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Hi, Estanislao</div>
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I got it, I selected Mean surface downward long-wave radiation flux instead of Surface thermal radiation downwards, so their units are different. Are there significant differences in the spatial distribution of these two variables?</div>
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-Mike</div>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>发件人:</b> MITgcm-support <mitgcm-support-bounces@mitgcm.org> 代表 ESTANISLAO GAVILAN PASCUAL-AHU <e.gavilan@hhu.edu.cn><br>
<b>发送时间:</b> 2020年3月17日 14:35<br>
<b>收件人:</b> mitgcm-support@mitgcm.org <mitgcm-support@mitgcm.org><br>
<b>主题:</b> Re: [MITgcm-support] MITgcm-support Digest, Vol 201, Issue 13</font>
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Hi Mike,<br>
<br>
I have just double checked the units in the documentation. Unless I am looking to the wrong parameter, the downward radiation is given in J m-2 see page.<br>
<a href="https://cds.climate.copernicus.eu/cdsapp#!/dataset/reanalysis-era5-single-levels">https://cds.climate.copernicus.eu/cdsapp#!/dataset/reanalysis-era5-single-levels</a><br>
Surface solar radiation downward:<br>
This parameter is the amount of solar radiation (also known as shortwave radiation)....The units are joules per square metre (J m-2 ). To convert to watts per square metre (W m-2 ), the accumulated values should be divided by the accumulation period
expressed in seconds. ....<br>
Surface thermal radiation downwards:<br>
Idem...<br>
<br>
Kind regards,<br>
<br>
Estanislao<br>
> Content-Type: text/plain; charset="gb2312"<br>
> <br>
> Hi,<br>
> <br>
> I am grateful to everyone for your reply, and here I will respond to your suggestions.<br>
> <br>
> 1.for Dr. Stanislav Martyanov =========================================<br>
> <br>
> Thank you for sharing the meteorological forcing variables used in the ERA5 dataset, which has benefited me a lot.<br>
> <br>
> But I am a bit puzzled. The GLOBAL_REANALYSIS_PHY_001_030 you mentioned should be a product of the NEMO model. Is this the open boundary forcing data you use?<br>
> <br>
> <br>
> 2.for Estanislao ===================================================<br>
> <br>
> Thank you for your reminding. Before using the data, it is very important to know the unit of the variable, just like the unit of precipitation in ERA5 is kg ? m-2 s-1, and the unit of the corresponding variable in MITgcm-EXF is m ? s-1. In this case, you
need to divide by the density of fresh water for conversion.<br>
> <br>
> About the unit of long and short wave radiation flux in ERA5, I'm sure that it is W ? m-2, and there should be no problem in the unit of other variables.<br>
> <br>
> <br>
> 3.for Raf =======================================================<br>
> <br>
> Thank you for your experience. The package I use is EXF. I simply looked at the code of EXF and found that it is calling exf_bulkformulae.F for related calculations.<br>
