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The synthesis

Watch the solar wind leave the Sun (Heliophysics), then catch the aurora it triggers in Earth's night imagery (Earth). One physical chain, two divisions.

Where will the aurora be visible tonight?

What you can answer

See the aurora directly in VIIRS’ Day/Night Band over the polar night.
Connect a bright auroral night to the solar-wind shock that caused it.

What you can NOT answer with these datasets alone

Forecast the exact curtain shape hours ahead — that needs a magnetosphere model.
See aurora through cloud — the night band still sees cloud tops.

The cross-division bridge

Earth-anchored, reaching into Heliophysics. The Earth side is the VIIRS Day/Night Band, which images auroral glow during polar night. The Heliophysics side is DSCOVR at the L1 Lagrange point — its plasma-magnetometer measures the incoming solar wind ~30–60 minutes before it hits Earth, giving the physical cause for the auroral effect seen from orbit.

Sources

⚲ How a scientist answers this

Parameters

VIIRS Day/Night Band radiance from Black Marble VNP46A2 (nW·cm⁻²·sr⁻¹, ~500 m) imaging auroral emission during polar night; solar-wind driver from DSCOVR plasma/magnetometer at L1 (speed km·s⁻¹, density, and Bz interplanetary magnetic-field component in nT) ~30–60 min upstream.

Method

Identify auroral glow in the DNB over the night side (separating it from city lights and clouds by location and morphology), and time-align a bright auroral night with the preceding DSCOVR solar-wind shock — a southward Bz and elevated speed/density — to connect cause to effect.

Validation

Confirm DNB brightening is aurora and not moonlit cloud or anthropogenic light using the moon-phase/cloud QA flags, and corroborate timing against the Kp/geomagnetic index; note the DNB still sees cloud tops so overcast hides the curtain.

In plain EnglishThe night-vision satellite band shows the aurora glowing over the dark polar regions, and a space-weather sensor upstream of Earth shows the solar-wind gust that lit it up about half an hour earlier.

Make it yours → Pick the night and polar AOI in the notebook and pull the matching DSCOVR solar-wind window.

⌨ Run the core method · no login

The robust trend (Theil–Sen + Mann–Kendall) at the heart of this question — runnable on synthetic data, right here. The full earthaccess code template further down does it on real NASA data (needs an Earthdata login).

editable · runs in your browser

import numpy as np, pymannkendall as mk
from scipy.stats import theilslopes
rng = np.random.default_rng(0)
years = np.arange(2001, 2023)
# real code returns this after area-weighting a data cube; here it's synthetic so it runs.
series = 100 - 0.8*(years - 2001) + rng.normal(0, 12, years.size)   # edit slope/noise & rerun
s, _, lo, hi = theilslopes(series, years); r = mk.original_test(series)
print(f"trend {s:+.2f}/yr   (95% CI {lo:+.2f} .. {hi:+.2f})   Mann-Kendall p={r.p:.3f}")
print(">>>", "significant" if r.h else "no significant trend (an earned null)")

From another NASA division

☉ Heliophysics

DSCOVR Solar Wind (Plasma-Magnetometer)

Solar-wind speed and magnetic field measured a million miles upstream — the ~30–60 min early warning for geomagnetic storms.

DSCOVR_PlasMag · L1, real-time