**File Specification for GEOS-5 DAS Gridded Output**

**Addendum for Supporting the *Tropical Composition Cloud and Climate
Coupling (TC4)* Mission**

![](media/image1.png){width="1.207638888888889in"
height="1.6444444444444444in"}

*Global Modeling and Assimilation Office*

*Goddard Space Flight Center, Greenbelt, Maryland*

http://gmao.gsfc.nasa.gov

Release Date: 19 June 2007

Based on the GEOS-5 File Specification Version 6.1

To support NASA instrument teams with GEOS-5 DAS V1.0

This addendum maintained by Arlindo da Silva (Arlindo.dasilva@nasa.gov)

*Permission to quote from this document should be obtained from the
GMAO.*

![](media/image2.png){width="0.8270833333333333in" height="0.7125in"}

**Michele Rienecker**

**Global Modeling and Assimilation Office**

**Earth Sciences Division**

**NASA Goddard Space Flight Center**

**Greenbelt, Maryland 20771**

**REVISION HISTORY**

  -------------------------------------------------------------------------
  **Version     **Revision    **Extent of Changes**           **Approval
  Number**      Date**                                        Authority**
  ------------- ------------- ------------------------------- -------------
  6.1-TC4-r3    06/07/2007    Merged with TC4 GEOS-5 Data     Michele
                              document.                       Rienecker

  -------------------------------------------------------------------------

Table of Contents

1\. Introduction [5](#introduction)

2\. Format and File Organization [5](#format-and-file-organization)

3\. Assimilated Instantaneous Products vs. Model-generated Time-averaged
Products
[5](#assimilated-instantaneous-products-vs.-model-generated-time-averaged-products)

4\. Grid Structure [7](#grid-structure)

Figure 1: Schematic of GEOS-5 LCV coordinate system
[9](#figure-1-schematic-of-geos-5-lcv-coordinate-system)

5\. File Naming Convention [10](#file-naming-convention)

6\. TC4 File Collections [12](#tc4-file-collections)

6.1 Summary of Data Products [12](#summary-of-data-products)

6.2 Caculation of file sizes [14](#calculation-of-file-sizes)

6.3 Forecast Files -- ½ by 1/3 Degree Resolution: Twice-daily at 00Z and
12Z
[14](#forecast-files-½-by-23-degree-resolution-twice-daily-at-00z-and-12z)

6.4 Forecast Files -- ¼ x 1/3 Degree Resolution: Once-daily at 12Z
[21](#forecast-files-¼-x-13-degree-resolution-once-daily-at-12z)

6.5 Analysis/Assimilation Files -- ½ by 1/3 Degree Resolution:
[22](#analysisassimilation-files-½-by-13-degree-resolution)

Appendix A. Types of Assimilation Configurations
[25](#appendix-a.-types-of-assimilation-configurations)

Appendix E: Detailed Description of Output Variables
[26](#appendix-e-detailed-description-of-output-variables)

REFERENCES [34](#references)

# 1. Introduction

The "*File Specification for GEOS-5 DAS Gridded Output"* document[^1]
describes the gridded output files from the version 5 of the Goddard
Earth Observing System Data Assimilation System (GEOS-5 DAS), which
supports level-4 product generation. This document describes additional
data products being generated in support of the Tropical Composition
Cloud and Climate Coupling (TC4) Mission[^2].

The GMAO operational assimilation runs 4 times/day approximately 12
hours behind real-time. During the TC4 Flight Campaign (16 July through
8 August 2007) the GMAO will produce twice daily ½ x 2/3 degree
forecasts at 00Z and 12Z and once daily ¼ x 1/3 degree forecasts at 12Z
with data products tailored to the needs of the TC4 Mission. Information
on the status of GMAO product generation can be found at
<http://gmao.gsfc.nasa.gov/operations/>.

# 2. Format and File Organization

GEOS-5 DAS files are in HDF-EOS format, which is an extension of the
Hierarchical Data Format (HDF), Version 4 developed at the National
Center for Supercomputing Applications (NCSA); files from GEOS-5
forecasts will be in a CF-compliant HDF-4 format without the HDF-EOS
extensions. Each GEOS-5 file will contain a single HDF-EOS grid, which
in turn contains a number of geophysical quantities that we will refer
to as \"fields\" or \"variables.\" Some files will contain 2-D variables
on a lon/lat grid and some files will contain 3-D variables on the same
lon/lat grid but with an additional vertical dimension. In order to keep
individual file sizes manageable, all files will contain only one valid
data time, in contrast to the daily files produced by earlier GEOS
systems.

In addition to the geophysical variables, the files will have SDS arrays
that define dimension scales (or coordinate variables). There will be
two distinct scales for each dimension, which will insure that a wide
variety of graphical display tools can interpret the dimension scales.
In particular, there is a set of dimension scales that adhere to the CF
conventions as well as the older COARDS conventions (see References).

Due to the large size of these data files we will use the internal GZIP
compression capability of HDF-4, which provides a lossless compression
of scientific data. In order to achieve a higher level of compression,
we will pre-condition the data values to be archived by "shaving" digits
off the mantissa of each 32 bit float point prior to applying the GZIP
lossless compression. Using this lossy compression scheme, we can reduce
file sizes by 50% to 80% or even more, and yet not require any
adjustment in the end user's software. Unlike SZIP compression in HDF-4,
GZIP compression comes standard with HDF-4 and these files can be
directly read by desktop applications such as IDL, Matlab and GrADS.

# 3. Assimilated Instantaneous Products vs. Model-generated Time-averaged Products

GEOS-5 gridded output files are identified as either instantaneous or
time-averaged products. For upper-air fields, all pressure products are
instantaneous and all lagrangian control volume (lcv) products are
time-averaged. Single-level or surface products may be either
instantaneous or time-averaged. The GMAO is no longer producing
time-averaged pressure products, as was done with GEOS-3 and GEOS-4.

The instantaneous products are generated by the analysis segment of the
assimilation process. All instantaneous products contain fields that are
snapshots of a specific time, with a single time per file. Upper-air
products such as "inst3d_met_p\" have a time frequency of 6 hours, with
data valid at the four standard *synoptic times* (00 GMT, 06 GMT, 12
GMT, and 18 GMT). Instantaneous single-level products, such as
"inst2d_met_x," have a time-frequency of 3 hours, valid at the times
listed above, plus the interim times of 03 GMT, 09 GMT, 15 GMT, and 21
GMT**.**

The time-averaged products are generated by the Incremental Analysis
Update (IAU) segment of the analysis process. The IAU gradually forces
the model integration through the 6-hour period between analysis times.
Time-averaged products are averaged over a 3-hour period for
single-level files and over a 6-hour period for lcv files. Single-level
products consist of 8 files per day, with time-stamps at the center of
the 3-hour averaging interval (i.e., 01:30, 04:30, 07:30, 10:30, 13:30,
16:30, 19:30, and 22:30 GMT), and there is a single time period per file
(e.g., the first file for a given day is time stamped with 01:30 GMT and
represents the average between 00 GMT and 03 GMT). Time-averaged
lcv-level products consist of 4 files/day, with time-stamps of 00, 06,
12, and 18 GMT, with each file time-stamped at the center of a 6-hour
average (e.g., the first file of a given day is time-stamped with 00 GMT
and represents an average between 21 GMT of the previous day and 03 GMT
of the given day).

# 4. Grid Structure

**[4.1 Horizontal Grids]{.underline}**

GEOS-5 gridded output will be provided on 2 different horizontal grids:

a)  ***Global 2/3 x 1/2 degree longitude-latitude horizontal grid***,
    consisting of IM**=540** points in the longitudinal direction and
    **JM=361** points in the latitudinal direction. The horizontal grid
    origin is the lower-left corner of the first grid box (I=1, J=1) and
    represents the geographical location (180W, 90S). Latitude and
    longitude as a function of their indices (I,J) can be determined by:

    i.  LON~I~ = -180 + (I-1) \* dLON, I=1, IM

    ii. LAT~J~ = -90 + (J-1) \* dLAT, J=1, JM

> where dLON = 2/3 and dLAT = 1/2. For all parameters of each file, a
> grid point represents the center of a box, i.e., the value at (LON=0,
> LAT=0) represents a box bounded by the points (LON=-0.33, LAT=0.25),
> (LON=-0.33, LAT=-0.25), (LON=0.33, LAT=-0.25), and (LON=0.33,
> LAT=0.25). Scalar values usually represent the volume mean within the
> box.

b)  ***Global 1/3 x 1/4 degree longitude-latitude horizontal grid***,
    consisting of IM**=1080** points in the longitudinal direction and
    **JM=721** points in the latitudinal direction. The horizontal grid
    origin is the lower-left corner of the first grid box (I=1, J=1) and
    represents the geographical location (180W, 90S). Latitude and
    longitude as a function of their indices (I,J) can be determined by:

    i.  LON~I~ = -180 + (I-1) \* dLON, I=1, IM

    ii. LAT~J~ = -90 + (J-1) \* dLAT, J=1, JM

> where dLON = 1/3 and dLAT = 1/4. For all parameters of each file, a
> grid point represents the center of a box, i.e., the value at (LON=0,
> LAT=0) represents a box bounded by the points (LON=-0.33, LAT=0.125),
> (LON=-0.33, LAT=-0.125), (LON=0.1666, LAT=-0.25), and (LON=0.1666,
> LAT=0.25). Scalar values usually represent the volume mean within the
> box.

**[4.2 Vertical Grid]{.underline}**

The **vertical structure of gridded products** will have three different
configurations: single-level (can be vertical averages or surface
values), pressure-level, or lcv-level. Single-level data for a given
variable appear as 3-dimensional fields (x, y, time) with multiple times
spanning multiple files, while pressure-level data appear as
4-dimensional fields (x, y, z, time). Pressure-level data will be output
on **LMP=26** pressure levels (hPa): 1000, 975, 950, 925, 900, 850, 800,
750, 700, 650, 600, 550, 500, 450, 400, 350, 300, 250, 200,150, 100, 70,
50, 30, 20, 10. The appropriate grid structure will be specified both in
the filename and the metadata.