> <br>
> C us - mean wind speed (m/s) at height hu (m)<br>
> C th - mean air temperature (K) at height ht (m)<br>
> C qh - mean air humidity (kg/kg) at height hq (m)<br>
> <br>
> As for the definition of various variables in height, exf_readparms. F has made relevant definitions, and I have checked that it is correct.<br>
> <br>
> zref = 10.000 _d 0<br>
> hu = 10.000 _d 0<br>
> ht = 2.000 _d 0<br>
> <br>
> <br>
> 4.for Hong =======================================================<br>
> <br>
> Thank you for your checking. I'm sorry I didn't make it clear. I put net short-wave radiation flux (nswrs) in swfluxfile, since swdown will be ignored when using swdown and swflux at the same time, so I removed swdownfile.<br>
> <br>
> (PID.TID 0000.0001) ** WARNING ** EXF_CHECK: "swdown" field is loaded from file but not used within pkg/exf<br>
> <br>
> <br>
> Next ============================================================<br>
> It seems that you don't have the same problem as me. Next, I plan to use ERA5 and NCEP data at the same time to find the reason for the difference between the results of model by the method of exclusion.<br>
> <br>
> <br>
> <br>
> Best,<br>
> -Mike<br>
> ________________________________<br>
> ???: MITgcm-support <mitgcm-support-bounces@mitgcm.org> ?? Raphael Dussin <raphael.dussin@gmail.com><br>
> ????: 2020?3?16? 20:24<br>
> ???: mitgcm-support@mitgcm.org <mitgcm-support@mitgcm.org><br>
> ??: Re: [MITgcm-support] ??: ??: The obvious difference between ERA5 and NCEP-R1 forcing<br>
> <br>
> Have you checked the heights for the atmospheric variables are correctly set?<br>
> you should have something like this in data.blk<br>
> <br>
> zref = 10.0<br>
> zwd = 10.0<br>
> zth = 2.0<br>
> <br>
> I've seen a lot of runs going off the rails because of this kind of problem:<br>
> If the height is not set right, the fluxes are not either and you end up with large biases.<br>
> <br>
> hope it helps,<br>
> Raf<br>
> <br>
> <br>
> <br>
> <br>
> Raf<br>
> <br>
> <br>
> <br>
> Le lun. 16 mars 2020 ? 04:49, Stanislav Martyanov <martyanov.sd@gmail.com<mailto:martyanov.sd@gmail.com>> a ?crit :<br>
> Hello, Mike!<br>
> <br>
> I have recently downloaded the ERA5 reanalysis data (daily fields, GLOBAL_REANALYSIS_PHY_001_030 as labeled in Copernicus network) in order to construct the meteorological forcing for a regional ocean model (Kara Sea) based on the MITgcm. I chose the following
fields:<br>
> <br>
> % 10m u-component of wind<br>
> % 10m v-component of wind<br>
> % 2m dewpoint temperature<br>
> % 2m temperature<br>
> % Mean total precipitation rate<br>
> % Mean sea level pressure<br>
> % Mean surface downward long-wave radiation flux<br>
> % Mean surface downward short-wave radiation flux<br>
> <br>
> In order to compute the specific humidity, as advised in the ERA5 documentation, I used formulas given in IFS Documentation CY46R1 - part-iv-physical-processes (2m dewpoint temperature and Mean sea level pressure are used there).<br>
