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GEM_Airborne_Data_Readme
Greenhouse Emissions in the Midwest (GEM) airborne dataset

README file (v5)
10/14/2019
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Data PIs: Dylan Millet (dbm@umn.edu) and Eric Kort (eakort@umich.edu)

The files contained in GEM_Airborne_Data.tar contain all trace
gas measurements from the GEM aircraft campaigns (GEM-1, GEM-2,
and GEM-3. 

These data are available for use on a collaborative basis. We request
that you contact the above PIs if using the data, and prior to
including it in any presentations or publication.

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Campaign dates
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GEM1: 2017-08-12 -> 2017-08-24
GEM2: 2018-01-17 -> 2018-01-28
GEM3: 2018-05-21 -> 2018-06-02

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Trace gas instrumentation
=======================================================

GEM1:
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Picarro CRDS (model G2301, CH4, CO2, H2O)
Aerodyne (N2O, CO2, CO, H2O)
2B Technologies (model 205, O3)

GEM2:
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Picarro CRDS (model G2210-m, CH4, CO2(wet), H2O, C2H6)
Aerodyne (N2O, CO2, CO, H2O)
2B Technologies (model 205, O3)

GEM3:
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Picarro CRDS (model G2210-m, CH4, CO2(wet), H2O, C2H6)
Aerodyne (N2O, H2O, [CO2&CO removed due to high noise])
2B Technologies (model 205, O3)

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Data files and format
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1-sec, 2-sec, 5-sec, and 1-min merge files are included for each flight
in GEM-1, GEM-2, and GEM-3. Also included are all-flight 1-min merges
for each campaign.

Reported variables are as follows, with missing data flagged as -999999.

********                 ***********
Variable                 Description
********                 ***********
year                     Year of measurement
month                    Month of measurement
day                      Day of month
time.out.utc             Fractional day of year UTC

Hemisphere Precision GPS variables:
--------
g.lat                    GPS latitude (deg)
g.lon                    GPS longitude (deg)
g.alt.asl.m              Altitude above sea level (m)
g.zonal.speed.m.s        Zonal speed (m/s)
g.meridional.speed.m.s   Meridional speed (m/s)
g.heading.deg            Heading (deg)
g.pitch.deg              Pitch (deg)
g.roll.deg               Roll (deg)

Aspen flight information variables:
--------
a.u.m.s                  E-W wind speed (m/s)
a.v.m.s	                 N-S wind speed (m/s)
a.pressure.mb            Ambient pressure (mb)
a.ias.kts                Indicated air speed (knots)
a.tas.kts                True air speed (knots)
a.alt.ft                 Altitude (feet)
a.oat.k                  Outside air temperature rounded to nearest degree (K)
a.rot.deg.s              Rate of turn (deg/s)
a.vertical.speed.ft.s    Vertical speed (feet/s)
a.heading.deg            Heading based on magnetic compass (deg)
a.magnetic.variation.deg Magnetic variation (deg)

Vaisala HMP60 variables:
--------
t.temp.c                 Outside temperature (C)
t.rh.pct	         Outside RH (%)

Picarro variables:
--------
p.specific.humidity.pct  Specific humidity (%)
p.ambient.pressure.mb    Ambient pressure (mb)
p.ch4.corrected.ppb      CH4 mixing ratio (ppb)
p.co2.corrected.ppm      CO2 mixing ratio (ppm)

2B variables:
--------
oz.o3.ppb                Ozone mixing ratio (ppb)

Aerodyne variables:
--------
an.n2o                   N2O mixing ratio (ppb)
an.co                    CO mixing ratio (ppb)
an.co2                   CO2 mixing ratio (ppm)
an.h2o                   Specific humidity (%)
co2.Flag                 Flag indicating > 2ppm disagreement between Picarro + Aerodyne CO2