Air Pollution Trends in Myanmar

This notebook summarizes tropospheric nitrogen dioxide (NO₂) levels in Myanmar using data from NASA’s Ozone Monitoring Instrument (OMI). This analysis focuses on annual national trends across Myanmar (ADM0) and monthly/annual trends for Yangon (ADM1).

Annual National NO₂ Trend

The chart below shows the mean annual tropospheric NO₂ column density across Myanmar.

nearest = alt.selection_point(
    on="mouseover", fields=["date"], nearest=True, empty=False
)
base = alt.Chart(omi_annual_adm0.reset_index())
line = base.mark_line(strokeWidth=2.5).encode(
    x=alt.X("date:T", title="", axis=alt.Axis(format="%Y")),
    y=alt.Y("no2:Q", title="NO₂"),
)
points = base.mark_point(filled=True, size=60).encode(
    x=alt.X("date:T"),
    y=alt.Y("no2:Q"),
)
rules = (
    base.mark_rule(color="gray")
    .encode(
        x="date:T",
        opacity=alt.when(nearest).then(alt.value(0.3)).otherwise(alt.value(0)),
        tooltip=[
            alt.Tooltip("date:T", title="Year", format="%Y"),
            alt.Tooltip("no2:Q", title="NO₂", format=".6f"),
        ],
    )
    .add_params(nearest)
)

(line + points + rules).properties(
    width=600,
    height=300,
    title={
        "text": "Annual National NO₂ Trend in Myanmar",
        "subtitle": "Source: NASA OMI (Ozone Monitoring Instrument), 2010–2025",
    },
)

Yangon NO₂ Trends

The charts below show the monthly and annual mean tropospheric NO₂ column density for Yangon.

nearest = alt.selection_point(
    on="mouseover", fields=["date"], nearest=True, empty=False
)
base = alt.Chart(omi_monthly_yangon.reset_index())
line = base.mark_line(color="steelblue").encode(
    x=alt.X("date:T", title=""),
    y=alt.Y("no2:Q", title="NO₂"),
)
rules = (
    base.mark_rule(color="gray")
    .encode(
        x="date:T",
        opacity=alt.when(nearest).then(alt.value(0.3)).otherwise(alt.value(0)),
        tooltip=[
            alt.Tooltip("date:T", title="Month", format="%b %Y"),
            alt.Tooltip("no2:Q", title="NO₂", format=".6f"),
        ],
    )
    .add_params(nearest)
)

(line + rules).properties(
    width=700,
    height=280,
    title={
        "text": "Monthly NO₂ in Yangon",
        "subtitle": "Source: NASA OMI, 2010–2025",
    },
)

nearest = alt.selection_point(
    on="mouseover", fields=["date"], nearest=True, empty=False
)
base = alt.Chart(omi_annual_yangon.reset_index())
line = base.mark_line().encode(
    x=alt.X("date:T", title="", axis=alt.Axis(format="%Y")),
    y=alt.Y("no2:Q", title="NO₂ (×10¹⁵ molecules/cm²)"),
)
points = base.mark_point(filled=True, size=60).encode(
    x=alt.X("date:T"),
    y=alt.Y("no2:Q"),
)
rules = (
    base.mark_rule(color="gray")
    .encode(
        x="date:T",
        opacity=alt.when(nearest).then(alt.value(0.3)).otherwise(alt.value(0)),
        tooltip=[
            alt.Tooltip("date:T", title="Year", format="%Y"),
            alt.Tooltip("no2:Q", title="NO₂", format=".6f"),
        ],
    )
    .add_params(nearest)
)

(line + points + rules).properties(
    width=600,
    height=280,
    title={
        "text": "Annual NO₂ Trend in Yangon",
        "subtitle": "Source: NASA OMI, 2010–2025",
    },
)