The GEOS-5 terrain-following lagrangian control volume (lcv) coordinates
are similar to an eta coordinate system. There are []{#LM
.anchor}**LM=72** layers in the 5 lcv products: tavg3d_dyn_v,
tavg3d_cld_v, tavg3d_mst_v, tavg3d_tmp_v, and tavg3d_wnd_v, with the
values representing a layer-mean unless otherwise noted. Additionally
there is the tavg3d_prs_v product, which contains the
[**LM**](#LM)-layer 3D variable **[PL](#PL)~ijl~**, which defines the
layer-mean pressure at every horizontal grid-point. Note that the delta
pressure for each layer (**[DELP](#DELP)~ijl~**) and the surface
pressure (**[PS](#PS)~ij~**) are also included in the tavg3d_prs_v
product, allowing one to easily compute the pressure at the edges of
each layer. In the GEOS-4 eta files, one could compute the pressure on
the edges by using the "ak" and "bk" values and the surface pressure;
once the edge pressures were known, they could be used to compute the
average pressure in the layer. In GEOS-5, the full 3-dimensional
pressure variables are explicitly provided at both layer centers
(**[PL](#PL)~ijl~**) and layer edges (**[PLE](#PLE)~ijl~**). As of this
writing the pressures reported are on a hybrid-sigma coordinate, and
could be obtained from the "ak-bk" relationship. But this may change in
the future and so users should rely on the reported 3-dimensional
pressures and not attempt to compute them from "ak" and "bk". Figure 1
is a schematic (not to scale) of the GEOS-5 LCV coordinate system. Note
that the indexing in the vertical starts at the top, i.e., lcv layer 1
is the layer at the top of the atmosphere while lcv layer [**LM**](#LM)
is adjacent to the earth's surface.

Variables that are only defined on layer edges (such as vertical fluxes
between layers) are provided in the tavg3d_met_e product, which has
[**LM**](#LM)+1 levels representing the top and bottom edges of the
[**LM**](#LM) lcv layers of the model. This product also contains the
3-D variable edge pressures, [**PLE**](#PLE).

![](media/image3.png){width="5.979166666666667in"
height="5.895833333333333in"}

# Figure 1: Schematic of GEOS-5 LCV coordinate system

# 5. File Naming Convention

The standard generic complete name for the *[assimilated]{.underline}*
GEOS-5 configuration products will appear as follows:

**expid.filetype.yyyymmdd_hhnn.hdf**

GEOS-5 *[forecasts]{.underline}* files have an additional date string
(separated by "+") to indicate the initial conditions for that forecast.

**expid.filetype.YYYMMDD_HH+yyyymmdd_hhnn.hdf**

A brief description of the node fields appear below:

**expid:**

Experiment Identification. The GEOS-5 DAS data sets will be labeled:

GEOS5##

where \## is a two-digit number. The first operational release of GEOS-5
will have an experiment identification of GEOS501. When a modified
version of GEOS-5 is used for either forward processing or reprocessing,
we will increment the \## appropriately. As updated versions of the GEOS
software are implemented in operations, the cvs tag in the metadata
parameter \"History\" will be modified. Information on version upgrades
will also be available on the GMAO operations status web page
(<http://gmao.gsfc.nasa.gov/operations>/).

**filetype:**

The major file types are subdivided into file collections. Collections
contain several fields with common characteristics. These collections
are necessary to keep file sizes reasonable. Each file type will contain
the following information:

type/dimension_group_level

> *type/dimension:*
>
> There are four possible type/dimension conventions for the DAS data
> products:
>
> **inst2d** - 2-dimensional instantaneous fields (no time averaging).
>
> **inst3d** - 3-dimensional instantaneous fields (no time averaging).
>
> **tavg2d** - 2-dimensional 3-hour time-averaged fields, time-stamped
> at the center of the averaging period. For example, 04:30 GMT30z
> output would be a 3 GMT -- 6 GMT time average).
>
> **tavg3d** - 3-dimensional 6-hour time-averaged fields, time-stamped
> at the center of the averaging period. For example, 6 GMT output would
> be a 3 GMT -- 9 GMT time average.
>
> *group*:
>
> **met**: meteorological fields
>
> **prs**: pressure fields
>
> **dyn**: dynamical fields
>
> **mst**: moisture fields
>
> **tmp**: temperature fields
>
> **wnd**: wind fields
>
> **chm**: CO, CO2 and O3
>
> **aer**: aerosols: dust, sea salt, sulfates and carbonaceous aerosols
>
> *level*: There are four possible level types for the DAS data:
>
> **x**: single-level data (surface, column-integrated, single-level)
>
> **p**: pressure-level data (see Appendix C for pressure levels)
>
> **v**: lagrangian control volume (lcv) layers
>
> **e**: lagrangian control volume (lcv) layer edges

**yyyymmdd_hhnn:**

> This node defines the date and time of the data in the file.
>
> **yyyy** - **y**ear string (e.g. \"2002\")
>
> **mm** - **m**onth string (e.g. \"09\" for September)
>
> **dd** - **d**ay of the month string (e.g. \"10\" for the tenth day of
> the month)
>
> **hh** -- valid **h**our

**nn** -- valid mi**n**utes (either "00" or "30")

**YYYMMDD_HH**

Similarly, this denotes the date and time of the initial conditions for
the forecasts.

EXAMPLE:

GEOS501.tavg3d_dyn_v.20020915_00z.hdf

This is an example of a DAS filename from the operational GEOS-5 DAS.
The data are 6-hour time averaged output on lcv levels (rank 3: ). The
filetype consists of dynamical fields. The valid time for the data is
Sep 15 at 00 GMT, which represents the 6-hour average from Sep 14 at 21
GMT through Sep 15 at 03 GMT. See the discussion on time-averaged data
in section 3 for more information.

# 6. TC4 File Collections

## 6.1 Summary of Data Products

Table 1 summarizes the forecast files to be produced during TC4. The
meteorological products **inst3d_met_p** and **tavg2d_met_x** will be
produced at ½ x 2/3 degree resolution twice daily (00Z and 12Z) and ¼ x
1/3 degree horizontal resolution once a day (12Z). The remaining aerosol
and chemical constituent files will produced only at ½ x 2/3 degree
resolution twice daily. See sections 6.3 and 6.4 for a detailed list of
variable names.

The analysis data products will consist of the standard GEOS-5 DAS near
real-time offerings, supplemented by the aerosol and chemical
constituent products listed in Table 2. All these products will be
produced in ½ x 2/3 degree resolution only. See the "*File Specification
for GEOS-5 DAS Gridded Output"* document for a list of standard
products, and sections 6.5 for a detailed list of variable names in the
supplemental files.

[Table 1. Summary of GEOS-5 Forecast files]{.underline}

+------------+------------+-----------------+---+------+----+------+
| **File     | **Des      | **Variables**   | * | **Re | ** | **   |
| Type**     | cription** |                 | * | f.** | Fi | GZIP |
|            |            |                 | R |      | le | si   |
|            |            |                 | e | *    | Fr | ze** |
|            |            |                 | s | *Tim | eq |      |
|            |            |                 | . | es** | ** | **M  |
|            |            |                 | ( |      |    | b/fc |
|            |            |                 | \ |      |    | st** |
|            |            |                 | * |      |    |      |
|            |            |                 | ) |      |    |      |
|            |            |                 | * |      |    |      |
|            |            |                 | * |      |    |      |
+------------+------------+-----------------+---+------+----+------+
| In         | Ins        | **U, V,T, Q,    | D | 0Z,  | 3  | 3360 |
| st3d_met_p | tantaneous | OMEGA, H, RH,   | 2 | 12Z  | hr |      |
|            | 3D         | EPV,** *PS,     | 6 |      |    | 6592 |
|            | mete       | SLP*, PHIS,     |   | 12Z  |    |      |
|            | orological | *TSKIN,         | E |      |    |      |
|            | state on   | \_\_\_10M*      | 2 |      |    |      |
|            | pressure   |                 | 6 |      |    |      |
|            | c          |                 |   |      |    |      |
|            | oordinates |                 |   |      |    |      |
+------------+------------+-----------------+---+------+----+------+
| Ta         | Time       | *PS,* PHIS,     | D | 0Z,  | 3  | 340  |
| vg2d_met_x | averaged   | *SLP,           |   | 12Z  | hr |      |
|            | 2D misc    | PREC\_\_\_,     | E |      |    | 504  |
|            | fields,    | CLD\_\_\_,      |   | 12Z  |    |      |
|            | s          | TROP\_\_\_,     |   |      |    |      |
|            | ingle-leve | PBLH, CAPE,     |   |      |    |      |
|            | l/vertical | TSKIN, TQV,     |   |      |    |      |
|            | average    | TQL, TQI*       |   |      |    |      |
+------------+------------+-----------------+---+------+----+------+
| Ta         | Time       | *LWI, PS*,      | D | 0Z,  | 3  | 1240 |
| vg3d_chm_p | averaged   | **CO, CO2, O3** | 2 | 12Z  | hr |      |
|            | 3D         |                 | 6 |      |    |      |
|            | chemical   |                 |   | 12Z  |    |      |
|            | state on   |                 | # |      |    |      |
|            | pressure   |                 | # |      |    |      |
|            | c          |                 |   |      |    |      |
|            | oordinates |                 |   |      |    |      |
+------------+------------+-----------------+---+------+----+------+
| Ta         | Time       | *LWI, SCO, TCO, | D | 0Z,  | 3  | 100  |
| vg2d_chm_x | averaged   | SCO2, TCO2,     |   | 12Z  | hr |      |
|            | 2D         | SO3, TTO3, TO3  | # |      |    |      |
|            | chemical   | (includes       | # | 12Z  |    |      |
|            | state,     | production/     |   |      |    |      |
|            | single     | loss terms)*    |   |      |    |      |
|            | leve       |                 |   |      |    |      |
|            | l/vertical |                 |   |      |    |      |
|            | average    |                 |   |      |    |      |
+------------+------------+-----------------+---+------+----+------+
| Ta         | Time       | *LWI, PS***,    | D | 0Z,  | 3  | 2440 |
| vg3d_aer_p | averaged   | DU, SS, SO4,    | 2 | 12Z  | hr |      |
|            | 3D aerosol | SO2, BC, OC**   | 6 |      |    |      |
|            | con        |                 |   |      |    |      |
|            | centration |                 |   |      |    |      |
|            | on         |                 |   |      |    |      |
|            | pressure   |                 |   |      |    |      |
|            | c          |                 |   |      |    |      |
|            | oordinates |                 |   |      |    |      |
+------------+------------+-----------------+---+------+----+------+
| Ta         | Time       | Many (100+):    | D | 0Z,  | 3  | 1640 |
| vg2d_aer_x | average 2D | *AOT,           |   | 12Z  | hr |      |
|            | aerosol    | surface/column  |   |      |    |      |
|            | d          | mass,           |   |      |    |      |
|            | iagnostics | production &    |   |      |    |      |
|            |            | loss terms*     |   |      |    |      |
+------------+------------+-----------------+---+------+----+------+
| In         | Ins        | *SLP, H500,     | D | 0Z,  | 1  | 660  |
| st2d_hwl_x | tantaneous | DUAOT, SSAOT,   |   | 12Z  | hr |      |
|            | 2D fields  | BCAOT, OCAOT,   |   |      |    |      |
|            | for        | SO4AOT, SCO,    |   |      |    |      |
|            | Hyperwall  | SCO2,SSO2, TCO, |   |      |    |      |
|            |            | TCO2,TTO3, TO3, |   |      |    |      |
|            |            | TSO2*           |   |      |    |      |
+------------+------------+-----------------+---+------+----+------+

