I feel the need to point out that it is your opinion that the "firmament" mentioned in Genesis is a reference to the atmosphere.
You cannot claim that the Genesis account is wrong or in error if all you did was discredit your own opinion about it.
That all depends on what they meant by the "firmament".
We can assume that they meant "atmosphere", but we cannot know it.
The Jewish word for firmament is רָקִ֖יעַ , which is transliterated to as rā·qî·a‘. The firmament is used in the KJV translation, which the literal meaning of firmament is “dome”, which some modern translations used (eg NRSV), while others preferred “expanse” (eg NASB).
To give you you some run downs on the Hebrew words and their respective transliterations, here are the followings:
“sky”, “heaven”: šā·mā·yim (שָׁמָ֑יִם), eg Genesis 1:8; “the heavens”: haš·šā·ma·yim (הַשָּׁמַ֖יִם), eg 1:1
earth: ’ā·reṣ (אָֽרֶץ); “the earth”: hā ’ā·reṣ (הָאָֽרֶץ)
waters: ma·yim (מַ֖יִם)
Noticed that word singular heaven and the plural heavens, are virtually identical, except the “the” would either be hā (הָ) or haš (הַ) are often accompanied as prefixed to the noun(s).
To put the above in perspective I have included 3 translations, which used the words - firmament, dome or expanse:
“Genesis 1:6-8 KJV” said:
6 And God said, Let there be a firmament in the midst of the waters, and let it divide the waters from the waters.
7 And God made the firmament, and divided the waters which were under the firmament from the waters which were above the firmament: and it was so.
8 And God called the firmament Heaven.
“Genesis 1:6-8 NSRV” said:
6 And God said, “Let there be a dome in the midst of the waters, and let it separate the waters from the waters.” 7 So God made the dome and separated the waters that were under the dome from the waters that were above the dome. And it was so. 8 God called the dome Sky.
“Genesis 1:6-8 NASB” said:
6 Then God said, “Let there be an expanse, and separated expanse from the waters expanse; and it was so. 7 God made the expanse, and separated expanse from the waters expanse; and it was so. 8 God called the expanse heaven.
This indicate the firmament is the “sky”.
Does it explicitly referred to atmosphere?
“Explicitly”, no. But it does talk of “waters” (ma·yim) being above and the waters below, so the firmament is between these two waters.
Does that mean the waters exist above the sky?
I will get more about the waters later, but I want to talk first of the 4th and 6th days, so for the sake of completeness, I’ll include the same 3 translations:
“Genesis 1:14-17 KJV” said:
14 And God said, Let there be lights in the firmament of the heaven to divide the day from the night; and let them be for signs, and for seasons, and for days, and years:
15 And let them be for lights in the firmament of the heaven to give light upon the earth: and it was so.
16 And God made two great lights; the greater light to rule the day, and the lesser light to rule the night: he made the stars also.
17 And God set them in the firmament of the heaven to give light upon the earth,
“Genesis 1:14-17 NRSV” said:
14 And God said, “Let there be lights in the dome of the sky to separate the day from the night; and let them be for signs and for seasons and for days and years, 15 and let them be lights in the dome of the sky to give light upon the earth.” And it was so. 16 God made the two great lights—the greater light to rule the day and the lesser light to rule the night—and the stars. 17 God set them in the dome of the sky to give light upon the earth,
“Genesis 1:14-17 NASB” said:
14 Then God said, “Let there be lights in the expanse of the heavens to give light on the earth”; and it was so.16 God made the two great lights, the greater light to govern the day, and the lesser light to govern the night; He made the stars also. 17 God placed them in the expanse of the heavens to give light on the earth,
Now just focused what I highlighted in red.
In all cases, the god created the sun, moon and stars in the firmament or the sky (or heaven), and that would means these were created below “the waters above”.
How can these astronomical bodies be below “the waters above”?
And below, are the translations for the 5th day, but only what it say about the creation of birds or fowls.
“Genesis 1:20 KJV” said:
20 And God said, Let the waters bring forth abundantly the moving creature that hath life, and fowl that may fly above the earth in the open firmament of heaven.
“Genesis 1:20 NSRV” said:
20 And God said, “Let the waters bring forth swarms of living creatures, and let birds fly above the earth across the dome of the sky.”
“Genesis 1:20 NASB” said:
20 Then God said, “Let the waters teem with swarms of living creatures, and let birds fly above the earth in the open expanse of the heavens.”
Just as the sun, moon and stars were created in the firmament or sky, so were the birds or fowls in the sky (firmament). And above the birds and sun and stars, were the waters.
If both birds and astronomical objects can be on the same plane, then you must considered that the author had no really understanding of how far away are the moon, sun and other stars.
Then there are matters the “waters above” the firmament (sky), which are not possible, if you have understanding of space and Earth.
According to the Flood myth, the waters became from below as the “great fountains” and from above when the heaven opened up and rain:
“Genesis 7:11 NSRV” said:
11 In the six hundredth year of Noah’s life, in the second month, on the seventeenth day of the month, on that day all the fountains of the great deep burst forth, and the windows of the heavens were opened.
Is this flood water (7:11) the same waters from above the sky or firmament (1:7)?
If so, then Genesis 1:7-8 is wrong.
Our current knowledge of the chemical composition of the Earth’s atmosphere, most water vapors and the rain we get, are found in the Troposphere, the lowest layer of the above atmosphere, and only trace amount of water vapors can reach the next atmosphere - Stratosphere. Beyond the stratosphere, is the Mesosphere and higher (Thermosphere, Exosphere), completely no water vapors.
So what Genesis described of there being “waters above”, is nothing more than a complete fiction, and it is scientifically wrong.
