try to get unit string right so pyaerocom understands it

setup.cfg

@@ -1,6 +1,6 @@
 [metadata]
 name = pyaro_readers
-version = 0.0.5dev
+version = 0.0.5dev1
 author = MET Norway
 description = implementations of pyaerocom reading plugings using pyaro as interface
 long_description = file: README.md

src/pyaro_readers/__init__.py

@@ -0,0 +1,5 @@
+from importlib import metadata
+
+__version__ = metadata.version(__package__)
+
+from .units_helpers import *

src/pyaro_readers/harpreader/harpreader.py

@@ -14,6 +14,7 @@
 from pathlib import Path
 from tqdm import tqdm
 import cfunits
+from ..units_helpers import UALIASES
 
 logger = logging.getLogger(__name__)
 
@@ -116,6 +117,8 @@ def _read_file_variables(self, filename) -> dict[str, str]:
                     # we can make sure that cfunits understands them
                     # otherwise variables[vname] = var.attrs["units"] should work as well
                     variables[vname] = str(cfunits.Units(var.attrs["units"]))
+                    if variables[vname] in UALIASES:
+                        variables[vname] = UALIASES[variables[vname]]
 
         return variables
 

src/pyaro_readers/units_helpers.py

@@ -0,0 +1,104 @@
+import pandas as pd
+
+
+class UnitConversionError(ValueError):
+    pass
+
+
+# from pyaerocom.tstype import TsType
+# from pyaerocom.variable_helpers import get_variable
+
+#: default frequency for rates variables (e.g. deposition, precip)
+RATES_FREQ_DEFAULT = "d"
+
+# 1. DEFINITION OF ATOM and MOLECULAR MASSES
+
+# Atoms
+M_O = 15.999  # u
+M_S = 32.065  # u
+M_N = 14.0067  # u
+M_H = 1.00784  # u
+
+# Molecules
+M_SO2 = M_S + 2 * M_O
+M_SO4 = M_S + 4 * M_O
+
+M_NO2 = M_N + 2 * M_O
+M_NO3 = M_N + 3 * M_O
+
+M_NH3 = M_N + 3 * M_H
+M_NH4 = M_N + 4 * M_H
+
+# Unit conversion and custom units definitions
+
+# 2.1 Other conversion factors
+HA_TO_SQM = 10000  # hectar to square metre.
+
+# 3. LOOKUP TABLE FOR CONVERSION FACTORS
+
+#: Custom unit conversion factors for certain variables
+#: columns: variable -> from unit -> to_unit -> conversion
+#: factor
+UCONV_MUL_FACS = pd.DataFrame(
+    [
+        # ["dryso4", "mg/m2/d", "mgS m-2 d-1", M_S / M_SO4],
+        # ["drynh4", "mg/m2/d", "mgN m-2 d-1", M_N/ M_NH4],
+        # ["concso4", "ug S/m3", "ug m-3", M_SO4 / M_S],
+        # ["SO4ugSm3", "ug/m3", "ug S m-3", M_S / M_SO4],
+        # ["concso4pm25", "ug S/m3", "ug m-3", M_SO4 / M_S],
+        # ["concso4pm10", "ug S/m3", "ug m-3", M_SO4 / M_S],
+        ["concso2", "ug S/m3", "ug m-3", M_SO2 / M_S],
+        ["concbc", "ug C/m3", "ug m-3", 1.0],
+        ["concoa", "ug C/m3", "ug m-3", 1.0],
+        ["concoc", "ug C/m3", "ug m-3", 1.0],
+        ["conctc", "ug C/m3", "ug m-3", 1.0],
+        # a little hacky for ratpm10pm25...
+        # ["ratpm10pm25", "ug m-3", "1", 1.0],
+        ["concpm25", "ug m-3", "1", 1.0],
+        ["concpm10", "ug m-3", "1", 1.0],
+        ["concno2", "ug N/m3", "ug m-3", M_NO2 / M_N],
+        # ["concno3", "ug N/m3", "ug m-3", M_NO3 / M_N],
+        ["concnh3", "ug N/m3", "ug m-3", M_NH3 / M_N],
+        # ["concnh4", "ug N/m3", "ug m-3", M_NH4 / M_N],
+        ["wetso4", "kg S/ha", "kg m-2", M_SO4 / M_S / HA_TO_SQM],
+        ["concso4pr", "mg S/L", "g m-3", M_SO4 / M_S],
+    ],
+    columns=["var_name", "from", "to", "fac"],
+).set_index(["var_name", "from"])
+
+# may be used to specify alternative names for custom units  defined
+# in UCONV_MUL_FACS
+
+UALIASES = {
+    # mass concentrations
+    # "ug S m-3": "ug S/m3",
+    # "ug C m-3": "ug C/m3",
+    # "ug N m-3": "ug N/m3",
+    "ugC/m3": "ug C m-3",
+    "ug/m3": "ug m-3",
+    # deposition rates (implicit)
+    ## sulphur species
+    "mgS/m2": "mg S m-2",
+    "mgSm-2": "mg S m-2",
+    ## nitrogen species
+    "mgN/m2": "mg N m-2",
+    "mgNm-2": "mg N m-2",
+    # deposition rates (explicit)
+    ## sulphur species
+    "mgS/m2/h": "mg S m-2 h-1",
+    "mg/m2/h": "mg m-2 h-1",
+    "mgS/m**2/h": "mg S m-2 h-1",
+    "mgSm-2h-1": "mg S m-2 h-1",
+    "mgSm**-2h-1": "mg S m-2 h-1",
+    "mgS/m2/d": "mg S m-2 d-1",
+    ## nitrogen species
+    "mgN/m2/h": "mg N m-2 h-1",
+    "mgN/m**2/h": "mg N m-2 h-1",
+    "mgNm-2h-1": "mg N m-2 h-1",
+    "mgNm**-2h-1": "mg N m-2 h-1",
+    "mgN/m2/d": "mg N m-2 d-1",
+    ## others
+    "MM/H": "mm h-1",
+    # others
+    "/m": "m-1",
+}

tests/test_HARPReader.py

@@ -18,7 +18,7 @@ class TestHARPReader(unittest.TestCase):
         "/lustre/storeB/project/aerocom/aerocom1/AEROCOM_OBSDATA/CNEMC/aggregated/"
     )
     test_vars = ["PM10_density", "CO_volume_mixing_ratio", "PM2p5_density"]
-    test_units = ["ug/m3", "ppm", "ug/m3"]
+    test_units = ["ug m-3", "ppm", "ug m-3"]
 
     def test_1read(self):
         with pyaro.open_timeseries(