(\*) "D" resolution corresponds to 2/3^o^ longitude x 1/2 ^o^ latitude,
while "E" resolution corresponds to 1/3 ^o^ longitude x 1/4 ^o^
latitude. The 2 digits specify the number of vertical levels.

[Table 2. Summary of GEOS-5 Analysis/Assimilation files: additions to
GEOS-5 File Specification.]{.underline}

+-------------+------------+--------------------+----+-----+--------+
| **File      | **Des      | **Variables**      | ** | **F | **GZIP |
| Type**      | cription** |                    | Re | ile | Size** |
|             |            |                    | s. | Fre |        |
|             |            |                    | ** | q** | **Mb   |
|             |            |                    |    |     | /day** |
+-------------+------------+--------------------+----+-----+--------+
| I           | Ins        | *LWI, PS*, **DELP, | D  | 6hr | 904    |
| nst3d_chm_v | tantaneous | CO, CO2, O3**      | 72 |     |        |
|             | 3D         |                    |    |     |        |
|             | chemical   |                    |    |     |        |
|             | state on   |                    |    |     |        |
|             | LCV        |                    |    |     |        |
|             | c          |                    |    |     |        |
|             | oordinates |                    |    |     |        |
+-------------+------------+--------------------+----+-----+--------+
| T           | Time       | *LWI, PS*, **CO,   | D  | 3   | 248    |
| avg3d_chm_p | averaged   | CO2, O3**          | 26 | hr  |        |
|             | 3D         |                    |    |     |        |
|             | chemical   |                    | #  |     |        |
|             | state on   |                    | #  |     |        |
|             | pressure   |                    |    |     |        |
|             | c          |                    |    |     |        |
|             | oordinates |                    |    |     |        |
+-------------+------------+--------------------+----+-----+--------+
| T           | Time       | *LWI, SCO, TCO,    | D  | 3   | 20     |
| avg2d_chm_x | averaged   | SCO2, TCO2, SO3,   |    | hr  |        |
|             | 2D         | TTO3, TO3          | #  |     |        |
|             | chemical   | (includes          | #  |     |        |
|             | state,     | production/ loss   |    |     |        |
|             | single     | terms)*            |    |     |        |
|             | leve       |                    |    |     |        |
|             | l/vertical |                    |    |     |        |
|             | average    |                    |    |     |        |
+-------------+------------+--------------------+----+-----+--------+
| I           | Ins        | *LWI, PS***, DELP, | D  | 6hr | 4264   |
| nst3d_aer_v | tantaneous | RH, DU(5), SS(5),  | 72 |     |        |
|             | 3D aerosol | SO(4), BC(2),      |    |     |        |
|             | state on   | OC(2)**            |    |     |        |
|             | LCV        |                    |    |     |        |
|             | c          |                    |    |     |        |
|             | oordinates |                    |    |     |        |
+-------------+------------+--------------------+----+-----+--------+
| T           | Time       | *LWI, PS***, DU,   | D  | 3   | 976    |
| avg3d_aer_p | averaged   | SS, SO4, SO2, BC,  | 26 | hr  |        |
|             | 3D aerosol | OC**               |    |     |        |
|             | con        |                    |    |     |        |
|             | centration |                    |    |     |        |
|             | on         |                    |    |     |        |
|             | pressure   |                    |    |     |        |
|             | c          |                    |    |     |        |
|             | oordinates |                    |    |     |        |
+-------------+------------+--------------------+----+-----+--------+
| T           | Time       | Many (100+): *AOT, | D  | 3   | 328    |
| avg2d_aer_x | average 2D | surface/column     |    | hr  |        |
|             | aerosol    | mass, production & |    |     |        |
|             | d          | loss terms*        |    |     |        |
|             | iagnostics |                    |    |     |        |
+-------------+------------+--------------------+----+-----+--------+
| I           | Ins        | *SLP, H500, DUAOT, | D  | 1   | 44     |
| nst2d_hwl_x | tantaneous | SSAOT, BCAOT,      |    | hr  |        |
|             | 2D fields  | OCAOT, SO4AOT,     |    |     |        |
|             | for        | SCO, SCO2,SSO2,    |    |     |        |
|             | Hyperwall  | TCO, TCO2,TTO3,    |    |     |        |
|             |            | TO3, TSO2*         |    |     |        |
+-------------+------------+--------------------+----+-----+--------+

##  6.2 Calculation of file sizes

Below are the variables that are output into each **inst** file. These
are instantaneous fields (no time averaging). The approximate size of
each file below is determined by the following:

A x B x C x D x E = bytes/file

where:

> A: X-Dimension
>
> B: Y-Dimension
>
> C: Vertical dimension

D: Number of fields in file

> E: Number of bytes per floating point number

The method for calculating sizes is the same in 6.1 and 6.2.

NOTE: All HDF variable names are UPPERCASE. Italicized sizes in ( ) are
estimates of the compressed file size, which will vary from day to day.

## 6.3 Forecast Files -- ½ by 2/3 Degree Resolution: Twice-daily at 00Z and 12Z

-   **inst3d_met_p** (1 time per file, 8 files per day: 00, 03, 06, 09,
    12, 15, 18, 21 GMT)

> Description: 3D meteorological state, instantaneous on pressure
> coordinates
>
> Dimensions:
>
> longitude: 540
>
> latitude: 361
>
> vertical pressure levels: 26
>
> Number of 3D variables: 8
>
> Number of 2D variables: 10
>
> Size: 168 MB (84 MB)
>
> Size/day: 1344 MB (672 MB)

  ------------------------------------------------------------------------------
  [Variable           [Description]{.underline}            [Units]{.underline}
  Name]{.underline}                                        
  ------------------- ------------------------------------ ---------------------
  H                   Geopotential height                  m

  EPV                 Ertel Potential vorticity            m^2^kg^-1^s^-1^

  OMEGA               Vertical velocity                    Pa s^-1^

  QV                  Specific humidity                    kg kg^-1^

  RH                  Relative humidity                    percent

  T                   Air temperature                      K

  U                   Eastward wind component              m s^-1^

  V                   Northward wind component             m s^-1^

  [PS](#PS)           Surface pressure                     Pa

  [SLP](#SLP)         Sea-level pressure                   Pa

  [PHIS](#PHIS)       Surface geopotential                 m^2^s^-2^

  [TSKIN](#TSKIN)     Skin temperature                     K

  [U10M](#U50M)       Eastward (zonal) wind at 10 m above  m s^-1^
                      displacement height                  

  [V10M](#V50M)       Meridional (zonal) wind at 10 m      m s^-1^
                      above displacement height            

  [T10M](#T10M)       Temperature interpolated to 10 m     K
                      above the displacement height        

  [QV10M](#QV10M)     Specific humidity interpolated to 10 kg kg^-1^
                      m above the displacement height      

  [T2M](#T10M)        Temperature interpolated to 2 m      K
                      above the displacement height        

  [QV2M](#QV10M)      Specific humidity interpolated to 2  kg kg^-1^
                      m above the displacement height      
  ------------------------------------------------------------------------------

-   **tavg2d_met_x** (1 file per time, 8 files per day: 01:30, 04:30,
    07:30, 10:30, 13:30, 16:30, 19:30, 22:30 GMT)

> Description: Time averaged 2D miscellaneous fields,
> single-level/vertical average
>
> Dimensions:
>
> longitude: 540
>
> latitude: 361
>
> Number of 2D variables: 21
>
> Size: 17 MB (8.5MB)
>
> Size/day: 136 MB (68 MB)

  ------------------------------------------------------------------------------------
  [Variable             [Description]{.underline}                [Units]{.underline}
  Name]{.underline}                                              
  --------------------- ---------------------------------------- ---------------------
  [PS](#PS)             Surface pressure                         Pa

  [SLP](#SLP)           Sea-level pressure                       Pa

  [PHIS](#PHIS)         Surface geopoptential                    m^2^s^-2^

  CAPE                  Convective Available Potential Energy    J m^-2^

  [CLDHGH](#CLDHIGH)    High-level (above 400 hPa) cloud         fraction
                        fraction                                 

  [CLDLOW](#CLDHIGH)    Low-level (1000-700 hPa) cloud fraction  fraction

  [CLDMID](#CLDHIGH)    Mid-level (700-400 hPa) cloud fraction   fraction

  [CLDTOT](#CLDHIGH)    Total cloud fraction                     fraction

  [PBLH](#PBLH)         Planetary boundary layer height          m

  [DISPH](#DISPH)       Displacement height                      m

  [PRECANV](#PRECANV)   Surface precipitation flux from anvils   kg m^-2^ s^-1^

  [PRECCON](#PRECANV)   Surface precipitation flux from          kg m^-2^ s^-1^
                        convection                               

