2,1p,4e11.3) where: hT - horizontal advection of T vT - vertical advection of T hq - horizontal advection of q vq - vertical advection of q - These horizontal and vertical advection terms were computed using centered differences as follows: horizontal advection of "f": h(f) = u*df/dx + v*df/dy where: dx = a cos(phi)*d(lambda) dy = a d(phi) phi = latitude lambda = longitude vertical advection of "f": v(f) = omega*df/dp - Note: vt is only part of vertical temperature forcing (vtf) vtp = (p/po)**cappa * omega * d(theta)/dp = omega * (dT/dp - alpha/cp) where: alpha is specific volume alpha = RT/p can be computed from basic fields File format for MOIST STATIC ENERGY (mse) TERMS (complete form): msec.nsa_{ver} =============================================================== msec.ssa_{ver} - Contain 736 periods of 3-hourly mse terms (01 Oct. - 31 Dec. 2011). - For each 3 hour period there is one line with date/time information followed by 40 lines with data as a function of pressure: - Line 1: year(yy) month(mm) day(dd) hour(hh) Fortran format: (4(1x,i2)) - Lines 2 - 41: p(hPa) th(m^2/s^3) uh(m^2/s^3) vh(m^2/s^3) wh(m^2/s^3) \ h(m^2/s^2) Fortran format: (f8.2,1p,5e11.3) where: th - local time tendency of h (moist static energy) uh - zonal advection of h vh - meridional advection of h wh - vertical advection of h h - moist static energy (cp*T + Lv*q + g*z) cp = 1004 m^2/(s^2*K) Lv = 2.5e6 m^2/s^2 g = 9.81 m/s^2 - Note: g*z is used in computing all terms for moist static energy equation - These horizontal and vertical advection terms were computed using centered differences. File format for MOIST STATIC ENERGY TERMS (primitive eqn. form): msep.nsa_{ver} =============================================================== msep.ssa_{ver} - Contain 736 periods of 3-hourly mse terms (01 Oct. - 31 Dec. 2011). - For each 3 hour period there is one line with date/time information followed by 40 lines with data as a function of pressure: - Line 1: year(yy) month(mm) day(dd) hour(hh) Fortran format: (4(1x,i2)) - Lines 2 - 41: p(hPa) th(m^2/s^3) uh(m^2/s^3) vh(m^2/s^3) wh(m^2/s^3) \ h(m^2/s^2) Fortran format: (f8.2,1p,5e11.3) where: th - local time tendency of (cp*T+Lv*q) uh - zonal advection of (cp*T+Lv*q) vh - meridional advection of (cp*T+Lv*q) wh - vertical advection of h (moist static energy) h - moist static energy (cp*T + Lv*q + g*z) cp = 1004 m^2/(s^2*K) Lv = 2.5e6 m^2/s^2 g = 9.81 m/s^2 - Note: moist static energy equation is based on primitive equations where g*z is used only for computing the vertical advection term (for details see Neelin 2007; http://www.atmos.ucla.edu/~csi/REF/pdfs/gencircrev.pdf) - These horizontal and vertical advection terms were computed using centered differences. File format for DRY STATIC ENERGY (dse) TERMS: dse.nsa_{ver} ============================================= dse.ssa_{ver} - Contain 736 periods of 3-hourly dse terms (01 Oct. - 31 Dec. 2011). - For each 3 hour period there is one line with date/time information followed by 40 lines with data as a function of pressure: - Line 1: year(yy) month(mm) day(dd) hour(hh) Fortran format: (4(1x,i2)) - Lines 2 - 41: p(hPa) ts(m^2/s^3) us(m^2/s^3) vs(m^2/s^3) ws(m^2/s^3) \ s(m^2/s^2) Fortran format: (f8.2,1p,5e11.3) where: ts - local time tendency of s us - zonal advection of s vs - meridional advection of s ws - vertical advection of s s - dry static energy (cp*T + g*z) cp = 1004 m^2/(s^2*K) g = 9.81 m/s^2 - These horizontal and vertical advection terms were computed using centered differences. File format for ARRAY-AVERAGED Q1 and Q2: q1q2.nsa_{ver} ======================================== q1q2.ssa_{ver} - Contain 736 periods of 3-hourly data (01 Oct. - 31 Dec. 2011). - For each 3 hour period there is one line with date/time information followed by 40 lines with data as a function of pressure: - Line 1: year(yy) month(mm) day(dd) hour(hh) Fortran format: (4(1x,i2)) - Lines 2 - 41: p(hPa) Q1(K/day) Q2(K/day) Fortran format: (3f8.2) cp = 1004 m^2/(s^2*K) g = 9.81 m/s^2 - The apparent heat source, Q1, and moisture sink, Q2 (Yanai et al. 1973) were computed as: Q1/cp = [dT/dt + h(T) + (p/po)**kappa * omega * d(theta)/dp] Q2/cp = -Lv/cp * [dq/dt + h(q) + v(q)] where: dt = 12 hours po = 1000 mb kappa = .286 cp=1004 Lv = 2.5e6 g = 9.81 File format for BUDGET-DERIVED QUANTITIES: eopo.nsa_{ver} ========================================= eopo.ssa_{ver} - Contain 736 lines of 3-hourly data (01 Oct. - 31 Dec. 2011). - Each data line: year(yy) month(mm) day(dd) hour(hh) eo(mm/day) po2(mm/day) sh(mm/day) \ po1(mm/day) qr(mm/day) qrnet_ceres(mm/day) Fortran format: (4i3,6f8.2) - Where: eo - LH flux from WHOI TropFlux product averaged over sounding array po2 - Q2-budget derived rainfall computed using eo estimate sh - SH flux from WHOI TropFlux product averaged sounding array po1 - Q1-budget derived rainfall computed using sh and qrnet_ceres estimates qr - column net radiation computed from combine Q1/Q2-budget residual using LH and SH from WHOI OAFLUX qrnet_ceres - column net radiation from CERES - Note: 100 W/m^2 = 3.45 mm/day = 0.93 K/day File format for TRMM RAINFALL OVER VARIOUS REGIONS: trmm_rain ================================================== - Contains 736 lines of 3-hourly trmm 3b42V7 area averaged rainfall data in mm/day (01 Oct. - 31 Dec. 2011) plus one final data line giving the temporal mean for each area. - Each data line: yymmddhh nsa ssa colombo male gan revelle diego mirai manus \ (np(i),i=1,9) Fortran format: (4i2,9f9.4,9i4) - Where: nsa - over northern enhanced sounding array ssa - over southern enhanced sounding array colombo - area with 1 degree radius centered on Colombo male - area with 1 degree radius centered on Male gan - area with 1 degree radius centered on Gan revelle - area with 1 degree radius centered on Revelle (at nominal position: 0.1N, 80.5E) diego - area with 1 degree radius centered on Diego mirai - area with 1 degree radius centered on Mirai (at nominal position: 8.0S, 80.5E) manus - area with 1 degree radius centered on Manus np(9) - number of 0.25 degree points in each averaging area