[MITgcm-support] 回复: 转发: The obvious difference between ERA5 and NCEP-R1 forcing
Leming Van
ifanliming at outlook.com
Mon Mar 16 02:26:29 EDT 2020
Hi, Matt
Thank you for your advice. I'm sorry that I didn't provide enough information.
I downloaded the ERA5 dataset at https://cds.climate.copernicus.eu/cdsapp#!/dataset/reanalysis-era5-single-levels?tab=form
Copernicus Climate Data Store | Copernicus Climate Data Store<https://cds.climate.copernicus.eu/cdsapp#!/dataset/reanalysis-era5-single-levels?tab=form>
CDS Menu. Home; Search; Datasets; Applications; Toolbox; FAQ; Live; Copernicus Climate Data Store
cds.climate.copernicus.eu
And I selected precip[mean_total_precipitation_rate. kg m-2 s-1], atemp[2m_temperature. K], swdown[mean_surface_downward_short_wave_radiation_flux. W m-2], lwdown[mean_surface_downward_long_wave_radiation_flux. W m-2], uwind[10m_u_component_of_wind. m s-1], vwind[10m_v_component_of_wind. m s-1], because ERA5 does not provide aqh directly, I used air pressure[surface_pressure Pa] and dewpoint temperature[2m_dewpoint_temperature K] to calculate aqh.
Since the data is hourly, I only downloaded the area of interest(bigger than South China Sea), and besides, the data is zonally aligned from 35N to 5S, I flipped it to 5S-35N.
I compared the ERA5 with NCEP, and I don't think there is much difference except for the short-wave radiation. Please check the attachment.
I only have one question, do you choose the same ERA5 variables like me? If not, could you tell me which variables you choose?
Please let me know if any other files are needed for diagnosis. Thanks in advance.
-Mike
Here is the setting of my data.exf
# $Header: /u/gcmpack/MITgcm_contrib/eh3/llc/ecco-godae/input_50lev/data.exf,v 1.1 2007/03/06 19:13:51 heimbach Exp $
#
# *********************
# External Forcing Data
# *********************
&EXF_NML_01
useAtmWind = .TRUE.,
# rotateStressOnAgrid = .TRUE.,
exf_iprec = 32,
exf_yftype = 'RL',
useExfYearlyFields = .false.,
twoDigitYear = .false.,
useExfCheckRange =.false.,
&
&EXF_NML_02
climsstfile = 'woa13_sst_monthly_globe_relax.box',
climsssfile = 'woa13_sss_monthly_globe_relax.box',
precipfile = 'era5_prate_2002-2005_hourly.box',
atempfile = 'era5_air_2002-2005_hourly.box',
aqhfile = 'era5_shum_2002-2005_hourly.box',
swdownfile = '',
swfluxfile = 'era5_nswrs_2002-2005_hourly.box',
lwfluxfile = '',
lwdownfile = 'era5_dlwrf_2002-2005_hourly.box',
uwindfile = 'era5_uwnd_2002-2005_hourly.box',
vwindfile = 'era5_vwnd_2002-2005_hourly.box',
runofffile = 'run-off.bin_1x1',
#
climsststartdate1 = 20020101,
climsststartdate2 = 000000,
climsstperiod = -12,
climsssstartdate1 = 20020101,
climsssstartdate2 = 000000,
climsssperiod = -12,
runoffstartdate1 = 20020101,
runoffstartdate2 = 000000,
runoffperiod = -12,
#
precipstartdate1=20020101,
precipstartdate2=000000,
precipperiod=3600.0,
atempstartdate1=20020101,
atempstartdate2=000000,
atempperiod=3600.0,
aqhstartdate1=20020101,
aqhstartdate2=000000,
aqhperiod=3600.0,
swdownstartdate1=20020101,
swdownstartdate2=000000,
swdownperiod=3600.0,
lwfluxstartdate1=20020101,
lwfluxstartdate2=000000,
lwfluxperiod=3600.0,
swfluxstartdate1=20020101,
swfluxstartdate2=000000,
swfluxperiod=3600.0,
lwdownstartdate1=20020101,
lwdownstartdate2=000000,
lwdownperiod=3600.0,
uwindstartdate1=20020101,
uwindstartdate2=000000,
uwindperiod=3600.0,
vwindstartdate1=20020101,
vwindstartdate2=000000,
vwindperiod=3600.0,
hfluxstartdate1=20020101,
hfluxstartdate2=000000,
hfluxperiod=3600.0,
sfluxstartdate1=20020101,
sfluxstartdate2=000000,
sfluxperiod=3600.0,
ustressstartdate1=20020101,
ustressstartdate2=000000,
ustressperiod=3600.0,
vstressstartdate1=20020101,
vstressstartdate2=000000,
vstressperiod=3600.0,
&
&EXF_NML_03
exf_inscal_precip=1.,
exf_offset_atemp=0.0,
exf_inscal_runoff = 3.1710e-08,
&
&EXF_NML_04