  [PRECLSC](#PRECANV)   Surface precipitation flux from          kg m^-2^ s^-1^
                        large-scale                              

  [PRECSNO](#PRECSNO)   Surface snowfall flux                    kg m^-2^ s^-1^

  [PRECTOT](#PRECTOT)   Total surface precipitation flux         kg m^-2^ s^-1^

  [TPW](#TPW)           Total precipitable water                 kg m^-2^

  [TROPP](#TROPP)       Tropopause pressure                      Pa

  [TROPQ](#TROPQ)       Tropopause specific humidity             kg kg^-1^

  [TROPT](#TROPT)       Tropopause temperature                   K
  ------------------------------------------------------------------------------------

-   **tavg3d_chm_p** (1 file per time, 8 files per day: 01:30, 04:30,
    07:30, 10:30, 13:30, 16:30, 19:30, 22:30 GMT)

> Description: Time averaged 3D chemical state on pressure coordinates
>
> Dimensions:
>
> longitude: 540
>
> latitude: 361
>
> vertical pressure levels: 26
>
> Number of 2D variables: 2
>
> Number of 3D variables: 3
>
> Size: 62 MB (31MB)
>
> Size/day: 496 MB (248 MB)

  ---------------------------------------------------------------------------------------
  [Variable           [Description]{.underline}                     [Units]{.underline}
  Name]{.underline}                                                 
  ------------------- ------------------------------------ -------- ---------------------
  LWI                 Land-Water-Ice mask                  none     

  PS                  Surface pressure (2D)                Pa       

  CO                  Carbon monoxide volume mixing ratio  kg       
                                                           kg^-1^   

  CO~2~               Carbon dioxide volume mixing ratio   kg       
                                                           kg^-1^   

  O~3~                Ozone mass mixing ratio              kg       
                                                           kg^-1^   
  ---------------------------------------------------------------------------------------

-   **tavg2d_chm_x** (1 file per time, 8 files per day: 01:30, 04:30,
    07:30, 10:30, 13:30, 16:30, 19:30, 22:30 GMT)

> Description: Time averaged 2D chemical state, single level/vertical
> average
>
> Dimensions:
>
> longitude: 540
>
> latitude: 361
>
> Number of 2D variables: 12
>
> Size: 5 MB (5 MB)
>
> Size/day: 40 MB (40 MB)

  ---------------------------------------------------------------------------------------
  [Variable           [Description]{.underline}                     [Units]{.underline}
  Name]{.underline}                                                 
  ------------------- ------------------------------------ -------- ---------------------
  SCO                 Surface Carbon Monoxide              kg m^-2^ 

  SCO2                Surface Carbon Dioxide               kg m^-2^ 

  TTO3                Total Tropospheric Ozone             Dobson   

  TO3                 Total Column Ozone                   Dobson   

  TCO                 Carbon Monoxide Column Burden        kg m^-2^ 

  TCO2                Carbon Dioxide Column Burden         kg m^-2^ 

  COEMIS              CO Emission                          kg m^-2^ 
                                                           s^-1^    

  COPROD              CO Chemical Production               kg m^-2^ 
                                                           s^-1^    

  COLOSS              CO Chemical Loss                     kg m^-2^ 
                                                           s^-1^    

  CO2EMIS             CO2 Emission                         kg m^-2^ 
                                                           s^-1^    

  CO2PROD             CO2 Chemical Production              kg m^-2^ 
                                                           s^-1^    

  CO2LOSS             CO2 Chemical Loss                    kg m^-2^ 
                                                           s^-1^    
  ---------------------------------------------------------------------------------------

-   **tavg3d_aer_p** (1 file per time, 8 files per day: 01:30, 04:30,
    07:30, 10:30, 13:30, 16:30, 19:30, 22:30 GMT)

> Description: Time averaged 3D aerosol state on pressure coordinates
>
> Dimensions:
>
> longitude: 540
>
> latitude: 361
>
> vertical pressure levels: 26
>
> Number of 2D variables: 2
>
> Number of 3D variables: 6
>
> Size: 122 MB ( 61 MB)
>
> Size/day: 976 MB (488 MB)

  --------------------------------------------------------------------------------------
  [Variable           [Description]{.underline}                    [Units]{.underline}
  Name]{.underline}                                                
  ------------------- ------------------------------------ ------- ---------------------
  LWI                 Land-Water-Ice mask                  none    

  PS                  Surface pressure (2D)                Pa      

  DU                  Dust Mass Mixing Ratio               kg/kg   

  SS                  Seasalt Mass Mixing Ratio            kg/kg   

  BC                  Black Carbon Mass Mixing Ratio       kg/kg   

  OC                  Organic Carbon Mass Mixing Ratio     kg/kg   

  SO2                 SO~2~ Aerosol Mass Mixing Ratio      kg/kg   

  SO4                 SO~4~ Aerosol Mass Mixing Ratio      kg/kg   
  --------------------------------------------------------------------------------------

-   **tavg2d_aer_x** (1 file per time, 8 files per day: 01:30, 04:30,
    07:30, 10:30, 13:30, 16:30, 19:30, 22:30 GMT)

> Description: Time averaged 2D miscellaneous aerosol fields, single
> level/vertical average
>
> Dimensions:
>
> longitude: 540
>
> latitude: 361
>
> vertical layers (lcv): 109
>
> Number of 2D variables:
>
> Size: 85 MB (43 MB)
>
> Size/day: 680 MB (335 MB)

  ------------------------------------------------------------------------------------------
  [Variable           [Description]{.underline}                        [Units]{.underline}
  Name]{.underline}                                                    
  ------------------- ------------------------------------ ----------- ---------------------
  CLDTOT              Total cloud cover                    fraction    

  GWETTOP             Top soil layer wetness               fraction    

  H500                500 hPa Geopotential height          m           

  LWI                 Surface type flag                    flag        

  PBLH                Planetary boundary layer height      m           

  PRECTOT             Total precipitation rate             mm/day      

  SLP                 Sea level pressure                   Pa          

  TQV                 Total precipitable water             kg/m^2^     

  DUEM001             Dust Emission Bin 1                  kg/m^2^/s   

  DUEM002             Dust Emission Bin 2                  kg/m^2^/s   

  DUEM003             Dust Emission Bin 3                  kg/m^2^/s   

  DUEM004             Dust Emission Bin 4                  kg/m^2^/s   

  DUEM005             Dust Emission Bin 5                  kg/m^2^/s   

  DUSD001             Dust Sedimentation Bin 1             kg/m^2^/s   

  DUSD002             Dust Sedimentation Bin 2             kg/m^2^/s   

  DUSD003             Dust Sedimentation Bin 3             kg/m^2^/s   

  DUSD004             Dust Sedimentation Bin 4             kg/m^2^/s   

  DUSD005             Dust Sedimentation Bin 5             kg/m^2^/s   

  DUDP001             Dust Dry Deposition Bin 1            kg/m^2^/s   

  DUDP002             Dust Dry Deposition Bin 2            kg/m^2^/s   

  DUDP003             Dust Dry Deposition Bin 3            kg/m^2^/s   

  DUDP004             Dust Dry Deposition Bin 4            kg/m^2^/s   

  DUDP005             Dust Dry Deposition Bin 5            kg/m^2^/s   

  DUWT001             Dust Wet Deposition Bin 1            kg/m^2^/s   

  DUWT002             Dust Wet Deposition Bin 2            kg/m^2^/s   

  DUWT003             Dust Wet Deposition Bin 3            kg/m^2^/s   

  DUWT004             Dust Wet Deposition Bin 4            kg/m^2^/s   

  DUWT005             Dust Wet Deposition Bin 5            kg/m^2^/s   

  DUSMASS             Dust Surface Mass Concentration      kg/m^3^     

  DUCMASS             Dust Column Mass Density             kg/m^2^     

  DUEXTTAU            Dust Extinction AOT 550 nm           unitless    

  DUSCATAU            Dust Scattering AOT 550 nm           unitless    

  DUAERIDX            Dust TOMS UV Aerosol Index           unitless    

  DUSMASS25           Dust Surface Mass Concentration (PM  kg/m^3^     
                      2.5)                                             

  DUCMASS25           Dust Column Mass Density (PM 2.5)    kg/m^2^     

  DUEXTT25            Dust Extinction AOT 550 nm (PM 2.5)  unitless    

  DUSCAT25            Dust Scattering AOT 550 nm (PM 2.5)  unitless    

  SSEM001             Seasalt Emission Bin 1               kg/m^2^/s   

  SSEM002             Seasalt Emission Bin 2               kg/m^2^/s   

  SSEM003             Seasalt Emission Bin 3               kg/m^2^/s   

  SSEM004             Seasalt Emission Bin 4               kg/m^2^/s   

  SSEM005             Seasalt Emission Bin 5               kg/m^2^/s   

  SSSD001             Seasalt Sedimentation Bin 1          kg/m^2^/s   

  SSSD002             Seasalt Sedimentation Bin 2          kg/m^2^/s   

  SSSD003             Seasalt Sedimentation Bin 3          kg/m^2^/s   

  SSSD004             Seasalt Sedimentation Bin 4          kg/m^2^/s   

  SSSD005             Seasalt Sedimentation Bin 5          kg/m^2^/s   

  SSDP001             Seasalt Dry Deposition Bin 1         kg/m^2^/s   

  SSDP002             Seasalt Dry Deposition Bin 2         kg/m^2^/s   

  SSDP003             Seasalt Dry Deposition Bin 3         kg/m^2^/s   

  SSDP004             Seasalt Dry Deposition Bin 4         kg/m^2^/s   

  SSDP005             Seasalt Dry Deposition Bin 5         kg/m^2^/s   

  SSWT001             Seasalt Wet Deposition Bin 1         kg/m^2^/s   

  SSWT002             Seasalt Wet Deposition Bin 2         kg/m^2^/s   

  SSWT003             Seasalt Wet Deposition Bin 3         kg/m^2^/s   

  SSWT004             Seasalt Wet Deposition Bin 4         kg/m^2^/s   

  SSWT005             Seasalt Wet Deposition Bin 5         kg/m^2^/s   

  SSSMASS             Seasalt Surface Mass Concentration   kg/m^3^     

  SSCMASS             Seasalt Column Mass Density          kg/m^2^     

  SSEXTTAU            Seasalt Extinction AOT 550 nm        unitless    

  SSSCATAU            Seasalt Scattering AOT 550 nm        unitless    

  SSSMASS25           Seasalt Surface Mass Concentration   kg/m^3^     
                      (PM 2.5)                                         