> <br>
> Regards,<br>
> <br>
> Dr. Stanislav Martyanov,<br>
> Shirshov Institute of Oceanology,<br>
> Russia<br>
> <br>
> <br>
> ??, 16 ???. 2020 ?. ? 09:27, Leming Van <ifanliming@outlook.com<mailto:ifanliming@outlook.com>>:<br>
> Hi, Matt<br>
> <br>
> Thank you for your advice. I'm sorry that I didn't provide enough information.<br>
> <br>
> I downloaded the ERA5 dataset at <a href="https://cds.climate.copernicus.eu/cdsapp#!/dataset/reanalysis-era5-single-levels?tab=form">
https://cds.climate.copernicus.eu/cdsapp#!/dataset/reanalysis-era5-single-levels?tab=form</a><br>
> Copernicus Climate Data Store | Copernicus Climate Data Store<<a href="https://cds.climate.copernicus.eu/cdsapp#!/dataset/reanalysis-era5-single-levels?tab=form">https://cds.climate.copernicus.eu/cdsapp#!/dataset/reanalysis-era5-single-levels?tab=form</a>><br>
> CDS Menu. Home; Search; Datasets; Applications; Toolbox; FAQ; Live; Copernicus Climate Data Store<br>
> cds.climate.copernicus.eu<http://cds.climate.copernicus.eu><br>
> <br>
> 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.<br>
> <br>
> 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.<br>
> <br>
> 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.<br>
> <br>
> I only have one question, do you choose the same ERA5 variables like me? If not, could you tell me which variables you choose?<br>
> <br>
> Please let me know if any other files are needed for diagnosis. Thanks in advance.<br>
> <br>
> <br>
> -Mike<br>
> <br>
> <br>
> Here is the setting of my data.exf<br>
> <br>
> # $Header: /u/gcmpack/MITgcm_contrib/eh3/llc/ecco-godae/input_50lev/data.exf,v 1.1 2007/03/06 19:13:51 heimbach Exp $<br>
> #<br>
> # *********************<br>
> # External Forcing Data<br>
> # *********************<br>
> &EXF_NML_01<br>
> useAtmWind = .TRUE.,<br>
> # rotateStressOnAgrid = .TRUE.,<br>
> exf_iprec = 32,<br>
> exf_yftype = 'RL',<br>
> useExfYearlyFields = .false.,<br>
> twoDigitYear = .false.,<br>
> useExfCheckRange =.false.,<br>
> &<br>
> <br>
> &EXF_NML_02<br>
> climsstfile = 'woa13_sst_monthly_globe_relax.box',<br>
> climsssfile = 'woa13_sss_monthly_globe_relax.box',<br>
> precipfile = 'era5_prate_2002-2005_hourly.box',<br>
> atempfile = 'era5_air_2002-2005_hourly.box',<br>
> aqhfile = 'era5_shum_2002-2005_hourly.box',<br>
> swdownfile = '',<br>
> swfluxfile = 'era5_nswrs_2002-2005_hourly.box',<br>
> lwfluxfile = '',<br>
> lwdownfile = 'era5_dlwrf_2002-2005_hourly.box',<br>
> uwindfile = 'era5_uwnd_2002-2005_hourly.box',<br>
> vwindfile = 'era5_vwnd_2002-2005_hourly.box',<br>
> runofffile = 'run-off.bin_1x1',<br>
> #<br>
> climsststartdate1 = 20020101,<br>
> climsststartdate2 = 000000,<br>
> climsstperiod = -12,<br>
> climsssstartdate1 = 20020101,<br>
> climsssstartdate2 = 000000,<br>
> climsssperiod = -12,<br>
> runoffstartdate1 = 20020101,<br>
> runoffstartdate2 = 000000,<br>