precip_lon0 = 95.0D0,
precip_lon_inc = 0.25D0,
precip_lat0 = -5.0D0,
precip_lat_inc = 160*0.25D0,
precip_nlon = 160,
precip_nlat = 160,
#
atemp_lon0 = 95.0D0,
atemp_lon_inc = 0.25D0,
atemp_lat0 = -5.0D0,
atemp_lat_inc = 160*0.25D0,
atemp_nlon = 160,
atemp_nlat = 160,
#
aqh_lon0 = 95.0D0,
aqh_lon_inc = 0.25D0,
aqh_lat0 = -5.0D0,
aqh_lat_inc = 160*0.25D0,
aqh_nlon = 160,
aqh_nlat = 160,
#
swdown_lon0 = 95.0D0,
swdown_lon_inc = 0.25D0,
swdown_lat0 = -5.0D0,
swdown_lat_inc = 160*0.25D0,
swdown_nlon = 160,
swdown_nlat = 160,
#
lwflux_lon0 = 95.0D0,
lwflux_lon_inc = 0.25D0,
lwflux_lat0 = -5.0D0,
lwflux_lat_inc = 160*0.25D0,
lwflux_nlon = 160,
lwflux_nlat = 160,
#
swflux_lon0 = 95.0D0,
swflux_lon_inc = 0.25D0,
swflux_lat0 = -5.0D0,
swflux_lat_inc = 160*0.25D0,
swflux_nlon = 160,
swflux_nlat = 160,
#
lwdown_lon0 = 95.0D0,
lwdown_lon_inc = 0.25D0,
lwdown_lat0 = -5.0D0,
lwdown_lat_inc = 160*0.25D0,
lwdown_nlon = 160,
lwdown_nlat = 160,
#
uwind_lon0 = 95.0D0,
uwind_lon_inc = 0.25D0,
uwind_lat0 = -5.0D0,
uwind_lat_inc = 160*0.25D0,
uwind_nlon = 160,
uwind_nlat = 160,
#
vwind_lon0 = 95.0D0,
vwind_lon_inc = 0.25D0,
vwind_lat0 = -5.0D0,
vwind_lat_inc = 160*0.25D0,
vwind_nlon = 160,
vwind_nlat = 160,
#
ustress_lon0 = 95.0D0,
ustress_lon_inc = 0.25D0,
ustress_lat0 = -5.0D0,
ustress_lat_inc = 160*0.25D0,
ustress_nlon = 160,
ustress_nlat = 160,
#
vstress_lon0 = 95.0D0,
vstress_lon_inc = 0.25D0,
vstress_lat0 = -5.0D0,
vstress_lat_inc = 160*0.25D0,
vstress_nlon = 160,
vstress_nlat = 160,
#
hflux_lon0 = 95.0D0,
hflux_lon_inc = 0.25D0,
hflux_lat0 = -5.0D0,
hflux_lat_inc = 160*0.25D0,
hflux_nlon = 160,
hflux_nlat = 160,
#
sflux_lon0 = 95.0D0,
sflux_lon_inc = 0.25D0,
sflux_lat0 = -5.0D0,
sflux_lat_inc = 160*0.25D0,
sflux_nlon = 160,
sflux_nlat = 160,
#
runoff_lon0 = 0.50D0,
runoff_lon_inc = 1.0D0,
runoff_lat0 = -79.5D0,
runoff_lat_inc = 159*1.0D0,
runoff_nlon = 360,
runoff_nlat = 160,
#
climsst_lon0 = -179.875D0,
climsst_lon_inc = 0.25D0,
climsst_lat0 = -89.875D0,
climsst_lat_inc = 719*0.25D0,
climsst_nlon = 1440,
climsst_nlat = 720,
#
climsss_lon0 = -179.875D0,
climsss_lon_inc = 0.25D0,
climsss_lat0 = -89.875D0,
climsss_lat_inc = 719*0.25D0,
climsss_nlon = 1440,
climsss_nlat = 720,
#
&
&EXF_NML_OBCS
obcsNstartdate1 = 20020101,
obcsNstartdate2 = 000000,
obcsNperiod = 2628000.0,
obcsEstartdate1 = 20020101,
obcsEstartdate2 = 000000,
obcsEperiod = 2628000.0,
obcsSstartdate1 = 20020101,
obcsSstartdate2 = 000000,
obcsSperiod = 2628000.,
&
________________________________
发件人: MITgcm-support <mitgcm-support-bounces at mitgcm.org> 代表 Matthew Mazloff <mmazloff at ucsd.edu>
发送时间: 2020年3月16日 0:44
收件人: mitgcm-support at mitgcm.org <mitgcm-support at mitgcm.org>
主题: Re: [MITgcm-support] 转发: The obvious difference between ERA5 and NCEP-R1 forcing
Hi Mike
It is possible it could give worse results, but very unlikely. However its too hard for me to diagnose what is going on. There are many variables to your problem.
For ERA5 I have this in my data.exf:
&EXF_NML_03
exf_offset_atemp = 273.15,
exf_inscal_swdown = -1.0,
exf_inscal_lwdown = -1.0,
Not sure how to help you,
Matt
On Mar 15, 2020, at 5:41 AM, Leming Van <ifanliming at outlook.com<mailto:ifanliming at outlook.com>> wrote:
Hi, everyone
Recently I tried to change forcing dataset from NCEP-R1(6-hourly) to ERA5(hourly), but the results of them look so different. I compared the results of NCEP-R1 with the reanalysis data of HYCOM, and these two data look similar.
Did I pick the wrong variables from ERA5? Or does this mean that higher temporal and spatial resolution atmospheric forcing ERA5 results in worse simulation results than lower resolution NCEP-R1?
I put the results at here, https://1drv.ms/u/s!AoS5GLJhmvDtjB5Ovnz63FidKeMo?e=c2hS7z
Suggestions are welcome.
-Mike
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