  SSCMASS25           Seasalt Column Mass Density (PM 2.5) kg/m^2^     

  SSEXTT25            Seasalt Extinction AOT 550 nm (PM    unitless    
                      2.5)                                             

  SSSCAT25            Seasalt Scattering AOT 550 nm (PM    unitless    
                      2.5)                                             

  BCEM001             Black Carbon Emission Bin 1          kg/m^2^/s   

  BCEM002             Black Carbon Emission Bin 2          kg/m^2^/s   

  BCDP001             Black Carbon Deposition Bin 1        kg/m^2^/s   

  BCDP002             Black Carbon Deposition Bin 2        kg/m^2^/s   

  BCWT001             Black Carbon Wet Deposition Bin 1    kg/m^2^/s   

  BCWT002             Black Carbon Wet Deposition Bin 2    kg/m^2^/s   

  BCSMASS             Black Carbon Surface Mass            kg/m^3^     
                      Concentration                                    

  BCCMASS             Black Carbon Column Mass Density     kg/m^2^     

  BCEXTTAU            Black Carbon Extinction AOT 550 nm   unitless    

  BCSCATAU            Black Carbon Scattering AOT 550 nm   unitless    

  OCEM001             Organic Carbon Emission Bin 1        kg/m^2^/s   

  OCEM002             Organic Carbon Emission Bin 2        kg/m^2^/s   

  OCDP001             Organic Carbon Deposition Bin 1      kg/m^2^/s   

  OCDP002             Organic Carbon Deposition Bin 2      kg/m^2^/s   

  OCWT001             Organic Carbon Wet Deposition Bin 1  kg/m^2^/s   

  OCWT002             Organic Carbon Wet Deposition Bin 2  kg/m^2^/s   

  OCSMASS             Organic Carbon Surface Mass          kg/m^3^     
                      Concentration                                    

  OCCMASS             Organic Carbon Column Mass Density   kg/m^2^     

  OCEXTTAU            Organic Carbon Extinction AOT 550 nm unitless    

  OCSCATAU            Organic Carbon Scattering AOT 550 nm unitless    

  SUEM001             Sulfate Emission Bin 1               kg/m^2^/s   

  SUEM002             Sulfate Emission Bin 2               kg/m^2^/s   

  SUEM003             Sulfate Emission Bin 3               kg/m^2^/s   

  SUEM004             Sulfate Emission Bin 4               kg/m^2^/s   

  SUDP001             Sulfate Deposition Bin 1             kg/m^2^/s   

  SUDP002             Sulfate Deposition Bin 2             kg/m^2^/s   

  SUDP003             Sulfate Deposition Bin 3             kg/m^2^/s   

  SUDP004             Sulfate Deposition Bin 4             kg/m^2^/s   

  SUWT001             Sulfate Wet Deposition Bin 1         kg/m^2^/s   

  SUWT002             Sulfate Wet Deposition Bin 2         kg/m^2^/s   

  SUWT003             Sulfate Wet Deposition Bin 3         kg/m^2^/s   

  SUWT004             Sulfate Wet Deposition Bin 4         kg/m^2^/s   

  SO2SMASS            SO2 Surface Mass Concentration       kg/m^3^     

  SO2CMASS            SO2 Column Mass Density              kg/m^2^     

  SO4SMASS            SO4 Surface Mass Concentration       kg/m^3^     

  SO4CMASS            SO4 Column Mass Density              kg/m^2^     

  DMSSMASS            SO2 Surface Mass Concentration       kg/m^3^     

  DMSCMASS            SO2 Column Mass Density              kg/m^2^     

  SUPSO2              SO2 Production from DMS Oxidation    kg/m^2^/s   
                      column integrated                                

  SUPSO4g             SO4 Production from gas-phase SO2    kg/m^2^/s   
                      Oxidation column integrated                      

  SUPSO4aq            SO4 Production from aqueous SO2      kg/m^2^/s   
                      Oxidation (column)                               

  SUPMSA              MSA Production from DMS Oxidation    kg/m^2^/s   
                      column integrated                                

  SUPSO4wt            SO~4~ Production from aqueous SO2    kg/m^2^/s   
                      Oxidation (wet dep) column                       
                      integrated                                       

  SUEXTAU             SO~4~ Extinction AOT 550 nm          unitless    

  SUSCATAU            SO~4~ Scattering AOT 550 nm          unitless    
  ------------------------------------------------------------------------------------------

-   **tinst2d_hwl_x** (1 file per time, 24 files per day: 00, 01, 02,
    ..., 23 GMT)

> Description: Instantaneous 2D fields for Hyperwall, single
> level/vertical average
>
> Dimensions:
>
> longitude: 540
>
> latitude: 361
>
> Number of 2D variables: 14
>
> Size: 11 MB ( 5.5 MB)
>
> Size/day: 264 MB ( 132 MB)

  ----------------------------------------------------------------------------------------
  [Variable           [Description]{.underline}                      [Units]{.underline}
  Name]{.underline}                                                  
  ------------------- ------------------------------------ --------- ---------------------
  H500                500 hPa Geopotential height          m         

  SLP                 Sea level pressure                   Pa        

  PRECTOT             Total surface precipitation flux     kg m^-2^  
                                                           s^-1^     

  DUAOT               Dust Extinction AOT 550 nm           none      

  SSAOT               Seasalt Extinction AOT 550 nm        none      

  BCAOT               Black Carbon Extinction AOT 550 nm   none      

  OCAOT               Organic Carbon Extinction AOT 550 nm none      

  SO4AOT              SO4 Extinction AOT 550 nm            none      

  SCO                 Surface Carbon Monoxide              kg m^-2^  

  SCO2                Surface Carbon Dioxide               kg m^-2^  

  SSO2                Surface SO2                          kg m^-2^  

  TTO3                Total Tropospheric Column Ozone      Dobson    

  TO3                 Total Column Ozone                   Dobson    

  TCO                 Carbon Monoxide Column Burden        kg/m^2^   

  TCO2                Carbon Dioxide Column Burden         kg/m^2^   

  TSO2                SO2 Column Burden                    kg/m^2^   
  ----------------------------------------------------------------------------------------

## 6.4 Forecast Files -- ¼ x 1/3 Degree Resolution: Once-daily at 12Z

-   **inst3d_met_p** (1 time per file, 8 files per day: 00, 03, 06, 09,
    12, 15, 18, 21 GMT)

> Description: 3D meteorological state, instantaneous on pressure
> coordinates
>
> Dimensions:
>
> longitude: 1080
>
> latitude: 721
>
> levels: 26 (pressure)
>
> Number of 3D variables: 8
>
> Number of 2D variables: 10
>
> Size: 824 MB (412 MB)
>
> Size/day: 6592 MB (3296 MB)

  ---------------------------------------------------------------------------------
  [Variable           [Description]{.underline}               [Units]{.underline}
  Name]{.underline}                                           
  ------------------- ------------------------------------ -- ---------------------
                      Same variables as **inst3d_met_p**      
                      in section 6.3                          

  ---------------------------------------------------------------------------------

-   **tavg2d_met_x** (1 file per time, 8 files per day: 01:30, 04:30,
    07:30, 10:30, 13:30, 16:30, 19:30, 22:30 GMT)

> Description: Time averaged 2D miscellaneous fields,
> single-level/vertical average
>
> Dimensions:
>
> longitude: 1080
>
> latitude: 721
>
> Number of 2D variables: 21
>
> Size: 63 MB ( 31.5 MB)
>
> Size/day: 504 MB (252 MB)

  ---------------------------------------------------------------------------------
  [Variable           [Description]{.underline}               [Units]{.underline}
  Name]{.underline}                                           
  ------------------- ------------------------------------ -- ---------------------
                      Same variables as **tavg2d_met_x**      
                      in section 6.3                          

  ---------------------------------------------------------------------------------

##  

## 6.5 Analysis/Assimilation Files -- ½ by 1/3 Degree Resolution:

The GMAO will continue producing its standard data products as described
in the *File Specification for GEOS-5 DAS Gridded Output.* All the
quantities listed in that document will be made available in the OpenDAP
server <http://opendap.gsfc.nasa.gov:9090/dods/GEOS-5/TC4>. However, the
individual datasets will not contain the additional HDF-EOS metadata
described in the GEOS-5 FileSpec document.