> runoffperiod = -12,<br>
> #<br>
> precipstartdate1=20020101,<br>
> precipstartdate2=000000,<br>
> precipperiod=3600.0,<br>
> atempstartdate1=20020101,<br>
> atempstartdate2=000000,<br>
> atempperiod=3600.0,<br>
> aqhstartdate1=20020101,<br>
> aqhstartdate2=000000,<br>
> aqhperiod=3600.0,<br>
> swdownstartdate1=20020101,<br>
> swdownstartdate2=000000,<br>
> swdownperiod=3600.0,<br>
> lwfluxstartdate1=20020101,<br>
> lwfluxstartdate2=000000,<br>
> lwfluxperiod=3600.0,<br>
> swfluxstartdate1=20020101,<br>
> swfluxstartdate2=000000,<br>
> swfluxperiod=3600.0,<br>
> lwdownstartdate1=20020101,<br>
> lwdownstartdate2=000000,<br>
> lwdownperiod=3600.0,<br>
> uwindstartdate1=20020101,<br>
> uwindstartdate2=000000,<br>
> uwindperiod=3600.0,<br>
> vwindstartdate1=20020101,<br>
> vwindstartdate2=000000,<br>
> vwindperiod=3600.0,<br>
> hfluxstartdate1=20020101,<br>
> hfluxstartdate2=000000,<br>
> hfluxperiod=3600.0,<br>
> sfluxstartdate1=20020101,<br>
> sfluxstartdate2=000000,<br>
> sfluxperiod=3600.0,<br>
> ustressstartdate1=20020101,<br>
> ustressstartdate2=000000,<br>
> ustressperiod=3600.0,<br>
> vstressstartdate1=20020101,<br>
> vstressstartdate2=000000,<br>
> vstressperiod=3600.0,<br>
> &<br>
> <br>
> &EXF_NML_03<br>
> exf_inscal_precip=1.,<br>
> exf_offset_atemp=0.0,<br>
> exf_inscal_runoff = 3.1710e-08,<br>
> &<br>
> <br>
> &EXF_NML_04<br>
> precip_lon0 = 95.0D0,<br>
> precip_lon_inc = 0.25D0,<br>
> precip_lat0 = -5.0D0,<br>
> precip_lat_inc = 160*0.25D0,<br>
> precip_nlon = 160,<br>
> precip_nlat = 160,<br>
> #<br>
> atemp_lon0 = 95.0D0,<br>
> atemp_lon_inc = 0.25D0,<br>
> atemp_lat0 = -5.0D0,<br>
> atemp_lat_inc = 160*0.25D0,<br>
> atemp_nlon = 160,<br>
> atemp_nlat = 160,<br>
> #<br>
> aqh_lon0 = 95.0D0,<br>
> aqh_lon_inc = 0.25D0,<br>
> aqh_lat0 = -5.0D0,<br>
> aqh_lat_inc = 160*0.25D0,<br>
> aqh_nlon = 160,<br>
> aqh_nlat = 160,<br>
> #<br>
> swdown_lon0 = 95.0D0,<br>
> swdown_lon_inc = 0.25D0,<br>
> swdown_lat0 = -5.0D0,<br>
> swdown_lat_inc = 160*0.25D0,<br>
> swdown_nlon = 160,<br>
> swdown_nlat = 160,<br>
> #<br>
> lwflux_lon0 = 95.0D0,<br>
> lwflux_lon_inc = 0.25D0,<br>
> lwflux_lat0 = -5.0D0,<br>
> lwflux_lat_inc = 160*0.25D0,<br>
> lwflux_nlon = 160,<br>
> lwflux_nlat = 160,<br>
> #<br>
> swflux_lon0 = 95.0D0,<br>
> swflux_lon_inc = 0.25D0,<br>
> swflux_lat0 = -5.0D0,<br>
> swflux_lat_inc = 160*0.25D0,<br>
> swflux_nlon = 160,<br>
> swflux_nlat = 160,<br>
> #<br>
> lwdown_lon0 = 95.0D0,<br>
> lwdown_lon_inc = 0.25D0,<br>
> lwdown_lat0 = -5.0D0,<br>
> lwdown_lat_inc = 160*0.25D0,<br>
> lwdown_nlon = 160,<br>
> lwdown_nlat = 160,<br>
> #<br>
> uwind_lon0 = 95.0D0,<br>
> uwind_lon_inc = 0.25D0,<br>
> uwind_lat0 = -5.0D0,<br>
> uwind_lat_inc = 160*0.25D0,<br>
> uwind_nlon = 160,<br>
> uwind_nlat = 160,<br>
> #<br>
> vwind_lon0 = 95.0D0,<br>
> vwind_lon_inc = 0.25D0,<br>
> vwind_lat0 = -5.0D0,<br>
> vwind_lat_inc = 160*0.25D0,<br>
> vwind_nlon = 160,<br>
> vwind_nlat = 160,<br>
> #<br>
> ustress_lon0 = 95.0D0,<br>