-   **inst3d_chm_v** (1 file per time, 4 files per day: 00, 06, 12 and
    18 GMT)

> Description: Instantaneous 3D chemical state on LCV coordinates
>
> Dimensions:
>
> longitude: 540
>
> latitude: 361
>
> layers : 72 (lcv)
>
> Number of 2D variables: 2
>
> Number of 3D variables: 4
>
> Size: 226 MB (113 MB)
>
> Size/day: 1808 MB (904 MB)

  ----------------------------------------------------------------------------------------
  [Variable           [Description]{.underline}                      [Units]{.underline}
  Name]{.underline}                                                  
  ------------------- ------------------------------------ --------- ---------------------
  LWI                 Land-Water-Ice mask                  none      

  PS                  Surface pressure (2D)                Pa        

  DELP                Pressure difference between layer    Pa        
                      edges                                          

  CO                  Carbon monoxide volume mixing ratio  mol/mol   

  CO~2~               Carbon dioxide volume mixing ratio   mol/mol   

  O~3~                Ozone mass mixing ratio              kg kg^-1^ 
  ----------------------------------------------------------------------------------------

-   **tavg3d_chm_p** (1 file per time, 8 files per day: 01:30, 04:30,
    07:30, 10:30, 13:30, 16:30, 19:30, 22:30 GMT)

> Description: Time averaged 3D chemical state on pressure coordinates
>
> Dimensions:
>
> longitude: 540
>
> latitude: 361
>
> levels: 26 (pressure)
>
> Number of 2D variables: 2
>
> Number of 3D variables: 3
>
> Size: 62 MB (31 MB)
>
> Size/day: 496 MB (248 MB)

  ---------------------------------------------------------------------------------
  [Variable           [Description]{.underline}               [Units]{.underline}
  Name]{.underline}                                           
  ------------------- ------------------------------------ -- ---------------------
                      Same variables as **tavg3d_chm_p**      
                      in section 6.3                          

  ---------------------------------------------------------------------------------

-   **tavg2d_chm_x** (1 file per time, 8 files per day: 01:30, 04:30,
    07:30, 10:30, 13:30, 16:30, 19:30, 22:30 GMT)

> Description: Time averaged 2D chemical state, single level/vertical
> average
>
> Dimensions:
>
> longitude: 540
>
> latitude: 361
>
> Number of 2D variables: 6
>
> Size: 5 MB (2.5 MB)
>
> Size/day: 40 MB (20 MB)

  ---------------------------------------------------------------------------------
  [Variable           [Description]{.underline}               [Units]{.underline}
  Name]{.underline}                                           
  ------------------- ------------------------------------ -- ---------------------
                      Same variables as **tavg2d_chm_x**      
                      in section 6.3                          

  ---------------------------------------------------------------------------------

-   **inst3d_aer_v** (1 file per time, 4 files per day: 00, 06, 12 and
    18 GMT)

> Description: Instantaneous 3D aerosol state on LCV coordinates
>
> Dimensions:
>
> longitude: 540
>
> latitude: 361
>
> layers: 72 (lcv)
>
> Number of 2D variables: 3
>
> Number of 3D variables: 19
>
> Size: 1066 MB (533 MB)
>
> Size/day: 8528 MB (4264 MB)

  ----------------------------------------------------------------------------------------
  [Variable           [Description]{.underline}                      [Units]{.underline}
  Name]{.underline}                                                  
  ------------------- ------------------------------------ --------- ---------------------
  LWI                 Land-Water-Ice mask                  None      

  PS                  Surface pressure (2D)                Pa        

  DELP                Pressure difference between layer    Pa        
                      edges                                          

  RH                  Relative humidity                    percent   

  DU001               Dust mass mixing ratio -- Bin 001    kg kg^-1^ 

  DU002               Dust mass mixing ratio -- Bin 002    kg kg^-1^ 

  DU003               Dust mass mixing ratio -- Bin 003    kg kg^-1^ 

  DU004               Dust mass mixing ratio -- Bin 004    kg kg^-1^ 

  DU005               Dust mass mixing ratio -- Bin 005    kg kg^-1^ 

  SS001               Sea salt mass mixing ratio -- Bin    kg kg^-1^ 
                      001                                            

  SS002               Sea salt mass mixing ratio -- Bin    kg kg^-1^ 
                      002                                            

  SS003               Sea salt mass mixing ratio -- Bin    kg kg^-1^ 
                      003                                            

  SS004               Sea salt mass mixing ratio -- Bin    kg kg^-1^ 
                      004                                            

  SS005               Sea salt mass mixing ratio -- Bin    kg kg^-1^ 
                      005                                            

  DMS                 Dimethylsulphide                     kg kg^-1^ 

  SO2                 Sulphur dioxide                      kg kg^-1^ 

  SO4                 Sulphate aerosol                     kg kg^-1^ 

  MSA                 Methanesulphonic acid                kg kg^-1^ 

  BCphobic            Hydrophobic Black Carbon             kg kg^-1^ 

  BCphilic            Hydrophilic Black Carbon             kg kg^-1^ 

  OCphobic            Hydrophobic Organic Carbon           kg kg^-1^ 
                      (Particulate Matter)                           

  OCphilic            Hydrophilic Organic Carbon           kg kg^-1^ 
                      (Particulate Matter)                           
  ----------------------------------------------------------------------------------------

-   **tavg3d_aer_p** (1 file per time, 8 files per day: 01:30, 04:30,
    07:30, 10:30, 13:30, 16:30, 19:30, 22:30 GMT)

> Description: Time averaged 3D aerosol concentration on pressure
> coordinates
>
> Dimensions:
>
> longitude: 540
>
> latitude: 361
>
> levels: 26 (pressure)
>
> Number of 2D variables: 2
>
> Number of 3D variables: 6
>
> Size: 122 MB (61 MB)
>
> Size/day: 976 MB (488 MB)

  ---------------------------------------------------------------------------------
  [Variable           [Description]{.underline}               [Units]{.underline}
  Name]{.underline}                                           
  ------------------- ------------------------------------ -- ---------------------
                      Same variables as **tavg3d_aer_p**      
                      in section 6.3                          

  ---------------------------------------------------------------------------------

-   **tavg2d_aer_x** (1 file per time, 8 files per day: 01:30, 04:30,
    07:30, 10:30, 13:30, 16:30, 19:30, 22:30 GMT)

> Description: Time average 2D aerosol diagnostics
>
> Dimensions:
>
> longitude: 540
>
> latitude: 361
>
> Number of 2D variables: 102
>
> Size: 82 MB (41 MB)
>
> Size/day: 656 MB (328 MB)

  ---------------------------------------------------------------------------------
  [Variable           [Description]{.underline}               [Units]{.underline}
  Name]{.underline}                                           
  ------------------- ------------------------------------ -- ---------------------
                      Same variables as **tavg2d_aer_x**      
                      in section 6.3                          

  ---------------------------------------------------------------------------------

-   **tavg2d_hwl_x** (1 file per time, 24 files per day: 00, 01, 02,
    ..., 23 GMT)

> Description: Instantaneous 2D fields for Hyperwall, single
> level/vertical average
>
> Dimensions:
>
> longitude: 540
>
> latitude: 361
>
> Number of 2D variables: 14
>
> Size: 11 MB (5.5 MB)
>
> Size/day: 88 MB (44 MB)

  ---------------------------------------------------------------------------------
  [Variable           [Description]{.underline}               [Units]{.underline}
  Name]{.underline}                                           
  ------------------- ------------------------------------ -- ---------------------
                      Same variables as **tavg2d_hwl_x**      
                      in section 6.3                          

  ---------------------------------------------------------------------------------

# Appendix A. Types of Assimilation Configurations

**Operational Assimilation:** Atmospheric observations from satellites,
balloons, aircraft, ships, and other sources are grouped into six-hour
data windows and processed by the atmospheric analysis four times each
day. The operational analysis will run approximately 12 hours after the
4 analysis times (0Z, 6Z, 12Z, 18Z). It will run using whatever
conventional and satellite observations are available at the data
cut-off time. Products produced from this and any other *assimilation*
are a combination of output from the statistical analysis system and a
short GCM forecast.

**Forecast/Simulation:** This is a GCM forecast, with no insertion of
atmospheric data via the analysis. The only outside data that enters the
system are the boundary conditions, i.e., sea surface temperature and
sea-ice concentration. Five-day forecasts are typically generated to
support NASA field campaigns and to assess assimilation and forecast
skill. Multi-year simulations are produced to investigate the
climatology of the GCM. GMAO forecast products are not distributed to
ECS and file formats are not discussed in this document.

**Reprocessing:** The GMAO may reprocess specified time periods since
EOS-Terra launch using a recent version of the GEOS DAS software to
support instrument team reprocessing requirements. It is expected that
new ECS ESDTs will be generated for each reprocessing run.

**Reanalysis:** The GMAO will occasionally run reanalysis experiments.
Reanalysis is the same as reprocessing except the time period is often
much longer and not necessarily part of the EOS period. Reanalysis
experiments are often run using baseline versions of the GEOS DAS system
to support a wide variety of research activities internal and external
to the GMAO. Unique ESDTs will be generated for any reanalysis data
distributed through GES DAAC.

#  {#section-5 .unnumbered}

# Appendix E: Detailed Description of Output Variables

**[E.1: 3D Variables]{.underline}**

**CLOUD:** The horizontal fractional cloud cover for each layer. In the
vertical, clouds are assumed to fill the layer. This fraction is the
combination of the model's predicted large-scale and convective
fractions that is used for radiative purposes. See
**[CLDTOT](#CLDHIGH)** for a description of how these fractions are
overlapped in the radiation calculations.

**CMFMC:** The total vertical convective mass flux through levels
between model layers (edges), in kg m^-2^ s^-1^. This is produced by the
convection parameterization (RAS) and it includes the mass flux due to
all cloud types crossing the level.

[]{#DELP .anchor}**DELP:** Pressure thickness of model layers, in Pa.
See [**PLE**](#PLE). The layer mass is **DELP / 9.81** kg m^-2^.

**DQRCON, DQRLSC:** The layer production rate of precipitating
condensate from convective and large-scale processes per unit horizontal
area, in kg m^-2^ s^-1^ Includes both liquid and frozen precipitating
condensate, but not the production cloud condensates.

**DQVDTMST, DQLDTMST, DQIDTMST:** Tendency of vapor, liquid and ice
water due to moist processes, in kg kg^-1^ s^-1^. This includes the
effects of the convection parameterization (RAS) and all other effects
from the cloud microphysics and large scale and anvil precipitation
schemes.

**DQVDTDYN:** Tendency of water vapor due to resolved dynamics, in kg
kg^-1^ s^-1^.

**DQVDTTRB:** Tendency of water vapor due to turbulence, including
surface evaporation,\
in kg kg^-1^ s^-1^.

[]{#DTDTDYN .anchor}**DTDTDYN:** Temperature tendency due to dynamics,
including the spurious frictional dissipation of kinetic energy by
numerical processes.

[]{#DTDTFRI .anchor}**DTDTFRI:** Temperature tendency due to the
frictional dissipation of kinetic energy by turbulence, including
surface friction, in K s^-1^. It does not include dissipation from
gravity wave drag or the implicit dissipation in the model's dynamics.

**DTDTGWD:** Temperature tendency due to the frictional dissipation of
kinetic energy by gravity wave drag, in K s^-1^.

**DTDTLWR, DTDTLWRCLR:** Temperature tendency due to terrestrial
(longwave) radiation for all-sky and clear-sky conditions, in K s^-1^.

**DTDTMST:** Temperature tendency due to terrestrial (longwave)
radiation, in K s^-1^.

**DTDTSWR, DTDTSWRCLR:** Temperature tendency due to solar (shortwave)
radiation for all-sky and clear-sky conditions, in K s^-1^.

**DTDTTOT:** The total diabatic temperature tendency for the model
layers, in K s^-1^ . It is the same as the sum
**DTDTFRI+DTDTGWD+DTDTLWR+DTDTSWR+DTDTMST+DTDTTRB,** and in the lon-term
mean should balance [**DTDTDYN**](#DTDTDYN).

**DTDTTRB:** Temperature tendency due to turbulence, including surface
sensible heat flux, but not including the heating due to frictional
dissipation (see [**DTDTFRI**](#DTDTFRI)), in K s^-1^. Above the surface
it includes the diffusive effects due to the Louis and Lock turbulence
schemes (see [**KH**](#KH)).

**DTRAIN:** Mass flux detrained at cloud top from each convective cloud
type in RAS, the model's convection parameterization, in kg m^-2^ s^-1^.

**DUDTDYN, DVDTDYN:** Eastward (zonal) and northward (meridional) wind
tendency due to dynamics, in m s^-2^.

**DUDTGWD, DVDTGWD:** Eastward (zonal) and northward (meridional) wind
tendencies due to gravity wave drag, in m s^-2^.

**DUDTMST, DVDTMST:** Eastward (zonal) and northward (meridional) wind
tendencies due to moist processes, in m s^-2^. Currently this represents
the "cumulus friction" effect of mixing momentum in a conservative way,
using the convective mass fluxes from RAS.

**DUDTTRB, DVDTTRB:** Eastward (zonal) and northward (meridional) wind
tendencies due to turbulent processes, in m s^-2^. This includes surface
friction. Above the surface, it includes the diffusive effects due to
the Louis and Lock turbulence schemes (see [**KM**](#KH)).

**HGHT**: Geopotential height at the layer centers, in m. It is simply
the average of **[HGHTE](#HGHTE)** at the layer's bounding edges.

[]{#HGHTE .anchor}**HGHTE**: Geopotential height at the layer edges, in
m. At the surface ([LM](#LM)+1) it is set to **[PHIS](#PHIS)/**g**.**
Above the surface $\frac{1}{g}($**PHIS +**
c~P~$\sum_{l = L}^{\text{LM}}{}\theta_{v}\Delta P)$**,** where
$\Delta P$is the difference in
$\left( \frac{p}{p_{o}} \right)^{\kappa}$at the lower and upper edges of
layer $l$, and $\theta_{v}$ is the virtual potential temperature,

[]{#KH .anchor}**KH, KM :** Turbulent diffusivity for heat and other
scalars and for momentum (**U** and **V**), in m^2^ s ^-1^. This is
defined at the layer edges, beginning at the top, where it is zero. At
the surface ([LM](#LM)+1) it is set ..... It includes the diffusive
effects due to the Louis and Lock turbulence schemes.

**MFXC, MFYC:** The eastward and northward layer mass fluxes on the
C-Grid, in Pa m^2^ s^-1^.\
**MF\[X,Y\]C =**
$\lbrack U,V\rbrack\text{DELP }\lbrack a\Delta\phi,a\text{cos}(\phi)\Delta\lambda\rbrack$**,**
where **U** and **V** are the C-grid velocity components, *a* is the
earth's radius, and
$\lbrack a\Delta\phi,a\text{cos}(\phi)\Delta\lambda\rbrack \equiv \lbrack\Delta y,\Delta x\rbrack$
are the meridional and zonal grid spacings at the appropriate C-grid
locations, in meters.

**MFZ:** The vertical component of the large-scale mass flux at the lcv
edges, in kg m^-2^ s^-1^. Together with **MFXC, MFYC,** and **PS,**
these satisfy the continuity equation
$\frac{\partial}{\partial t}\text{ PS } = \text{ -}\frac{1}{\Delta y\Delta x}(\delta_{x}\text{ MFXC } + \delta_{y}\text{ MFYC})\text{ -g }\delta_{z}\text{ MFZ}$

**OMEGA:** The kinematic vertical pressure velocity estimated by the
Finite-Volume dynamics. It is defined for the layers, not the edges. For
layer $l$, it is discretized vertically as
$\omega_{l} = \left( \overline{\frac{\partial p}{\partial t}} + \overline{\overset{}{\eta}\frac{\partial p}{\partial\eta}} \right)_{l} + (V \cdot \nabla\overline{p})_{l}$,
where the pressure is defined at the layer edges and the overbar
indicates the average of the layer's upper and lower edges.

[]{#PL .anchor}**PL:** The layer pressure defined as the average of the
upper and lower edge pressures, **[PLE](#PLE),** in Pa (see
[**DELP**](#DELP)).

[]{#PLE .anchor}**PLE:** The time-averaged pressure at the upper edge of
a layer**. PLE** = **[PS](#PS) +**
$\sum_{l = L}^{\text{LM}}{}$**[DELP](#DELP)** ${}_{l}$. This is the
preferred way of obtaining edge pressures in lcv-coordinates, rather
than relying on the model's hybrid-sigma coordinate system (i.e., the
**AK**s and **BK**s), which may change in future releases.

**PV**: A modified Ertel's potential vorticity, approximated as
$g(\zeta + f)\frac{\partial\text{ln}(\theta_{v})}{\partial p}$, in m^2^
kg^-1^ sec^-1^. Here$\zeta$is the vertical component of relative
vorticity,$f$is the Coriolis parameter, and $\theta_{v}$ is the virtual
potential temperature. Note the definition in terms of entropy instead
of potential temperature and the neglect of the part associated with the
horizontal components of vorticity.

**TAUCLI, TAUCLW:** Each layer's total cloud optical thickness in the
visible (0.40 to 0.69 micron band), for ice clouds and liquid water
clouds, respectively.

**[E.2: 2D Variables]{.underline}**

**ALBEDO:** The time-averaged surface albedo defined as the ratio of the
time-averaged incident and reflected fluxes and should satisfy **ALBEDO
= [SWGDWN](#SWGDWN)/(SWGDWN-[SWGNET](#SWGNET)).** At night points, this
is set to [**\_FillValue**](#FillValue).

**ALBVISDF, ALBVISDR, ALBNIRDF, ALBNIRDR:** The direct (beam) and
diffuse albedos for the "visible" (the GCM uses the same albedos for the
UV and the PAR spectral regions----0.175 to 0.69 microns) and the
"near-infrared" (0.69 to 3.85 microns). These are simply time-averaged
surface properties, but are defined only where there was daylight at the
point during the averaging interval. They do not correspond to the
ratios of time-averaged incident and reflected fluxes.

**BSTAR:** The buoyancy scale of the surface layer in m s^-2^. It is
defined as $\frac{g}{\rho_{a}u^{}}\frac{F_{s_{v}}}{c_{P}T_{a}}$, where
$\rho_{a}$ is the near-surface air density ([**RHOA**](#RHOA)) and
$T_{a}$ the near-surface air temperature, $u^{}$is the friction velocity
([**USTAR**](#USTAR)), and $F_{s_{v}}$is the surface flux of virtual dry
static energy in W m^-2^, $F_{s_{v}} =$ (**[HFLUX](#HFLUX)** +
$(1 - \varepsilon)$**[EFLUX](#EFLUX)).**

[]{#CLDHIGH .anchor}**CLDHGH, CLDMID, CLDLOW, CLDTOT:** High, middle,
low, and total cloudiness. The high, middle, low-level values correspond
to the three superlayers used in the GEOS-5 solar and terrestrial
radiation parameterizations. Clouds within these superlayers are assumed
to be maximally overlapped. High clouds are those occurring above
roughly 400 hPa and low clouds are those occurring below 700 hPa,
although the groupings are done ion the model's terrain following
coordinate and so the bounding pressures will differ significantly from
these values over high topography. The model assumes that the overlapped
between the superlayers is random, and the total cloudiness uses this
assumption. The total cloudiness is computed each time the radiation is
called, and so its time mean cannot be exactly constructed from the
time-mean cloudiness in the three super layers.

[]{#DISPH .anchor}**DISPH:** Surface displacement height in meters. See
the description of the neutral drag coefficient.

**DTG:** Change in surface temperature during the averaging interval in
deg K. This refers to the area-mean surface temperature under each
atmospheric column, and so, it may contain contributions from land-,
water-, and ice-covered parts of the grid box.

[]{#EFLUX .anchor}**EFLUX:** The upward turbulent flux of latent heat
flux at the surface, in W m^-2^. This includes the latent heat relative
to liquid of all turbulent moisture fluxes through the surface (see
**[EVAP](#EVAP))**.

**EMIS:** The surface emissivity. This is a really averaged over all
surface tiles and is constant in time.

[]{#EVAP .anchor}**EVAP:** Evaporation in kg m^-2^ s^-1^. Actually the
total turbulent flux of water vapor at the surface, including fluxes
from transpiration, sublimation, and surface condensation. The turbulent
flux of could condensate (fog) is assumed to be zero. .

[]{#FRLAKE .anchor}**FRLAKE, FRLAND, FRLANDICE, FROCEAN:** GEOS-5 uses
these four primary surface types and these are their fractions under
each atmospheric column.

**GRN:** The "greenness" or fraction transpiring leaves averaged over
the land areas of a grid box. If there are several vegetation tiles
within the land part of a grid box, the average is **LAI** weighted.
**GRN** is set to **[\_FillValue](#FillValue)** where
[**FRLAND**](#FRLAKE) = 0.