> ustress_lon_inc = 0.25D0,<br>
> ustress_lat0 = -5.0D0,<br>
> ustress_lat_inc = 160*0.25D0,<br>
> ustress_nlon = 160,<br>
> ustress_nlat = 160,<br>
> #<br>
> vstress_lon0 = 95.0D0,<br>
> vstress_lon_inc = 0.25D0,<br>
> vstress_lat0 = -5.0D0,<br>
> vstress_lat_inc = 160*0.25D0,<br>
> vstress_nlon = 160,<br>
> vstress_nlat = 160,<br>
> #<br>
> hflux_lon0 = 95.0D0,<br>
> hflux_lon_inc = 0.25D0,<br>
> hflux_lat0 = -5.0D0,<br>
> hflux_lat_inc = 160*0.25D0,<br>
> hflux_nlon = 160,<br>
> hflux_nlat = 160,<br>
> #<br>
> sflux_lon0 = 95.0D0,<br>
> sflux_lon_inc = 0.25D0,<br>
> sflux_lat0 = -5.0D0,<br>
> sflux_lat_inc = 160*0.25D0,<br>
> sflux_nlon = 160,<br>
> sflux_nlat = 160,<br>
> #<br>
> runoff_lon0 = 0.50D0,<br>
> runoff_lon_inc = 1.0D0,<br>
> runoff_lat0 = -79.5D0,<br>
> runoff_lat_inc = 159*1.0D0,<br>
> runoff_nlon = 360,<br>
> runoff_nlat = 160,<br>
> #<br>
> climsst_lon0 = -179.875D0,<br>
> climsst_lon_inc = 0.25D0,<br>
> climsst_lat0 = -89.875D0,<br>
> climsst_lat_inc = 719*0.25D0,<br>
> climsst_nlon = 1440,<br>
> climsst_nlat = 720,<br>
> #<br>
> climsss_lon0 = -179.875D0,<br>
> climsss_lon_inc = 0.25D0,<br>
> climsss_lat0 = -89.875D0,<br>
> climsss_lat_inc = 719*0.25D0,<br>
> climsss_nlon = 1440,<br>
> climsss_nlat = 720,<br>
> #<br>
> &<br>
> <br>
> &EXF_NML_OBCS<br>
> obcsNstartdate1 = 20020101,<br>
> obcsNstartdate2 = 000000,<br>
> obcsNperiod = 2628000.0,<br>
> obcsEstartdate1 = 20020101,<br>
> obcsEstartdate2 = 000000,<br>
> obcsEperiod = 2628000.0,<br>
> obcsSstartdate1 = 20020101,<br>
> obcsSstartdate2 = 000000,<br>
> obcsSperiod = 2628000.,<br>
> &<br>
> <br>
> ________________________________<br>
> ???: MITgcm-support <mitgcm-support-bounces@mitgcm.org<mailto:mitgcm-support-bounces@mitgcm.org>> ?? Matthew Mazloff <mmazloff@ucsd.edu<mailto:mmazloff@ucsd.edu>><br>
> ????: 2020?3?16? 0:44<br>
> ???: mitgcm-support@mitgcm.org<mailto:mitgcm-support@mitgcm.org> <mitgcm-support@mitgcm.org<mailto:mitgcm-support@mitgcm.org>><br>
> ??: Re: [MITgcm-support] ??: The obvious difference between ERA5 and NCEP-R1 forcing<br>
> <br>
> Hi Mike<br>
> <br>
> 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.<br>
> <br>
> For ERA5 I have this in my data.exf:<br>
> &EXF_NML_03<br>
> exf_offset_atemp = 273.15,<br>
> exf_inscal_swdown = -1.0,<br>
> exf_inscal_lwdown = -1.0,<br>
> <br>
> Not sure how to help you,<br>
> Matt<br>
> <br>
> <br>
> <br>
> On Mar 15, 2020, at 5:41 AM, Leming Van <ifanliming@outlook.com<mailto:ifanliming@outlook.com>> wrote:<br>
> <br>
> Hi, everyone<br>
> <br>
> 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.<br>
> <br>
> 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?<br>
> <br>
> I put the results at here, <a href="https://1drv.ms/u/s!AoS5GLJhmvDtjB5Ovnz63FidKeMo?e=c2hS7z">
https://1drv.ms/u/s!AoS5GLJhmvDtjB5Ovnz63FidKeMo?e=c2hS7z</a><br>
> Suggestions are welcome.<br>
> <br>
> <br>
> -Mike<br>
> <br>
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