**GWETROOT, GWETTOP:** The degree of saturation or "wetness" in the
root-zone (top meter of soil) and top soil layer (top 2 cm). These are
defined as the ratio of the volumetric soil moisture to the porosity.
These quantities are set to **[\_FillValue](#FillValue)** where
[**FRLAND**](#FRLAKE) = 0. Elsewhere they are time-mean and area-mean
values of the ratio over the land part of the grid box.

[]{#HFLUX .anchor}**HFLUX:** The upward turbulent sensible heat flux at
the surface, in W m^-2^.

**LAI:** The a real average of the leaf-area index over all land parts
of a grid box. **LAI** is set to **[\_FillValue](#FillValue)** where
[**FRLAND**](#FRLAKE) = 0.

**LWGDWN, LWGDWNCLR:** The all-sky and cloud-free fluxes of downwelling
terrestrial (longwave) radiation at the surface in W m^-2^.

**LWGNET:** The net downward flux of terrestrial (longwave) radiation at
the surface in W m^-2^. This is identical to **LWGDWN- LWGUP.**

**LWGUP:** The all-sky upwelling terrestrial (longwave) radiation at the
surface, in W m^-2^. This includes both the surface emission and the
reflection..

**LWI:** A Land-Water-Ice mask provided for backward compatibility with
the GEOS-4 product. It is 1 over continental areas, 0 over open ocean,
and 2 over sea-ice covered ocean. Since in GEOS-5 a grid box can be a
combination of these, continental areas are arbitrarily defined as those
where **[FRLAND+FRLANDICE](#FRLAKE)\>=0.5.** The remaining grid boxes
are designated as sea-ice if the ice cover exceeds 50%; otherwise they
are open (ice-free) ocean.

**LWTUP, LWTUPCLR:** Outgoing longwave (terrestrial) radiation at the
top of the model's atmosphere (currently 0.01 hPa) for all-sky and
clear-sky conditions, in W m^-2^.

**PARDF, PARDR:** Incident flux of of diffuse and direct PAR at the
surface, in W m^-2^. PAR is defied as the solar radiation between 0.4
and 0.69 microns.

[]{#PBLH .anchor}**PBLH:** Height above the surface of the planetary
boundary layer in meters. This is obtained diagnostically at every time
step from the heat diffusivity in the model layers. It is defined as the
height of the lowest layer in which the diffusivity falls below 2 m^2^
s^-1^. Where no layer is above this value, the boundary layer height is
set to the height of the surface layer.

[]{#PHIS .anchor}**PHIS:** The surface geopotential, $\text{gh}_{s}$, in
m^-2^ s^-2^. Here $h_{s}$is the height of the surface above sea level,
and $g = 9\text{.}\text{81}$ m s^-2^.

[]{#PRECANV .anchor}**PRECANV, PRECLSC, PRECCON:** the large-scale
precipitation from anvils, the non-anvil large-scale precipitation, and
the convective precipitation, in kg m^-2^ s^-1^. These include both
rainfall and snowfall.

[]{#PRECTOT .anchor}**PRECTOT:** The total precipitation
(**PRECANV+PRECLSC+PRECCON**) in kg m^-2^ s^-1^.

[]{#PRECSNO .anchor}**PRECSNO:** The "snowfall" includes all frozen
precipitation, in kg m^-2^ s^-1^.

[]{#PS .anchor}**PS:** The surface pressure in Pa. The height at this
pressure can be obtained from the surface geopotential
**[PHIS](#PHIS).** The total atmospheric mass is $\frac{1}{g}$**PS** kg
m^-2^.

[]{#QV10M .anchor}**QV10M, QV2M:** The specific humidity at 10 m and 2m
above the displacement height ([**DISPH**](#DISPH)) in the surface
layer, in kg kg^-1^.

[]{#RHOA .anchor}**RHOA:** Surface air density in the lowest model
layer, in kg m^-3^. This is the density used in bulk formulas.

[]{#SLP .anchor}**SLP:** The surface pressure reduced to sea level, in
Pa. Over topography the reduction is done by assuming a lapse rate of
6.5 K km^-1^ from a free atmospheric temperature, which is currently
taken as the lowest model layer above 150 hPa above the surface.

**SNOMAS:** The mass of snow in per unit of land area in meters of
liquid-water-equivalent depth (i.e., 10^3^ kg m^-2^). In grid boxes with
no land (**[FRLAND+FRLANDICE](#FRLAKE)=0**) it is set to
**[\_FillValue](#FillValue).** Where **FRLANDICE\>0.9** it is
arbitrarily set to 4 meters. Over other land areas it represents an
average over the non-glaciated part.

**SNODP:** The geometric snow depth in meters. This accounts for packing
and aging of the snow.

[]{#SWGDWN .anchor}**SWGDWN, SWGDWNCLR**: Incident solar radiation
(0.175 to 3.85 microns) at the surface for all-sky and clear-sky
conditions, in W m^-2^. Since we do a single atmospheric transfer
calculation in a grid box, we assume the incident diffuse radiation is
the same for all land tiles within the box.

[]{#SWGNET .anchor}**SWGNET, SWGNETCLR:** Net downward flux of solar
radiation at the surface averaged over all land tiles for all-sky and
clear-sky conditions, in W m^-2^.

**SWTUP, SWTUPCLR:** The outgoing (reflected) flux of solar radiation at
the top of the model's atmosphere (currently 0.01 hPa) for all-sky and
clear-sky conditions, in W m^-2^.

**SWTDWN:** Incident flux of solar radiation at the top of the
atmosphere, in W m^-2^.

[]{#T10M .anchor}**T10M, T2M:** The air temperature at 10 m and 2m above
the displacement height ([**DISPH**](#DISPH)) in the surface layer, in
K.

**TAUGWX, TAUGWY:** The eastward (zonal) and northward (meridional)
components of the atmospheric stress on the surface due to atmospheric
gravity wave drag, in N m^-2^.

**TAUHGH, TAUMID, TAULOW, TAUTOT:** Total cloud optical thickness in the
0.40 to 0.69 micron band for the high, middle, and low cloud regions
(see **[CLDHGH](#CLDHIGH))** and for the entire column.

[]{#TAUX .anchor}**TAUX, TAUY:** The eastward (zonal) and northward
(meridional) components of the atmospheric frictional stress on the
surface, in N m^-2^.

**TO3 :** The vertically integrated ozone, in Dobson units.

[]{#TPW .anchor}**TPW, TQV:** The vertically integrated water vapor in
the column, in kg m^-2^.. These are synonyms.

**TQL, TQI:** The vertically integrated liquid and ice water in the
column, in kg m^-2^.

**TQC:** The vertically integrated combined liquid and ice water in the
column, in kg m^-2^.

[]{#TROPP .anchor}**TROPP:** The tropopause pressure in Pa. The
tropopause pressure is defined as the pressure where the function
$\alpha T(p) - \text{log}_{\text{10}}p$ reaches its first minimum above
the surface. Here $\alpha = 0\text{.}\text{03}$ and $p$ is in hPa. If no
minimum is found between 550 hPa and 40 hPa, **TROPP** is set to
**[\_FillValue](#FillValue).**

[]{#TROPQ .anchor}**TROPQ:** The tropopause specific humidity in kg
kg^-1^. The tropopause is defined as in **TROPP.**

[]{#TROPT .anchor}**TROPT:** The tropopause temperature in K. The
tropopause is defined as in **TROPP.**

[]{#TSKIN .anchor}**TSKIN:** The area weighted skin temperature of all
surface tiles in a grid box, in K.

**TTO3:** The vertically integrated ozone in the troposphere, in Dobson
units. The troposphere is defined as all levels below **[TROPP](#TROPP).
TTO3** and **TROPP** are computed at every time step and averaged
separately.

[]{#U50M .anchor}**U50M, U10M, U2M:** The eastward wind component at
50m, 10 m, and 2m above the displacement height ([**DISPH**](#DISPH)) in
the surface layer, in m s^-1^.

[]{#USTAR .anchor}**USTAR:** The surface friction velocity,
$u^{} = \sqrt{\frac{|\tau|}{\rho_{a}}}$, in m s^-1^. This mean quantity
is formed by doing the the areal average over the surface tiles in a
grid box instantaneously to $|\tau|$, and the time averaging on
$u^{}$itself. It is thus not exactly what would be obtained from
**[TAUX, TAUY](#TAUX),** and **[RHOA](#RHOA).**

[]{#V50M .anchor}**V50M, V10M, V2M:** The northward wind component at
50m, 10 m, and 2m above the displacement height ([**DISPH**](#DISPH)) in
the surface layer, in m s^-1^.

**Z0H:** The surface roughness for heat, in m.

**Z0M:** The dynamic surface roughness, in m.

# REFERENCES

GMAO web site: <http://gmao.gsfc.nasa.gov/>

GMAO Operations page: <http://gmao.gsfc.nasa.gov/operations/>

CF Standard Description:
<http://www.cgd.ucar.edu/cms/eaton/cf-metadata/CF-current.html>

CF Standard Names:
<http://www.cgd.ucar.edu/cms/eaton/cf-metadata/standard_name.xml>

Dopplick, T., 1997: The Role of Metadata in EOSDIS. EOSDIS Technical

Paper 160-TP-013-001.

Gross, C., 1997: B.0 Earth Science Data Model for the ECS Project.
EOSDIS

Technical Paper 420-TP-015-001.

NOAA, 1995: Conventions for the Standardization of NetCDF Files
(COARDS). http://ferret.wrc.noaa.gov/noaa_coop/coop_cdf_profile.html

NCSA, 1999: The NCSA HDF Home Page. <http://hdf.ncsa.uiuc.edu/>

SZIP compression in HDF: http://hdf.ncsa.uiuc.edu/doc_resource/SZIP/

NASA, 1999: HDF-EOS Standards. http://hdfeos.gsfc.nasa.gov/

deWitt, Shaun, 1996: Writing HDF-EOS Grid Products for Optimum
Subsetting Services. ECS Technical Paper 170-TP-007-001.

[^1]: Available from
    <http://gmao.gsfc.nasa.gov/operations/GEOS5_File_Specification.pdf>
    .

[^2]: TC4 Home Page: <http://cloud1.arc.nasa.gov/tc4/>